Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { ISemver } from "src/universal/ISemver.sol";
import { Constants } from "src/libraries/Constants.sol";
import { GasPayingToken, IGasToken } from "src/libraries/GasPayingToken.sol";
import "src/libraries/L1BlockErrors.sol";

/// @custom:proxied
/// @custom:predeploy 0x4200000000000000000000000000000000000015
/// @title L1Block
/// @notice The L1Block predeploy gives users access to information about the last known L1 block.
///         Values within this contract are updated once per epoch (every L1 block) and can only be
///         set by the "depositor" account, a special system address. Depositor account transactions
///         are created by the protocol whenever we move to a new epoch.
contract L1Block is ISemver, IGasToken {
    /// @notice Event emitted when the gas paying token is set.
    event GasPayingTokenSet(address indexed token, uint8 indexed decimals, bytes32 name, bytes32 symbol);

    /// @notice Address of the special depositor account.
    function DEPOSITOR_ACCOUNT() public pure returns (address addr_) {
        addr_ = Constants.DEPOSITOR_ACCOUNT;
    }

    /// @notice The latest L1 block number known by the L2 system.
    uint64 public number;

    /// @notice The latest L1 timestamp known by the L2 system.
    uint64 public timestamp;

    /// @notice The latest L1 base fee.
    uint256 public basefee;

    /// @notice The latest L1 blockhash.
    bytes32 public hash;

    /// @notice The number of L2 blocks in the same epoch.
    uint64 public sequenceNumber;

    /// @notice The scalar value applied to the L1 blob base fee portion of the blob-capable L1 cost func.
    uint32 public blobBaseFeeScalar;

    /// @notice The scalar value applied to the L1 base fee portion of the blob-capable L1 cost func.
    uint32 public baseFeeScalar;

    /// @notice The versioned hash to authenticate the batcher by.
    bytes32 public batcherHash;

    /// @notice The overhead value applied to the L1 portion of the transaction fee.
    /// @custom:legacy
    uint256 public l1FeeOverhead;

    /// @notice The scalar value applied to the L1 portion of the transaction fee.
    /// @custom:legacy
    uint256 public l1FeeScalar;

    /// @notice The latest L1 blob base fee.
    uint256 public blobBaseFee;

    /// @custom:semver 1.4.1-beta.1
    function version() public pure virtual returns (string memory) {
        return "1.4.1-beta.1";
    }

    /// @notice Returns the gas paying token, its decimals, name and symbol.
    ///         If nothing is set in state, then it means ether is used.
    function gasPayingToken() public view returns (address addr_, uint8 decimals_) {
        (addr_, decimals_) = GasPayingToken.getToken();
    }

    /// @notice Returns the gas paying token name.
    ///         If nothing is set in state, then it means ether is used.
    function gasPayingTokenName() public view returns (string memory name_) {
        name_ = GasPayingToken.getName();
    }

    /// @notice Returns the gas paying token symbol.
    ///         If nothing is set in state, then it means ether is used.
    function gasPayingTokenSymbol() public view returns (string memory symbol_) {
        symbol_ = GasPayingToken.getSymbol();
    }

    /// @notice Getter for custom gas token paying networks. Returns true if the
    ///         network uses a custom gas token.
    function isCustomGasToken() public view returns (bool) {
        (address token,) = gasPayingToken();
        return token != Constants.ETHER;
    }

    /// @custom:legacy
    /// @notice Updates the L1 block values.
    /// @param _number         L1 blocknumber.
    /// @param _timestamp      L1 timestamp.
    /// @param _basefee        L1 basefee.
    /// @param _hash           L1 blockhash.
    /// @param _sequenceNumber Number of L2 blocks since epoch start.
    /// @param _batcherHash    Versioned hash to authenticate batcher by.
    /// @param _l1FeeOverhead  L1 fee overhead.
    /// @param _l1FeeScalar    L1 fee scalar.
    function setL1BlockValues(
        uint64 _number,
        uint64 _timestamp,
        uint256 _basefee,
        bytes32 _hash,
        uint64 _sequenceNumber,
        bytes32 _batcherHash,
        uint256 _l1FeeOverhead,
        uint256 _l1FeeScalar
    )
        external
    {
        require(msg.sender == DEPOSITOR_ACCOUNT(), "L1Block: only the depositor account can set L1 block values");

        number = _number;
        timestamp = _timestamp;
        basefee = _basefee;
        hash = _hash;
        sequenceNumber = _sequenceNumber;
        batcherHash = _batcherHash;
        l1FeeOverhead = _l1FeeOverhead;
        l1FeeScalar = _l1FeeScalar;
    }

    /// @notice Updates the L1 block values for an Ecotone upgraded chain.
    /// Params are packed and passed in as raw msg.data instead of ABI to reduce calldata size.
    /// Params are expected to be in the following order:
    ///   1. _baseFeeScalar      L1 base fee scalar
    ///   2. _blobBaseFeeScalar  L1 blob base fee scalar
    ///   3. _sequenceNumber     Number of L2 blocks since epoch start.
    ///   4. _timestamp          L1 timestamp.
    ///   5. _number             L1 blocknumber.
    ///   6. _basefee            L1 base fee.
    ///   7. _blobBaseFee        L1 blob base fee.
    ///   8. _hash               L1 blockhash.
    ///   9. _batcherHash        Versioned hash to authenticate batcher by.
    function setL1BlockValuesEcotone() external {
        address depositor = DEPOSITOR_ACCOUNT();
        assembly {
            // Revert if the caller is not the depositor account.
            if xor(caller(), depositor) {
                mstore(0x00, 0x3cc50b45) // 0x3cc50b45 is the 4-byte selector of "NotDepositor()"
                revert(0x1C, 0x04) // returns the stored 4-byte selector from above
            }
            // sequencenum (uint64), blobBaseFeeScalar (uint32), baseFeeScalar (uint32)
            sstore(sequenceNumber.slot, shr(128, calldataload(4)))
            // number (uint64) and timestamp (uint64)
            sstore(number.slot, shr(128, calldataload(20)))
            sstore(basefee.slot, calldataload(36)) // uint256
            sstore(blobBaseFee.slot, calldataload(68)) // uint256
            sstore(hash.slot, calldataload(100)) // bytes32
            sstore(batcherHash.slot, calldataload(132)) // bytes32
        }
    }

    /// @notice Sets the gas paying token for the L2 system. Can only be called by the special
    ///         depositor account. This function is not called on every L2 block but instead
    ///         only called by specially crafted L1 deposit transactions.
    function setGasPayingToken(address _token, uint8 _decimals, bytes32 _name, bytes32 _symbol) external {
        if (msg.sender != DEPOSITOR_ACCOUNT()) revert NotDepositor();

        GasPayingToken.set({ _token: _token, _decimals: _decimals, _name: _name, _symbol: _symbol });

        emit GasPayingTokenSet({ token: _token, decimals: _decimals, name: _name, symbol: _symbol });
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/// @title Burn
/// @notice Utilities for burning stuff.
library Burn {
    /// @notice Burns a given amount of ETH.
    /// @param _amount Amount of ETH to burn.
    function eth(uint256 _amount) internal {
        new Burner{ value: _amount }();
    }

    /// @notice Burns a given amount of gas.
    /// @param _amount Amount of gas to burn.
    function gas(uint256 _amount) internal view {
        uint256 i = 0;
        uint256 initialGas = gasleft();
        while (initialGas - gasleft() < _amount) {
            ++i;
        }
    }
}

/// @title Burner
/// @notice Burner self-destructs on creation and sends all ETH to itself, removing all ETH given to
///         the contract from the circulating supply. Self-destructing is the only way to remove ETH
///         from the circulating supply.
contract Burner {
    constructor() payable {
        selfdestruct(payable(address(this)));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { OwnableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import { ISemver } from "src/universal/ISemver.sol";
import { ResourceMetering } from "src/L1/ResourceMetering.sol";
import { Storage } from "src/libraries/Storage.sol";
import { Constants } from "src/libraries/Constants.sol";
import { OptimismPortal } from "src/L1/OptimismPortal.sol";
import { GasPayingToken, IGasToken } from "src/libraries/GasPayingToken.sol";
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";

/// @title SystemConfig
/// @notice The SystemConfig contract is used to manage configuration of an Optimism network.
///         All configuration is stored on L1 and picked up by L2 as part of the derviation of
///         the L2 chain.
contract SystemConfig is OwnableUpgradeable, ISemver, IGasToken {
    /// @notice Enum representing different types of updates.
    /// @custom:value BATCHER              Represents an update to the batcher hash.
    /// @custom:value GAS_CONFIG           Represents an update to txn fee config on L2.
    /// @custom:value GAS_LIMIT            Represents an update to gas limit on L2.
    /// @custom:value UNSAFE_BLOCK_SIGNER  Represents an update to the signer key for unsafe
    ///                                    block distrubution.
    enum UpdateType {
        BATCHER,
        GAS_CONFIG,
        GAS_LIMIT,
        UNSAFE_BLOCK_SIGNER
    }

    /// @notice Struct representing the addresses of L1 system contracts. These should be the
    ///         contracts that users interact with (not implementations for proxied contracts)
    ///         and are network specific.
    struct Addresses {
        address l1CrossDomainMessenger;
        address l1ERC721Bridge;
        address l1StandardBridge;
        address disputeGameFactory;
        address optimismPortal;
        address optimismMintableERC20Factory;
        address gasPayingToken;
    }

    /// @notice Version identifier, used for upgrades.
    uint256 public constant VERSION = 0;

    /// @notice Storage slot that the unsafe block signer is stored at.
    ///         Storing it at this deterministic storage slot allows for decoupling the storage
    ///         layout from the way that `solc` lays out storage. The `op-node` uses a storage
    ///         proof to fetch this value.
    /// @dev    NOTE: this value will be migrated to another storage slot in a future version.
    ///         User input should not be placed in storage in this contract until this migration
    ///         happens. It is unlikely that keccak second preimage resistance will be broken,
    ///         but it is better to be safe than sorry.
    bytes32 public constant UNSAFE_BLOCK_SIGNER_SLOT = keccak256("systemconfig.unsafeblocksigner");

    /// @notice Storage slot that the L1CrossDomainMessenger address is stored at.
    bytes32 public constant L1_CROSS_DOMAIN_MESSENGER_SLOT =
        bytes32(uint256(keccak256("systemconfig.l1crossdomainmessenger")) - 1);

    /// @notice Storage slot that the L1ERC721Bridge address is stored at.
    bytes32 public constant L1_ERC_721_BRIDGE_SLOT = bytes32(uint256(keccak256("systemconfig.l1erc721bridge")) - 1);

    /// @notice Storage slot that the L1StandardBridge address is stored at.
    bytes32 public constant L1_STANDARD_BRIDGE_SLOT = bytes32(uint256(keccak256("systemconfig.l1standardbridge")) - 1);

    /// @notice Storage slot that the OptimismPortal address is stored at.
    bytes32 public constant OPTIMISM_PORTAL_SLOT = bytes32(uint256(keccak256("systemconfig.optimismportal")) - 1);

    /// @notice Storage slot that the OptimismMintableERC20Factory address is stored at.
    bytes32 public constant OPTIMISM_MINTABLE_ERC20_FACTORY_SLOT =
        bytes32(uint256(keccak256("systemconfig.optimismmintableerc20factory")) - 1);

    /// @notice Storage slot that the batch inbox address is stored at.
    bytes32 public constant BATCH_INBOX_SLOT = bytes32(uint256(keccak256("systemconfig.batchinbox")) - 1);

    /// @notice Storage slot for block at which the op-node can start searching for logs from.
    bytes32 public constant START_BLOCK_SLOT = bytes32(uint256(keccak256("systemconfig.startBlock")) - 1);

    /// @notice Storage slot for the DisputeGameFactory address.
    bytes32 public constant DISPUTE_GAME_FACTORY_SLOT =
        bytes32(uint256(keccak256("systemconfig.disputegamefactory")) - 1);

    /// @notice The number of decimals that the gas paying token has.
    uint8 internal constant GAS_PAYING_TOKEN_DECIMALS = 18;

    /// @notice The maximum gas limit that can be set for L2 blocks. This limit is used to enforce that the blocks
    ///         on L2 are not too large to process and prove. Over time, this value can be increased as various
    ///         optimizations and improvements are made to the system at large.
    uint64 internal constant MAX_GAS_LIMIT = 200_000_000;

    /// @notice Fixed L2 gas overhead. Used as part of the L2 fee calculation.
    ///         Deprecated since the Ecotone network upgrade
    uint256 public overhead;

    /// @notice Dynamic L2 gas overhead. Used as part of the L2 fee calculation.
    ///         The most significant byte is used to determine the version since the
    ///         Ecotone network upgrade.
    uint256 public scalar;

    /// @notice Identifier for the batcher.
    ///         For version 1 of this configuration, this is represented as an address left-padded
    ///         with zeros to 32 bytes.
    bytes32 public batcherHash;

    /// @notice L2 block gas limit.
    uint64 public gasLimit;

    /// @notice Basefee scalar value. Part of the L2 fee calculation since the Ecotone network upgrade.
    uint32 public basefeeScalar;

    /// @notice Blobbasefee scalar value. Part of the L2 fee calculation since the Ecotone network upgrade.
    uint32 public blobbasefeeScalar;

    /// @notice The configuration for the deposit fee market.
    ///         Used by the OptimismPortal to meter the cost of buying L2 gas on L1.
    ///         Set as internal with a getter so that the struct is returned instead of a tuple.
    ResourceMetering.ResourceConfig internal _resourceConfig;

    /// @notice Emitted when configuration is updated.
    /// @param version    SystemConfig version.
    /// @param updateType Type of update.
    /// @param data       Encoded update data.
    event ConfigUpdate(uint256 indexed version, UpdateType indexed updateType, bytes data);

    /// @notice Semantic version.
    /// @custom:semver 2.3.0-beta.2
    function version() public pure virtual returns (string memory) {
        return "2.3.0-beta.2";
    }

    /// @notice Constructs the SystemConfig contract. Cannot set
    ///         the owner to `address(0)` due to the Ownable contract's
    ///         implementation, so set it to `address(0xdEaD)`
    /// @dev    START_BLOCK_SLOT is set to type(uint256).max here so that it will be a dead value
    ///         in the singleton and is skipped by initialize when setting the start block.
    constructor() {
        Storage.setUint(START_BLOCK_SLOT, type(uint256).max);
        initialize({
            _owner: address(0xdEaD),
            _basefeeScalar: 0,
            _blobbasefeeScalar: 0,
            _batcherHash: bytes32(0),
            _gasLimit: 1,
            _unsafeBlockSigner: address(0),
            _config: ResourceMetering.ResourceConfig({
                maxResourceLimit: 1,
                elasticityMultiplier: 1,
                baseFeeMaxChangeDenominator: 2,
                minimumBaseFee: 0,
                systemTxMaxGas: 0,
                maximumBaseFee: 0
            }),
            _batchInbox: address(0),
            _addresses: SystemConfig.Addresses({
                l1CrossDomainMessenger: address(0),
                l1ERC721Bridge: address(0),
                l1StandardBridge: address(0),
                disputeGameFactory: address(0),
                optimismPortal: address(0),
                optimismMintableERC20Factory: address(0),
                gasPayingToken: address(0)
            })
        });
    }

    /// @notice Initializer.
    ///         The resource config must be set before the require check.
    /// @param _owner             Initial owner of the contract.
    /// @param _basefeeScalar     Initial basefee scalar value.
    /// @param _blobbasefeeScalar Initial blobbasefee scalar value.
    /// @param _batcherHash       Initial batcher hash.
    /// @param _gasLimit          Initial gas limit.
    /// @param _unsafeBlockSigner Initial unsafe block signer address.
    /// @param _config            Initial ResourceConfig.
    /// @param _batchInbox        Batch inbox address. An identifier for the op-node to find
    ///                           canonical data.
    /// @param _addresses         Set of L1 contract addresses. These should be the proxies.
    function initialize(
        address _owner,
        uint32 _basefeeScalar,
        uint32 _blobbasefeeScalar,
        bytes32 _batcherHash,
        uint64 _gasLimit,
        address _unsafeBlockSigner,
        ResourceMetering.ResourceConfig memory _config,
        address _batchInbox,
        SystemConfig.Addresses memory _addresses
    )
        public
        initializer
    {
        __Ownable_init();
        transferOwnership(_owner);

        // These are set in ascending order of their UpdateTypes.
        _setBatcherHash(_batcherHash);
        _setGasConfigEcotone({ _basefeeScalar: _basefeeScalar, _blobbasefeeScalar: _blobbasefeeScalar });
        _setGasLimit(_gasLimit);

        Storage.setAddress(UNSAFE_BLOCK_SIGNER_SLOT, _unsafeBlockSigner);
        Storage.setAddress(BATCH_INBOX_SLOT, _batchInbox);
        Storage.setAddress(L1_CROSS_DOMAIN_MESSENGER_SLOT, _addresses.l1CrossDomainMessenger);
        Storage.setAddress(L1_ERC_721_BRIDGE_SLOT, _addresses.l1ERC721Bridge);
        Storage.setAddress(L1_STANDARD_BRIDGE_SLOT, _addresses.l1StandardBridge);
        Storage.setAddress(DISPUTE_GAME_FACTORY_SLOT, _addresses.disputeGameFactory);
        Storage.setAddress(OPTIMISM_PORTAL_SLOT, _addresses.optimismPortal);
        Storage.setAddress(OPTIMISM_MINTABLE_ERC20_FACTORY_SLOT, _addresses.optimismMintableERC20Factory);

        _setStartBlock();
        _setGasPayingToken(_addresses.gasPayingToken);

        _setResourceConfig(_config);
        require(_gasLimit >= minimumGasLimit(), "SystemConfig: gas limit too low");
    }

    /// @notice Returns the minimum L2 gas limit that can be safely set for the system to
    ///         operate. The L2 gas limit must be larger than or equal to the amount of
    ///         gas that is allocated for deposits per block plus the amount of gas that
    ///         is allocated for the system transaction.
    ///         This function is used to determine if changes to parameters are safe.
    /// @return uint64 Minimum gas limit.
    function minimumGasLimit() public view returns (uint64) {
        return uint64(_resourceConfig.maxResourceLimit) + uint64(_resourceConfig.systemTxMaxGas);
    }

    /// @notice Returns the maximum L2 gas limit that can be safely set for the system to
    ///         operate. This bound is used to prevent the gas limit from being set too high
    ///         and causing the system to be unable to process and/or prove L2 blocks.
    /// @return uint64 Maximum gas limit.
    function maximumGasLimit() public pure returns (uint64) {
        return MAX_GAS_LIMIT;
    }

    /// @notice High level getter for the unsafe block signer address.
    ///         Unsafe blocks can be propagated across the p2p network if they are signed by the
    ///         key corresponding to this address.
    /// @return addr_ Address of the unsafe block signer.
    function unsafeBlockSigner() public view returns (address addr_) {
        addr_ = Storage.getAddress(UNSAFE_BLOCK_SIGNER_SLOT);
    }

    /// @notice Getter for the L1CrossDomainMessenger address.
    function l1CrossDomainMessenger() external view returns (address addr_) {
        addr_ = Storage.getAddress(L1_CROSS_DOMAIN_MESSENGER_SLOT);
    }

    /// @notice Getter for the L1ERC721Bridge address.
    function l1ERC721Bridge() external view returns (address addr_) {
        addr_ = Storage.getAddress(L1_ERC_721_BRIDGE_SLOT);
    }

    /// @notice Getter for the L1StandardBridge address.
    function l1StandardBridge() external view returns (address addr_) {
        addr_ = Storage.getAddress(L1_STANDARD_BRIDGE_SLOT);
    }

    /// @notice Getter for the DisputeGameFactory address.
    function disputeGameFactory() external view returns (address addr_) {
        addr_ = Storage.getAddress(DISPUTE_GAME_FACTORY_SLOT);
    }

    /// @notice Getter for the OptimismPortal address.
    function optimismPortal() public view returns (address addr_) {
        addr_ = Storage.getAddress(OPTIMISM_PORTAL_SLOT);
    }

    /// @notice Getter for the OptimismMintableERC20Factory address.
    function optimismMintableERC20Factory() external view returns (address addr_) {
        addr_ = Storage.getAddress(OPTIMISM_MINTABLE_ERC20_FACTORY_SLOT);
    }

    /// @notice Getter for the BatchInbox address.
    function batchInbox() external view returns (address addr_) {
        addr_ = Storage.getAddress(BATCH_INBOX_SLOT);
    }

    /// @notice Getter for the StartBlock number.
    function startBlock() external view returns (uint256 startBlock_) {
        startBlock_ = Storage.getUint(START_BLOCK_SLOT);
    }

    /// @notice Getter for the gas paying asset address.
    function gasPayingToken() public view returns (address addr_, uint8 decimals_) {
        (addr_, decimals_) = GasPayingToken.getToken();
    }

    /// @notice Getter for custom gas token paying networks. Returns true if the
    ///         network uses a custom gas token.
    function isCustomGasToken() public view returns (bool) {
        (address token,) = gasPayingToken();
        return token != Constants.ETHER;
    }

    /// @notice Getter for the gas paying token name.
    function gasPayingTokenName() external view returns (string memory name_) {
        name_ = GasPayingToken.getName();
    }

    /// @notice Getter for the gas paying token symbol.
    function gasPayingTokenSymbol() external view returns (string memory symbol_) {
        symbol_ = GasPayingToken.getSymbol();
    }

    /// @notice Internal setter for the gas paying token address, includes validation.
    ///         The token must not already be set and must be non zero and not the ether address
    ///         to set the token address. This prevents the token address from being changed
    ///         and makes it explicitly opt-in to use custom gas token.
    /// @param _token Address of the gas paying token.
    function _setGasPayingToken(address _token) internal virtual {
        if (_token != address(0) && _token != Constants.ETHER && !isCustomGasToken()) {
            require(
                ERC20(_token).decimals() == GAS_PAYING_TOKEN_DECIMALS, "SystemConfig: bad decimals of gas paying token"
            );
            bytes32 name = GasPayingToken.sanitize(ERC20(_token).name());
            bytes32 symbol = GasPayingToken.sanitize(ERC20(_token).symbol());

            // Set the gas paying token in storage and in the OptimismPortal.
            GasPayingToken.set({ _token: _token, _decimals: GAS_PAYING_TOKEN_DECIMALS, _name: name, _symbol: symbol });
            OptimismPortal(payable(optimismPortal())).setGasPayingToken({
                _token: _token,
                _decimals: GAS_PAYING_TOKEN_DECIMALS,
                _name: name,
                _symbol: symbol
            });
        }
    }

    /// @notice Updates the unsafe block signer address. Can only be called by the owner.
    /// @param _unsafeBlockSigner New unsafe block signer address.
    function setUnsafeBlockSigner(address _unsafeBlockSigner) external onlyOwner {
        _setUnsafeBlockSigner(_unsafeBlockSigner);
    }

    /// @notice Updates the unsafe block signer address.
    /// @param _unsafeBlockSigner New unsafe block signer address.
    function _setUnsafeBlockSigner(address _unsafeBlockSigner) internal {
        Storage.setAddress(UNSAFE_BLOCK_SIGNER_SLOT, _unsafeBlockSigner);

        bytes memory data = abi.encode(_unsafeBlockSigner);
        emit ConfigUpdate(VERSION, UpdateType.UNSAFE_BLOCK_SIGNER, data);
    }

    /// @notice Updates the batcher hash. Can only be called by the owner.
    /// @param _batcherHash New batcher hash.
    function setBatcherHash(bytes32 _batcherHash) external onlyOwner {
        _setBatcherHash(_batcherHash);
    }

    /// @notice Internal function for updating the batcher hash.
    /// @param _batcherHash New batcher hash.
    function _setBatcherHash(bytes32 _batcherHash) internal {
        batcherHash = _batcherHash;

        bytes memory data = abi.encode(_batcherHash);
        emit ConfigUpdate(VERSION, UpdateType.BATCHER, data);
    }

    /// @notice Updates gas config. Can only be called by the owner.
    ///         Deprecated in favor of setGasConfigEcotone since the Ecotone upgrade.
    /// @param _overhead New overhead value.
    /// @param _scalar   New scalar value.
    function setGasConfig(uint256 _overhead, uint256 _scalar) external onlyOwner {
        _setGasConfig(_overhead, _scalar);
    }

    /// @notice Internal function for updating the gas config.
    /// @param _overhead New overhead value.
    /// @param _scalar   New scalar value.
    function _setGasConfig(uint256 _overhead, uint256 _scalar) internal {
        require((uint256(0xff) << 248) & _scalar == 0, "SystemConfig: scalar exceeds max.");

        overhead = _overhead;
        scalar = _scalar;

        bytes memory data = abi.encode(_overhead, _scalar);
        emit ConfigUpdate(VERSION, UpdateType.GAS_CONFIG, data);
    }

    /// @notice Updates gas config as of the Ecotone upgrade. Can only be called by the owner.
    /// @param _basefeeScalar     New basefeeScalar value.
    /// @param _blobbasefeeScalar New blobbasefeeScalar value.
    function setGasConfigEcotone(uint32 _basefeeScalar, uint32 _blobbasefeeScalar) external onlyOwner {
        _setGasConfigEcotone(_basefeeScalar, _blobbasefeeScalar);
    }

    /// @notice Internal function for updating the fee scalars as of the Ecotone upgrade.
    /// @param _basefeeScalar     New basefeeScalar value.
    /// @param _blobbasefeeScalar New blobbasefeeScalar value.
    function _setGasConfigEcotone(uint32 _basefeeScalar, uint32 _blobbasefeeScalar) internal {
        basefeeScalar = _basefeeScalar;
        blobbasefeeScalar = _blobbasefeeScalar;

        scalar = (uint256(0x01) << 248) | (uint256(_blobbasefeeScalar) << 32) | _basefeeScalar;

        bytes memory data = abi.encode(overhead, scalar);
        emit ConfigUpdate(VERSION, UpdateType.GAS_CONFIG, data);
    }

    /// @notice Updates the L2 gas limit. Can only be called by the owner.
    /// @param _gasLimit New gas limit.
    function setGasLimit(uint64 _gasLimit) external onlyOwner {
        _setGasLimit(_gasLimit);
    }

    /// @notice Internal function for updating the L2 gas limit.
    /// @param _gasLimit New gas limit.
    function _setGasLimit(uint64 _gasLimit) internal {
        require(_gasLimit >= minimumGasLimit(), "SystemConfig: gas limit too low");
        require(_gasLimit <= maximumGasLimit(), "SystemConfig: gas limit too high");
        gasLimit = _gasLimit;

        bytes memory data = abi.encode(_gasLimit);
        emit ConfigUpdate(VERSION, UpdateType.GAS_LIMIT, data);
    }

    /// @notice Sets the start block in a backwards compatible way. Proxies
    ///         that were initialized before the startBlock existed in storage
    ///         can have their start block set by a user provided override.
    ///         A start block of 0 indicates that there is no override and the
    ///         start block will be set by `block.number`.
    /// @dev    This logic is used to patch legacy deployments with new storage values.
    ///         Use the override if it is provided as a non zero value and the value
    ///         has not already been set in storage. Use `block.number` if the value
    ///         has already been set in storage
    function _setStartBlock() internal {
        if (Storage.getUint(START_BLOCK_SLOT) == 0) {
            Storage.setUint(START_BLOCK_SLOT, block.number);
        }
    }

    /// @notice A getter for the resource config.
    ///         Ensures that the struct is returned instead of a tuple.
    /// @return ResourceConfig
    function resourceConfig() external view returns (ResourceMetering.ResourceConfig memory) {
        return _resourceConfig;
    }

    /// @notice An internal setter for the resource config.
    ///         Ensures that the config is sane before storing it by checking for invariants.
    ///         In the future, this method may emit an event that the `op-node` picks up
    ///         for when the resource config is changed.
    /// @param _config The new resource config.
    function _setResourceConfig(ResourceMetering.ResourceConfig memory _config) internal {
        // Min base fee must be less than or equal to max base fee.
        require(
            _config.minimumBaseFee <= _config.maximumBaseFee, "SystemConfig: min base fee must be less than max base"
        );
        // Base fee change denominator must be greater than 1.
        require(_config.baseFeeMaxChangeDenominator > 1, "SystemConfig: denominator must be larger than 1");
        // Max resource limit plus system tx gas must be less than or equal to the L2 gas limit.
        // The gas limit must be increased before these values can be increased.
        require(_config.maxResourceLimit + _config.systemTxMaxGas <= gasLimit, "SystemConfig: gas limit too low");
        // Elasticity multiplier must be greater than 0.
        require(_config.elasticityMultiplier > 0, "SystemConfig: elasticity multiplier cannot be 0");
        // No precision loss when computing target resource limit.
        require(
            ((_config.maxResourceLimit / _config.elasticityMultiplier) * _config.elasticityMultiplier)
                == _config.maxResourceLimit,
            "SystemConfig: precision loss with target resource limit"
        );

        _resourceConfig = _config;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Bytes
/// @notice Bytes is a library for manipulating byte arrays.
library Bytes {
    /// @custom:attribution https://github.com/GNSPS/solidity-bytes-utils
    /// @notice Slices a byte array with a given starting index and length. Returns a new byte array
    ///         as opposed to a pointer to the original array. Will throw if trying to slice more
    ///         bytes than exist in the array.
    /// @param _bytes Byte array to slice.
    /// @param _start Starting index of the slice.
    /// @param _length Length of the slice.
    /// @return Slice of the input byte array.
    function slice(bytes memory _bytes, uint256 _start, uint256 _length) internal pure returns (bytes memory) {
        unchecked {
            require(_length + 31 >= _length, "slice_overflow");
            require(_start + _length >= _start, "slice_overflow");
            require(_bytes.length >= _start + _length, "slice_outOfBounds");
        }

        bytes memory tempBytes;

        assembly {
            switch iszero(_length)
            case 0 {
                // Get a location of some free memory and store it in tempBytes as
                // Solidity does for memory variables.
                tempBytes := mload(0x40)

                // The first word of the slice result is potentially a partial
                // word read from the original array. To read it, we calculate
                // the length of that partial word and start copying that many
                // bytes into the array. The first word we copy will start with
                // data we don't care about, but the last `lengthmod` bytes will
                // land at the beginning of the contents of the new array. When
                // we're done copying, we overwrite the full first word with
                // the actual length of the slice.
                let lengthmod := and(_length, 31)

                // The multiplication in the next line is necessary
                // because when slicing multiples of 32 bytes (lengthmod == 0)
                // the following copy loop was copying the origin's length
                // and then ending prematurely not copying everything it should.
                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                let end := add(mc, _length)

                for {
                    // The multiplication in the next line has the same exact purpose
                    // as the one above.
                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                } lt(mc, end) {
                    mc := add(mc, 0x20)
                    cc := add(cc, 0x20)
                } { mstore(mc, mload(cc)) }

                mstore(tempBytes, _length)

                //update free-memory pointer
                //allocating the array padded to 32 bytes like the compiler does now
                mstore(0x40, and(add(mc, 31), not(31)))
            }
            //if we want a zero-length slice let's just return a zero-length array
            default {
                tempBytes := mload(0x40)

                //zero out the 32 bytes slice we are about to return
                //we need to do it because Solidity does not garbage collect
                mstore(tempBytes, 0)

                mstore(0x40, add(tempBytes, 0x20))
            }
        }

        return tempBytes;
    }

    /// @notice Slices a byte array with a given starting index up to the end of the original byte
    ///         array. Returns a new array rathern than a pointer to the original.
    /// @param _bytes Byte array to slice.
    /// @param _start Starting index of the slice.
    /// @return Slice of the input byte array.
    function slice(bytes memory _bytes, uint256 _start) internal pure returns (bytes memory) {
        if (_start >= _bytes.length) {
            return bytes("");
        }
        return slice(_bytes, _start, _bytes.length - _start);
    }

    /// @notice Converts a byte array into a nibble array by splitting each byte into two nibbles.
    ///         Resulting nibble array will be exactly twice as long as the input byte array.
    /// @param _bytes Input byte array to convert.
    /// @return Resulting nibble array.
    function toNibbles(bytes memory _bytes) internal pure returns (bytes memory) {
        bytes memory _nibbles;
        assembly {
            // Grab a free memory offset for the new array
            _nibbles := mload(0x40)

            // Load the length of the passed bytes array from memory
            let bytesLength := mload(_bytes)

            // Calculate the length of the new nibble array
            // This is the length of the input array times 2
            let nibblesLength := shl(0x01, bytesLength)

            // Update the free memory pointer to allocate memory for the new array.
            // To do this, we add the length of the new array + 32 bytes for the array length
            // rounded up to the nearest 32 byte boundary to the current free memory pointer.
            mstore(0x40, add(_nibbles, and(not(0x1F), add(nibblesLength, 0x3F))))

            // Store the length of the new array in memory
            mstore(_nibbles, nibblesLength)

            // Store the memory offset of the _bytes array's contents on the stack
            let bytesStart := add(_bytes, 0x20)

            // Store the memory offset of the nibbles array's contents on the stack
            let nibblesStart := add(_nibbles, 0x20)

            // Loop through each byte in the input array
            for { let i := 0x00 } lt(i, bytesLength) { i := add(i, 0x01) } {
                // Get the starting offset of the next 2 bytes in the nibbles array
                let offset := add(nibblesStart, shl(0x01, i))
                // Load the byte at the current index within the `_bytes` array
                let b := byte(0x00, mload(add(bytesStart, i)))

                // Pull out the first nibble and store it in the new array
                mstore8(offset, shr(0x04, b))
                // Pull out the second nibble and store it in the new array
                mstore8(add(offset, 0x01), and(b, 0x0F))
            }
        }
        return _nibbles;
    }

    /// @notice Compares two byte arrays by comparing their keccak256 hashes.
    /// @param _bytes First byte array to compare.
    /// @param _other Second byte array to compare.
    /// @return True if the two byte arrays are equal, false otherwise.
    function equal(bytes memory _bytes, bytes memory _other) internal pure returns (bool) {
        return keccak256(_bytes) == keccak256(_other);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Types
/// @notice Contains various types used throughout the Optimism contract system.
library Types {
    /// @notice OutputProposal represents a commitment to the L2 state. The timestamp is the L1
    ///         timestamp that the output root is posted. This timestamp is used to verify that the
    ///         finalization period has passed since the output root was submitted.
    /// @custom:field outputRoot    Hash of the L2 output.
    /// @custom:field timestamp     Timestamp of the L1 block that the output root was submitted in.
    /// @custom:field l2BlockNumber L2 block number that the output corresponds to.
    struct OutputProposal {
        bytes32 outputRoot;
        uint128 timestamp;
        uint128 l2BlockNumber;
    }

    /// @notice Struct representing the elements that are hashed together to generate an output root
    ///         which itself represents a snapshot of the L2 state.
    /// @custom:field version                  Version of the output root.
    /// @custom:field stateRoot                Root of the state trie at the block of this output.
    /// @custom:field messagePasserStorageRoot Root of the message passer storage trie.
    /// @custom:field latestBlockhash          Hash of the block this output was generated from.
    struct OutputRootProof {
        bytes32 version;
        bytes32 stateRoot;
        bytes32 messagePasserStorageRoot;
        bytes32 latestBlockhash;
    }

    /// @notice Struct representing a deposit transaction (L1 => L2 transaction) created by an end
    ///         user (as opposed to a system deposit transaction generated by the system).
    /// @custom:field from        Address of the sender of the transaction.
    /// @custom:field to          Address of the recipient of the transaction.
    /// @custom:field isCreation  True if the transaction is a contract creation.
    /// @custom:field value       Value to send to the recipient.
    /// @custom:field mint        Amount of ETH to mint.
    /// @custom:field gasLimit    Gas limit of the transaction.
    /// @custom:field data        Data of the transaction.
    /// @custom:field l1BlockHash Hash of the block the transaction was submitted in.
    /// @custom:field logIndex    Index of the log in the block the transaction was submitted in.
    struct UserDepositTransaction {
        address from;
        address to;
        bool isCreation;
        uint256 value;
        uint256 mint;
        uint64 gasLimit;
        bytes data;
        bytes32 l1BlockHash;
        uint256 logIndex;
    }

    /// @notice Struct representing a withdrawal transaction.
    /// @custom:field nonce    Nonce of the withdrawal transaction
    /// @custom:field sender   Address of the sender of the transaction.
    /// @custom:field target   Address of the recipient of the transaction.
    /// @custom:field value    Value to send to the recipient.
    /// @custom:field gasLimit Gas limit of the transaction.
    /// @custom:field data     Data of the transaction.
    struct WithdrawalTransaction {
        uint256 nonce;
        address sender;
        address target;
        uint256 value;
        uint256 gasLimit;
        bytes data;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { ISemver } from "src/universal/ISemver.sol";
import { Types } from "src/libraries/Types.sol";
import { Constants } from "src/libraries/Constants.sol";

/// @custom:proxied
/// @title L2OutputOracle
/// @notice The L2OutputOracle contains an array of L2 state outputs, where each output is a
///         commitment to the state of the L2 chain. Other contracts like the OptimismPortal use
///         these outputs to verify information about the state of L2.
contract L2OutputOracle is Initializable, ISemver {
    /// @notice The number of the first L2 block recorded in this contract.
    uint256 public startingBlockNumber;

    /// @notice The timestamp of the first L2 block recorded in this contract.
    uint256 public startingTimestamp;

    /// @notice An array of L2 output proposals.
    Types.OutputProposal[] internal l2Outputs;

    /// @notice The interval in L2 blocks at which checkpoints must be submitted.
    /// @custom:network-specific
    uint256 public submissionInterval;

    /// @notice The time between L2 blocks in seconds. Once set, this value MUST NOT be modified.
    /// @custom:network-specific
    uint256 public l2BlockTime;

    /// @notice The address of the challenger. Can be updated via upgrade.
    /// @custom:network-specific
    address public challenger;

    /// @notice The address of the proposer. Can be updated via upgrade.
    /// @custom:network-specific
    address public proposer;

    /// @notice The minimum time (in seconds) that must elapse before a withdrawal can be finalized.
    /// @custom:network-specific
    uint256 public finalizationPeriodSeconds;

    /// @notice Emitted when an output is proposed.
    /// @param outputRoot    The output root.
    /// @param l2OutputIndex The index of the output in the l2Outputs array.
    /// @param l2BlockNumber The L2 block number of the output root.
    /// @param l1Timestamp   The L1 timestamp when proposed.
    event OutputProposed(
        bytes32 indexed outputRoot, uint256 indexed l2OutputIndex, uint256 indexed l2BlockNumber, uint256 l1Timestamp
    );

    /// @notice Emitted when outputs are deleted.
    /// @param prevNextOutputIndex Next L2 output index before the deletion.
    /// @param newNextOutputIndex  Next L2 output index after the deletion.
    event OutputsDeleted(uint256 indexed prevNextOutputIndex, uint256 indexed newNextOutputIndex);

    /// @notice Semantic version.
    /// @custom:semver 1.8.0
    string public constant version = "1.8.0";

    /// @notice Constructs the L2OutputOracle contract. Initializes variables to the same values as
    ///         in the getting-started config.
    constructor() {
        initialize({
            _submissionInterval: 1,
            _l2BlockTime: 1,
            _startingBlockNumber: 0,
            _startingTimestamp: 0,
            _proposer: address(0),
            _challenger: address(0),
            _finalizationPeriodSeconds: 0
        });
    }

    /// @notice Initializer.
    /// @param _submissionInterval  Interval in blocks at which checkpoints must be submitted.
    /// @param _l2BlockTime         The time per L2 block, in seconds.
    /// @param _startingBlockNumber The number of the first L2 block.
    /// @param _startingTimestamp   The timestamp of the first L2 block.
    /// @param _proposer            The address of the proposer.
    /// @param _challenger          The address of the challenger.
    /// @param _finalizationPeriodSeconds The minimum time (in seconds) that must elapse before a withdrawal
    ///                                   can be finalized.
    function initialize(
        uint256 _submissionInterval,
        uint256 _l2BlockTime,
        uint256 _startingBlockNumber,
        uint256 _startingTimestamp,
        address _proposer,
        address _challenger,
        uint256 _finalizationPeriodSeconds
    )
        public
        initializer
    {
        require(_submissionInterval > 0, "L2OutputOracle: submission interval must be greater than 0");
        require(_l2BlockTime > 0, "L2OutputOracle: L2 block time must be greater than 0");
        require(
            _startingTimestamp <= block.timestamp,
            "L2OutputOracle: starting L2 timestamp must be less than current time"
        );

        submissionInterval = _submissionInterval;
        l2BlockTime = _l2BlockTime;
        startingBlockNumber = _startingBlockNumber;
        startingTimestamp = _startingTimestamp;
        proposer = _proposer;
        challenger = _challenger;
        finalizationPeriodSeconds = _finalizationPeriodSeconds;
    }

    /// @notice Getter for the submissionInterval.
    ///         Public getter is legacy and will be removed in the future. Use `submissionInterval` instead.
    /// @return Submission interval.
    /// @custom:legacy
    function SUBMISSION_INTERVAL() external view returns (uint256) {
        return submissionInterval;
    }

    /// @notice Getter for the l2BlockTime.
    ///         Public getter is legacy and will be removed in the future. Use `l2BlockTime` instead.
    /// @return L2 block time.
    /// @custom:legacy
    function L2_BLOCK_TIME() external view returns (uint256) {
        return l2BlockTime;
    }

    /// @notice Getter for the challenger address.
    ///         Public getter is legacy and will be removed in the future. Use `challenger` instead.
    /// @return Address of the challenger.
    /// @custom:legacy
    function CHALLENGER() external view returns (address) {
        return challenger;
    }

    /// @notice Getter for the proposer address.
    ///         Public getter is legacy and will be removed in the future. Use `proposer` instead.
    /// @return Address of the proposer.
    /// @custom:legacy
    function PROPOSER() external view returns (address) {
        return proposer;
    }

    /// @notice Getter for the finalizationPeriodSeconds.
    ///         Public getter is legacy and will be removed in the future. Use `finalizationPeriodSeconds` instead.
    /// @return Finalization period in seconds.
    /// @custom:legacy
    function FINALIZATION_PERIOD_SECONDS() external view returns (uint256) {
        return finalizationPeriodSeconds;
    }

    /// @notice Deletes all output proposals after and including the proposal that corresponds to
    ///         the given output index. Only the challenger address can delete outputs.
    /// @param _l2OutputIndex Index of the first L2 output to be deleted.
    ///                       All outputs after this output will also be deleted.
    function deleteL2Outputs(uint256 _l2OutputIndex) external {
        require(msg.sender == challenger, "L2OutputOracle: only the challenger address can delete outputs");

        // Make sure we're not *increasing* the length of the array.
        require(
            _l2OutputIndex < l2Outputs.length, "L2OutputOracle: cannot delete outputs after the latest output index"
        );

        // Do not allow deleting any outputs that have already been finalized.
        require(
            block.timestamp - l2Outputs[_l2OutputIndex].timestamp < finalizationPeriodSeconds,
            "L2OutputOracle: cannot delete outputs that have already been finalized"
        );

        uint256 prevNextL2OutputIndex = nextOutputIndex();

        // Use assembly to delete the array elements because Solidity doesn't allow it.
        assembly {
            sstore(l2Outputs.slot, _l2OutputIndex)
        }

        emit OutputsDeleted(prevNextL2OutputIndex, _l2OutputIndex);
    }

    /// @notice Accepts an outputRoot and the timestamp of the corresponding L2 block.
    ///         The timestamp must be equal to the current value returned by `nextTimestamp()` in
    ///         order to be accepted. This function may only be called by the Proposer.
    /// @param _outputRoot    The L2 output of the checkpoint block.
    /// @param _l2BlockNumber The L2 block number that resulted in _outputRoot.
    /// @param _l1BlockHash   A block hash which must be included in the current chain.
    /// @param _l1BlockNumber The block number with the specified block hash.
    function proposeL2Output(
        bytes32 _outputRoot,
        uint256 _l2BlockNumber,
        bytes32 _l1BlockHash,
        uint256 _l1BlockNumber
    )
        external
        payable
    {
        require(msg.sender == proposer, "L2OutputOracle: only the proposer address can propose new outputs");

        require(
            _l2BlockNumber == nextBlockNumber(),
            "L2OutputOracle: block number must be equal to next expected block number"
        );

        require(
            computeL2Timestamp(_l2BlockNumber) < block.timestamp,
            "L2OutputOracle: cannot propose L2 output in the future"
        );

        require(_outputRoot != bytes32(0), "L2OutputOracle: L2 output proposal cannot be the zero hash");

        if (_l1BlockHash != bytes32(0)) {
            // This check allows the proposer to propose an output based on a given L1 block,
            // without fear that it will be reorged out.
            // It will also revert if the blockheight provided is more than 256 blocks behind the
            // chain tip (as the hash will return as zero). This does open the door to a griefing
            // attack in which the proposer's submission is censored until the block is no longer
            // retrievable, if the proposer is experiencing this attack it can simply leave out the
            // blockhash value, and delay submission until it is confident that the L1 block is
            // finalized.
            require(
                blockhash(_l1BlockNumber) == _l1BlockHash,
                "L2OutputOracle: block hash does not match the hash at the expected height"
            );
        }

        emit OutputProposed(_outputRoot, nextOutputIndex(), _l2BlockNumber, block.timestamp);

        l2Outputs.push(
            Types.OutputProposal({
                outputRoot: _outputRoot,
                timestamp: uint128(block.timestamp),
                l2BlockNumber: uint128(_l2BlockNumber)
            })
        );
    }

    /// @notice Returns an output by index. Needed to return a struct instead of a tuple.
    /// @param _l2OutputIndex Index of the output to return.
    /// @return The output at the given index.
    function getL2Output(uint256 _l2OutputIndex) external view returns (Types.OutputProposal memory) {
        return l2Outputs[_l2OutputIndex];
    }

    /// @notice Returns the index of the L2 output that checkpoints a given L2 block number.
    ///         Uses a binary search to find the first output greater than or equal to the given
    ///         block.
    /// @param _l2BlockNumber L2 block number to find a checkpoint for.
    /// @return Index of the first checkpoint that commits to the given L2 block number.
    function getL2OutputIndexAfter(uint256 _l2BlockNumber) public view returns (uint256) {
        // Make sure an output for this block number has actually been proposed.
        require(
            _l2BlockNumber <= latestBlockNumber(),
            "L2OutputOracle: cannot get output for a block that has not been proposed"
        );

        // Make sure there's at least one output proposed.
        require(l2Outputs.length > 0, "L2OutputOracle: cannot get output as no outputs have been proposed yet");

        // Find the output via binary search, guaranteed to exist.
        uint256 lo = 0;
        uint256 hi = l2Outputs.length;
        while (lo < hi) {
            uint256 mid = (lo + hi) / 2;
            if (l2Outputs[mid].l2BlockNumber < _l2BlockNumber) {
                lo = mid + 1;
            } else {
                hi = mid;
            }
        }

        return lo;
    }

    /// @notice Returns the L2 output proposal that checkpoints a given L2 block number.
    ///         Uses a binary search to find the first output greater than or equal to the given
    ///         block.
    /// @param _l2BlockNumber L2 block number to find a checkpoint for.
    /// @return First checkpoint that commits to the given L2 block number.
    function getL2OutputAfter(uint256 _l2BlockNumber) external view returns (Types.OutputProposal memory) {
        return l2Outputs[getL2OutputIndexAfter(_l2BlockNumber)];
    }

    /// @notice Returns the number of outputs that have been proposed.
    ///         Will revert if no outputs have been proposed yet.
    /// @return The number of outputs that have been proposed.
    function latestOutputIndex() external view returns (uint256) {
        return l2Outputs.length - 1;
    }

    /// @notice Returns the index of the next output to be proposed.
    /// @return The index of the next output to be proposed.
    function nextOutputIndex() public view returns (uint256) {
        return l2Outputs.length;
    }

    /// @notice Returns the block number of the latest submitted L2 output proposal.
    ///         If no proposals been submitted yet then this function will return the starting
    ///         block number.
    /// @return Latest submitted L2 block number.
    function latestBlockNumber() public view returns (uint256) {
        return l2Outputs.length == 0 ? startingBlockNumber : l2Outputs[l2Outputs.length - 1].l2BlockNumber;
    }

    /// @notice Computes the block number of the next L2 block that needs to be checkpointed.
    /// @return Next L2 block number.
    function nextBlockNumber() public view returns (uint256) {
        return latestBlockNumber() + submissionInterval;
    }

    /// @notice Returns the L2 timestamp corresponding to a given L2 block number.
    /// @param _l2BlockNumber The L2 block number of the target block.
    /// @return L2 timestamp of the given block.
    function computeL2Timestamp(uint256 _l2BlockNumber) public view returns (uint256) {
        return startingTimestamp + ((_l2BlockNumber - startingBlockNumber) * l2BlockTime);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { SafeCall } from "src/libraries/SafeCall.sol";
import { L2OutputOracle } from "src/L1/L2OutputOracle.sol";
import { SystemConfig } from "src/L1/SystemConfig.sol";
import { SuperchainConfig } from "src/L1/SuperchainConfig.sol";
import { Constants } from "src/libraries/Constants.sol";
import { Types } from "src/libraries/Types.sol";
import { Hashing } from "src/libraries/Hashing.sol";
import { SecureMerkleTrie } from "src/libraries/trie/SecureMerkleTrie.sol";
import { AddressAliasHelper } from "src/vendor/AddressAliasHelper.sol";
import { ResourceMetering } from "src/L1/ResourceMetering.sol";
import { ISemver } from "src/universal/ISemver.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { L1Block } from "src/L2/L1Block.sol";
import { Predeploys } from "src/libraries/Predeploys.sol";
import "src/libraries/PortalErrors.sol";

/// @custom:proxied
/// @title OptimismPortal
/// @notice The OptimismPortal is a low-level contract responsible for passing messages between L1
///         and L2. Messages sent directly to the OptimismPortal have no form of replayability.
///         Users are encouraged to use the L1CrossDomainMessenger for a higher-level interface.
contract OptimismPortal is Initializable, ResourceMetering, ISemver {
    /// @notice Allows for interactions with non standard ERC20 tokens.
    using SafeERC20 for IERC20;

    /// @notice Represents a proven withdrawal.
    /// @custom:field outputRoot    Root of the L2 output this was proven against.
    /// @custom:field timestamp     Timestamp at whcih the withdrawal was proven.
    /// @custom:field l2OutputIndex Index of the output this was proven against.
    struct ProvenWithdrawal {
        bytes32 outputRoot;
        uint128 timestamp;
        uint128 l2OutputIndex;
    }

    /// @notice Version of the deposit event.
    uint256 internal constant DEPOSIT_VERSION = 0;

    /// @notice The L2 gas limit set when eth is deposited using the receive() function.
    uint64 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 100_000;

    /// @notice The L2 gas limit for system deposit transactions that are initiated from L1.
    uint32 internal constant SYSTEM_DEPOSIT_GAS_LIMIT = 200_000;

    /// @notice Address of the L2 account which initiated a withdrawal in this transaction.
    ///         If the of this variable is the default L2 sender address, then we are NOT inside of
    ///         a call to finalizeWithdrawalTransaction.
    address public l2Sender;

    /// @notice A list of withdrawal hashes which have been successfully finalized.
    mapping(bytes32 => bool) public finalizedWithdrawals;

    /// @notice A mapping of withdrawal hashes to `ProvenWithdrawal` data.
    mapping(bytes32 => ProvenWithdrawal) public provenWithdrawals;

    /// @custom:legacy
    /// @custom:spacer paused
    /// @notice Spacer for backwards compatibility.
    bool private spacer_53_0_1;

    /// @notice Contract of the Superchain Config.
    SuperchainConfig public superchainConfig;

    /// @notice Contract of the L2OutputOracle.
    /// @custom:network-specific
    L2OutputOracle public l2Oracle;

    /// @notice Contract of the SystemConfig.
    /// @custom:network-specific
    SystemConfig public systemConfig;

    /// @custom:spacer disputeGameFactory
    /// @notice Spacer for backwards compatibility.
    address private spacer_56_0_20;

    /// @custom:spacer provenWithdrawals
    /// @notice Spacer for backwards compatibility.
    bytes32 private spacer_57_0_32;

    /// @custom:spacer disputeGameBlacklist
    /// @notice Spacer for backwards compatibility.
    bytes32 private spacer_58_0_32;

    /// @custom:spacer respectedGameType + respectedGameTypeUpdatedAt
    /// @notice Spacer for backwards compatibility.
    bytes32 private spacer_59_0_32;

    /// @custom:spacer proofSubmitters
    /// @notice Spacer for backwards compatibility.
    bytes32 private spacer_60_0_32;

    /// @notice Represents the amount of native asset minted in L2. This may not
    ///         be 100% accurate due to the ability to send ether to the contract
    ///         without triggering a deposit transaction. It also is used to prevent
    ///         overflows for L2 account balances when custom gas tokens are used.
    ///         It is not safe to trust `ERC20.balanceOf` as it may lie.
    uint256 internal _balance;

    /// @notice Emitted when a transaction is deposited from L1 to L2.
    ///         The parameters of this event are read by the rollup node and used to derive deposit
    ///         transactions on L2.
    /// @param from       Address that triggered the deposit transaction.
    /// @param to         Address that the deposit transaction is directed to.
    /// @param version    Version of this deposit transaction event.
    /// @param opaqueData ABI encoded deposit data to be parsed off-chain.
    event TransactionDeposited(address indexed from, address indexed to, uint256 indexed version, bytes opaqueData);

    /// @notice Emitted when a withdrawal transaction is proven.
    /// @param withdrawalHash Hash of the withdrawal transaction.
    /// @param from           Address that triggered the withdrawal transaction.
    /// @param to             Address that the withdrawal transaction is directed to.
    event WithdrawalProven(bytes32 indexed withdrawalHash, address indexed from, address indexed to);

    /// @notice Emitted when a withdrawal transaction is finalized.
    /// @param withdrawalHash Hash of the withdrawal transaction.
    /// @param success        Whether the withdrawal transaction was successful.
    event WithdrawalFinalized(bytes32 indexed withdrawalHash, bool success);

    /// @notice Reverts when paused.
    modifier whenNotPaused() {
        if (paused()) revert CallPaused();
        _;
    }

    /// @notice Semantic version.
    /// @custom:semver 2.8.1-beta.1
    function version() public pure virtual returns (string memory) {
        return "2.8.1-beta.1";
    }

    /// @notice Constructs the OptimismPortal contract.
    constructor() {
        initialize({
            _l2Oracle: L2OutputOracle(address(0)),
            _systemConfig: SystemConfig(address(0)),
            _superchainConfig: SuperchainConfig(address(0))
        });
    }

    /// @notice Initializer.
    /// @param _l2Oracle Contract of the L2OutputOracle.
    /// @param _systemConfig Contract of the SystemConfig.
    /// @param _superchainConfig Contract of the SuperchainConfig.
    function initialize(
        L2OutputOracle _l2Oracle,
        SystemConfig _systemConfig,
        SuperchainConfig _superchainConfig
    )
        public
        initializer
    {
        l2Oracle = _l2Oracle;
        systemConfig = _systemConfig;
        superchainConfig = _superchainConfig;
        if (l2Sender == address(0)) {
            l2Sender = Constants.DEFAULT_L2_SENDER;
        }
        __ResourceMetering_init();
    }

    /// @notice Getter for the balance of the contract.
    function balance() public view returns (uint256) {
        (address token,) = gasPayingToken();
        if (token == Constants.ETHER) {
            return address(this).balance;
        } else {
            return _balance;
        }
    }

    /// @notice Getter function for the address of the guardian.
    ///         Public getter is legacy and will be removed in the future. Use `SuperchainConfig.guardian()` instead.
    /// @return Address of the guardian.
    /// @custom:legacy
    function guardian() public view returns (address) {
        return superchainConfig.guardian();
    }

    /// @notice Getter for the current paused status.
    /// @return paused_ Whether or not the contract is paused.
    function paused() public view returns (bool paused_) {
        paused_ = superchainConfig.paused();
    }

    /// @notice Computes the minimum gas limit for a deposit.
    ///         The minimum gas limit linearly increases based on the size of the calldata.
    ///         This is to prevent users from creating L2 resource usage without paying for it.
    ///         This function can be used when interacting with the portal to ensure forwards
    ///         compatibility.
    /// @param _byteCount Number of bytes in the calldata.
    /// @return The minimum gas limit for a deposit.
    function minimumGasLimit(uint64 _byteCount) public pure returns (uint64) {
        return _byteCount * 16 + 21000;
    }

    /// @notice Accepts value so that users can send ETH directly to this contract and have the
    ///         funds be deposited to their address on L2. This is intended as a convenience
    ///         function for EOAs. Contracts should call the depositTransaction() function directly
    ///         otherwise any deposited funds will be lost due to address aliasing.
    receive() external payable {
        depositTransaction(msg.sender, msg.value, RECEIVE_DEFAULT_GAS_LIMIT, false, bytes(""));
    }

    /// @notice Accepts ETH value without triggering a deposit to L2.
    ///         This function mainly exists for the sake of the migration between the legacy
    ///         Optimism system and Bedrock.
    function donateETH() external payable {
        // Intentionally empty.
    }

    /// @notice Returns the gas paying token and its decimals.
    function gasPayingToken() internal view returns (address addr_, uint8 decimals_) {
        (addr_, decimals_) = systemConfig.gasPayingToken();
    }

    /// @notice Getter for the resource config.
    ///         Used internally by the ResourceMetering contract.
    ///         The SystemConfig is the source of truth for the resource config.
    /// @return ResourceMetering ResourceConfig
    function _resourceConfig() internal view override returns (ResourceMetering.ResourceConfig memory) {
        return systemConfig.resourceConfig();
    }

    /// @notice Proves a withdrawal transaction.
    /// @param _tx              Withdrawal transaction to finalize.
    /// @param _l2OutputIndex   L2 output index to prove against.
    /// @param _outputRootProof Inclusion proof of the L2ToL1MessagePasser contract's storage root.
    /// @param _withdrawalProof Inclusion proof of the withdrawal in L2ToL1MessagePasser contract.
    function proveWithdrawalTransaction(
        Types.WithdrawalTransaction memory _tx,
        uint256 _l2OutputIndex,
        Types.OutputRootProof calldata _outputRootProof,
        bytes[] calldata _withdrawalProof
    )
        external
        whenNotPaused
    {
        // Prevent users from creating a deposit transaction where this address is the message
        // sender on L2. Because this is checked here, we do not need to check again in
        // `finalizeWithdrawalTransaction`.
        if (_tx.target == address(this)) revert BadTarget();

        // Get the output root and load onto the stack to prevent multiple mloads. This will
        // revert if there is no output root for the given block number.
        bytes32 outputRoot = l2Oracle.getL2Output(_l2OutputIndex).outputRoot;

        // Verify that the output root can be generated with the elements in the proof.
        require(
            outputRoot == Hashing.hashOutputRootProof(_outputRootProof), "OptimismPortal: invalid output root proof"
        );

        // Load the ProvenWithdrawal into memory, using the withdrawal hash as a unique identifier.
        bytes32 withdrawalHash = Hashing.hashWithdrawal(_tx);
        ProvenWithdrawal memory provenWithdrawal = provenWithdrawals[withdrawalHash];

        // We generally want to prevent users from proving the same withdrawal multiple times
        // because each successive proof will update the timestamp. A malicious user can take
        // advantage of this to prevent other users from finalizing their withdrawal. However,
        // since withdrawals are proven before an output root is finalized, we need to allow users
        // to re-prove their withdrawal only in the case that the output root for their specified
        // output index has been updated.
        require(
            provenWithdrawal.timestamp == 0
                || l2Oracle.getL2Output(provenWithdrawal.l2OutputIndex).outputRoot != provenWithdrawal.outputRoot,
            "OptimismPortal: withdrawal hash has already been proven"
        );

        // Compute the storage slot of the withdrawal hash in the L2ToL1MessagePasser contract.
        // Refer to the Solidity documentation for more information on how storage layouts are
        // computed for mappings.
        bytes32 storageKey = keccak256(
            abi.encode(
                withdrawalHash,
                uint256(0) // The withdrawals mapping is at the first slot in the layout.
            )
        );

        // Verify that the hash of this withdrawal was stored in the L2toL1MessagePasser contract
        // on L2. If this is true, under the assumption that the SecureMerkleTrie does not have
        // bugs, then we know that this withdrawal was actually triggered on L2 and can therefore
        // be relayed on L1.
        require(
            SecureMerkleTrie.verifyInclusionProof({
                _key: abi.encode(storageKey),
                _value: hex"01",
                _proof: _withdrawalProof,
                _root: _outputRootProof.messagePasserStorageRoot
            }),
            "OptimismPortal: invalid withdrawal inclusion proof"
        );

        // Designate the withdrawalHash as proven by storing the `outputRoot`, `timestamp`, and
        // `l2BlockNumber` in the `provenWithdrawals` mapping. A `withdrawalHash` can only be
        // proven once unless it is submitted again with a different outputRoot.
        provenWithdrawals[withdrawalHash] = ProvenWithdrawal({
            outputRoot: outputRoot,
            timestamp: uint128(block.timestamp),
            l2OutputIndex: uint128(_l2OutputIndex)
        });

        // Emit a `WithdrawalProven` event.
        emit WithdrawalProven(withdrawalHash, _tx.sender, _tx.target);
    }

    /// @notice Finalizes a withdrawal transaction.
    /// @param _tx Withdrawal transaction to finalize.
    function finalizeWithdrawalTransaction(Types.WithdrawalTransaction memory _tx) external whenNotPaused {
        // Make sure that the l2Sender has not yet been set. The l2Sender is set to a value other
        // than the default value when a withdrawal transaction is being finalized. This check is
        // a defacto reentrancy guard.
        if (l2Sender != Constants.DEFAULT_L2_SENDER) revert NonReentrant();

        // Grab the proven withdrawal from the `provenWithdrawals` map.
        bytes32 withdrawalHash = Hashing.hashWithdrawal(_tx);
        ProvenWithdrawal memory provenWithdrawal = provenWithdrawals[withdrawalHash];

        // A withdrawal can only be finalized if it has been proven. We know that a withdrawal has
        // been proven at least once when its timestamp is non-zero. Unproven withdrawals will have
        // a timestamp of zero.
        require(provenWithdrawal.timestamp != 0, "OptimismPortal: withdrawal has not been proven yet");

        // As a sanity check, we make sure that the proven withdrawal's timestamp is greater than
        // starting timestamp inside the L2OutputOracle. Not strictly necessary but extra layer of
        // safety against weird bugs in the proving step.
        require(
            provenWithdrawal.timestamp >= l2Oracle.startingTimestamp(),
            "OptimismPortal: withdrawal timestamp less than L2 Oracle starting timestamp"
        );

        // A proven withdrawal must wait at least the finalization period before it can be
        // finalized. This waiting period can elapse in parallel with the waiting period for the
        // output the withdrawal was proven against. In effect, this means that the minimum
        // withdrawal time is proposal submission time + finalization period.
        require(
            _isFinalizationPeriodElapsed(provenWithdrawal.timestamp),
            "OptimismPortal: proven withdrawal finalization period has not elapsed"
        );

        // Grab the OutputProposal from the L2OutputOracle, will revert if the output that
        // corresponds to the given index has not been proposed yet.
        Types.OutputProposal memory proposal = l2Oracle.getL2Output(provenWithdrawal.l2OutputIndex);

        // Check that the output root that was used to prove the withdrawal is the same as the
        // current output root for the given output index. An output root may change if it is
        // deleted by the challenger address and then re-proposed.
        require(
            proposal.outputRoot == provenWithdrawal.outputRoot,
            "OptimismPortal: output root proven is not the same as current output root"
        );

        // Check that the output proposal has also been finalized.
        require(
            _isFinalizationPeriodElapsed(proposal.timestamp),
            "OptimismPortal: output proposal finalization period has not elapsed"
        );

        // Check that this withdrawal has not already been finalized, this is replay protection.
        require(finalizedWithdrawals[withdrawalHash] == false, "OptimismPortal: withdrawal has already been finalized");

        // Mark the withdrawal as finalized so it can't be replayed.
        finalizedWithdrawals[withdrawalHash] = true;

        // Set the l2Sender so contracts know who triggered this withdrawal on L2.
        // This acts as a reentrancy guard.
        l2Sender = _tx.sender;

        bool success;
        (address token,) = gasPayingToken();
        if (token == Constants.ETHER) {
            // Trigger the call to the target contract. We use a custom low level method
            // SafeCall.callWithMinGas to ensure two key properties
            //   1. Target contracts cannot force this call to run out of gas by returning a very large
            //      amount of data (and this is OK because we don't care about the returndata here).
            //   2. The amount of gas provided to the execution context of the target is at least the
            //      gas limit specified by the user. If there is not enough gas in the current context
            //      to accomplish this, `callWithMinGas` will revert.
            success = SafeCall.callWithMinGas(_tx.target, _tx.gasLimit, _tx.value, _tx.data);
        } else {
            // Cannot call the token contract directly from the portal. This would allow an attacker
            // to call approve from a withdrawal and drain the balance of the portal.
            if (_tx.target == token) revert BadTarget();

            // Only transfer value when a non zero value is specified. This saves gas in the case of
            // using the standard bridge or arbitrary message passing.
            if (_tx.value != 0) {
                // Update the contracts internal accounting of the amount of native asset in L2.
                _balance -= _tx.value;

                // Read the balance of the target contract before the transfer so the consistency
                // of the transfer can be checked afterwards.
                uint256 startBalance = IERC20(token).balanceOf(address(this));

                // Transfer the ERC20 balance to the target, accounting for non standard ERC20
                // implementations that may not return a boolean. This reverts if the low level
                // call is not successful.
                IERC20(token).safeTransfer({ to: _tx.target, value: _tx.value });

                // The balance must be transferred exactly.
                if (IERC20(token).balanceOf(address(this)) != startBalance - _tx.value) {
                    revert TransferFailed();
                }
            }

            // Make a call to the target contract only if there is calldata.
            if (_tx.data.length != 0) {
                success = SafeCall.callWithMinGas(_tx.target, _tx.gasLimit, 0, _tx.data);
            } else {
                success = true;
            }
        }

        // Reset the l2Sender back to the default value.
        l2Sender = Constants.DEFAULT_L2_SENDER;

        // All withdrawals are immediately finalized. Replayability can
        // be achieved through contracts built on top of this contract
        emit WithdrawalFinalized(withdrawalHash, success);

        // Reverting here is useful for determining the exact gas cost to successfully execute the
        // sub call to the target contract if the minimum gas limit specified by the user would not
        // be sufficient to execute the sub call.
        if (success == false && tx.origin == Constants.ESTIMATION_ADDRESS) {
            revert GasEstimation();
        }
    }

    /// @notice Entrypoint to depositing an ERC20 token as a custom gas token.
    ///         This function depends on a well formed ERC20 token. There are only
    ///         so many checks that can be done on chain for this so it is assumed
    ///         that chain operators will deploy chains with well formed ERC20 tokens.
    /// @param _to         Target address on L2.
    /// @param _mint       Units of ERC20 token to deposit into L2.
    /// @param _value      Units of ERC20 token to send on L2 to the recipient.
    /// @param _gasLimit   Amount of L2 gas to purchase by burning gas on L1.
    /// @param _isCreation Whether or not the transaction is a contract creation.
    /// @param _data       Data to trigger the recipient with.
    function depositERC20Transaction(
        address _to,
        uint256 _mint,
        uint256 _value,
        uint64 _gasLimit,
        bool _isCreation,
        bytes memory _data
    )
        public
        metered(_gasLimit)
    {
        // Can only be called if an ERC20 token is used for gas paying on L2
        (address token,) = gasPayingToken();
        if (token == Constants.ETHER) revert OnlyCustomGasToken();

        // Gives overflow protection for L2 account balances.
        _balance += _mint;

        // Get the balance of the portal before the transfer.
        uint256 startBalance = IERC20(token).balanceOf(address(this));

        // Take ownership of the token. It is assumed that the user has given the portal an approval.
        IERC20(token).safeTransferFrom({ from: msg.sender, to: address(this), value: _mint });

        // Double check that the portal now has the exact amount of token.
        if (IERC20(token).balanceOf(address(this)) != startBalance + _mint) {
            revert TransferFailed();
        }

        _depositTransaction({
            _to: _to,
            _mint: _mint,
            _value: _value,
            _gasLimit: _gasLimit,
            _isCreation: _isCreation,
            _data: _data
        });
    }

    /// @notice Accepts deposits of ETH and data, and emits a TransactionDeposited event for use in
    ///         deriving deposit transactions. Note that if a deposit is made by a contract, its
    ///         address will be aliased when retrieved using `tx.origin` or `msg.sender`. Consider
    ///         using the CrossDomainMessenger contracts for a simpler developer experience.
    /// @param _to         Target address on L2.
    /// @param _value      ETH value to send to the recipient.
    /// @param _gasLimit   Amount of L2 gas to purchase by burning gas on L1.
    /// @param _isCreation Whether or not the transaction is a contract creation.
    /// @param _data       Data to trigger the recipient with.
    function depositTransaction(
        address _to,
        uint256 _value,
        uint64 _gasLimit,
        bool _isCreation,
        bytes memory _data
    )
        public
        payable
        metered(_gasLimit)
    {
        (address token,) = gasPayingToken();
        if (token != Constants.ETHER && msg.value != 0) revert NoValue();

        _depositTransaction({
            _to: _to,
            _mint: msg.value,
            _value: _value,
            _gasLimit: _gasLimit,
            _isCreation: _isCreation,
            _data: _data
        });
    }

    /// @notice Common logic for creating deposit transactions.
    /// @param _to         Target address on L2.
    /// @param _mint       Units of asset to deposit into L2.
    /// @param _value      Units of asset to send on L2 to the recipient.
    /// @param _gasLimit   Amount of L2 gas to purchase by burning gas on L1.
    /// @param _isCreation Whether or not the transaction is a contract creation.
    /// @param _data       Data to trigger the recipient with.
    function _depositTransaction(
        address _to,
        uint256 _mint,
        uint256 _value,
        uint64 _gasLimit,
        bool _isCreation,
        bytes memory _data
    )
        internal
    {
        // Just to be safe, make sure that people specify address(0) as the target when doing
        // contract creations.
        if (_isCreation && _to != address(0)) revert BadTarget();

        // Prevent depositing transactions that have too small of a gas limit. Users should pay
        // more for more resource usage.
        if (_gasLimit < minimumGasLimit(uint64(_data.length))) revert SmallGasLimit();

        // Prevent the creation of deposit transactions that have too much calldata. This gives an
        // upper limit on the size of unsafe blocks over the p2p network. 120kb is chosen to ensure
        // that the transaction can fit into the p2p network policy of 128kb even though deposit
        // transactions are not gossipped over the p2p network.
        if (_data.length > 120_000) revert LargeCalldata();

        // Transform the from-address to its alias if the caller is a contract.
        address from = msg.sender;
        if (msg.sender != tx.origin) {
            from = AddressAliasHelper.applyL1ToL2Alias(msg.sender);
        }

        // Compute the opaque data that will be emitted as part of the TransactionDeposited event.
        // We use opaque data so that we can update the TransactionDeposited event in the future
        // without breaking the current interface.
        bytes memory opaqueData = abi.encodePacked(_mint, _value, _gasLimit, _isCreation, _data);

        // Emit a TransactionDeposited event so that the rollup node can derive a deposit
        // transaction for this deposit.
        emit TransactionDeposited(from, _to, DEPOSIT_VERSION, opaqueData);
    }

    /// @notice Sets the gas paying token for the L2 system. This token is used as the
    ///         L2 native asset. Only the SystemConfig contract can call this function.
    function setGasPayingToken(address _token, uint8 _decimals, bytes32 _name, bytes32 _symbol) external {
        if (msg.sender != address(systemConfig)) revert Unauthorized();

        // Set L2 deposit gas as used without paying burning gas. Ensures that deposits cannot use too much L2 gas.
        // This value must be large enough to cover the cost of calling `L1Block.setGasPayingToken`.
        useGas(SYSTEM_DEPOSIT_GAS_LIMIT);

        // Emit the special deposit transaction directly that sets the gas paying
        // token in the L1Block predeploy contract.
        emit TransactionDeposited(
            Constants.DEPOSITOR_ACCOUNT,
            Predeploys.L1_BLOCK_ATTRIBUTES,
            DEPOSIT_VERSION,
            abi.encodePacked(
                uint256(0), // mint
                uint256(0), // value
                uint64(SYSTEM_DEPOSIT_GAS_LIMIT), // gasLimit
                false, // isCreation,
                abi.encodeCall(L1Block.setGasPayingToken, (_token, _decimals, _name, _symbol))
            )
        );
    }

    /// @notice Determine if a given output is finalized.
    ///         Reverts if the call to l2Oracle.getL2Output reverts.
    ///         Returns a boolean otherwise.
    /// @param _l2OutputIndex Index of the L2 output to check.
    /// @return Whether or not the output is finalized.
    function isOutputFinalized(uint256 _l2OutputIndex) external view returns (bool) {
        return _isFinalizationPeriodElapsed(l2Oracle.getL2Output(_l2OutputIndex).timestamp);
    }

    /// @notice Determines whether the finalization period has elapsed with respect to
    ///         the provided block timestamp.
    /// @param _timestamp Timestamp to check.
    /// @return Whether or not the finalization period has elapsed.
    function _isFinalizationPeriodElapsed(uint256 _timestamp) internal view returns (bool) {
        return block.timestamp > _timestamp + l2Oracle.FINALIZATION_PERIOD_SECONDS();
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Types } from "src/libraries/Types.sol";
import { Encoding } from "src/libraries/Encoding.sol";

/// @title Hashing
/// @notice Hashing handles Optimism's various different hashing schemes.
library Hashing {
    /// @notice Computes the hash of the RLP encoded L2 transaction that would be generated when a
    ///         given deposit is sent to the L2 system. Useful for searching for a deposit in the L2
    ///         system.
    /// @param _tx User deposit transaction to hash.
    /// @return Hash of the RLP encoded L2 deposit transaction.
    function hashDepositTransaction(Types.UserDepositTransaction memory _tx) internal pure returns (bytes32) {
        return keccak256(Encoding.encodeDepositTransaction(_tx));
    }

    /// @notice Computes the deposit transaction's "source hash", a value that guarantees the hash
    ///         of the L2 transaction that corresponds to a deposit is unique and is
    ///         deterministically generated from L1 transaction data.
    /// @param _l1BlockHash Hash of the L1 block where the deposit was included.
    /// @param _logIndex    The index of the log that created the deposit transaction.
    /// @return Hash of the deposit transaction's "source hash".
    function hashDepositSource(bytes32 _l1BlockHash, uint256 _logIndex) internal pure returns (bytes32) {
        bytes32 depositId = keccak256(abi.encode(_l1BlockHash, _logIndex));
        return keccak256(abi.encode(bytes32(0), depositId));
    }

    /// @notice Hashes the cross domain message based on the version that is encoded into the
    ///         message nonce.
    /// @param _nonce    Message nonce with version encoded into the first two bytes.
    /// @param _sender   Address of the sender of the message.
    /// @param _target   Address of the target of the message.
    /// @param _value    ETH value to send to the target.
    /// @param _gasLimit Gas limit to use for the message.
    /// @param _data     Data to send with the message.
    /// @return Hashed cross domain message.
    function hashCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    )
        internal
        pure
        returns (bytes32)
    {
        (, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
        if (version == 0) {
            return hashCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return hashCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Hashing: unknown cross domain message version");
        }
    }

    /// @notice Hashes a cross domain message based on the V0 (legacy) encoding.
    /// @param _target Address of the target of the message.
    /// @param _sender Address of the sender of the message.
    /// @param _data   Data to send with the message.
    /// @param _nonce  Message nonce.
    /// @return Hashed cross domain message.
    function hashCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    )
        internal
        pure
        returns (bytes32)
    {
        return keccak256(Encoding.encodeCrossDomainMessageV0(_target, _sender, _data, _nonce));
    }

    /// @notice Hashes a cross domain message based on the V1 (current) encoding.
    /// @param _nonce    Message nonce.
    /// @param _sender   Address of the sender of the message.
    /// @param _target   Address of the target of the message.
    /// @param _value    ETH value to send to the target.
    /// @param _gasLimit Gas limit to use for the message.
    /// @param _data     Data to send with the message.
    /// @return Hashed cross domain message.
    function hashCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    )
        internal
        pure
        returns (bytes32)
    {
        return keccak256(Encoding.encodeCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data));
    }

    /// @notice Derives the withdrawal hash according to the encoding in the L2 Withdrawer contract
    /// @param _tx Withdrawal transaction to hash.
    /// @return Hashed withdrawal transaction.
    function hashWithdrawal(Types.WithdrawalTransaction memory _tx) internal pure returns (bytes32) {
        return keccak256(abi.encode(_tx.nonce, _tx.sender, _tx.target, _tx.value, _tx.gasLimit, _tx.data));
    }

    /// @notice Hashes the various elements of an output root proof into an output root hash which
    ///         can be used to check if the proof is valid.
    /// @param _outputRootProof Output root proof which should hash to an output root.
    /// @return Hashed output root proof.
    function hashOutputRootProof(Types.OutputRootProof memory _outputRootProof) internal pure returns (bytes32) {
        return keccak256(
            abi.encode(
                _outputRootProof.version,
                _outputRootProof.stateRoot,
                _outputRootProof.messagePasserStorageRoot,
                _outputRootProof.latestBlockhash
            )
        );
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Storage
/// @notice Storage handles reading and writing to arbitary storage locations
library Storage {
    /// @notice Returns an address stored in an arbitrary storage slot.
    ///         These storage slots decouple the storage layout from
    ///         solc's automation.
    /// @param _slot The storage slot to retrieve the address from.
    function getAddress(bytes32 _slot) internal view returns (address addr_) {
        assembly {
            addr_ := sload(_slot)
        }
    }

    /// @notice Stores an address in an arbitrary storage slot, `_slot`.
    /// @param _slot The storage slot to store the address in.
    /// @param _address The protocol version to store
    /// @dev WARNING! This function must be used cautiously, as it allows for overwriting addresses
    ///      in arbitrary storage slots.
    function setAddress(bytes32 _slot, address _address) internal {
        assembly {
            sstore(_slot, _address)
        }
    }

    /// @notice Returns a uint256 stored in an arbitrary storage slot.
    ///         These storage slots decouple the storage layout from
    ///         solc's automation.
    /// @param _slot The storage slot to retrieve the address from.
    function getUint(bytes32 _slot) internal view returns (uint256 value_) {
        assembly {
            value_ := sload(_slot)
        }
    }

    /// @notice Stores a value in an arbitrary storage slot, `_slot`.
    /// @param _slot The storage slot to store the address in.
    /// @param _value The protocol version to store
    /// @dev WARNING! This function must be used cautiously, as it allows for overwriting values
    ///      in arbitrary storage slots.
    function setUint(bytes32 _slot, uint256 _value) internal {
        assembly {
            sstore(_slot, _value)
        }
    }

    /// @notice Returns a bytes32 stored in an arbitrary storage slot.
    ///         These storage slots decouple the storage layout from
    ///         solc's automation.
    /// @param _slot The storage slot to retrieve the address from.
    function getBytes32(bytes32 _slot) internal view returns (bytes32 value_) {
        assembly {
            value_ := sload(_slot)
        }
    }

    /// @notice Stores a bytes32 value in an arbitrary storage slot, `_slot`.
    /// @param _slot The storage slot to store the address in.
    /// @param _value The bytes32 value to store.
    /// @dev WARNING! This function must be used cautiously, as it allows for overwriting values
    ///      in arbitrary storage slots.
    function setBytes32(bytes32 _slot, bytes32 _value) internal {
        assembly {
            sstore(_slot, _value)
        }
    }

    /// @notice Stores a bool value in an arbitrary storage slot, `_slot`.
    /// @param _slot The storage slot to store the bool in.
    /// @param _value The bool value to store
    /// @dev WARNING! This function must be used cautiously, as it allows for overwriting values
    ///      in arbitrary storage slots.
    function setBool(bytes32 _slot, bool _value) internal {
        assembly {
            sstore(_slot, _value)
        }
    }

    /// @notice Returns a bool stored in an arbitrary storage slot.
    /// @param _slot The storage slot to retrieve the bool from.
    function getBool(bytes32 _slot) internal view returns (bool value_) {
        assembly {
            value_ := sload(_slot)
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title ISemver
/// @notice ISemver is a simple contract for ensuring that contracts are
///         versioned using semantic versioning.
interface ISemver {
    /// @notice Getter for the semantic version of the contract. This is not
    ///         meant to be used onchain but instead meant to be used by offchain
    ///         tooling.
    /// @return Semver contract version as a string.
    function version() external view returns (string memory);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Types } from "src/libraries/Types.sol";
import { Hashing } from "src/libraries/Hashing.sol";
import { RLPWriter } from "src/libraries/rlp/RLPWriter.sol";

/// @title Encoding
/// @notice Encoding handles Optimism's various different encoding schemes.
library Encoding {
    /// @notice RLP encodes the L2 transaction that would be generated when a given deposit is sent
    ///         to the L2 system. Useful for searching for a deposit in the L2 system. The
    ///         transaction is prefixed with 0x7e to identify its EIP-2718 type.
    /// @param _tx User deposit transaction to encode.
    /// @return RLP encoded L2 deposit transaction.
    function encodeDepositTransaction(Types.UserDepositTransaction memory _tx) internal pure returns (bytes memory) {
        bytes32 source = Hashing.hashDepositSource(_tx.l1BlockHash, _tx.logIndex);
        bytes[] memory raw = new bytes[](8);
        raw[0] = RLPWriter.writeBytes(abi.encodePacked(source));
        raw[1] = RLPWriter.writeAddress(_tx.from);
        raw[2] = _tx.isCreation ? RLPWriter.writeBytes("") : RLPWriter.writeAddress(_tx.to);
        raw[3] = RLPWriter.writeUint(_tx.mint);
        raw[4] = RLPWriter.writeUint(_tx.value);
        raw[5] = RLPWriter.writeUint(uint256(_tx.gasLimit));
        raw[6] = RLPWriter.writeBool(false);
        raw[7] = RLPWriter.writeBytes(_tx.data);
        return abi.encodePacked(uint8(0x7e), RLPWriter.writeList(raw));
    }

    /// @notice Encodes the cross domain message based on the version that is encoded into the
    ///         message nonce.
    /// @param _nonce    Message nonce with version encoded into the first two bytes.
    /// @param _sender   Address of the sender of the message.
    /// @param _target   Address of the target of the message.
    /// @param _value    ETH value to send to the target.
    /// @param _gasLimit Gas limit to use for the message.
    /// @param _data     Data to send with the message.
    /// @return Encoded cross domain message.
    function encodeCrossDomainMessage(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    )
        internal
        pure
        returns (bytes memory)
    {
        (, uint16 version) = decodeVersionedNonce(_nonce);
        if (version == 0) {
            return encodeCrossDomainMessageV0(_target, _sender, _data, _nonce);
        } else if (version == 1) {
            return encodeCrossDomainMessageV1(_nonce, _sender, _target, _value, _gasLimit, _data);
        } else {
            revert("Encoding: unknown cross domain message version");
        }
    }

    /// @notice Encodes a cross domain message based on the V0 (legacy) encoding.
    /// @param _target Address of the target of the message.
    /// @param _sender Address of the sender of the message.
    /// @param _data   Data to send with the message.
    /// @param _nonce  Message nonce.
    /// @return Encoded cross domain message.
    function encodeCrossDomainMessageV0(
        address _target,
        address _sender,
        bytes memory _data,
        uint256 _nonce
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSignature("relayMessage(address,address,bytes,uint256)", _target, _sender, _data, _nonce);
    }

    /// @notice Encodes a cross domain message based on the V1 (current) encoding.
    /// @param _nonce    Message nonce.
    /// @param _sender   Address of the sender of the message.
    /// @param _target   Address of the target of the message.
    /// @param _value    ETH value to send to the target.
    /// @param _gasLimit Gas limit to use for the message.
    /// @param _data     Data to send with the message.
    /// @return Encoded cross domain message.
    function encodeCrossDomainMessageV1(
        uint256 _nonce,
        address _sender,
        address _target,
        uint256 _value,
        uint256 _gasLimit,
        bytes memory _data
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSignature(
            "relayMessage(uint256,address,address,uint256,uint256,bytes)",
            _nonce,
            _sender,
            _target,
            _value,
            _gasLimit,
            _data
        );
    }

    /// @notice Adds a version number into the first two bytes of a message nonce.
    /// @param _nonce   Message nonce to encode into.
    /// @param _version Version number to encode into the message nonce.
    /// @return Message nonce with version encoded into the first two bytes.
    function encodeVersionedNonce(uint240 _nonce, uint16 _version) internal pure returns (uint256) {
        uint256 nonce;
        assembly {
            nonce := or(shl(240, _version), _nonce)
        }
        return nonce;
    }

    /// @notice Pulls the version out of a version-encoded nonce.
    /// @param _nonce Message nonce with version encoded into the first two bytes.
    /// @return Nonce without encoded version.
    /// @return Version of the message.
    function decodeVersionedNonce(uint256 _nonce) internal pure returns (uint240, uint16) {
        uint240 nonce;
        uint16 version;
        assembly {
            nonce := and(_nonce, 0x0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
            version := shr(240, _nonce)
        }
        return (nonce, version);
    }

    /// @notice Returns an appropriately encoded call to L1Block.setL1BlockValuesEcotone
    /// @param baseFeeScalar       L1 base fee Scalar
    /// @param blobBaseFeeScalar   L1 blob base fee Scalar
    /// @param sequenceNumber      Number of L2 blocks since epoch start.
    /// @param timestamp           L1 timestamp.
    /// @param number              L1 blocknumber.
    /// @param baseFee             L1 base fee.
    /// @param blobBaseFee         L1 blob base fee.
    /// @param hash                L1 blockhash.
    /// @param batcherHash         Versioned hash to authenticate batcher by.
    function encodeSetL1BlockValuesEcotone(
        uint32 baseFeeScalar,
        uint32 blobBaseFeeScalar,
        uint64 sequenceNumber,
        uint64 timestamp,
        uint64 number,
        uint256 baseFee,
        uint256 blobBaseFee,
        bytes32 hash,
        bytes32 batcherHash
    )
        internal
        pure
        returns (bytes memory)
    {
        bytes4 functionSignature = bytes4(keccak256("setL1BlockValuesEcotone()"));
        return abi.encodePacked(
            functionSignature,
            baseFeeScalar,
            blobBaseFeeScalar,
            sequenceNumber,
            timestamp,
            number,
            baseFee,
            blobBaseFee,
            hash,
            batcherHash
        );
    }

    /// @notice Returns an appropriately encoded call to L1Block.setL1BlockValuesInterop
    /// @param _baseFeeScalar       L1 base fee Scalar
    /// @param _blobBaseFeeScalar   L1 blob base fee Scalar
    /// @param _sequenceNumber      Number of L2 blocks since epoch start.
    /// @param _timestamp           L1 timestamp.
    /// @param _number              L1 blocknumber.
    /// @param _baseFee             L1 base fee.
    /// @param _blobBaseFee         L1 blob base fee.
    /// @param _hash                L1 blockhash.
    /// @param _batcherHash         Versioned hash to authenticate batcher by.
    /// @param _dependencySet       Array of the chain IDs in the interop dependency set.
    function encodeSetL1BlockValuesInterop(
        uint32 _baseFeeScalar,
        uint32 _blobBaseFeeScalar,
        uint64 _sequenceNumber,
        uint64 _timestamp,
        uint64 _number,
        uint256 _baseFee,
        uint256 _blobBaseFee,
        bytes32 _hash,
        bytes32 _batcherHash,
        uint256[] memory _dependencySet
    )
        internal
        pure
        returns (bytes memory)
    {
        require(_dependencySet.length <= type(uint8).max, "Encoding: dependency set length is too large");
        // Check that the batcher hash is just the address with 0 padding to the left for version 0.
        require(uint160(uint256(_batcherHash)) == uint256(_batcherHash), "Encoding: invalid batcher hash");

        bytes4 functionSignature = bytes4(keccak256("setL1BlockValuesInterop()"));
        return abi.encodePacked(
            functionSignature,
            _baseFeeScalar,
            _blobBaseFeeScalar,
            _sequenceNumber,
            _timestamp,
            _number,
            _baseFee,
            _blobBaseFee,
            _hash,
            _batcherHash,
            uint8(_dependencySet.length),
            _dependencySet
        );
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/// @title SafeCall
/// @notice Perform low level safe calls
library SafeCall {
    /// @notice Performs a low level call without copying any returndata.
    /// @dev Passes no calldata to the call context.
    /// @param _target   Address to call
    /// @param _gas      Amount of gas to pass to the call
    /// @param _value    Amount of value to pass to the call
    function send(address _target, uint256 _gas, uint256 _value) internal returns (bool success_) {
        assembly {
            success_ :=
                call(
                    _gas, // gas
                    _target, // recipient
                    _value, // ether value
                    0, // inloc
                    0, // inlen
                    0, // outloc
                    0 // outlen
                )
        }
    }

    /// @notice Perform a low level call with all gas without copying any returndata
    /// @param _target   Address to call
    /// @param _value    Amount of value to pass to the call
    function send(address _target, uint256 _value) internal returns (bool success_) {
        success_ = send(_target, gasleft(), _value);
    }

    /// @notice Perform a low level call without copying any returndata
    /// @param _target   Address to call
    /// @param _gas      Amount of gas to pass to the call
    /// @param _value    Amount of value to pass to the call
    /// @param _calldata Calldata to pass to the call
    function call(
        address _target,
        uint256 _gas,
        uint256 _value,
        bytes memory _calldata
    )
        internal
        returns (bool success_)
    {
        assembly {
            success_ :=
                call(
                    _gas, // gas
                    _target, // recipient
                    _value, // ether value
                    add(_calldata, 32), // inloc
                    mload(_calldata), // inlen
                    0, // outloc
                    0 // outlen
                )
        }
    }

    /// @notice Helper function to determine if there is sufficient gas remaining within the context
    ///         to guarantee that the minimum gas requirement for a call will be met as well as
    ///         optionally reserving a specified amount of gas for after the call has concluded.
    /// @param _minGas      The minimum amount of gas that may be passed to the target context.
    /// @param _reservedGas Optional amount of gas to reserve for the caller after the execution
    ///                     of the target context.
    /// @return `true` if there is enough gas remaining to safely supply `_minGas` to the target
    ///         context as well as reserve `_reservedGas` for the caller after the execution of
    ///         the target context.
    /// @dev !!!!! FOOTGUN ALERT !!!!!
    ///      1.) The 40_000 base buffer is to account for the worst case of the dynamic cost of the
    ///          `CALL` opcode's `address_access_cost`, `positive_value_cost`, and
    ///          `value_to_empty_account_cost` factors with an added buffer of 5,700 gas. It is
    ///          still possible to self-rekt by initiating a withdrawal with a minimum gas limit
    ///          that does not account for the `memory_expansion_cost` & `code_execution_cost`
    ///          factors of the dynamic cost of the `CALL` opcode.
    ///      2.) This function should *directly* precede the external call if possible. There is an
    ///          added buffer to account for gas consumed between this check and the call, but it
    ///          is only 5,700 gas.
    ///      3.) Because EIP-150 ensures that a maximum of 63/64ths of the remaining gas in the call
    ///          frame may be passed to a subcontext, we need to ensure that the gas will not be
    ///          truncated.
    ///      4.) Use wisely. This function is not a silver bullet.
    function hasMinGas(uint256 _minGas, uint256 _reservedGas) internal view returns (bool) {
        bool _hasMinGas;
        assembly {
            // Equation: gas × 63 ≥ minGas × 64 + 63(40_000 + reservedGas)
            _hasMinGas := iszero(lt(mul(gas(), 63), add(mul(_minGas, 64), mul(add(40000, _reservedGas), 63))))
        }
        return _hasMinGas;
    }

    /// @notice Perform a low level call without copying any returndata. This function
    ///         will revert if the call cannot be performed with the specified minimum
    ///         gas.
    /// @param _target   Address to call
    /// @param _minGas   The minimum amount of gas that may be passed to the call
    /// @param _value    Amount of value to pass to the call
    /// @param _calldata Calldata to pass to the call
    function callWithMinGas(
        address _target,
        uint256 _minGas,
        uint256 _value,
        bytes memory _calldata
    )
        internal
        returns (bool)
    {
        bool _success;
        bool _hasMinGas = hasMinGas(_minGas, 0);
        assembly {
            // Assertion: gasleft() >= (_minGas * 64) / 63 + 40_000
            if iszero(_hasMinGas) {
                // Store the "Error(string)" selector in scratch space.
                mstore(0, 0x08c379a0)
                // Store the pointer to the string length in scratch space.
                mstore(32, 32)
                // Store the string.
                //
                // SAFETY:
                // - We pad the beginning of the string with two zero bytes as well as the
                // length (24) to ensure that we override the free memory pointer at offset
                // 0x40. This is necessary because the free memory pointer is likely to
                // be greater than 1 byte when this function is called, but it is incredibly
                // unlikely that it will be greater than 3 bytes. As for the data within
                // 0x60, it is ensured that it is 0 due to 0x60 being the zero offset.
                // - It's fine to clobber the free memory pointer, we're reverting.
                mstore(88, 0x0000185361666543616c6c3a204e6f7420656e6f75676820676173)

                // Revert with 'Error("SafeCall: Not enough gas")'
                revert(28, 100)
            }

            // The call will be supplied at least ((_minGas * 64) / 63) gas due to the
            // above assertion. This ensures that, in all circumstances (except for when the
            // `_minGas` does not account for the `memory_expansion_cost` and `code_execution_cost`
            // factors of the dynamic cost of the `CALL` opcode), the call will receive at least
            // the minimum amount of gas specified.
            _success :=
                call(
                    gas(), // gas
                    _target, // recipient
                    _value, // ether value
                    add(_calldata, 32), // inloc
                    mload(_calldata), // inlen
                    0x00, // outloc
                    0x00 // outlen
                )
        }
        return _success;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Burn } from "src/libraries/Burn.sol";
import { Arithmetic } from "src/libraries/Arithmetic.sol";

/// @custom:upgradeable
/// @title ResourceMetering
/// @notice ResourceMetering implements an EIP-1559 style resource metering system where pricing
///         updates automatically based on current demand.
abstract contract ResourceMetering is Initializable {
    /// @notice Error returned when too much gas resource is consumed.
    error OutOfGas();

    /// @notice Represents the various parameters that control the way in which resources are
    ///         metered. Corresponds to the EIP-1559 resource metering system.
    /// @custom:field prevBaseFee   Base fee from the previous block(s).
    /// @custom:field prevBoughtGas Amount of gas bought so far in the current block.
    /// @custom:field prevBlockNum  Last block number that the base fee was updated.
    struct ResourceParams {
        uint128 prevBaseFee;
        uint64 prevBoughtGas;
        uint64 prevBlockNum;
    }

    /// @notice Represents the configuration for the EIP-1559 based curve for the deposit gas
    ///         market. These values should be set with care as it is possible to set them in
    ///         a way that breaks the deposit gas market. The target resource limit is defined as
    ///         maxResourceLimit / elasticityMultiplier. This struct was designed to fit within a
    ///         single word. There is additional space for additions in the future.
    /// @custom:field maxResourceLimit             Represents the maximum amount of deposit gas that
    ///                                            can be purchased per block.
    /// @custom:field elasticityMultiplier         Determines the target resource limit along with
    ///                                            the resource limit.
    /// @custom:field baseFeeMaxChangeDenominator  Determines max change on fee per block.
    /// @custom:field minimumBaseFee               The min deposit base fee, it is clamped to this
    ///                                            value.
    /// @custom:field systemTxMaxGas               The amount of gas supplied to the system
    ///                                            transaction. This should be set to the same
    ///                                            number that the op-node sets as the gas limit
    ///                                            for the system transaction.
    /// @custom:field maximumBaseFee               The max deposit base fee, it is clamped to this
    ///                                            value.
    struct ResourceConfig {
        uint32 maxResourceLimit;
        uint8 elasticityMultiplier;
        uint8 baseFeeMaxChangeDenominator;
        uint32 minimumBaseFee;
        uint32 systemTxMaxGas;
        uint128 maximumBaseFee;
    }

    /// @notice EIP-1559 style gas parameters.
    ResourceParams public params;

    /// @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
    uint256[48] private __gap;

    /// @notice Meters access to a function based an amount of a requested resource.
    /// @param _amount Amount of the resource requested.
    modifier metered(uint64 _amount) {
        // Record initial gas amount so we can refund for it later.
        uint256 initialGas = gasleft();

        // Run the underlying function.
        _;

        // Run the metering function.
        _metered(_amount, initialGas);
    }

    /// @notice An internal function that holds all of the logic for metering a resource.
    /// @param _amount     Amount of the resource requested.
    /// @param _initialGas The amount of gas before any modifier execution.
    function _metered(uint64 _amount, uint256 _initialGas) internal {
        // Update block number and base fee if necessary.
        uint256 blockDiff = block.number - params.prevBlockNum;

        ResourceConfig memory config = _resourceConfig();
        int256 targetResourceLimit =
            int256(uint256(config.maxResourceLimit)) / int256(uint256(config.elasticityMultiplier));

        if (blockDiff > 0) {
            // Handle updating EIP-1559 style gas parameters. We use EIP-1559 to restrict the rate
            // at which deposits can be created and therefore limit the potential for deposits to
            // spam the L2 system. Fee scheme is very similar to EIP-1559 with minor changes.
            int256 gasUsedDelta = int256(uint256(params.prevBoughtGas)) - targetResourceLimit;
            int256 baseFeeDelta = (int256(uint256(params.prevBaseFee)) * gasUsedDelta)
                / (targetResourceLimit * int256(uint256(config.baseFeeMaxChangeDenominator)));

            // Update base fee by adding the base fee delta and clamp the resulting value between
            // min and max.
            int256 newBaseFee = Arithmetic.clamp({
                _value: int256(uint256(params.prevBaseFee)) + baseFeeDelta,
                _min: int256(uint256(config.minimumBaseFee)),
                _max: int256(uint256(config.maximumBaseFee))
            });

            // If we skipped more than one block, we also need to account for every empty block.
            // Empty block means there was no demand for deposits in that block, so we should
            // reflect this lack of demand in the fee.
            if (blockDiff > 1) {
                // Update the base fee by repeatedly applying the exponent 1-(1/change_denominator)
                // blockDiff - 1 times. Simulates multiple empty blocks. Clamp the resulting value
                // between min and max.
                newBaseFee = Arithmetic.clamp({
                    _value: Arithmetic.cdexp({
                        _coefficient: newBaseFee,
                        _denominator: int256(uint256(config.baseFeeMaxChangeDenominator)),
                        _exponent: int256(blockDiff - 1)
                    }),
                    _min: int256(uint256(config.minimumBaseFee)),
                    _max: int256(uint256(config.maximumBaseFee))
                });
            }

            // Update new base fee, reset bought gas, and update block number.
            params.prevBaseFee = uint128(uint256(newBaseFee));
            params.prevBoughtGas = 0;
            params.prevBlockNum = uint64(block.number);
        }

        // Make sure we can actually buy the resource amount requested by the user.
        params.prevBoughtGas += _amount;
        if (int256(uint256(params.prevBoughtGas)) > int256(uint256(config.maxResourceLimit))) {
            revert OutOfGas();
        }

        // Determine the amount of ETH to be paid.
        uint256 resourceCost = uint256(_amount) * uint256(params.prevBaseFee);

        // We currently charge for this ETH amount as an L1 gas burn, so we convert the ETH amount
        // into gas by dividing by the L1 base fee. We assume a minimum base fee of 1 gwei to avoid
        // division by zero for L1s that don't support 1559 or to avoid excessive gas burns during
        // periods of extremely low L1 demand. One-day average gas fee hasn't dipped below 1 gwei
        // during any 1 day period in the last 5 years, so should be fine.
        uint256 gasCost = resourceCost / Math.max(block.basefee, 1 gwei);

        // Give the user a refund based on the amount of gas they used to do all of the work up to
        // this point. Since we're at the end of the modifier, this should be pretty accurate. Acts
        // effectively like a dynamic stipend (with a minimum value).
        uint256 usedGas = _initialGas - gasleft();
        if (gasCost > usedGas) {
            Burn.gas(gasCost - usedGas);
        }
    }

    /// @notice Adds an amount of L2 gas consumed to the prev bought gas params. This is meant to be used
    ///         when L2 system transactions are generated from L1.
    /// @param _amount Amount of the L2 gas resource requested.
    function useGas(uint32 _amount) internal {
        params.prevBoughtGas += uint64(_amount);
    }

    /// @notice Virtual function that returns the resource config.
    ///         Contracts that inherit this contract must implement this function.
    /// @return ResourceConfig
    function _resourceConfig() internal virtual returns (ResourceConfig memory);

    /// @notice Sets initial resource parameter values.
    ///         This function must either be called by the initializer function of an upgradeable
    ///         child contract.
    function __ResourceMetering_init() internal onlyInitializing {
        if (params.prevBlockNum == 0) {
            params = ResourceParams({ prevBaseFee: 1 gwei, prevBoughtGas: 0, prevBlockNum: uint64(block.number) });
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { ISemver } from "src/universal/ISemver.sol";
import { Storage } from "src/libraries/Storage.sol";

/// @custom:audit none This contracts is not yet audited.
/// @title SuperchainConfig
/// @notice The SuperchainConfig contract is used to manage configuration of global superchain values.
contract SuperchainConfig is Initializable, ISemver {
    /// @notice Enum representing different types of updates.
    /// @custom:value GUARDIAN            Represents an update to the guardian.
    enum UpdateType {
        GUARDIAN
    }

    /// @notice Whether or not the Superchain is paused.
    bytes32 public constant PAUSED_SLOT = bytes32(uint256(keccak256("superchainConfig.paused")) - 1);

    /// @notice The address of the guardian, which can pause withdrawals from the System.
    ///         It can only be modified by an upgrade.
    bytes32 public constant GUARDIAN_SLOT = bytes32(uint256(keccak256("superchainConfig.guardian")) - 1);

    /// @notice Emitted when the pause is triggered.
    /// @param identifier A string helping to identify provenance of the pause transaction.
    event Paused(string identifier);

    /// @notice Emitted when the pause is lifted.
    event Unpaused();

    /// @notice Emitted when configuration is updated.
    /// @param updateType Type of update.
    /// @param data       Encoded update data.
    event ConfigUpdate(UpdateType indexed updateType, bytes data);

    /// @notice Semantic version.
    /// @custom:semver 1.1.0
    string public constant version = "1.1.0";

    /// @notice Constructs the SuperchainConfig contract.
    constructor() {
        initialize({ _guardian: address(0), _paused: false });
    }

    /// @notice Initializer.
    /// @param _guardian    Address of the guardian, can pause the OptimismPortal.
    /// @param _paused      Initial paused status.
    function initialize(address _guardian, bool _paused) public initializer {
        _setGuardian(_guardian);
        if (_paused) {
            _pause("Initializer paused");
        }
    }

    /// @notice Getter for the guardian address.
    function guardian() public view returns (address guardian_) {
        guardian_ = Storage.getAddress(GUARDIAN_SLOT);
    }

    /// @notice Getter for the current paused status.
    function paused() public view returns (bool paused_) {
        paused_ = Storage.getBool(PAUSED_SLOT);
    }

    /// @notice Pauses withdrawals.
    /// @param _identifier (Optional) A string to identify provenance of the pause transaction.
    function pause(string memory _identifier) external {
        require(msg.sender == guardian(), "SuperchainConfig: only guardian can pause");
        _pause(_identifier);
    }

    /// @notice Pauses withdrawals.
    /// @param _identifier (Optional) A string to identify provenance of the pause transaction.
    function _pause(string memory _identifier) internal {
        Storage.setBool(PAUSED_SLOT, true);
        emit Paused(_identifier);
    }

    /// @notice Unpauses withdrawals.
    function unpause() external {
        require(msg.sender == guardian(), "SuperchainConfig: only guardian can unpause");
        Storage.setBool(PAUSED_SLOT, false);
        emit Unpaused();
    }

    /// @notice Sets the guardian address. This is only callable during initialization, so an upgrade
    ///         will be required to change the guardian.
    /// @param _guardian The new guardian address.
    function _setGuardian(address _guardian) internal {
        Storage.setAddress(GUARDIAN_SLOT, _guardian);
        emit ConfigUpdate(UpdateType.GUARDIAN, abi.encode(_guardian));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { ResourceMetering } from "src/L1/ResourceMetering.sol";

/// @title Constants
/// @notice Constants is a library for storing constants. Simple! Don't put everything in here, just
///         the stuff used in multiple contracts. Constants that only apply to a single contract
///         should be defined in that contract instead.
library Constants {
    /// @notice Special address to be used as the tx origin for gas estimation calls in the
    ///         OptimismPortal and CrossDomainMessenger calls. You only need to use this address if
    ///         the minimum gas limit specified by the user is not actually enough to execute the
    ///         given message and you're attempting to estimate the actual necessary gas limit. We
    ///         use address(1) because it's the ecrecover precompile and therefore guaranteed to
    ///         never have any code on any EVM chain.
    address internal constant ESTIMATION_ADDRESS = address(1);

    /// @notice Value used for the L2 sender storage slot in both the OptimismPortal and the
    ///         CrossDomainMessenger contracts before an actual sender is set. This value is
    ///         non-zero to reduce the gas cost of message passing transactions.
    address internal constant DEFAULT_L2_SENDER = 0x000000000000000000000000000000000000dEaD;

    /// @notice The storage slot that holds the address of a proxy implementation.
    /// @dev `bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)`
    bytes32 internal constant PROXY_IMPLEMENTATION_ADDRESS =
        0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /// @notice The storage slot that holds the address of the owner.
    /// @dev `bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1)`
    bytes32 internal constant PROXY_OWNER_ADDRESS = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /// @notice The address that represents ether when dealing with ERC20 token addresses.
    address internal constant ETHER = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    /// @notice The address that represents the system caller responsible for L1 attributes
    ///         transactions.
    address internal constant DEPOSITOR_ACCOUNT = 0xDeaDDEaDDeAdDeAdDEAdDEaddeAddEAdDEAd0001;

    /// @notice Returns the default values for the ResourceConfig. These are the recommended values
    ///         for a production network.
    function DEFAULT_RESOURCE_CONFIG() internal pure returns (ResourceMetering.ResourceConfig memory) {
        ResourceMetering.ResourceConfig memory config = ResourceMetering.ResourceConfig({
            maxResourceLimit: 20_000_000,
            elasticityMultiplier: 10,
            baseFeeMaxChangeDenominator: 8,
            minimumBaseFee: 1 gwei,
            systemTxMaxGas: 1_000_000,
            maximumBaseFee: type(uint128).max
        });
        return config;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { SignedMath } from "@openzeppelin/contracts/utils/math/SignedMath.sol";
import { FixedPointMathLib } from "@rari-capital/solmate/src/utils/FixedPointMathLib.sol";

/// @title Arithmetic
/// @notice Even more math than before.
library Arithmetic {
    /// @notice Clamps a value between a minimum and maximum.
    /// @param _value The value to clamp.
    /// @param _min   The minimum value.
    /// @param _max   The maximum value.
    /// @return The clamped value.
    function clamp(int256 _value, int256 _min, int256 _max) internal pure returns (int256) {
        return SignedMath.min(SignedMath.max(_value, _min), _max);
    }

    /// @notice (c)oefficient (d)enominator (exp)onentiation function.
    ///         Returns the result of: c * (1 - 1/d)^exp.
    /// @param _coefficient Coefficient of the function.
    /// @param _denominator Fractional denominator.
    /// @param _exponent    Power function exponent.
    /// @return Result of c * (1 - 1/d)^exp.
    function cdexp(int256 _coefficient, int256 _denominator, int256 _exponent) internal pure returns (int256) {
        return (_coefficient * (FixedPointMathLib.powWad(1e18 - (1e18 / _denominator), _exponent * 1e18))) / 1e18;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title Predeploys
/// @notice Contains constant addresses for protocol contracts that are pre-deployed to the L2 system.
//          This excludes the preinstalls (non-protocol contracts).
library Predeploys {
    /// @notice Number of predeploy-namespace addresses reserved for protocol usage.
    uint256 internal constant PREDEPLOY_COUNT = 2048;

    /// @custom:legacy
    /// @notice Address of the LegacyMessagePasser predeploy. Deprecate. Use the updated
    ///         L2ToL1MessagePasser contract instead.
    address internal constant LEGACY_MESSAGE_PASSER = 0x4200000000000000000000000000000000000000;

    /// @custom:legacy
    /// @notice Address of the L1MessageSender predeploy. Deprecated. Use L2CrossDomainMessenger
    ///         or access tx.origin (or msg.sender) in a L1 to L2 transaction instead.
    ///         Not embedded into new OP-Stack chains.
    address internal constant L1_MESSAGE_SENDER = 0x4200000000000000000000000000000000000001;

    /// @custom:legacy
    /// @notice Address of the DeployerWhitelist predeploy. No longer active.
    address internal constant DEPLOYER_WHITELIST = 0x4200000000000000000000000000000000000002;

    /// @notice Address of the canonical WETH contract.
    address internal constant WETH = 0x4200000000000000000000000000000000000006;

    /// @notice Address of the L2CrossDomainMessenger predeploy.
    address internal constant L2_CROSS_DOMAIN_MESSENGER = 0x4200000000000000000000000000000000000007;

    /// @notice Address of the GasPriceOracle predeploy. Includes fee information
    ///         and helpers for computing the L1 portion of the transaction fee.
    address internal constant GAS_PRICE_ORACLE = 0x420000000000000000000000000000000000000F;

    /// @notice Address of the L2StandardBridge predeploy.
    address internal constant L2_STANDARD_BRIDGE = 0x4200000000000000000000000000000000000010;

    //// @notice Address of the SequencerFeeWallet predeploy.
    address internal constant SEQUENCER_FEE_WALLET = 0x4200000000000000000000000000000000000011;

    /// @notice Address of the OptimismMintableERC20Factory predeploy.
    address internal constant OPTIMISM_MINTABLE_ERC20_FACTORY = 0x4200000000000000000000000000000000000012;

    /// @custom:legacy
    /// @notice Address of the L1BlockNumber predeploy. Deprecated. Use the L1Block predeploy
    ///         instead, which exposes more information about the L1 state.
    address internal constant L1_BLOCK_NUMBER = 0x4200000000000000000000000000000000000013;

    /// @notice Address of the L2ERC721Bridge predeploy.
    address internal constant L2_ERC721_BRIDGE = 0x4200000000000000000000000000000000000014;

    /// @notice Address of the L1Block predeploy.
    address internal constant L1_BLOCK_ATTRIBUTES = 0x4200000000000000000000000000000000000015;

    /// @notice Address of the L2ToL1MessagePasser predeploy.
    address internal constant L2_TO_L1_MESSAGE_PASSER = 0x4200000000000000000000000000000000000016;

    /// @notice Address of the OptimismMintableERC721Factory predeploy.
    address internal constant OPTIMISM_MINTABLE_ERC721_FACTORY = 0x4200000000000000000000000000000000000017;

    /// @notice Address of the ProxyAdmin predeploy.
    address internal constant PROXY_ADMIN = 0x4200000000000000000000000000000000000018;

    /// @notice Address of the BaseFeeVault predeploy.
    address internal constant BASE_FEE_VAULT = 0x4200000000000000000000000000000000000019;

    /// @notice Address of the L1FeeVault predeploy.
    address internal constant L1_FEE_VAULT = 0x420000000000000000000000000000000000001A;

    /// @notice Address of the SchemaRegistry predeploy.
    address internal constant SCHEMA_REGISTRY = 0x4200000000000000000000000000000000000020;

    /// @notice Address of the EAS predeploy.
    address internal constant EAS = 0x4200000000000000000000000000000000000021;

    /// @notice Address of the GovernanceToken predeploy.
    address internal constant GOVERNANCE_TOKEN = 0x4200000000000000000000000000000000000042;

    /// @custom:legacy
    /// @notice Address of the LegacyERC20ETH predeploy. Deprecated. Balances are migrated to the
    ///         state trie as of the Bedrock upgrade. Contract has been locked and write functions
    ///         can no longer be accessed.
    address internal constant LEGACY_ERC20_ETH = 0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000;

    /// @notice Address of the CrossL2Inbox predeploy.
    address internal constant CROSS_L2_INBOX = 0x4200000000000000000000000000000000000022;

    /// @notice Address of the L2ToL2CrossDomainMessenger predeploy.
    address internal constant L2_TO_L2_CROSS_DOMAIN_MESSENGER = 0x4200000000000000000000000000000000000023;

    /// @notice Returns the name of the predeploy at the given address.
    function getName(address _addr) internal pure returns (string memory out_) {
        require(isPredeployNamespace(_addr), "Predeploys: address must be a predeploy");
        if (_addr == LEGACY_MESSAGE_PASSER) return "LegacyMessagePasser";
        if (_addr == L1_MESSAGE_SENDER) return "L1MessageSender";
        if (_addr == DEPLOYER_WHITELIST) return "DeployerWhitelist";
        if (_addr == WETH) return "WETH";
        if (_addr == L2_CROSS_DOMAIN_MESSENGER) return "L2CrossDomainMessenger";
        if (_addr == GAS_PRICE_ORACLE) return "GasPriceOracle";
        if (_addr == L2_STANDARD_BRIDGE) return "L2StandardBridge";
        if (_addr == SEQUENCER_FEE_WALLET) return "SequencerFeeVault";
        if (_addr == OPTIMISM_MINTABLE_ERC20_FACTORY) return "OptimismMintableERC20Factory";
        if (_addr == L1_BLOCK_NUMBER) return "L1BlockNumber";
        if (_addr == L2_ERC721_BRIDGE) return "L2ERC721Bridge";
        if (_addr == L1_BLOCK_ATTRIBUTES) return "L1Block";
        if (_addr == L2_TO_L1_MESSAGE_PASSER) return "L2ToL1MessagePasser";
        if (_addr == OPTIMISM_MINTABLE_ERC721_FACTORY) return "OptimismMintableERC721Factory";
        if (_addr == PROXY_ADMIN) return "ProxyAdmin";
        if (_addr == BASE_FEE_VAULT) return "BaseFeeVault";
        if (_addr == L1_FEE_VAULT) return "L1FeeVault";
        if (_addr == SCHEMA_REGISTRY) return "SchemaRegistry";
        if (_addr == EAS) return "EAS";
        if (_addr == GOVERNANCE_TOKEN) return "GovernanceToken";
        if (_addr == LEGACY_ERC20_ETH) return "LegacyERC20ETH";
        if (_addr == CROSS_L2_INBOX) return "CrossL2Inbox";
        if (_addr == L2_TO_L2_CROSS_DOMAIN_MESSENGER) return "L2ToL2CrossDomainMessenger";
        revert("Predeploys: unnamed predeploy");
    }

    /// @notice Returns true if the predeploy is not proxied.
    function notProxied(address _addr) internal pure returns (bool) {
        return _addr == GOVERNANCE_TOKEN || _addr == WETH;
    }

    /// @notice Returns true if the address is a defined predeploy that is embedded into new OP-Stack chains.
    function isSupportedPredeploy(address _addr, bool _useInterop) internal pure returns (bool) {
        return _addr == LEGACY_MESSAGE_PASSER || _addr == DEPLOYER_WHITELIST || _addr == WETH
            || _addr == L2_CROSS_DOMAIN_MESSENGER || _addr == GAS_PRICE_ORACLE || _addr == L2_STANDARD_BRIDGE
            || _addr == SEQUENCER_FEE_WALLET || _addr == OPTIMISM_MINTABLE_ERC20_FACTORY || _addr == L1_BLOCK_NUMBER
            || _addr == L2_ERC721_BRIDGE || _addr == L1_BLOCK_ATTRIBUTES || _addr == L2_TO_L1_MESSAGE_PASSER
            || _addr == OPTIMISM_MINTABLE_ERC721_FACTORY || _addr == PROXY_ADMIN || _addr == BASE_FEE_VAULT
            || _addr == L1_FEE_VAULT || _addr == SCHEMA_REGISTRY || _addr == EAS || _addr == GOVERNANCE_TOKEN
            || (_useInterop && _addr == CROSS_L2_INBOX) || (_useInterop && _addr == L2_TO_L2_CROSS_DOMAIN_MESSENGER);
    }

    function isPredeployNamespace(address _addr) internal pure returns (bool) {
        return uint160(_addr) >> 11 == uint160(0x4200000000000000000000000000000000000000) >> 11;
    }

    /// @notice Function to compute the expected address of the predeploy implementation
    ///         in the genesis state.
    function predeployToCodeNamespace(address _addr) internal pure returns (address) {
        require(
            isPredeployNamespace(_addr), "Predeploys: can only derive code-namespace address for predeploy addresses"
        );
        return address(
            uint160(uint256(uint160(_addr)) & 0xffff | uint256(uint160(0xc0D3C0d3C0d3C0D3c0d3C0d3c0D3C0d3c0d30000)))
        );
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @notice Error for when a deposit or withdrawal is to a bad target.
error BadTarget();
/// @notice Error for when a deposit has too much calldata.
error LargeCalldata();
/// @notice Error for when a deposit has too small of a gas limit.
error SmallGasLimit();
/// @notice Error for when a withdrawal transfer fails.
error TransferFailed();
/// @notice Error for when a method is called that only works when using a custom gas token.
error OnlyCustomGasToken();
/// @notice Error for when a method cannot be called with non zero CALLVALUE.
error NoValue();
/// @notice Error for an unauthorized CALLER.
error Unauthorized();
/// @notice Error for when a method cannot be called when paused. This could be renamed
///         to `Paused` in the future, but it collides with the `Paused` event.
error CallPaused();
/// @notice Error for special gas estimation.
error GasEstimation();
/// @notice Error for when a method is being reentered.
error NonReentrant();

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @notice Error returns when a non-depositor account tries to set L1 block values.
error NotDepositor();

/// @notice Error when a chain ID is not in the interop dependency set.
error NotDependency();

/// @notice Error when the interop dependency set size is too large.
error DependencySetSizeTooLarge();

/// @notice Error when a chain ID already in the interop dependency set is attempted to be added.
error AlreadyDependency();

/// @notice Error when the chain's chain ID is attempted to be removed from the interop dependency set.
error CantRemovedDependency();

// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

/// @notice The length of an RLP item must be greater than zero to be decodable
error EmptyItem();

/// @notice The decoded item type for list is not a list item
error UnexpectedString();

/// @notice The RLP item has an invalid data remainder
error InvalidDataRemainder();

/// @notice Decoded item type for bytes is not a string item
error UnexpectedList();

/// @notice The length of the content must be greater than the RLP item length
error ContentLengthMismatch();

/// @notice Invalid RLP header for RLP item
error InvalidHeader();

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.8;

import "./RLPErrors.sol";

/// @custom:attribution https://github.com/hamdiallam/Solidity-RLP
/// @title RLPReader
/// @notice RLPReader is a library for parsing RLP-encoded byte arrays into Solidity types. Adapted
///         from Solidity-RLP (https://github.com/hamdiallam/Solidity-RLP) by Hamdi Allam with
///         various tweaks to improve readability.
library RLPReader {
    /// @notice Custom pointer type to avoid confusion between pointers and uint256s.
    type MemoryPointer is uint256;

    /// @notice RLP item types.
    /// @custom:value DATA_ITEM Represents an RLP data item (NOT a list).
    /// @custom:value LIST_ITEM Represents an RLP list item.
    enum RLPItemType {
        DATA_ITEM,
        LIST_ITEM
    }

    /// @notice Struct representing an RLP item.
    /// @custom:field length Length of the RLP item.
    /// @custom:field ptr    Pointer to the RLP item in memory.
    struct RLPItem {
        uint256 length;
        MemoryPointer ptr;
    }

    /// @notice Max list length that this library will accept.
    uint256 internal constant MAX_LIST_LENGTH = 32;

    /// @notice Converts bytes to a reference to memory position and length.
    /// @param _in Input bytes to convert.
    /// @return out_ Output memory reference.
    function toRLPItem(bytes memory _in) internal pure returns (RLPItem memory out_) {
        // Empty arrays are not RLP items.
        if (_in.length == 0) revert EmptyItem();

        MemoryPointer ptr;
        assembly {
            ptr := add(_in, 32)
        }

        out_ = RLPItem({ length: _in.length, ptr: ptr });
    }

    /// @notice Reads an RLP list value into a list of RLP items.
    /// @param _in RLP list value.
    /// @return out_ Decoded RLP list items.
    function readList(RLPItem memory _in) internal pure returns (RLPItem[] memory out_) {
        (uint256 listOffset, uint256 listLength, RLPItemType itemType) = _decodeLength(_in);

        if (itemType != RLPItemType.LIST_ITEM) revert UnexpectedString();

        if (listOffset + listLength != _in.length) revert InvalidDataRemainder();

        // Solidity in-memory arrays can't be increased in size, but *can* be decreased in size by
        // writing to the length. Since we can't know the number of RLP items without looping over
        // the entire input, we'd have to loop twice to accurately size this array. It's easier to
        // simply set a reasonable maximum list length and decrease the size before we finish.
        out_ = new RLPItem[](MAX_LIST_LENGTH);

        uint256 itemCount = 0;
        uint256 offset = listOffset;
        while (offset < _in.length) {
            (uint256 itemOffset, uint256 itemLength,) = _decodeLength(
                RLPItem({ length: _in.length - offset, ptr: MemoryPointer.wrap(MemoryPointer.unwrap(_in.ptr) + offset) })
            );

            // We don't need to check itemCount < out.length explicitly because Solidity already
            // handles this check on our behalf, we'd just be wasting gas.
            out_[itemCount] = RLPItem({
                length: itemLength + itemOffset,
                ptr: MemoryPointer.wrap(MemoryPointer.unwrap(_in.ptr) + offset)
            });

            itemCount += 1;
            offset += itemOffset + itemLength;
        }

        // Decrease the array size to match the actual item count.
        assembly {
            mstore(out_, itemCount)
        }
    }

    /// @notice Reads an RLP list value into a list of RLP items.
    /// @param _in RLP list value.
    /// @return out_ Decoded RLP list items.
    function readList(bytes memory _in) internal pure returns (RLPItem[] memory out_) {
        out_ = readList(toRLPItem(_in));
    }

    /// @notice Reads an RLP bytes value into bytes.
    /// @param _in RLP bytes value.
    /// @return out_ Decoded bytes.
    function readBytes(RLPItem memory _in) internal pure returns (bytes memory out_) {
        (uint256 itemOffset, uint256 itemLength, RLPItemType itemType) = _decodeLength(_in);

        if (itemType != RLPItemType.DATA_ITEM) revert UnexpectedList();

        if (_in.length != itemOffset + itemLength) revert InvalidDataRemainder();

        out_ = _copy(_in.ptr, itemOffset, itemLength);
    }

    /// @notice Reads an RLP bytes value into bytes.
    /// @param _in RLP bytes value.
    /// @return out_ Decoded bytes.
    function readBytes(bytes memory _in) internal pure returns (bytes memory out_) {
        out_ = readBytes(toRLPItem(_in));
    }

    /// @notice Reads the raw bytes of an RLP item.
    /// @param _in RLP item to read.
    /// @return out_ Raw RLP bytes.
    function readRawBytes(RLPItem memory _in) internal pure returns (bytes memory out_) {
        out_ = _copy(_in.ptr, 0, _in.length);
    }

    /// @notice Decodes the length of an RLP item.
    /// @param _in RLP item to decode.
    /// @return offset_ Offset of the encoded data.
    /// @return length_ Length of the encoded data.
    /// @return type_ RLP item type (LIST_ITEM or DATA_ITEM).
    function _decodeLength(RLPItem memory _in)
        private
        pure
        returns (uint256 offset_, uint256 length_, RLPItemType type_)
    {
        // Short-circuit if there's nothing to decode, note that we perform this check when
        // the user creates an RLP item via toRLPItem, but it's always possible for them to bypass
        // that function and create an RLP item directly. So we need to check this anyway.
        if (_in.length == 0) revert EmptyItem();

        MemoryPointer ptr = _in.ptr;
        uint256 prefix;
        assembly {
            prefix := byte(0, mload(ptr))
        }

        if (prefix <= 0x7f) {
            // Single byte.
            return (0, 1, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xb7) {
            // Short string.

            // slither-disable-next-line variable-scope
            uint256 strLen = prefix - 0x80;

            if (_in.length <= strLen) revert ContentLengthMismatch();

            bytes1 firstByteOfContent;
            assembly {
                firstByteOfContent := and(mload(add(ptr, 1)), shl(248, 0xff))
            }

            if (strLen == 1 && firstByteOfContent < 0x80) revert InvalidHeader();

            return (1, strLen, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xbf) {
            // Long string.
            uint256 lenOfStrLen = prefix - 0xb7;

            if (_in.length <= lenOfStrLen) revert ContentLengthMismatch();

            bytes1 firstByteOfContent;
            assembly {
                firstByteOfContent := and(mload(add(ptr, 1)), shl(248, 0xff))
            }

            if (firstByteOfContent == 0x00) revert InvalidHeader();

            uint256 strLen;
            assembly {
                strLen := shr(sub(256, mul(8, lenOfStrLen)), mload(add(ptr, 1)))
            }

            if (strLen <= 55) revert InvalidHeader();

            if (_in.length <= lenOfStrLen + strLen) revert ContentLengthMismatch();

            return (1 + lenOfStrLen, strLen, RLPItemType.DATA_ITEM);
        } else if (prefix <= 0xf7) {
            // Short list.
            // slither-disable-next-line variable-scope
            uint256 listLen = prefix - 0xc0;

            if (_in.length <= listLen) revert ContentLengthMismatch();

            return (1, listLen, RLPItemType.LIST_ITEM);
        } else {
            // Long list.
            uint256 lenOfListLen = prefix - 0xf7;

            if (_in.length <= lenOfListLen) revert ContentLengthMismatch();

            bytes1 firstByteOfContent;
            assembly {
                firstByteOfContent := and(mload(add(ptr, 1)), shl(248, 0xff))
            }

            if (firstByteOfContent == 0x00) revert InvalidHeader();

            uint256 listLen;
            assembly {
                listLen := shr(sub(256, mul(8, lenOfListLen)), mload(add(ptr, 1)))
            }

            if (listLen <= 55) revert InvalidHeader();

            if (_in.length <= lenOfListLen + listLen) revert ContentLengthMismatch();

            return (1 + lenOfListLen, listLen, RLPItemType.LIST_ITEM);
        }
    }

    /// @notice Copies the bytes from a memory location.
    /// @param _src    Pointer to the location to read from.
    /// @param _offset Offset to start reading from.
    /// @param _length Number of bytes to read.
    /// @return out_ Copied bytes.
    function _copy(MemoryPointer _src, uint256 _offset, uint256 _length) private pure returns (bytes memory out_) {
        out_ = new bytes(_length);
        if (_length == 0) {
            return out_;
        }

        // Mostly based on Solidity's copy_memory_to_memory:
        // https://github.com/ethereum/solidity/blob/34dd30d71b4da730488be72ff6af7083cf2a91f6/libsolidity/codegen/YulUtilFunctions.cpp#L102-L114
        uint256 src = MemoryPointer.unwrap(_src) + _offset;
        assembly {
            let dest := add(out_, 32)
            let i := 0
            for { } lt(i, _length) { i := add(i, 32) } { mstore(add(dest, i), mload(add(src, i))) }

            if gt(i, _length) { mstore(add(dest, _length), 0) }
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @custom:attribution https://github.com/bakaoh/solidity-rlp-encode
/// @title RLPWriter
/// @author RLPWriter is a library for encoding Solidity types to RLP bytes. Adapted from Bakaoh's
///         RLPEncode library (https://github.com/bakaoh/solidity-rlp-encode) with minor
///         modifications to improve legibility.
library RLPWriter {
    /// @notice RLP encodes a byte string.
    /// @param _in The byte string to encode.
    /// @return out_ The RLP encoded string in bytes.
    function writeBytes(bytes memory _in) internal pure returns (bytes memory out_) {
        if (_in.length == 1 && uint8(_in[0]) < 128) {
            out_ = _in;
        } else {
            out_ = abi.encodePacked(_writeLength(_in.length, 128), _in);
        }
    }

    /// @notice RLP encodes a list of RLP encoded byte byte strings.
    /// @param _in The list of RLP encoded byte strings.
    /// @return list_ The RLP encoded list of items in bytes.
    function writeList(bytes[] memory _in) internal pure returns (bytes memory list_) {
        list_ = _flatten(_in);
        list_ = abi.encodePacked(_writeLength(list_.length, 192), list_);
    }

    /// @notice RLP encodes a string.
    /// @param _in The string to encode.
    /// @return out_ The RLP encoded string in bytes.
    function writeString(string memory _in) internal pure returns (bytes memory out_) {
        out_ = writeBytes(bytes(_in));
    }

    /// @notice RLP encodes an address.
    /// @param _in The address to encode.
    /// @return out_ The RLP encoded address in bytes.
    function writeAddress(address _in) internal pure returns (bytes memory out_) {
        out_ = writeBytes(abi.encodePacked(_in));
    }

    /// @notice RLP encodes a uint.
    /// @param _in The uint256 to encode.
    /// @return out_ The RLP encoded uint256 in bytes.
    function writeUint(uint256 _in) internal pure returns (bytes memory out_) {
        out_ = writeBytes(_toBinary(_in));
    }

    /// @notice RLP encodes a bool.
    /// @param _in The bool to encode.
    /// @return out_ The RLP encoded bool in bytes.
    function writeBool(bool _in) internal pure returns (bytes memory out_) {
        out_ = new bytes(1);
        out_[0] = (_in ? bytes1(0x01) : bytes1(0x80));
    }

    /// @notice Encode the first byte and then the `len` in binary form if `length` is more than 55.
    /// @param _len    The length of the string or the payload.
    /// @param _offset 128 if item is string, 192 if item is list.
    /// @return out_ RLP encoded bytes.
    function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory out_) {
        if (_len < 56) {
            out_ = new bytes(1);
            out_[0] = bytes1(uint8(_len) + uint8(_offset));
        } else {
            uint256 lenLen;
            uint256 i = 1;
            while (_len / i != 0) {
                lenLen++;
                i *= 256;
            }

            out_ = new bytes(lenLen + 1);
            out_[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
            for (i = 1; i <= lenLen; i++) {
                out_[i] = bytes1(uint8((_len / (256 ** (lenLen - i))) % 256));
            }
        }
    }

    /// @notice Encode integer in big endian binary form with no leading zeroes.
    /// @param _x The integer to encode.
    /// @return out_ RLP encoded bytes.
    function _toBinary(uint256 _x) private pure returns (bytes memory out_) {
        bytes memory b = abi.encodePacked(_x);

        uint256 i = 0;
        for (; i < 32; i++) {
            if (b[i] != 0) {
                break;
            }
        }

        out_ = new bytes(32 - i);
        for (uint256 j = 0; j < out_.length; j++) {
            out_[j] = b[i++];
        }
    }

    /// @custom:attribution https://github.com/Arachnid/solidity-stringutils
    /// @notice Copies a piece of memory to another location.
    /// @param _dest Destination location.
    /// @param _src  Source location.
    /// @param _len  Length of memory to copy.
    function _memcpy(uint256 _dest, uint256 _src, uint256 _len) private pure {
        uint256 dest = _dest;
        uint256 src = _src;
        uint256 len = _len;

        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        uint256 mask;
        unchecked {
            mask = 256 ** (32 - len) - 1;
        }
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /// @custom:attribution https://github.com/sammayo/solidity-rlp-encoder
    /// @notice Flattens a list of byte strings into one byte string.
    /// @param _list List of byte strings to flatten.
    /// @return out_ The flattened byte string.
    function _flatten(bytes[] memory _list) private pure returns (bytes memory out_) {
        if (_list.length == 0) {
            return new bytes(0);
        }

        uint256 len;
        uint256 i = 0;
        for (; i < _list.length; i++) {
            len += _list[i].length;
        }

        out_ = new bytes(len);
        uint256 flattenedPtr;
        assembly {
            flattenedPtr := add(out_, 0x20)
        }

        for (i = 0; i < _list.length; i++) {
            bytes memory item = _list[i];

            uint256 listPtr;
            assembly {
                listPtr := add(item, 0x20)
            }

            _memcpy(flattenedPtr, listPtr, item.length);
            flattenedPtr += _list[i].length;
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Storage } from "src/libraries/Storage.sol";
import { Constants } from "src/libraries/Constants.sol";
import { LibString } from "@solady/utils/LibString.sol";

/// @title IGasToken
/// @notice Implemented by contracts that are aware of the custom gas token used
///         by the L2 network.
interface IGasToken {
    /// @notice Getter for the ERC20 token address that is used to pay for gas and its decimals.
    function gasPayingToken() external view returns (address, uint8);
    /// @notice Returns the gas token name.
    function gasPayingTokenName() external view returns (string memory);
    /// @notice Returns the gas token symbol.
    function gasPayingTokenSymbol() external view returns (string memory);
    /// @notice Returns true if the network uses a custom gas token.
    function isCustomGasToken() external view returns (bool);
}

/// @title GasPayingToken
/// @notice Handles reading and writing the custom gas token to storage.
///         To be used in any place where gas token information is read or
///         written to state. If multiple contracts use this library, the
///         values in storage should be kept in sync between them.
library GasPayingToken {
    /// @notice The storage slot that contains the address and decimals of the gas paying token
    bytes32 internal constant GAS_PAYING_TOKEN_SLOT = bytes32(uint256(keccak256("opstack.gaspayingtoken")) - 1);

    /// @notice The storage slot that contains the ERC20 `name()` of the gas paying token
    bytes32 internal constant GAS_PAYING_TOKEN_NAME_SLOT = bytes32(uint256(keccak256("opstack.gaspayingtokenname")) - 1);

    /// @notice the storage slot that contains the ERC20 `symbol()` of the gas paying token
    bytes32 internal constant GAS_PAYING_TOKEN_SYMBOL_SLOT =
        bytes32(uint256(keccak256("opstack.gaspayingtokensymbol")) - 1);

    /// @notice Reads the gas paying token and its decimals from the magic
    ///         storage slot. If nothing is set in storage, then the ether
    ///         address is returned instead.
    function getToken() internal view returns (address addr_, uint8 decimals_) {
        bytes32 slot = Storage.getBytes32(GAS_PAYING_TOKEN_SLOT);
        addr_ = address(uint160(uint256(slot) & uint256(type(uint160).max)));
        if (addr_ == address(0)) {
            addr_ = Constants.ETHER;
            decimals_ = 18;
        } else {
            decimals_ = uint8(uint256(slot) >> 160);
        }
    }

    /// @notice Reads the gas paying token's name from the magic storage slot.
    ///         If nothing is set in storage, then the ether name, 'Ether', is returned instead.
    function getName() internal view returns (string memory name_) {
        (address addr,) = getToken();
        if (addr == Constants.ETHER) {
            name_ = "Ether";
        } else {
            name_ = LibString.fromSmallString(Storage.getBytes32(GAS_PAYING_TOKEN_NAME_SLOT));
        }
    }

    /// @notice Reads the gas paying token's symbol from the magic storage slot.
    ///         If nothing is set in storage, then the ether symbol, 'ETH', is returned instead.
    function getSymbol() internal view returns (string memory symbol_) {
        (address addr,) = getToken();
        if (addr == Constants.ETHER) {
            symbol_ = "ETH";
        } else {
            symbol_ = LibString.fromSmallString(Storage.getBytes32(GAS_PAYING_TOKEN_SYMBOL_SLOT));
        }
    }

    /// @notice Writes the gas paying token, its decimals, name and symbol to the magic storage slot.
    function set(address _token, uint8 _decimals, bytes32 _name, bytes32 _symbol) internal {
        Storage.setBytes32(GAS_PAYING_TOKEN_SLOT, bytes32(uint256(_decimals) << 160 | uint256(uint160(_token))));
        Storage.setBytes32(GAS_PAYING_TOKEN_NAME_SLOT, _name);
        Storage.setBytes32(GAS_PAYING_TOKEN_SYMBOL_SLOT, _symbol);
    }

    /// @notice Maps a string to a normalized null-terminated small string.
    function sanitize(string memory _str) internal pure returns (bytes32) {
        require(bytes(_str).length <= 32, "GasPayingToken: string cannot be greater than 32 bytes");

        return LibString.toSmallString(_str);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { Bytes } from "../Bytes.sol";
import { RLPReader } from "../rlp/RLPReader.sol";

/// @title MerkleTrie
/// @notice MerkleTrie is a small library for verifying standard Ethereum Merkle-Patricia trie
///         inclusion proofs. By default, this library assumes a hexary trie. One can change the
///         trie radix constant to support other trie radixes.
library MerkleTrie {
    /// @notice Struct representing a node in the trie.
    /// @custom:field encoded The RLP-encoded node.
    /// @custom:field decoded The RLP-decoded node.
    struct TrieNode {
        bytes encoded;
        RLPReader.RLPItem[] decoded;
    }

    /// @notice Determines the number of elements per branch node.
    uint256 internal constant TREE_RADIX = 16;

    /// @notice Branch nodes have TREE_RADIX elements and one value element.
    uint256 internal constant BRANCH_NODE_LENGTH = TREE_RADIX + 1;

    /// @notice Leaf nodes and extension nodes have two elements, a `path` and a `value`.
    uint256 internal constant LEAF_OR_EXTENSION_NODE_LENGTH = 2;

    /// @notice Prefix for even-nibbled extension node paths.
    uint8 internal constant PREFIX_EXTENSION_EVEN = 0;

    /// @notice Prefix for odd-nibbled extension node paths.
    uint8 internal constant PREFIX_EXTENSION_ODD = 1;

    /// @notice Prefix for even-nibbled leaf node paths.
    uint8 internal constant PREFIX_LEAF_EVEN = 2;

    /// @notice Prefix for odd-nibbled leaf node paths.
    uint8 internal constant PREFIX_LEAF_ODD = 3;

    /// @notice Verifies a proof that a given key/value pair is present in the trie.
    /// @param _key   Key of the node to search for, as a hex string.
    /// @param _value Value of the node to search for, as a hex string.
    /// @param _proof Merkle trie inclusion proof for the desired node. Unlike traditional Merkle
    ///               trees, this proof is executed top-down and consists of a list of RLP-encoded
    ///               nodes that make a path down to the target node.
    /// @param _root  Known root of the Merkle trie. Used to verify that the included proof is
    ///               correctly constructed.
    /// @return valid_ Whether or not the proof is valid.
    function verifyInclusionProof(
        bytes memory _key,
        bytes memory _value,
        bytes[] memory _proof,
        bytes32 _root
    )
        internal
        pure
        returns (bool valid_)
    {
        valid_ = Bytes.equal(_value, get(_key, _proof, _root));
    }

    /// @notice Retrieves the value associated with a given key.
    /// @param _key   Key to search for, as hex bytes.
    /// @param _proof Merkle trie inclusion proof for the key.
    /// @param _root  Known root of the Merkle trie.
    /// @return value_ Value of the key if it exists.
    function get(bytes memory _key, bytes[] memory _proof, bytes32 _root) internal pure returns (bytes memory value_) {
        require(_key.length > 0, "MerkleTrie: empty key");

        TrieNode[] memory proof = _parseProof(_proof);
        bytes memory key = Bytes.toNibbles(_key);
        bytes memory currentNodeID = abi.encodePacked(_root);
        uint256 currentKeyIndex = 0;

        // Proof is top-down, so we start at the first element (root).
        for (uint256 i = 0; i < proof.length; i++) {
            TrieNode memory currentNode = proof[i];

            // Key index should never exceed total key length or we'll be out of bounds.
            require(currentKeyIndex <= key.length, "MerkleTrie: key index exceeds total key length");

            if (currentKeyIndex == 0) {
                // First proof element is always the root node.
                require(
                    Bytes.equal(abi.encodePacked(keccak256(currentNode.encoded)), currentNodeID),
                    "MerkleTrie: invalid root hash"
                );
            } else if (currentNode.encoded.length >= 32) {
                // Nodes 32 bytes or larger are hashed inside branch nodes.
                require(
                    Bytes.equal(abi.encodePacked(keccak256(currentNode.encoded)), currentNodeID),
                    "MerkleTrie: invalid large internal hash"
                );
            } else {
                // Nodes smaller than 32 bytes aren't hashed.
                require(Bytes.equal(currentNode.encoded, currentNodeID), "MerkleTrie: invalid internal node hash");
            }

            if (currentNode.decoded.length == BRANCH_NODE_LENGTH) {
                if (currentKeyIndex == key.length) {
                    // Value is the last element of the decoded list (for branch nodes). There's
                    // some ambiguity in the Merkle trie specification because bytes(0) is a
                    // valid value to place into the trie, but for branch nodes bytes(0) can exist
                    // even when the value wasn't explicitly placed there. Geth treats a value of
                    // bytes(0) as "key does not exist" and so we do the same.
                    value_ = RLPReader.readBytes(currentNode.decoded[TREE_RADIX]);
                    require(value_.length > 0, "MerkleTrie: value length must be greater than zero (branch)");

                    // Extra proof elements are not allowed.
                    require(i == proof.length - 1, "MerkleTrie: value node must be last node in proof (branch)");

                    return value_;
                } else {
                    // We're not at the end of the key yet.
                    // Figure out what the next node ID should be and continue.
                    uint8 branchKey = uint8(key[currentKeyIndex]);
                    RLPReader.RLPItem memory nextNode = currentNode.decoded[branchKey];
                    currentNodeID = _getNodeID(nextNode);
                    currentKeyIndex += 1;
                }
            } else if (currentNode.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
                bytes memory path = _getNodePath(currentNode);
                uint8 prefix = uint8(path[0]);
                uint8 offset = 2 - (prefix % 2);
                bytes memory pathRemainder = Bytes.slice(path, offset);
                bytes memory keyRemainder = Bytes.slice(key, currentKeyIndex);
                uint256 sharedNibbleLength = _getSharedNibbleLength(pathRemainder, keyRemainder);

                // Whether this is a leaf node or an extension node, the path remainder MUST be a
                // prefix of the key remainder (or be equal to the key remainder) or the proof is
                // considered invalid.
                require(
                    pathRemainder.length == sharedNibbleLength,
                    "MerkleTrie: path remainder must share all nibbles with key"
                );

                if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                    // Prefix of 2 or 3 means this is a leaf node. For the leaf node to be valid,
                    // the key remainder must be exactly equal to the path remainder. We already
                    // did the necessary byte comparison, so it's more efficient here to check that
                    // the key remainder length equals the shared nibble length, which implies
                    // equality with the path remainder (since we already did the same check with
                    // the path remainder and the shared nibble length).
                    require(
                        keyRemainder.length == sharedNibbleLength,
                        "MerkleTrie: key remainder must be identical to path remainder"
                    );

                    // Our Merkle Trie is designed specifically for the purposes of the Ethereum
                    // state trie. Empty values are not allowed in the state trie, so we can safely
                    // say that if the value is empty, the key should not exist and the proof is
                    // invalid.
                    value_ = RLPReader.readBytes(currentNode.decoded[1]);
                    require(value_.length > 0, "MerkleTrie: value length must be greater than zero (leaf)");

                    // Extra proof elements are not allowed.
                    require(i == proof.length - 1, "MerkleTrie: value node must be last node in proof (leaf)");

                    return value_;
                } else if (prefix == PREFIX_EXTENSION_EVEN || prefix == PREFIX_EXTENSION_ODD) {
                    // Prefix of 0 or 1 means this is an extension node. We move onto the next node
                    // in the proof and increment the key index by the length of the path remainder
                    // which is equal to the shared nibble length.
                    currentNodeID = _getNodeID(currentNode.decoded[1]);
                    currentKeyIndex += sharedNibbleLength;
                } else {
                    revert("MerkleTrie: received a node with an unknown prefix");
                }
            } else {
                revert("MerkleTrie: received an unparseable node");
            }
        }

        revert("MerkleTrie: ran out of proof elements");
    }

    /// @notice Parses an array of proof elements into a new array that contains both the original
    ///         encoded element and the RLP-decoded element.
    /// @param _proof Array of proof elements to parse.
    /// @return proof_ Proof parsed into easily accessible structs.
    function _parseProof(bytes[] memory _proof) private pure returns (TrieNode[] memory proof_) {
        uint256 length = _proof.length;
        proof_ = new TrieNode[](length);
        for (uint256 i = 0; i < length;) {
            proof_[i] = TrieNode({ encoded: _proof[i], decoded: RLPReader.readList(_proof[i]) });
            unchecked {
                ++i;
            }
        }
    }

    /// @notice Picks out the ID for a node. Node ID is referred to as the "hash" within the
    ///         specification, but nodes < 32 bytes are not actually hashed.
    /// @param _node Node to pull an ID for.
    /// @return id_ ID for the node, depending on the size of its contents.
    function _getNodeID(RLPReader.RLPItem memory _node) private pure returns (bytes memory id_) {
        id_ = _node.length < 32 ? RLPReader.readRawBytes(_node) : RLPReader.readBytes(_node);
    }

    /// @notice Gets the path for a leaf or extension node.
    /// @param _node Node to get a path for.
    /// @return nibbles_ Node path, converted to an array of nibbles.
    function _getNodePath(TrieNode memory _node) private pure returns (bytes memory nibbles_) {
        nibbles_ = Bytes.toNibbles(RLPReader.readBytes(_node.decoded[0]));
    }

    /// @notice Utility; determines the number of nibbles shared between two nibble arrays.
    /// @param _a First nibble array.
    /// @param _b Second nibble array.
    /// @return shared_ Number of shared nibbles.
    function _getSharedNibbleLength(bytes memory _a, bytes memory _b) private pure returns (uint256 shared_) {
        uint256 max = (_a.length < _b.length) ? _a.length : _b.length;
        for (; shared_ < max && _a[shared_] == _b[shared_];) {
            unchecked {
                ++shared_;
            }
        }
    }
}

// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2019-2021, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

library AddressAliasHelper {
    uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);

    /// @notice Utility function that converts the address in the L1 that submitted a tx to
    /// the inbox to the msg.sender viewed in the L2
    /// @param l1Address the address in the L1 that triggered the tx to L2
    /// @return l2Address L2 address as viewed in msg.sender
    function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
        unchecked {
            l2Address = address(uint160(l1Address) + offset);
        }
    }

    /// @notice Utility function that converts the msg.sender viewed in the L2 to the
    /// address in the L1 that submitted a tx to the inbox
    /// @param l2Address L2 address as viewed in msg.sender
    /// @return l1Address the address in the L1 that triggered the tx to L2
    function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
        unchecked {
            l1Address = address(uint160(l2Address) - offset);
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Library for converting numbers into strings and other string operations.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/LibString.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/LibString.sol)
///
/// Note:
/// For performance and bytecode compactness, most of the string operations are restricted to
/// byte strings (7-bit ASCII), except where otherwise specified.
/// Usage of byte string operations on charsets with runes spanning two or more bytes
/// can lead to undefined behavior.
library LibString {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                        CUSTOM ERRORS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The length of the output is too small to contain all the hex digits.
    error HexLengthInsufficient();

    /// @dev The length of the string is more than 32 bytes.
    error TooBigForSmallString();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         CONSTANTS                          */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The constant returned when the `search` is not found in the string.
    uint256 internal constant NOT_FOUND = type(uint256).max;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                     DECIMAL OPERATIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the base 10 decimal representation of `value`.
    function toString(uint256 value) internal pure returns (string memory str) {
        /// @solidity memory-safe-assembly
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
            // We will need 1 word for the trailing zeros padding, 1 word for the length,
            // and 3 words for a maximum of 78 digits.
            str := add(mload(0x40), 0x80)
            // Update the free memory pointer to allocate.
            mstore(0x40, add(str, 0x20))
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end of the memory to calculate the length later.
            let end := str

            let w := not(0) // Tsk.
            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            for { let temp := value } 1 {} {
                str := add(str, w) // `sub(str, 1)`.
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }

    /// @dev Returns the base 10 decimal representation of `value`.
    function toString(int256 value) internal pure returns (string memory str) {
        if (value >= 0) {
            return toString(uint256(value));
        }
        unchecked {
            str = toString(uint256(-value));
        }
        /// @solidity memory-safe-assembly
        assembly {
            // We still have some spare memory space on the left,
            // as we have allocated 3 words (96 bytes) for up to 78 digits.
            let length := mload(str) // Load the string length.
            mstore(str, 0x2d) // Store the '-' character.
            str := sub(str, 1) // Move back the string pointer by a byte.
            mstore(str, add(length, 1)) // Update the string length.
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   HEXADECIMAL OPERATIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the hexadecimal representation of `value`,
    /// left-padded to an input length of `length` bytes.
    /// The output is prefixed with "0x" encoded using 2 hexadecimal digits per byte,
    /// giving a total length of `length * 2 + 2` bytes.
    /// Reverts if `length` is too small for the output to contain all the digits.
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(value, length);
        /// @solidity memory-safe-assembly
        assembly {
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(str, 0x3078) // Write the "0x" prefix.
            str := sub(str, 2) // Move the pointer.
            mstore(str, strLength) // Write the length.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`,
    /// left-padded to an input length of `length` bytes.
    /// The output is prefixed with "0x" encoded using 2 hexadecimal digits per byte,
    /// giving a total length of `length * 2` bytes.
    /// Reverts if `length` is too small for the output to contain all the digits.
    function toHexStringNoPrefix(uint256 value, uint256 length)
        internal
        pure
        returns (string memory str)
    {
        /// @solidity memory-safe-assembly
        assembly {
            // We need 0x20 bytes for the trailing zeros padding, `length * 2` bytes
            // for the digits, 0x02 bytes for the prefix, and 0x20 bytes for the length.
            // We add 0x20 to the total and round down to a multiple of 0x20.
            // (0x20 + 0x20 + 0x02 + 0x20) = 0x62.
            str := add(mload(0x40), and(add(shl(1, length), 0x42), not(0x1f)))
            // Allocate the memory.
            mstore(0x40, add(str, 0x20))
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end to calculate the length later.
            let end := str
            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            let start := sub(str, add(length, length))
            let w := not(1) // Tsk.
            let temp := value
            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            for {} 1 {} {
                str := add(str, w) // `sub(str, 2)`.
                mstore8(add(str, 1), mload(and(temp, 15)))
                mstore8(str, mload(and(shr(4, temp), 15)))
                temp := shr(8, temp)
                if iszero(xor(str, start)) { break }
            }

            if temp {
                mstore(0x00, 0x2194895a) // `HexLengthInsufficient()`.
                revert(0x1c, 0x04)
            }

            // Compute the string's length.
            let strLength := sub(end, str)
            // Move the pointer and write the length.
            str := sub(str, 0x20)
            mstore(str, strLength)
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is prefixed with "0x" and encoded using 2 hexadecimal digits per byte.
    /// As address are 20 bytes long, the output will left-padded to have
    /// a length of `20 * 2 + 2` bytes.
    function toHexString(uint256 value) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(value);
        /// @solidity memory-safe-assembly
        assembly {
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(str, 0x3078) // Write the "0x" prefix.
            str := sub(str, 2) // Move the pointer.
            mstore(str, strLength) // Write the length.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is prefixed with "0x".
    /// The output excludes leading "0" from the `toHexString` output.
    /// `0x00: "0x0", 0x01: "0x1", 0x12: "0x12", 0x123: "0x123"`.
    function toMinimalHexString(uint256 value) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(value);
        /// @solidity memory-safe-assembly
        assembly {
            let o := eq(byte(0, mload(add(str, 0x20))), 0x30) // Whether leading zero is present.
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(add(str, o), 0x3078) // Write the "0x" prefix, accounting for leading zero.
            str := sub(add(str, o), 2) // Move the pointer, accounting for leading zero.
            mstore(str, sub(strLength, o)) // Write the length, accounting for leading zero.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output excludes leading "0" from the `toHexStringNoPrefix` output.
    /// `0x00: "0", 0x01: "1", 0x12: "12", 0x123: "123"`.
    function toMinimalHexStringNoPrefix(uint256 value) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(value);
        /// @solidity memory-safe-assembly
        assembly {
            let o := eq(byte(0, mload(add(str, 0x20))), 0x30) // Whether leading zero is present.
            let strLength := mload(str) // Get the length.
            str := add(str, o) // Move the pointer, accounting for leading zero.
            mstore(str, sub(strLength, o)) // Write the length, accounting for leading zero.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is encoded using 2 hexadecimal digits per byte.
    /// As address are 20 bytes long, the output will left-padded to have
    /// a length of `20 * 2` bytes.
    function toHexStringNoPrefix(uint256 value) internal pure returns (string memory str) {
        /// @solidity memory-safe-assembly
        assembly {
            // We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
            // 0x02 bytes for the prefix, and 0x40 bytes for the digits.
            // The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x40) is 0xa0.
            str := add(mload(0x40), 0x80)
            // Allocate the memory.
            mstore(0x40, add(str, 0x20))
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end to calculate the length later.
            let end := str
            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            let w := not(1) // Tsk.
            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            for { let temp := value } 1 {} {
                str := add(str, w) // `sub(str, 2)`.
                mstore8(add(str, 1), mload(and(temp, 15)))
                mstore8(str, mload(and(shr(4, temp), 15)))
                temp := shr(8, temp)
                if iszero(temp) { break }
            }

            // Compute the string's length.
            let strLength := sub(end, str)
            // Move the pointer and write the length.
            str := sub(str, 0x20)
            mstore(str, strLength)
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is prefixed with "0x", encoded using 2 hexadecimal digits per byte,
    /// and the alphabets are capitalized conditionally according to
    /// https://eips.ethereum.org/EIPS/eip-55
    function toHexStringChecksummed(address value) internal pure returns (string memory str) {
        str = toHexString(value);
        /// @solidity memory-safe-assembly
        assembly {
            let mask := shl(6, div(not(0), 255)) // `0b010000000100000000 ...`
            let o := add(str, 0x22)
            let hashed := and(keccak256(o, 40), mul(34, mask)) // `0b10001000 ... `
            let t := shl(240, 136) // `0b10001000 << 240`
            for { let i := 0 } 1 {} {
                mstore(add(i, i), mul(t, byte(i, hashed)))
                i := add(i, 1)
                if eq(i, 20) { break }
            }
            mstore(o, xor(mload(o), shr(1, and(mload(0x00), and(mload(o), mask)))))
            o := add(o, 0x20)
            mstore(o, xor(mload(o), shr(1, and(mload(0x20), and(mload(o), mask)))))
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is prefixed with "0x" and encoded using 2 hexadecimal digits per byte.
    function toHexString(address value) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(value);
        /// @solidity memory-safe-assembly
        assembly {
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(str, 0x3078) // Write the "0x" prefix.
            str := sub(str, 2) // Move the pointer.
            mstore(str, strLength) // Write the length.
        }
    }

    /// @dev Returns the hexadecimal representation of `value`.
    /// The output is encoded using 2 hexadecimal digits per byte.
    function toHexStringNoPrefix(address value) internal pure returns (string memory str) {
        /// @solidity memory-safe-assembly
        assembly {
            str := mload(0x40)

            // Allocate the memory.
            // We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
            // 0x02 bytes for the prefix, and 0x28 bytes for the digits.
            // The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x28) is 0x80.
            mstore(0x40, add(str, 0x80))

            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            str := add(str, 2)
            mstore(str, 40)

            let o := add(str, 0x20)
            mstore(add(o, 40), 0)

            value := shl(96, value)

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            for { let i := 0 } 1 {} {
                let p := add(o, add(i, i))
                let temp := byte(i, value)
                mstore8(add(p, 1), mload(and(temp, 15)))
                mstore8(p, mload(shr(4, temp)))
                i := add(i, 1)
                if eq(i, 20) { break }
            }
        }
    }

    /// @dev Returns the hex encoded string from the raw bytes.
    /// The output is encoded using 2 hexadecimal digits per byte.
    function toHexString(bytes memory raw) internal pure returns (string memory str) {
        str = toHexStringNoPrefix(raw);
        /// @solidity memory-safe-assembly
        assembly {
            let strLength := add(mload(str), 2) // Compute the length.
            mstore(str, 0x3078) // Write the "0x" prefix.
            str := sub(str, 2) // Move the pointer.
            mstore(str, strLength) // Write the length.
        }
    }

    /// @dev Returns the hex encoded string from the raw bytes.
    /// The output is encoded using 2 hexadecimal digits per byte.
    function toHexStringNoPrefix(bytes memory raw) internal pure returns (string memory str) {
        /// @solidity memory-safe-assembly
        assembly {
            let length := mload(raw)
            str := add(mload(0x40), 2) // Skip 2 bytes for the optional prefix.
            mstore(str, add(length, length)) // Store the length of the output.

            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            let o := add(str, 0x20)
            let end := add(raw, length)

            for {} iszero(eq(raw, end)) {} {
                raw := add(raw, 1)
                mstore8(add(o, 1), mload(and(mload(raw), 15)))
                mstore8(o, mload(and(shr(4, mload(raw)), 15)))
                o := add(o, 2)
            }
            mstore(o, 0) // Zeroize the slot after the string.
            mstore(0x40, add(o, 0x20)) // Allocate the memory.
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   RUNE STRING OPERATIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Returns the number of UTF characters in the string.
    function runeCount(string memory s) internal pure returns (uint256 result) {
        /// @solidity memory-safe-assembly
        assembly {
            if mload(s) {
                mstore(0x00, div(not(0), 255))
                mstore(0x20, 0x0202020202020202020202020202020202020202020202020303030304040506)
                let o := add(s, 0x20)
                let end := add(o, mload(s))
                for { result := 1 } 1 { result := add(result, 1) } {
                    o := add(o, byte(0, mload(shr(250, mload(o)))))
                    if iszero(lt(o, end)) { break }
                }
            }
        }
    }

    /// @dev Returns if this string is a 7-bit ASCII string.
    /// (i.e. all characters codes are in [0..127])
    function is7BitASCII(string memory s) internal pure returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            let mask := shl(7, div(not(0), 255))
            result := 1
            let n := mload(s)
            if n {
                let o := add(s, 0x20)
                let end := add(o, n)
                let last := mload(end)
                mstore(end, 0)
                for {} 1 {} {
                    if and(mask, mload(o)) {
                        result := 0
                        break
                    }
                    o := add(o, 0x20)
                    if iszero(lt(o, end)) { break }
                }
                mstore(end, last)
            }
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   BYTE STRING OPERATIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    // For performance and bytecode compactness, byte string operations are restricted
    // to 7-bit ASCII strings. All offsets are byte offsets, not UTF character offsets.
    // Usage of byte string operations on charsets with runes spanning two or more bytes
    // can lead to undefined behavior.

    /// @dev Returns `subject` all occurrences of `search` replaced with `replacement`.
    function replace(string memory subject, string memory search, string memory replacement)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let subjectLength := mload(subject)
            let searchLength := mload(search)
            let replacementLength := mload(replacement)

            subject := add(subject, 0x20)
            search := add(search, 0x20)
            replacement := add(replacement, 0x20)
            result := add(mload(0x40), 0x20)

            let subjectEnd := add(subject, subjectLength)
            if iszero(gt(searchLength, subjectLength)) {
                let subjectSearchEnd := add(sub(subjectEnd, searchLength), 1)
                let h := 0
                if iszero(lt(searchLength, 0x20)) { h := keccak256(search, searchLength) }
                let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
                let s := mload(search)
                for {} 1 {} {
                    let t := mload(subject)
                    // Whether the first `searchLength % 32` bytes of
                    // `subject` and `search` matches.
                    if iszero(shr(m, xor(t, s))) {
                        if h {
                            if iszero(eq(keccak256(subject, searchLength), h)) {
                                mstore(result, t)
                                result := add(result, 1)
                                subject := add(subject, 1)
                                if iszero(lt(subject, subjectSearchEnd)) { break }
                                continue
                            }
                        }
                        // Copy the `replacement` one word at a time.
                        for { let o := 0 } 1 {} {
                            mstore(add(result, o), mload(add(replacement, o)))
                            o := add(o, 0x20)
                            if iszero(lt(o, replacementLength)) { break }
                        }
                        result := add(result, replacementLength)
                        subject := add(subject, searchLength)
                        if searchLength {
                            if iszero(lt(subject, subjectSearchEnd)) { break }
                            continue
                        }
                    }
                    mstore(result, t)
                    result := add(result, 1)
                    subject := add(subject, 1)
                    if iszero(lt(subject, subjectSearchEnd)) { break }
                }
            }

            let resultRemainder := result
            result := add(mload(0x40), 0x20)
            let k := add(sub(resultRemainder, result), sub(subjectEnd, subject))
            // Copy the rest of the string one word at a time.
            for {} lt(subject, subjectEnd) {} {
                mstore(resultRemainder, mload(subject))
                resultRemainder := add(resultRemainder, 0x20)
                subject := add(subject, 0x20)
            }
            result := sub(result, 0x20)
            let last := add(add(result, 0x20), k) // Zeroize the slot after the string.
            mstore(last, 0)
            mstore(0x40, add(last, 0x20)) // Allocate the memory.
            mstore(result, k) // Store the length.
        }
    }

    /// @dev Returns the byte index of the first location of `search` in `subject`,
    /// searching from left to right, starting from `from`.
    /// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
    function indexOf(string memory subject, string memory search, uint256 from)
        internal
        pure
        returns (uint256 result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            for { let subjectLength := mload(subject) } 1 {} {
                if iszero(mload(search)) {
                    if iszero(gt(from, subjectLength)) {
                        result := from
                        break
                    }
                    result := subjectLength
                    break
                }
                let searchLength := mload(search)
                let subjectStart := add(subject, 0x20)

                result := not(0) // Initialize to `NOT_FOUND`.

                subject := add(subjectStart, from)
                let end := add(sub(add(subjectStart, subjectLength), searchLength), 1)

                let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
                let s := mload(add(search, 0x20))

                if iszero(and(lt(subject, end), lt(from, subjectLength))) { break }

                if iszero(lt(searchLength, 0x20)) {
                    for { let h := keccak256(add(search, 0x20), searchLength) } 1 {} {
                        if iszero(shr(m, xor(mload(subject), s))) {
                            if eq(keccak256(subject, searchLength), h) {
                                result := sub(subject, subjectStart)
                                break
                            }
                        }
                        subject := add(subject, 1)
                        if iszero(lt(subject, end)) { break }
                    }
                    break
                }
                for {} 1 {} {
                    if iszero(shr(m, xor(mload(subject), s))) {
                        result := sub(subject, subjectStart)
                        break
                    }
                    subject := add(subject, 1)
                    if iszero(lt(subject, end)) { break }
                }
                break
            }
        }
    }

    /// @dev Returns the byte index of the first location of `search` in `subject`,
    /// searching from left to right.
    /// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
    function indexOf(string memory subject, string memory search)
        internal
        pure
        returns (uint256 result)
    {
        result = indexOf(subject, search, 0);
    }

    /// @dev Returns the byte index of the first location of `search` in `subject`,
    /// searching from right to left, starting from `from`.
    /// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
    function lastIndexOf(string memory subject, string memory search, uint256 from)
        internal
        pure
        returns (uint256 result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            for {} 1 {} {
                result := not(0) // Initialize to `NOT_FOUND`.
                let searchLength := mload(search)
                if gt(searchLength, mload(subject)) { break }
                let w := result

                let fromMax := sub(mload(subject), searchLength)
                if iszero(gt(fromMax, from)) { from := fromMax }

                let end := add(add(subject, 0x20), w)
                subject := add(add(subject, 0x20), from)
                if iszero(gt(subject, end)) { break }
                // As this function is not too often used,
                // we shall simply use keccak256 for smaller bytecode size.
                for { let h := keccak256(add(search, 0x20), searchLength) } 1 {} {
                    if eq(keccak256(subject, searchLength), h) {
                        result := sub(subject, add(end, 1))
                        break
                    }
                    subject := add(subject, w) // `sub(subject, 1)`.
                    if iszero(gt(subject, end)) { break }
                }
                break
            }
        }
    }

    /// @dev Returns the byte index of the first location of `search` in `subject`,
    /// searching from right to left.
    /// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
    function lastIndexOf(string memory subject, string memory search)
        internal
        pure
        returns (uint256 result)
    {
        result = lastIndexOf(subject, search, uint256(int256(-1)));
    }

    /// @dev Returns true if `search` is found in `subject`, false otherwise.
    function contains(string memory subject, string memory search) internal pure returns (bool) {
        return indexOf(subject, search) != NOT_FOUND;
    }

    /// @dev Returns whether `subject` starts with `search`.
    function startsWith(string memory subject, string memory search)
        internal
        pure
        returns (bool result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let searchLength := mload(search)
            // Just using keccak256 directly is actually cheaper.
            // forgefmt: disable-next-item
            result := and(
                iszero(gt(searchLength, mload(subject))),
                eq(
                    keccak256(add(subject, 0x20), searchLength),
                    keccak256(add(search, 0x20), searchLength)
                )
            )
        }
    }

    /// @dev Returns whether `subject` ends with `search`.
    function endsWith(string memory subject, string memory search)
        internal
        pure
        returns (bool result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let searchLength := mload(search)
            let subjectLength := mload(subject)
            // Whether `search` is not longer than `subject`.
            let withinRange := iszero(gt(searchLength, subjectLength))
            // Just using keccak256 directly is actually cheaper.
            // forgefmt: disable-next-item
            result := and(
                withinRange,
                eq(
                    keccak256(
                        // `subject + 0x20 + max(subjectLength - searchLength, 0)`.
                        add(add(subject, 0x20), mul(withinRange, sub(subjectLength, searchLength))),
                        searchLength
                    ),
                    keccak256(add(search, 0x20), searchLength)
                )
            )
        }
    }

    /// @dev Returns `subject` repeated `times`.
    function repeat(string memory subject, uint256 times)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let subjectLength := mload(subject)
            if iszero(or(iszero(times), iszero(subjectLength))) {
                subject := add(subject, 0x20)
                result := mload(0x40)
                let output := add(result, 0x20)
                for {} 1 {} {
                    // Copy the `subject` one word at a time.
                    for { let o := 0 } 1 {} {
                        mstore(add(output, o), mload(add(subject, o)))
                        o := add(o, 0x20)
                        if iszero(lt(o, subjectLength)) { break }
                    }
                    output := add(output, subjectLength)
                    times := sub(times, 1)
                    if iszero(times) { break }
                }
                mstore(output, 0) // Zeroize the slot after the string.
                let resultLength := sub(output, add(result, 0x20))
                mstore(result, resultLength) // Store the length.
                // Allocate the memory.
                mstore(0x40, add(result, add(resultLength, 0x20)))
            }
        }
    }

    /// @dev Returns a copy of `subject` sliced from `start` to `end` (exclusive).
    /// `start` and `end` are byte offsets.
    function slice(string memory subject, uint256 start, uint256 end)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let subjectLength := mload(subject)
            if iszero(gt(subjectLength, end)) { end := subjectLength }
            if iszero(gt(subjectLength, start)) { start := subjectLength }
            if lt(start, end) {
                result := mload(0x40)
                let resultLength := sub(end, start)
                mstore(result, resultLength)
                subject := add(subject, start)
                let w := not(0x1f)
                // Copy the `subject` one word at a time, backwards.
                for { let o := and(add(resultLength, 0x1f), w) } 1 {} {
                    mstore(add(result, o), mload(add(subject, o)))
                    o := add(o, w) // `sub(o, 0x20)`.
                    if iszero(o) { break }
                }
                // Zeroize the slot after the string.
                mstore(add(add(result, 0x20), resultLength), 0)
                // Allocate memory for the length and the bytes,
                // rounded up to a multiple of 32.
                mstore(0x40, add(result, and(add(resultLength, 0x3f), w)))
            }
        }
    }

    /// @dev Returns a copy of `subject` sliced from `start` to the end of the string.
    /// `start` is a byte offset.
    function slice(string memory subject, uint256 start)
        internal
        pure
        returns (string memory result)
    {
        result = slice(subject, start, uint256(int256(-1)));
    }

    /// @dev Returns all the indices of `search` in `subject`.
    /// The indices are byte offsets.
    function indicesOf(string memory subject, string memory search)
        internal
        pure
        returns (uint256[] memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let subjectLength := mload(subject)
            let searchLength := mload(search)

            if iszero(gt(searchLength, subjectLength)) {
                subject := add(subject, 0x20)
                search := add(search, 0x20)
                result := add(mload(0x40), 0x20)

                let subjectStart := subject
                let subjectSearchEnd := add(sub(add(subject, subjectLength), searchLength), 1)
                let h := 0
                if iszero(lt(searchLength, 0x20)) { h := keccak256(search, searchLength) }
                let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
                let s := mload(search)
                for {} 1 {} {
                    let t := mload(subject)
                    // Whether the first `searchLength % 32` bytes of
                    // `subject` and `search` matches.
                    if iszero(shr(m, xor(t, s))) {
                        if h {
                            if iszero(eq(keccak256(subject, searchLength), h)) {
                                subject := add(subject, 1)
                                if iszero(lt(subject, subjectSearchEnd)) { break }
                                continue
                            }
                        }
                        // Append to `result`.
                        mstore(result, sub(subject, subjectStart))
                        result := add(result, 0x20)
                        // Advance `subject` by `searchLength`.
                        subject := add(subject, searchLength)
                        if searchLength {
                            if iszero(lt(subject, subjectSearchEnd)) { break }
                            continue
                        }
                    }
                    subject := add(subject, 1)
                    if iszero(lt(subject, subjectSearchEnd)) { break }
                }
                let resultEnd := result
                // Assign `result` to the free memory pointer.
                result := mload(0x40)
                // Store the length of `result`.
                mstore(result, shr(5, sub(resultEnd, add(result, 0x20))))
                // Allocate memory for result.
                // We allocate one more word, so this array can be recycled for {split}.
                mstore(0x40, add(resultEnd, 0x20))
            }
        }
    }

    /// @dev Returns a arrays of strings based on the `delimiter` inside of the `subject` string.
    function split(string memory subject, string memory delimiter)
        internal
        pure
        returns (string[] memory result)
    {
        uint256[] memory indices = indicesOf(subject, delimiter);
        /// @solidity memory-safe-assembly
        assembly {
            let w := not(0x1f)
            let indexPtr := add(indices, 0x20)
            let indicesEnd := add(indexPtr, shl(5, add(mload(indices), 1)))
            mstore(add(indicesEnd, w), mload(subject))
            mstore(indices, add(mload(indices), 1))
            let prevIndex := 0
            for {} 1 {} {
                let index := mload(indexPtr)
                mstore(indexPtr, 0x60)
                if iszero(eq(index, prevIndex)) {
                    let element := mload(0x40)
                    let elementLength := sub(index, prevIndex)
                    mstore(element, elementLength)
                    // Copy the `subject` one word at a time, backwards.
                    for { let o := and(add(elementLength, 0x1f), w) } 1 {} {
                        mstore(add(element, o), mload(add(add(subject, prevIndex), o)))
                        o := add(o, w) // `sub(o, 0x20)`.
                        if iszero(o) { break }
                    }
                    // Zeroize the slot after the string.
                    mstore(add(add(element, 0x20), elementLength), 0)
                    // Allocate memory for the length and the bytes,
                    // rounded up to a multiple of 32.
                    mstore(0x40, add(element, and(add(elementLength, 0x3f), w)))
                    // Store the `element` into the array.
                    mstore(indexPtr, element)
                }
                prevIndex := add(index, mload(delimiter))
                indexPtr := add(indexPtr, 0x20)
                if iszero(lt(indexPtr, indicesEnd)) { break }
            }
            result := indices
            if iszero(mload(delimiter)) {
                result := add(indices, 0x20)
                mstore(result, sub(mload(indices), 2))
            }
        }
    }

    /// @dev Returns a concatenated string of `a` and `b`.
    /// Cheaper than `string.concat()` and does not de-align the free memory pointer.
    function concat(string memory a, string memory b)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let w := not(0x1f)
            result := mload(0x40)
            let aLength := mload(a)
            // Copy `a` one word at a time, backwards.
            for { let o := and(add(aLength, 0x20), w) } 1 {} {
                mstore(add(result, o), mload(add(a, o)))
                o := add(o, w) // `sub(o, 0x20)`.
                if iszero(o) { break }
            }
            let bLength := mload(b)
            let output := add(result, aLength)
            // Copy `b` one word at a time, backwards.
            for { let o := and(add(bLength, 0x20), w) } 1 {} {
                mstore(add(output, o), mload(add(b, o)))
                o := add(o, w) // `sub(o, 0x20)`.
                if iszero(o) { break }
            }
            let totalLength := add(aLength, bLength)
            let last := add(add(result, 0x20), totalLength)
            // Zeroize the slot after the string.
            mstore(last, 0)
            // Stores the length.
            mstore(result, totalLength)
            // Allocate memory for the length and the bytes,
            // rounded up to a multiple of 32.
            mstore(0x40, and(add(last, 0x1f), w))
        }
    }

    /// @dev Returns a copy of the string in either lowercase or UPPERCASE.
    /// WARNING! This function is only compatible with 7-bit ASCII strings.
    function toCase(string memory subject, bool toUpper)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let length := mload(subject)
            if length {
                result := add(mload(0x40), 0x20)
                subject := add(subject, 1)
                let flags := shl(add(70, shl(5, toUpper)), 0x3ffffff)
                let w := not(0)
                for { let o := length } 1 {} {
                    o := add(o, w)
                    let b := and(0xff, mload(add(subject, o)))
                    mstore8(add(result, o), xor(b, and(shr(b, flags), 0x20)))
                    if iszero(o) { break }
                }
                result := mload(0x40)
                mstore(result, length) // Store the length.
                let last := add(add(result, 0x20), length)
                mstore(last, 0) // Zeroize the slot after the string.
                mstore(0x40, add(last, 0x20)) // Allocate the memory.
            }
        }
    }

    /// @dev Returns a string from a small bytes32 string.
    /// `s` must be null-terminated, or behavior will be undefined.
    function fromSmallString(bytes32 s) internal pure returns (string memory result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := mload(0x40)
            let n := 0
            for {} byte(n, s) { n := add(n, 1) } {} // Scan for '\0'.
            mstore(result, n)
            let o := add(result, 0x20)
            mstore(o, s)
            mstore(add(o, n), 0)
            mstore(0x40, add(result, 0x40))
        }
    }

    /// @dev Returns the small string, with all bytes after the first null byte zeroized.
    function normalizeSmallString(bytes32 s) internal pure returns (bytes32 result) {
        /// @solidity memory-safe-assembly
        assembly {
            for {} byte(result, s) { result := add(result, 1) } {} // Scan for '\0'.
            mstore(0x00, s)
            mstore(result, 0x00)
            result := mload(0x00)
        }
    }

    /// @dev Returns the string as a normalized null-terminated small string.
    function toSmallString(string memory s) internal pure returns (bytes32 result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := mload(s)
            if iszero(lt(result, 33)) {
                mstore(0x00, 0xec92f9a3) // `TooBigForSmallString()`.
                revert(0x1c, 0x04)
            }
            result := shl(shl(3, sub(32, result)), mload(add(s, result)))
        }
    }

    /// @dev Returns a lowercased copy of the string.
    /// WARNING! This function is only compatible with 7-bit ASCII strings.
    function lower(string memory subject) internal pure returns (string memory result) {
        result = toCase(subject, false);
    }

    /// @dev Returns an UPPERCASED copy of the string.
    /// WARNING! This function is only compatible with 7-bit ASCII strings.
    function upper(string memory subject) internal pure returns (string memory result) {
        result = toCase(subject, true);
    }

    /// @dev Escapes the string to be used within HTML tags.
    function escapeHTML(string memory s) internal pure returns (string memory result) {
        /// @solidity memory-safe-assembly
        assembly {
            let end := add(s, mload(s))
            result := add(mload(0x40), 0x20)
            // Store the bytes of the packed offsets and strides into the scratch space.
            // `packed = (stride << 5) | offset`. Max offset is 20. Max stride is 6.
            mstore(0x1f, 0x900094)
            mstore(0x08, 0xc0000000a6ab)
            // Store "&quot;&amp;&#39;&lt;&gt;" into the scratch space.
            mstore(0x00, shl(64, 0x2671756f743b26616d703b262333393b266c743b2667743b))
            for {} iszero(eq(s, end)) {} {
                s := add(s, 1)
                let c := and(mload(s), 0xff)
                // Not in `["\"","'","&","<",">"]`.
                if iszero(and(shl(c, 1), 0x500000c400000000)) {
                    mstore8(result, c)
                    result := add(result, 1)
                    continue
                }
                let t := shr(248, mload(c))
                mstore(result, mload(and(t, 0x1f)))
                result := add(result, shr(5, t))
            }
            let last := result
            mstore(last, 0) // Zeroize the slot after the string.
            result := mload(0x40)
            mstore(result, sub(last, add(result, 0x20))) // Store the length.
            mstore(0x40, add(last, 0x20)) // Allocate the memory.
        }
    }

    /// @dev Escapes the string to be used within double-quotes in a JSON.
    /// If `addDoubleQuotes` is true, the result will be enclosed in double-quotes.
    function escapeJSON(string memory s, bool addDoubleQuotes)
        internal
        pure
        returns (string memory result)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let end := add(s, mload(s))
            result := add(mload(0x40), 0x20)
            if addDoubleQuotes {
                mstore8(result, 34)
                result := add(1, result)
            }
            // Store "\\u0000" in scratch space.
            // Store "0123456789abcdef" in scratch space.
            // Also, store `{0x08:"b", 0x09:"t", 0x0a:"n", 0x0c:"f", 0x0d:"r"}`.
            // into the scratch space.
            mstore(0x15, 0x5c75303030303031323334353637383961626364656662746e006672)
            // Bitmask for detecting `["\"","\\"]`.
            let e := or(shl(0x22, 1), shl(0x5c, 1))
            for {} iszero(eq(s, end)) {} {
                s := add(s, 1)
                let c := and(mload(s), 0xff)
                if iszero(lt(c, 0x20)) {
                    if iszero(and(shl(c, 1), e)) {
                        // Not in `["\"","\\"]`.
                        mstore8(result, c)
                        result := add(result, 1)
                        continue
                    }
                    mstore8(result, 0x5c) // "\\".
                    mstore8(add(result, 1), c)
                    result := add(result, 2)
                    continue
                }
                if iszero(and(shl(c, 1), 0x3700)) {
                    // Not in `["\b","\t","\n","\f","\d"]`.
                    mstore8(0x1d, mload(shr(4, c))) // Hex value.
                    mstore8(0x1e, mload(and(c, 15))) // Hex value.
                    mstore(result, mload(0x19)) // "\\u00XX".
                    result := add(result, 6)
                    continue
                }
                mstore8(result, 0x5c) // "\\".
                mstore8(add(result, 1), mload(add(c, 8)))
                result := add(result, 2)
            }
            if addDoubleQuotes {
                mstore8(result, 34)
                result := add(1, result)
            }
            let last := result
            mstore(last, 0) // Zeroize the slot after the string.
            result := mload(0x40)
            mstore(result, sub(last, add(result, 0x20))) // Store the length.
            mstore(0x40, add(last, 0x20)) // Allocate the memory.
        }
    }

    /// @dev Escapes the string to be used within double-quotes in a JSON.
    function escapeJSON(string memory s) internal pure returns (string memory result) {
        result = escapeJSON(s, false);
    }

    /// @dev Returns whether `a` equals `b`.
    function eq(string memory a, string memory b) internal pure returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            result := eq(keccak256(add(a, 0x20), mload(a)), keccak256(add(b, 0x20), mload(b)))
        }
    }

    /// @dev Returns whether `a` equals `b`, where `b` is a null-terminated small string.
    function eqs(string memory a, bytes32 b) internal pure returns (bool result) {
        /// @solidity memory-safe-assembly
        assembly {
            // These should be evaluated on compile time, as far as possible.
            let m := not(shl(7, div(not(iszero(b)), 255))) // `0x7f7f ...`.
            let x := not(or(m, or(b, add(m, and(b, m)))))
            let r := shl(7, iszero(iszero(shr(128, x))))
            r := or(r, shl(6, iszero(iszero(shr(64, shr(r, x))))))
            r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
            r := or(r, shl(4, lt(0xffff, shr(r, x))))
            r := or(r, shl(3, lt(0xff, shr(r, x))))
            // forgefmt: disable-next-item
            result := gt(eq(mload(a), add(iszero(x), xor(31, shr(3, r)))),
                xor(shr(add(8, r), b), shr(add(8, r), mload(add(a, 0x20)))))
        }
    }

    /// @dev Packs a single string with its length into a single word.
    /// Returns `bytes32(0)` if the length is zero or greater than 31.
    function packOne(string memory a) internal pure returns (bytes32 result) {
        /// @solidity memory-safe-assembly
        assembly {
            // We don't need to zero right pad the string,
            // since this is our own custom non-standard packing scheme.
            result :=
                mul(
                    // Load the length and the bytes.
                    mload(add(a, 0x1f)),
                    // `length != 0 && length < 32`. Abuses underflow.
                    // Assumes that the length is valid and within the block gas limit.
                    lt(sub(mload(a), 1), 0x1f)
                )
        }
    }

    /// @dev Unpacks a string packed using {packOne}.
    /// Returns the empty string if `packed` is `bytes32(0)`.
    /// If `packed` is not an output of {packOne}, the output behavior is undefined.
    function unpackOne(bytes32 packed) internal pure returns (string memory result) {
        /// @solidity memory-safe-assembly
        assembly {
            // Grab the free memory pointer.
            result := mload(0x40)
            // Allocate 2 words (1 for the length, 1 for the bytes).
            mstore(0x40, add(result, 0x40))
            // Zeroize the length slot.
            mstore(result, 0)
            // Store the length and bytes.
            mstore(add(result, 0x1f), packed)
            // Right pad with zeroes.
            mstore(add(add(result, 0x20), mload(result)), 0)
        }
    }

    /// @dev Packs two strings with their lengths into a single word.
    /// Returns `bytes32(0)` if combined length is zero or greater than 30.
    function packTwo(string memory a, string memory b) internal pure returns (bytes32 result) {
        /// @solidity memory-safe-assembly
        assembly {
            let aLength := mload(a)
            // We don't need to zero right pad the strings,
            // since this is our own custom non-standard packing scheme.
            result :=
                mul(
                    // Load the length and the bytes of `a` and `b`.
                    or(
                        shl(shl(3, sub(0x1f, aLength)), mload(add(a, aLength))),
                        mload(sub(add(b, 0x1e), aLength))
                    ),
                    // `totalLength != 0 && totalLength < 31`. Abuses underflow.
                    // Assumes that the leng...

// [truncated — 51931 bytes total]

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { MerkleTrie } from "./MerkleTrie.sol";

/// @title SecureMerkleTrie
/// @notice SecureMerkleTrie is a thin wrapper around the MerkleTrie library that hashes the input
///         keys. Ethereum's state trie hashes input keys before storing them.
library SecureMerkleTrie {
    /// @notice Verifies a proof that a given key/value pair is present in the Merkle trie.
    /// @param _key   Key of the node to search for, as a hex string.
    /// @param _value Value of the node to search for, as a hex string.
    /// @param _proof Merkle trie inclusion proof for the desired node. Unlike traditional Merkle
    ///               trees, this proof is executed top-down and consists of a list of RLP-encoded
    ///               nodes that make a path down to the target node.
    /// @param _root  Known root of the Merkle trie. Used to verify that the included proof is
    ///               correctly constructed.
    /// @return valid_ Whether or not the proof is valid.
    function verifyInclusionProof(
        bytes memory _key,
        bytes memory _value,
        bytes[] memory _proof,
        bytes32 _root
    )
        internal
        pure
        returns (bool valid_)
    {
        bytes memory key = _getSecureKey(_key);
        valid_ = MerkleTrie.verifyInclusionProof(key, _value, _proof, _root);
    }

    /// @notice Retrieves the value associated with a given key.
    /// @param _key   Key to search for, as hex bytes.
    /// @param _proof Merkle trie inclusion proof for the key.
    /// @param _root  Known root of the Merkle trie.
    /// @return value_ Value of the key if it exists.
    function get(bytes memory _key, bytes[] memory _proof, bytes32 _root) internal pure returns (bytes memory value_) {
        bytes memory key = _getSecureKey(_key);
        value_ = MerkleTrie.get(key, _proof, _root);
    }

    /// @notice Computes the hashed version of the input key.
    /// @param _key Key to hash.
    /// @return hash_ Hashed version of the key.
    function _getSecureKey(bytes memory _key) private pure returns (bytes memory hash_) {
        hash_ = abi.encodePacked(keccak256(_key));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/FixedPointMathLib.sol)
library FixedPointMathLib {
    /*//////////////////////////////////////////////////////////////
                    SIMPLIFIED FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.

    function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
    }

    function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
    }

    function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
    }

    function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
    }

    function powWad(int256 x, int256 y) internal pure returns (int256) {
        // Equivalent to x to the power of y because x ** y = (e ** ln(x)) ** y = e ** (ln(x) * y)
        return expWad((lnWad(x) * y) / int256(WAD)); // Using ln(x) means x must be greater than 0.
    }

    function expWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            // When the result is < 0.5 we return zero. This happens when
            // x <= floor(log(0.5e18) * 1e18) ~ -42e18
            if (x <= -42139678854452767551) return 0;

            // When the result is > (2**255 - 1) / 1e18 we can not represent it as an
            // int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
            if (x >= 135305999368893231589) revert("EXP_OVERFLOW");

            // x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
            // for more intermediate precision and a binary basis. This base conversion
            // is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
            x = (x << 78) / 5**18;

            // Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
            // of two such that exp(x) = exp(x') * 2**k, where k is an integer.
            // Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
            int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
            x = x - k * 54916777467707473351141471128;

            // k is in the range [-61, 195].

            // Evaluate using a (6, 7)-term rational approximation.
            // p is made monic, we'll multiply by a scale factor later.
            int256 y = x + 1346386616545796478920950773328;
            y = ((y * x) >> 96) + 57155421227552351082224309758442;
            int256 p = y + x - 94201549194550492254356042504812;
            p = ((p * y) >> 96) + 28719021644029726153956944680412240;
            p = p * x + (4385272521454847904659076985693276 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            int256 q = x - 2855989394907223263936484059900;
            q = ((q * x) >> 96) + 50020603652535783019961831881945;
            q = ((q * x) >> 96) - 533845033583426703283633433725380;
            q = ((q * x) >> 96) + 3604857256930695427073651918091429;
            q = ((q * x) >> 96) - 14423608567350463180887372962807573;
            q = ((q * x) >> 96) + 26449188498355588339934803723976023;

            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial won't have zeros in the domain as all its roots are complex.
                // No scaling is necessary because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r should be in the range (0.09, 0.25) * 2**96.

            // We now need to multiply r by:
            // * the scale factor s = ~6.031367120.
            // * the 2**k factor from the range reduction.
            // * the 1e18 / 2**96 factor for base conversion.
            // We do this all at once, with an intermediate result in 2**213
            // basis, so the final right shift is always by a positive amount.
            r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
        }
    }

    function lnWad(int256 x) internal pure returns (int256 r) {
        unchecked {
            require(x > 0, "UNDEFINED");

            // We want to convert x from 10**18 fixed point to 2**96 fixed point.
            // We do this by multiplying by 2**96 / 10**18. But since
            // ln(x * C) = ln(x) + ln(C), we can simply do nothing here
            // and add ln(2**96 / 10**18) at the end.

            // Reduce range of x to (1, 2) * 2**96
            // ln(2^k * x) = k * ln(2) + ln(x)
            int256 k = int256(log2(uint256(x))) - 96;
            x <<= uint256(159 - k);
            x = int256(uint256(x) >> 159);

            // Evaluate using a (8, 8)-term rational approximation.
            // p is made monic, we will multiply by a scale factor later.
            int256 p = x + 3273285459638523848632254066296;
            p = ((p * x) >> 96) + 24828157081833163892658089445524;
            p = ((p * x) >> 96) + 43456485725739037958740375743393;
            p = ((p * x) >> 96) - 11111509109440967052023855526967;
            p = ((p * x) >> 96) - 45023709667254063763336534515857;
            p = ((p * x) >> 96) - 14706773417378608786704636184526;
            p = p * x - (795164235651350426258249787498 << 96);

            // We leave p in 2**192 basis so we don't need to scale it back up for the division.
            // q is monic by convention.
            int256 q = x + 5573035233440673466300451813936;
            q = ((q * x) >> 96) + 71694874799317883764090561454958;
            q = ((q * x) >> 96) + 283447036172924575727196451306956;
            q = ((q * x) >> 96) + 401686690394027663651624208769553;
            q = ((q * x) >> 96) + 204048457590392012362485061816622;
            q = ((q * x) >> 96) + 31853899698501571402653359427138;
            q = ((q * x) >> 96) + 909429971244387300277376558375;
            assembly {
                // Div in assembly because solidity adds a zero check despite the unchecked.
                // The q polynomial is known not to have zeros in the domain.
                // No scaling required because p is already 2**96 too large.
                r := sdiv(p, q)
            }

            // r is in the range (0, 0.125) * 2**96

            // Finalization, we need to:
            // * multiply by the scale factor s = 5.549…
            // * add ln(2**96 / 10**18)
            // * add k * ln(2)
            // * multiply by 10**18 / 2**96 = 5**18 >> 78

            // mul s * 5e18 * 2**96, base is now 5**18 * 2**192
            r *= 1677202110996718588342820967067443963516166;
            // add ln(2) * k * 5e18 * 2**192
            r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
            // add ln(2**96 / 10**18) * 5e18 * 2**192
            r += 600920179829731861736702779321621459595472258049074101567377883020018308;
            // base conversion: mul 2**18 / 2**192
            r >>= 174;
        }
    }

    /*//////////////////////////////////////////////////////////////
                    LOW LEVEL FIXED POINT OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // Divide z by the denominator.
            z := div(z, denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // First, divide z - 1 by the denominator and add 1.
            // We allow z - 1 to underflow if z is 0, because we multiply the
            // end result by 0 if z is zero, ensuring we return 0 if z is zero.
            z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
        }
    }

    function rpow(
        uint256 x,
        uint256 n,
        uint256 scalar
    ) internal pure returns (uint256 z) {
        assembly {
            switch x
            case 0 {
                switch n
                case 0 {
                    // 0 ** 0 = 1
                    z := scalar
                }
                default {
                    // 0 ** n = 0
                    z := 0
                }
            }
            default {
                switch mod(n, 2)
                case 0 {
                    // If n is even, store scalar in z for now.
                    z := scalar
                }
                default {
                    // If n is odd, store x in z for now.
                    z := x
                }

                // Shifting right by 1 is like dividing by 2.
                let half := shr(1, scalar)

                for {
                    // Shift n right by 1 before looping to halve it.
                    n := shr(1, n)
                } n {
                    // Shift n right by 1 each iteration to halve it.
                    n := shr(1, n)
                } {
                    // Revert immediately if x ** 2 would overflow.
                    // Equivalent to iszero(eq(div(xx, x), x)) here.
                    if shr(128, x) {
                        revert(0, 0)
                    }

                    // Store x squared.
                    let xx := mul(x, x)

                    // Round to the nearest number.
                    let xxRound := add(xx, half)

                    // Revert if xx + half overflowed.
                    if lt(xxRound, xx) {
                        revert(0, 0)
                    }

                    // Set x to scaled xxRound.
                    x := div(xxRound, scalar)

                    // If n is even:
                    if mod(n, 2) {
                        // Compute z * x.
                        let zx := mul(z, x)

                        // If z * x overflowed:
                        if iszero(eq(div(zx, x), z)) {
                            // Revert if x is non-zero.
                            if iszero(iszero(x)) {
                                revert(0, 0)
                            }
                        }

                        // Round to the nearest number.
                        let zxRound := add(zx, half)

                        // Revert if zx + half overflowed.
                        if lt(zxRound, zx) {
                            revert(0, 0)
                        }

                        // Return properly scaled zxRound.
                        z := div(zxRound, scalar)
                    }
                }
            }
        }
    }

    /*//////////////////////////////////////////////////////////////
                        GENERAL NUMBER UTILITIES
    //////////////////////////////////////////////////////////////*/

    function sqrt(uint256 x) internal pure returns (uint256 z) {
        assembly {
            let y := x // We start y at x, which will help us make our initial estimate.

            z := 181 // The "correct" value is 1, but this saves a multiplication later.

            // This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
            // start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.

            // We check y >= 2^(k + 8) but shift right by k bits
            // each branch to ensure that if x >= 256, then y >= 256.
            if iszero(lt(y, 0x10000000000000000000000000000000000)) {
                y := shr(128, y)
                z := shl(64, z)
            }
            if iszero(lt(y, 0x1000000000000000000)) {
                y := shr(64, y)
                z := shl(32, z)
            }
            if iszero(lt(y, 0x10000000000)) {
                y := shr(32, y)
                z := shl(16, z)
            }
            if iszero(lt(y, 0x1000000)) {
                y := shr(16, y)
                z := shl(8, z)
            }

            // Goal was to get z*z*y within a small factor of x. More iterations could
            // get y in a tighter range. Currently, we will have y in [256, 256*2^16).
            // We ensured y >= 256 so that the relative difference between y and y+1 is small.
            // That's not possible if x < 256 but we can just verify those cases exhaustively.

            // Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
            // Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
            // Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.

            // For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
            // (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.

            // Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
            // sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.

            // There is no overflow risk here since y < 2^136 after the first branch above.
            z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.

            // Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))
            z := shr(1, add(z, div(x, z)))

            // If x+1 is a perfect square, the Babylonian method cycles between
            // floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
            // See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
            // Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
            // If you don't care whether the floor or ceil square root is returned, you can remove this statement.
            z := sub(z, lt(div(x, z), z))
        }
    }

    function log2(uint256 x) internal pure returns (uint256 r) {
        require(x > 0, "UNDEFINED");

        assembly {
            r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
            r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
            r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
            r := or(r, shl(4, lt(0xffff, shr(r, x))))
            r := or(r, shl(3, lt(0xff, shr(r, x))))
            r := or(r, shl(2, lt(0xf, shr(r, x))))
            r := or(r, shl(1, lt(0x3, shr(r, x))))
            r := or(r, lt(0x1, shr(r, x)))
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. It the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`.
        // We also know that `k`, the position of the most significant bit, is such that `msb(a) = 2**k`.
        // This gives `2**k < a <= 2**(k+1)` → `2**(k/2) <= sqrt(a) < 2 ** (k/2+1)`.
        // Using an algorithm similar to the msb conmputation, we are able to compute `result = 2**(k/2)` which is a
        // good first aproximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1;
        uint256 x = a;
        if (x >> 128 > 0) {
            x >>= 128;
            result <<= 64;
        }
        if (x >> 64 > 0) {
            x >>= 64;
            result <<= 32;
        }
        if (x >> 32 > 0) {
            x >>= 32;
            result <<= 16;
        }
        if (x >> 16 > 0) {
            x >>= 16;
            result <<= 8;
        }
        if (x >> 8 > 0) {
            x >>= 8;
            result <<= 4;
        }
        if (x >> 4 > 0) {
            x >>= 4;
            result <<= 2;
        }
        if (x >> 2 > 0) {
            result <<= 1;
        }

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        uint256 result = sqrt(a);
        if (rounding == Rounding.Up && result * result < a) {
            result += 1;
        }
        return result;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/Address.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!Address.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}