Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.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.
 *
 * The initial owner is set to the address provided by the deployer. 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 Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (access/Ownable2Step.sol)

pragma solidity ^0.8.20;

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

/**
 * @dev Contract module which provides access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * This extension of the {Ownable} contract includes a two-step mechanism to transfer
 * ownership, where the new owner must call {acceptOwnership} in order to replace the
 * old one. This can help prevent common mistakes, such as transfers of ownership to
 * incorrect accounts, or to contracts that are unable to interact with the
 * permission system.
 *
 * The initial owner is specified at deployment time in the constructor for `Ownable`. This
 * can later be changed with {transferOwnership} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2Step is Ownable {
    address private _pendingOwner;

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

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

    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     *
     * Setting `newOwner` to the zero address is allowed; this can be used to cancel an initiated ownership transfer.
     */
    function transferOwnership(address newOwner) public virtual override onlyOwner {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }

    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() public virtual {
        address sender = _msgSender();
        if (pendingOwner() != sender) {
            revert OwnableUnauthorizedAccount(sender);
        }
        _transferOwnership(sender);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

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

/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @author Permit2 operations from (https://github.com/Uniswap/permit2/blob/main/src/libraries/Permit2Lib.sol)
///
/// @dev Note:
/// - For ETH transfers, please use `forceSafeTransferETH` for DoS protection.
library SafeTransferLib {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       CUSTOM ERRORS                        */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The ETH transfer has failed.
    error ETHTransferFailed();

    /// @dev The ERC20 `transferFrom` has failed.
    error TransferFromFailed();

    /// @dev The ERC20 `transfer` has failed.
    error TransferFailed();

    /// @dev The ERC20 `approve` has failed.
    error ApproveFailed();

    /// @dev The ERC20 `totalSupply` query has failed.
    error TotalSupplyQueryFailed();

    /// @dev The Permit2 operation has failed.
    error Permit2Failed();

    /// @dev The Permit2 amount must be less than `2**160 - 1`.
    error Permit2AmountOverflow();

    /// @dev The Permit2 approve operation has failed.
    error Permit2ApproveFailed();

    /// @dev The Permit2 lockdown operation has failed.
    error Permit2LockdownFailed();

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

    /// @dev Suggested gas stipend for contract receiving ETH that disallows any storage writes.
    uint256 internal constant GAS_STIPEND_NO_STORAGE_WRITES = 2300;

    /// @dev Suggested gas stipend for contract receiving ETH to perform a few
    /// storage reads and writes, but low enough to prevent griefing.
    uint256 internal constant GAS_STIPEND_NO_GRIEF = 100000;

    /// @dev The unique EIP-712 domain separator for the DAI token contract.
    bytes32 internal constant DAI_DOMAIN_SEPARATOR =
        0xdbb8cf42e1ecb028be3f3dbc922e1d878b963f411dc388ced501601c60f7c6f7;

    /// @dev The address for the WETH9 contract on Ethereum mainnet.
    address internal constant WETH9 = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;

    /// @dev The canonical Permit2 address.
    /// [Github](https://github.com/Uniswap/permit2)
    /// [Etherscan](https://etherscan.io/address/0x000000000022D473030F116dDEE9F6B43aC78BA3)
    address internal constant PERMIT2 = 0x000000000022D473030F116dDEE9F6B43aC78BA3;

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

    // If the ETH transfer MUST succeed with a reasonable gas budget, use the force variants.
    //
    // The regular variants:
    // - Forwards all remaining gas to the target.
    // - Reverts if the target reverts.
    // - Reverts if the current contract has insufficient balance.
    //
    // The force variants:
    // - Forwards with an optional gas stipend
    //   (defaults to `GAS_STIPEND_NO_GRIEF`, which is sufficient for most cases).
    // - If the target reverts, or if the gas stipend is exhausted,
    //   creates a temporary contract to force send the ETH via `SELFDESTRUCT`.
    //   Future compatible with `SENDALL`: https://eips.ethereum.org/EIPS/eip-4758.
    // - Reverts if the current contract has insufficient balance.
    //
    // The try variants:
    // - Forwards with a mandatory gas stipend.
    // - Instead of reverting, returns whether the transfer succeeded.

    /// @dev Sends `amount` (in wei) ETH to `to`.
    function safeTransferETH(address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(call(gas(), to, amount, codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Sends all the ETH in the current contract to `to`.
    function safeTransferAllETH(address to) internal {
        /// @solidity memory-safe-assembly
        assembly {
            // Transfer all the ETH and check if it succeeded or not.
            if iszero(call(gas(), to, selfbalance(), codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Force sends `amount` (in wei) ETH to `to`, with a `gasStipend`.
    function forceSafeTransferETH(address to, uint256 amount, uint256 gasStipend) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if lt(selfbalance(), amount) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
            if iszero(call(gasStipend, to, amount, codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(amount, 0x0b, 0x16)) { revert(codesize(), codesize()) } // For gas estimation.
            }
        }
    }

    /// @dev Force sends all the ETH in the current contract to `to`, with a `gasStipend`.
    function forceSafeTransferAllETH(address to, uint256 gasStipend) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(call(gasStipend, to, selfbalance(), codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(selfbalance(), 0x0b, 0x16)) { revert(codesize(), codesize()) } // For gas estimation.
            }
        }
    }

    /// @dev Force sends `amount` (in wei) ETH to `to`, with `GAS_STIPEND_NO_GRIEF`.
    function forceSafeTransferETH(address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if lt(selfbalance(), amount) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
            if iszero(call(GAS_STIPEND_NO_GRIEF, to, amount, codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(amount, 0x0b, 0x16)) { revert(codesize(), codesize()) } // For gas estimation.
            }
        }
    }

    /// @dev Force sends all the ETH in the current contract to `to`, with `GAS_STIPEND_NO_GRIEF`.
    function forceSafeTransferAllETH(address to) internal {
        /// @solidity memory-safe-assembly
        assembly {
            // forgefmt: disable-next-item
            if iszero(call(GAS_STIPEND_NO_GRIEF, to, selfbalance(), codesize(), 0x00, codesize(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(selfbalance(), 0x0b, 0x16)) { revert(codesize(), codesize()) } // For gas estimation.
            }
        }
    }

    /// @dev Sends `amount` (in wei) ETH to `to`, with a `gasStipend`.
    function trySafeTransferETH(address to, uint256 amount, uint256 gasStipend)
        internal
        returns (bool success)
    {
        /// @solidity memory-safe-assembly
        assembly {
            success := call(gasStipend, to, amount, codesize(), 0x00, codesize(), 0x00)
        }
    }

    /// @dev Sends all the ETH in the current contract to `to`, with a `gasStipend`.
    function trySafeTransferAllETH(address to, uint256 gasStipend)
        internal
        returns (bool success)
    {
        /// @solidity memory-safe-assembly
        assembly {
            success := call(gasStipend, to, selfbalance(), codesize(), 0x00, codesize(), 0x00)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                      ERC20 OPERATIONS                      */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Sends `amount` of ERC20 `token` from `from` to `to`.
    /// Reverts upon failure.
    ///
    /// The `from` account must have at least `amount` approved for
    /// the current contract to manage.
    function safeTransferFrom(address token, address from, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Cache the free memory pointer.
            mstore(0x60, amount) // Store the `amount` argument.
            mstore(0x40, to) // Store the `to` argument.
            mstore(0x2c, shl(96, from)) // Store the `from` argument.
            mstore(0x0c, 0x23b872dd000000000000000000000000) // `transferFrom(address,address,uint256)`.
            let success := call(gas(), token, 0, 0x1c, 0x64, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x60, 0) // Restore the zero slot to zero.
            mstore(0x40, m) // Restore the free memory pointer.
        }
    }

    /// @dev Sends `amount` of ERC20 `token` from `from` to `to`.
    ///
    /// The `from` account must have at least `amount` approved for the current contract to manage.
    function trySafeTransferFrom(address token, address from, address to, uint256 amount)
        internal
        returns (bool success)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Cache the free memory pointer.
            mstore(0x60, amount) // Store the `amount` argument.
            mstore(0x40, to) // Store the `to` argument.
            mstore(0x2c, shl(96, from)) // Store the `from` argument.
            mstore(0x0c, 0x23b872dd000000000000000000000000) // `transferFrom(address,address,uint256)`.
            success := call(gas(), token, 0, 0x1c, 0x64, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                success := lt(or(iszero(extcodesize(token)), returndatasize()), success)
            }
            mstore(0x60, 0) // Restore the zero slot to zero.
            mstore(0x40, m) // Restore the free memory pointer.
        }
    }

    /// @dev Sends all of ERC20 `token` from `from` to `to`.
    /// Reverts upon failure.
    ///
    /// The `from` account must have their entire balance approved for the current contract to manage.
    function safeTransferAllFrom(address token, address from, address to)
        internal
        returns (uint256 amount)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Cache the free memory pointer.
            mstore(0x40, to) // Store the `to` argument.
            mstore(0x2c, shl(96, from)) // Store the `from` argument.
            mstore(0x0c, 0x70a08231000000000000000000000000) // `balanceOf(address)`.
            // Read the balance, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                    staticcall(gas(), token, 0x1c, 0x24, 0x60, 0x20)
                )
            ) {
                mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x00, 0x23b872dd) // `transferFrom(address,address,uint256)`.
            amount := mload(0x60) // The `amount` is already at 0x60. We'll need to return it.
            // Perform the transfer, reverting upon failure.
            let success := call(gas(), token, 0, 0x1c, 0x64, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x60, 0) // Restore the zero slot to zero.
            mstore(0x40, m) // Restore the free memory pointer.
        }
    }

    /// @dev Sends `amount` of ERC20 `token` from the current contract to `to`.
    /// Reverts upon failure.
    function safeTransfer(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0xa9059cbb000000000000000000000000) // `transfer(address,uint256)`.
            // Perform the transfer, reverting upon failure.
            let success := call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sends all of ERC20 `token` from the current contract to `to`.
    /// Reverts upon failure.
    function safeTransferAll(address token, address to) internal returns (uint256 amount) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, 0x70a08231) // Store the function selector of `balanceOf(address)`.
            mstore(0x20, address()) // Store the address of the current contract.
            // Read the balance, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                    staticcall(gas(), token, 0x1c, 0x24, 0x34, 0x20)
                )
            ) {
                mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x14, to) // Store the `to` argument.
            amount := mload(0x34) // The `amount` is already at 0x34. We'll need to return it.
            mstore(0x00, 0xa9059cbb000000000000000000000000) // `transfer(address,uint256)`.
            // Perform the transfer, reverting upon failure.
            let success := call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sets `amount` of ERC20 `token` for `to` to manage on behalf of the current contract.
    /// Reverts upon failure.
    function safeApprove(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
            let success := call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x00, 0x3e3f8f73) // `ApproveFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sets `amount` of ERC20 `token` for `to` to manage on behalf of the current contract.
    /// If the initial attempt to approve fails, attempts to reset the approved amount to zero,
    /// then retries the approval again (some tokens, e.g. USDT, requires this).
    /// Reverts upon failure.
    function safeApproveWithRetry(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
            // Perform the approval, retrying upon failure.
            let success := call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
            if iszero(and(eq(mload(0x00), 1), success)) {
                if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                    mstore(0x34, 0) // Store 0 for the `amount`.
                    mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
                    pop(call(gas(), token, 0, 0x10, 0x44, codesize(), 0x00)) // Reset the approval.
                    mstore(0x34, amount) // Store back the original `amount`.
                    // Retry the approval, reverting upon failure.
                    success := call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                    if iszero(and(eq(mload(0x00), 1), success)) {
                        // Check the `extcodesize` again just in case the token selfdestructs lol.
                        if iszero(lt(or(iszero(extcodesize(token)), returndatasize()), success)) {
                            mstore(0x00, 0x3e3f8f73) // `ApproveFailed()`.
                            revert(0x1c, 0x04)
                        }
                    }
                }
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Returns the amount of ERC20 `token` owned by `account`.
    /// Returns zero if the `token` does not exist.
    function balanceOf(address token, address account) internal view returns (uint256 amount) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, account) // Store the `account` argument.
            mstore(0x00, 0x70a08231000000000000000000000000) // `balanceOf(address)`.
            amount :=
                mul( // The arguments of `mul` are evaluated from right to left.
                    mload(0x20),
                    and( // The arguments of `and` are evaluated from right to left.
                        gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                        staticcall(gas(), token, 0x10, 0x24, 0x20, 0x20)
                    )
                )
        }
    }

    /// @dev Performs a `token.balanceOf(account)` check.
    /// `implemented` denotes whether the `token` does not implement `balanceOf`.
    /// `amount` is zero if the `token` does not implement `balanceOf`.
    function checkBalanceOf(address token, address account)
        internal
        view
        returns (bool implemented, uint256 amount)
    {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, account) // Store the `account` argument.
            mstore(0x00, 0x70a08231000000000000000000000000) // `balanceOf(address)`.
            implemented :=
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                    staticcall(gas(), token, 0x10, 0x24, 0x20, 0x20)
                )
            amount := mul(mload(0x20), implemented)
        }
    }

    /// @dev Returns the total supply of the `token`.
    /// Reverts if the token does not exist or does not implement `totalSupply()`.
    function totalSupply(address token) internal view returns (uint256 result) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, 0x18160ddd) // `totalSupply()`.
            if iszero(
                and(gt(returndatasize(), 0x1f), staticcall(gas(), token, 0x1c, 0x04, 0x00, 0x20))
            ) {
                mstore(0x00, 0x54cd9435) // `TotalSupplyQueryFailed()`.
                revert(0x1c, 0x04)
            }
            result := mload(0x00)
        }
    }

    /// @dev Sends `amount` of ERC20 `token` from `from` to `to`.
    /// If the initial attempt fails, try to use Permit2 to transfer the token.
    /// Reverts upon failure.
    ///
    /// The `from` account must have at least `amount` approved for the current contract to manage.
    function safeTransferFrom2(address token, address from, address to, uint256 amount) internal {
        if (!trySafeTransferFrom(token, from, to, amount)) {
            permit2TransferFrom(token, from, to, amount);
        }
    }

    /// @dev Sends `amount` of ERC20 `token` from `from` to `to` via Permit2.
    /// Reverts upon failure.
    function permit2TransferFrom(address token, address from, address to, uint256 amount)
        internal
    {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40)
            mstore(add(m, 0x74), shr(96, shl(96, token)))
            mstore(add(m, 0x54), amount)
            mstore(add(m, 0x34), to)
            mstore(add(m, 0x20), shl(96, from))
            // `transferFrom(address,address,uint160,address)`.
            mstore(m, 0x36c78516000000000000000000000000)
            let p := PERMIT2
            let exists := eq(chainid(), 1)
            if iszero(exists) { exists := iszero(iszero(extcodesize(p))) }
            if iszero(
                and(
                    call(gas(), p, 0, add(m, 0x10), 0x84, codesize(), 0x00),
                    lt(iszero(extcodesize(token)), exists) // Token has code and Permit2 exists.
                )
            ) {
                mstore(0x00, 0x7939f4248757f0fd) // `TransferFromFailed()` or `Permit2AmountOverflow()`.
                revert(add(0x18, shl(2, iszero(iszero(shr(160, amount))))), 0x04)
            }
        }
    }

    /// @dev Permit a user to spend a given amount of
    /// another user's tokens via native EIP-2612 permit if possible, falling
    /// back to Permit2 if native permit fails or is not implemented on the token.
    function permit2(
        address token,
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        bool success;
        /// @solidity memory-safe-assembly
        assembly {
            for {} shl(96, xor(token, WETH9)) {} {
                mstore(0x00, 0x3644e515) // `DOMAIN_SEPARATOR()`.
                if iszero(
                    and( // The arguments of `and` are evaluated from right to left.
                        lt(iszero(mload(0x00)), eq(returndatasize(), 0x20)), // Returns 1 non-zero word.
                        // Gas stipend to limit gas burn for tokens that don't refund gas when
                        // an non-existing function is called. 5K should be enough for a SLOAD.
                        staticcall(5000, token, 0x1c, 0x04, 0x00, 0x20)
                    )
                ) { break }
                // After here, we can be sure that token is a contract.
                let m := mload(0x40)
                mstore(add(m, 0x34), spender)
                mstore(add(m, 0x20), shl(96, owner))
                mstore(add(m, 0x74), deadline)
                if eq(mload(0x00), DAI_DOMAIN_SEPARATOR) {
                    mstore(0x14, owner)
                    mstore(0x00, 0x7ecebe00000000000000000000000000) // `nonces(address)`.
                    mstore(
                        add(m, 0x94),
                        lt(iszero(amount), staticcall(gas(), token, 0x10, 0x24, add(m, 0x54), 0x20))
                    )
                    mstore(m, 0x8fcbaf0c000000000000000000000000) // `IDAIPermit.permit`.
                    // `nonces` is already at `add(m, 0x54)`.
                    // `amount != 0` is already stored at `add(m, 0x94)`.
                    mstore(add(m, 0xb4), and(0xff, v))
                    mstore(add(m, 0xd4), r)
                    mstore(add(m, 0xf4), s)
                    success := call(gas(), token, 0, add(m, 0x10), 0x104, codesize(), 0x00)
                    break
                }
                mstore(m, 0xd505accf000000000000000000000000) // `IERC20Permit.permit`.
                mstore(add(m, 0x54), amount)
                mstore(add(m, 0x94), and(0xff, v))
                mstore(add(m, 0xb4), r)
                mstore(add(m, 0xd4), s)
                success := call(gas(), token, 0, add(m, 0x10), 0xe4, codesize(), 0x00)
                break
            }
        }
        if (!success) simplePermit2(token, owner, spender, amount, deadline, v, r, s);
    }

    /// @dev Simple permit on the Permit2 contract.
    function simplePermit2(
        address token,
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40)
            mstore(m, 0x927da105) // `allowance(address,address,address)`.
            {
                let addressMask := shr(96, not(0))
                mstore(add(m, 0x20), and(addressMask, owner))
                mstore(add(m, 0x40), and(addressMask, token))
                mstore(add(m, 0x60), and(addressMask, spender))
                mstore(add(m, 0xc0), and(addressMask, spender))
            }
            let p := mul(PERMIT2, iszero(shr(160, amount)))
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x5f), // Returns 3 words: `amount`, `expiration`, `nonce`.
                    staticcall(gas(), p, add(m, 0x1c), 0x64, add(m, 0x60), 0x60)
                )
            ) {
                mstore(0x00, 0x6b836e6b8757f0fd) // `Permit2Failed()` or `Permit2AmountOverflow()`.
                revert(add(0x18, shl(2, iszero(p))), 0x04)
            }
            mstore(m, 0x2b67b570) // `Permit2.permit` (PermitSingle variant).
            // `owner` is already `add(m, 0x20)`.
            // `token` is already at `add(m, 0x40)`.
            mstore(add(m, 0x60), amount)
            mstore(add(m, 0x80), 0xffffffffffff) // `expiration = type(uint48).max`.
            // `nonce` is already at `add(m, 0xa0)`.
            // `spender` is already at `add(m, 0xc0)`.
            mstore(add(m, 0xe0), deadline)
            mstore(add(m, 0x100), 0x100) // `signature` offset.
            mstore(add(m, 0x120), 0x41) // `signature` length.
            mstore(add(m, 0x140), r)
            mstore(add(m, 0x160), s)
            mstore(add(m, 0x180), shl(248, v))
            if iszero( // Revert if token does not have code, or if the call fails.
            mul(extcodesize(token), call(gas(), p, 0, add(m, 0x1c), 0x184, codesize(), 0x00))) {
                mstore(0x00, 0x6b836e6b) // `Permit2Failed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Approves `spender` to spend `amount` of `token` for `address(this)`.
    function permit2Approve(address token, address spender, uint160 amount, uint48 expiration)
        internal
    {
        /// @solidity memory-safe-assembly
        assembly {
            let addressMask := shr(96, not(0))
            let m := mload(0x40)
            mstore(m, 0x87517c45) // `approve(address,address,uint160,uint48)`.
            mstore(add(m, 0x20), and(addressMask, token))
            mstore(add(m, 0x40), and(addressMask, spender))
            mstore(add(m, 0x60), and(addressMask, amount))
            mstore(add(m, 0x80), and(0xffffffffffff, expiration))
            if iszero(call(gas(), PERMIT2, 0, add(m, 0x1c), 0xa0, codesize(), 0x00)) {
                mstore(0x00, 0x324f14ae) // `Permit2ApproveFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Revokes an approval for `token` and `spender` for `address(this)`.
    function permit2Lockdown(address token, address spender) internal {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40)
            mstore(m, 0xcc53287f) // `Permit2.lockdown`.
            mstore(add(m, 0x20), 0x20) // Offset of the `approvals`.
            mstore(add(m, 0x40), 1) // `approvals.length`.
            mstore(add(m, 0x60), shr(96, shl(96, token)))
            mstore(add(m, 0x80), shr(96, shl(96, spender)))
            if iszero(call(gas(), PERMIT2, 0, add(m, 0x1c), 0xa0, codesize(), 0x00)) {
                mstore(0x00, 0x96b3de23) // `Permit2LockdownFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }
}

// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.8.28;

import {Ownable2Step} from "@openzeppelin/contracts/access/Ownable2Step.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeTransferLib} from "solady/utils/SafeTransferLib.sol";

/**
 * @title PaymasterBuffer - A buffer fund manager for paymaster fund settlement.
 * @author David Kim - @PowerStream3604
 */
contract PaymasterBuffer is Ownable2Step {
    event BeneficiaryUpdated(address prevBeneficiary, address newBeneficiary);
    event FlusherUpdated(address prevFlusher, address newFlusher);

    error InvalidFlusher();
    error TokenFlushFailed(address token, address beneficiary, uint256 tokenAmount);
    error ZeroAddressBeneficiary();

    address public beneficiary;
    address public flusher;

    /**
     * @notice Sets the initial Beneficiary, Flusher and Owner of the PaymasterBuffer.
     * @param initialBeneficiary Address of beneficiary.
     * @param initialFlusher Address of flusher.
     * @param owner Address of owner.
     */
    constructor(address initialBeneficiary, address initialFlusher, address owner) Ownable(owner) {
        beneficiary = initialBeneficiary;
        flusher = initialFlusher;
        emit BeneficiaryUpdated(address(0), beneficiary);
        emit FlusherUpdated(address(0), flusher);
    }

    /**
     * @notice Sets the beneficiary of the PaymasterBuffer. Only callable by the Owner.
     * @param newBeneficiary Address of the new beneficiary.
     */
    function setBeneficiary(address newBeneficiary) external onlyOwner {
        address prevBeneficiary = beneficiary;
        beneficiary = newBeneficiary;
        emit BeneficiaryUpdated(prevBeneficiary, beneficiary);
    }

    /**
     * @notice Sets the flusher of the PaymasterBuffer. Only callable by the Owner.
     * @param newFlusher Address of the new flusher.
     */
    function setFlusher(address newFlusher) external onlyOwner {
        address prevFlusher = flusher;
        flusher = newFlusher;
        emit FlusherUpdated(prevFlusher, flusher);
    }

    /**
     * @notice Flush the token balance of PaymasterBuffer to the beneficiary. Only callable by the Flusher.
     * @param tokens List of token addresses to flush the balance.
     */
    function flushTokens(address[] calldata tokens) external {
        if (msg.sender != flusher) revert InvalidFlusher();
        if (beneficiary == address(0)) revert ZeroAddressBeneficiary();
        uint256 tokenLength = tokens.length;
        for (uint256 i; i < tokenLength; ++i) {
            uint256 balance = IERC20(tokens[i]).balanceOf(address(this));
            if (balance != 0) {
                SafeTransferLib.safeTransfer(tokens[i], beneficiary, balance);
            }
        }
    }
}