Forkchoice Ethereum Mainnet

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/draft-IERC6093.sol)
pragma solidity >=0.8.4;

/**
 * @dev Standard ERC-20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a `spender` is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}

/**
 * @dev Standard ERC-721 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-721 tokens.
 */
interface IERC721Errors {
    /**
     * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in ERC-20.
     * Used in balance queries.
     * @param owner Address of the current owner of a token.
     */
    error ERC721InvalidOwner(address owner);

    /**
     * @dev Indicates a `tokenId` whose `owner` is the zero address.
     * @param tokenId Identifier number of a token.
     */
    error ERC721NonexistentToken(uint256 tokenId);

    /**
     * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param tokenId Identifier number of a token.
     * @param owner Address of the current owner of a token.
     */
    error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC721InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC721InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param tokenId Identifier number of a token.
     */
    error ERC721InsufficientApproval(address operator, uint256 tokenId);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC721InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC721InvalidOperator(address operator);
}

/**
 * @dev Standard ERC-1155 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-1155 tokens.
 */
interface IERC1155Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     * @param tokenId Identifier number of a token.
     */
    error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC1155InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC1155InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param owner Address of the current owner of a token.
     */
    error ERC1155MissingApprovalForAll(address operator, address owner);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC1155InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC1155InvalidOperator(address operator);

    /**
     * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
     * Used in batch transfers.
     * @param idsLength Length of the array of token identifiers
     * @param valuesLength Length of the array of token amounts
     */
    error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC1363.sol)

pragma solidity >=0.6.2;

import {IERC20} from "./IERC20.sol";
import {IERC165} from "./IERC165.sol";

/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC165.sol)

pragma solidity >=0.4.16;

import {IERC165} from "../utils/introspection/IERC165.sol";

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC20.sol)

pragma solidity >=0.4.16;

import {IERC20} from "../token/ERC20/IERC20.sol";

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC4626.sol)

pragma solidity >=0.6.2;

import {IERC20} from "../token/ERC20/IERC20.sol";
import {IERC20Metadata} from "../token/ERC20/extensions/IERC20Metadata.sol";

/**
 * @dev Interface of the ERC-4626 "Tokenized Vault Standard", as defined in
 * https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
 */
interface IERC4626 is IERC20, IERC20Metadata {
    event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);

    event Withdraw(
        address indexed sender,
        address indexed receiver,
        address indexed owner,
        uint256 assets,
        uint256 shares
    );

    /**
     * @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
     *
     * - MUST be an ERC-20 token contract.
     * - MUST NOT revert.
     */
    function asset() external view returns (address assetTokenAddress);

    /**
     * @dev Returns the total amount of the underlying asset that is “managed” by Vault.
     *
     * - SHOULD include any compounding that occurs from yield.
     * - MUST be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT revert.
     */
    function totalAssets() external view returns (uint256 totalManagedAssets);

    /**
     * @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToShares(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToAssets(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
     * through a deposit call.
     *
     * - MUST return a limited value if receiver is subject to some deposit limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
     * - MUST NOT revert.
     */
    function maxDeposit(address receiver) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
     *   call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
     *   in the same transaction.
     * - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
     *   deposit would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewDeposit(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   deposit execution, and are accounted for during deposit.
     * - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function deposit(uint256 assets, address receiver) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
     * - MUST return a limited value if receiver is subject to some mint limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
     * - MUST NOT revert.
     */
    function maxMint(address receiver) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
     *   in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
     *   same transaction.
     * - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
     *   would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by minting.
     */
    function previewMint(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
     *   execution, and are accounted for during mint.
     * - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function mint(uint256 shares, address receiver) external returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
     * Vault, through a withdraw call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxWithdraw(address owner) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
     *   call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
     *   called
     *   in the same transaction.
     * - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
     *   the withdrawal would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewWithdraw(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   withdraw execution, and are accounted for during withdraw.
     * - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
     * through a redeem call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxRedeem(address owner) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their redemption at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
     *   in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
     *   same transaction.
     * - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
     *   redemption would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by redeeming.
     */
    function previewRedeem(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   redeem execution, and are accounted for during redeem.
     * - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.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}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * 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 ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both 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 returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual 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 default value returned by this function, unless
     * it's 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 returns (uint8) {
        return 18;
    }

    /// @inheritdoc IERC20
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /// @inheritdoc IERC20
    function balanceOf(address account) public view virtual 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 `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /// @inheritdoc IERC20
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` 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 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * 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 `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a `value` 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.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    /**
     * @dev Sets `value` 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.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
     * true using the following override:
     *
     * ```solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    /**
     * @dev Updates `owner`'s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/extensions/ERC4626.sol)

pragma solidity ^0.8.20;

import {IERC20, IERC20Metadata, ERC20} from "../ERC20.sol";
import {SafeERC20} from "../utils/SafeERC20.sol";
import {IERC4626} from "../../../interfaces/IERC4626.sol";
import {Math} from "../../../utils/math/Math.sol";

/**
 * @dev Implementation of the ERC-4626 "Tokenized Vault Standard" as defined in
 * https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
 *
 * This extension allows the minting and burning of "shares" (represented using the ERC-20 inheritance) in exchange for
 * underlying "assets" through standardized {deposit}, {mint}, {redeem} and {burn} workflows. This contract extends
 * the ERC-20 standard. Any additional extensions included along it would affect the "shares" token represented by this
 * contract and not the "assets" token which is an independent contract.
 *
 * [CAUTION]
 * ====
 * In empty (or nearly empty) ERC-4626 vaults, deposits are at high risk of being stolen through frontrunning
 * with a "donation" to the vault that inflates the price of a share. This is variously known as a donation or inflation
 * attack and is essentially a problem of slippage. Vault deployers can protect against this attack by making an initial
 * deposit of a non-trivial amount of the asset, such that price manipulation becomes infeasible. Withdrawals may
 * similarly be affected by slippage. Users can protect against this attack as well as unexpected slippage in general by
 * verifying the amount received is as expected, using a wrapper that performs these checks such as
 * https://github.com/fei-protocol/ERC4626#erc4626router-and-base[ERC4626Router].
 *
 * Since v4.9, this implementation introduces configurable virtual assets and shares to help developers mitigate that risk.
 * The `_decimalsOffset()` corresponds to an offset in the decimal representation between the underlying asset's decimals
 * and the vault decimals. This offset also determines the rate of virtual shares to virtual assets in the vault, which
 * itself determines the initial exchange rate. While not fully preventing the attack, analysis shows that the default
 * offset (0) makes it non-profitable even if an attacker is able to capture value from multiple user deposits, as a result
 * of the value being captured by the virtual shares (out of the attacker's donation) matching the attacker's expected gains.
 * With a larger offset, the attack becomes orders of magnitude more expensive than it is profitable. More details about the
 * underlying math can be found xref:ROOT:erc4626.adoc#inflation-attack[here].
 *
 * The drawback of this approach is that the virtual shares do capture (a very small) part of the value being accrued
 * to the vault. Also, if the vault experiences losses, the users try to exit the vault, the virtual shares and assets
 * will cause the first user to exit to experience reduced losses in detriment to the last users that will experience
 * bigger losses. Developers willing to revert back to the pre-v4.9 behavior just need to override the
 * `_convertToShares` and `_convertToAssets` functions.
 *
 * To learn more, check out our xref:ROOT:erc4626.adoc[ERC-4626 guide].
 * ====
 */
abstract contract ERC4626 is ERC20, IERC4626 {
    using Math for uint256;

    IERC20 private immutable _asset;
    uint8 private immutable _underlyingDecimals;

    /**
     * @dev Attempted to deposit more assets than the max amount for `receiver`.
     */
    error ERC4626ExceededMaxDeposit(address receiver, uint256 assets, uint256 max);

    /**
     * @dev Attempted to mint more shares than the max amount for `receiver`.
     */
    error ERC4626ExceededMaxMint(address receiver, uint256 shares, uint256 max);

    /**
     * @dev Attempted to withdraw more assets than the max amount for `receiver`.
     */
    error ERC4626ExceededMaxWithdraw(address owner, uint256 assets, uint256 max);

    /**
     * @dev Attempted to redeem more shares than the max amount for `receiver`.
     */
    error ERC4626ExceededMaxRedeem(address owner, uint256 shares, uint256 max);

    /**
     * @dev Set the underlying asset contract. This must be an ERC20-compatible contract (ERC-20 or ERC-777).
     */
    constructor(IERC20 asset_) {
        (bool success, uint8 assetDecimals) = _tryGetAssetDecimals(asset_);
        _underlyingDecimals = success ? assetDecimals : 18;
        _asset = asset_;
    }

    /**
     * @dev Attempts to fetch the asset decimals. A return value of false indicates that the attempt failed in some way.
     */
    function _tryGetAssetDecimals(IERC20 asset_) private view returns (bool ok, uint8 assetDecimals) {
        (bool success, bytes memory encodedDecimals) = address(asset_).staticcall(
            abi.encodeCall(IERC20Metadata.decimals, ())
        );
        if (success && encodedDecimals.length >= 32) {
            uint256 returnedDecimals = abi.decode(encodedDecimals, (uint256));
            if (returnedDecimals <= type(uint8).max) {
                return (true, uint8(returnedDecimals));
            }
        }
        return (false, 0);
    }

    /**
     * @dev Decimals are computed by adding the decimal offset on top of the underlying asset's decimals. This
     * "original" value is cached during construction of the vault contract. If this read operation fails (e.g., the
     * asset has not been created yet), a default of 18 is used to represent the underlying asset's decimals.
     *
     * See {IERC20Metadata-decimals}.
     */
    function decimals() public view virtual override(IERC20Metadata, ERC20) returns (uint8) {
        return _underlyingDecimals + _decimalsOffset();
    }

    /// @inheritdoc IERC4626
    function asset() public view virtual returns (address) {
        return address(_asset);
    }

    /// @inheritdoc IERC4626
    function totalAssets() public view virtual returns (uint256) {
        return IERC20(asset()).balanceOf(address(this));
    }

    /// @inheritdoc IERC4626
    function convertToShares(uint256 assets) public view virtual returns (uint256) {
        return _convertToShares(assets, Math.Rounding.Floor);
    }

    /// @inheritdoc IERC4626
    function convertToAssets(uint256 shares) public view virtual returns (uint256) {
        return _convertToAssets(shares, Math.Rounding.Floor);
    }

    /// @inheritdoc IERC4626
    function maxDeposit(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    /// @inheritdoc IERC4626
    function maxMint(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    /// @inheritdoc IERC4626
    function maxWithdraw(address owner) public view virtual returns (uint256) {
        return _convertToAssets(balanceOf(owner), Math.Rounding.Floor);
    }

    /// @inheritdoc IERC4626
    function maxRedeem(address owner) public view virtual returns (uint256) {
        return balanceOf(owner);
    }

    /// @inheritdoc IERC4626
    function previewDeposit(uint256 assets) public view virtual returns (uint256) {
        return _convertToShares(assets, Math.Rounding.Floor);
    }

    /// @inheritdoc IERC4626
    function previewMint(uint256 shares) public view virtual returns (uint256) {
        return _convertToAssets(shares, Math.Rounding.Ceil);
    }

    /// @inheritdoc IERC4626
    function previewWithdraw(uint256 assets) public view virtual returns (uint256) {
        return _convertToShares(assets, Math.Rounding.Ceil);
    }

    /// @inheritdoc IERC4626
    function previewRedeem(uint256 shares) public view virtual returns (uint256) {
        return _convertToAssets(shares, Math.Rounding.Floor);
    }

    /// @inheritdoc IERC4626
    function deposit(uint256 assets, address receiver) public virtual returns (uint256) {
        uint256 maxAssets = maxDeposit(receiver);
        if (assets > maxAssets) {
            revert ERC4626ExceededMaxDeposit(receiver, assets, maxAssets);
        }

        uint256 shares = previewDeposit(assets);
        _deposit(_msgSender(), receiver, assets, shares);

        return shares;
    }

    /// @inheritdoc IERC4626
    function mint(uint256 shares, address receiver) public virtual returns (uint256) {
        uint256 maxShares = maxMint(receiver);
        if (shares > maxShares) {
            revert ERC4626ExceededMaxMint(receiver, shares, maxShares);
        }

        uint256 assets = previewMint(shares);
        _deposit(_msgSender(), receiver, assets, shares);

        return assets;
    }

    /// @inheritdoc IERC4626
    function withdraw(uint256 assets, address receiver, address owner) public virtual returns (uint256) {
        uint256 maxAssets = maxWithdraw(owner);
        if (assets > maxAssets) {
            revert ERC4626ExceededMaxWithdraw(owner, assets, maxAssets);
        }

        uint256 shares = previewWithdraw(assets);
        _withdraw(_msgSender(), receiver, owner, assets, shares);

        return shares;
    }

    /// @inheritdoc IERC4626
    function redeem(uint256 shares, address receiver, address owner) public virtual returns (uint256) {
        uint256 maxShares = maxRedeem(owner);
        if (shares > maxShares) {
            revert ERC4626ExceededMaxRedeem(owner, shares, maxShares);
        }

        uint256 assets = previewRedeem(shares);
        _withdraw(_msgSender(), receiver, owner, assets, shares);

        return assets;
    }

    /**
     * @dev Internal conversion function (from assets to shares) with support for rounding direction.
     */
    function _convertToShares(uint256 assets, Math.Rounding rounding) internal view virtual returns (uint256) {
        return assets.mulDiv(totalSupply() + 10 ** _decimalsOffset(), totalAssets() + 1, rounding);
    }

    /**
     * @dev Internal conversion function (from shares to assets) with support for rounding direction.
     */
    function _convertToAssets(uint256 shares, Math.Rounding rounding) internal view virtual returns (uint256) {
        return shares.mulDiv(totalAssets() + 1, totalSupply() + 10 ** _decimalsOffset(), rounding);
    }

    /**
     * @dev Deposit/mint common workflow.
     */
    function _deposit(address caller, address receiver, uint256 assets, uint256 shares) internal virtual {
        // If asset() is ERC-777, `transferFrom` can trigger a reentrancy BEFORE the transfer happens through the
        // `tokensToSend` hook. On the other hand, the `tokenReceived` hook, that is triggered after the transfer,
        // calls the vault, which is assumed not malicious.
        //
        // Conclusion: we need to do the transfer before we mint so that any reentrancy would happen before the
        // assets are transferred and before the shares are minted, which is a valid state.
        // slither-disable-next-line reentrancy-no-eth
        SafeERC20.safeTransferFrom(IERC20(asset()), caller, address(this), assets);
        _mint(receiver, shares);

        emit Deposit(caller, receiver, assets, shares);
    }

    /**
     * @dev Withdraw/redeem common workflow.
     */
    function _withdraw(
        address caller,
        address receiver,
        address owner,
        uint256 assets,
        uint256 shares
    ) internal virtual {
        if (caller != owner) {
            _spendAllowance(owner, caller, shares);
        }

        // If asset() is ERC-777, `transfer` can trigger a reentrancy AFTER the transfer happens through the
        // `tokensReceived` hook. On the other hand, the `tokensToSend` hook, that is triggered before the transfer,
        // calls the vault, which is assumed not malicious.
        //
        // Conclusion: we need to do the transfer after the burn so that any reentrancy would happen after the
        // shares are burned and after the assets are transferred, which is a valid state.
        _burn(owner, shares);
        SafeERC20.safeTransfer(IERC20(asset()), receiver, assets);

        emit Withdraw(caller, receiver, owner, assets, shares);
    }

    function _decimalsOffset() internal view virtual returns (uint8) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity >=0.6.2;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
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 (last updated v5.4.0) (token/ERC20/IERC20.sol)

pragma solidity >=0.4.16;

/**
 * @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 v5.3.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC1363} from "../../../interfaces/IERC1363.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 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 {
    /**
     * @dev An operation with an ERC-20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            // bubble errors
            if iszero(success) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
            returnSize := returndatasize()
            returnValue := mload(0)
        }

        if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silently catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
    }
}

// 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
// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (utils/math/Math.sol)

pragma solidity ^0.8.20;

import {Panic} from "../Panic.sol";
import {SafeCast} from "./SafeCast.sol";

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Floor, // Toward negative infinity
        Ceil, // Toward positive infinity
        Trunc, // Toward zero
        Expand // Away from zero
    }

    /**
     * @dev Return the 512-bit addition of two uint256.
     *
     * The result is stored in two 256 variables such that sum = high * 2²⁵⁶ + low.
     */
    function add512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
        assembly ("memory-safe") {
            low := add(a, b)
            high := lt(low, a)
        }
    }

    /**
     * @dev Return the 512-bit multiplication of two uint256.
     *
     * The result is stored in two 256 variables such that product = high * 2²⁵⁶ + low.
     */
    function mul512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
        // 512-bit multiply [high low] = x * y. Compute the product mod 2²⁵⁶ and mod 2²⁵⁶ - 1, then use
        // the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
        // variables such that product = high * 2²⁵⁶ + low.
        assembly ("memory-safe") {
            let mm := mulmod(a, b, not(0))
            low := mul(a, b)
            high := sub(sub(mm, low), lt(mm, low))
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, with a success flag (no overflow).
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
        unchecked {
            uint256 c = a + b;
            success = c >= a;
            result = c * SafeCast.toUint(success);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with a success flag (no overflow).
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
        unchecked {
            uint256 c = a - b;
            success = c <= a;
            result = c * SafeCast.toUint(success);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with a success flag (no overflow).
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
        unchecked {
            uint256 c = a * b;
            assembly ("memory-safe") {
                // Only true when the multiplication doesn't overflow
                // (c / a == b) || (a == 0)
                success := or(eq(div(c, a), b), iszero(a))
            }
            // equivalent to: success ? c : 0
            result = c * SafeCast.toUint(success);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a success flag (no division by zero).
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
        unchecked {
            success = b > 0;
            assembly ("memory-safe") {
                // The `DIV` opcode returns zero when the denominator is 0.
                result := div(a, b)
            }
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a success flag (no division by zero).
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
        unchecked {
            success = b > 0;
            assembly ("memory-safe") {
                // The `MOD` opcode returns zero when the denominator is 0.
                result := mod(a, b)
            }
        }
    }

    /**
     * @dev Unsigned saturating addition, bounds to `2²⁵⁶ - 1` instead of overflowing.
     */
    function saturatingAdd(uint256 a, uint256 b) internal pure returns (uint256) {
        (bool success, uint256 result) = tryAdd(a, b);
        return ternary(success, result, type(uint256).max);
    }

    /**
     * @dev Unsigned saturating subtraction, bounds to zero instead of overflowing.
     */
    function saturatingSub(uint256 a, uint256 b) internal pure returns (uint256) {
        (, uint256 result) = trySub(a, b);
        return result;
    }

    /**
     * @dev Unsigned saturating multiplication, bounds to `2²⁵⁶ - 1` instead of overflowing.
     */
    function saturatingMul(uint256 a, uint256 b) internal pure returns (uint256) {
        (bool success, uint256 result) = tryMul(a, b);
        return ternary(success, result, type(uint256).max);
    }

    /**
     * @dev Branchless ternary evaluation for `a ? b : c`. Gas costs are constant.
     *
     * IMPORTANT: This function may reduce bytecode size and consume less gas when used standalone.
     * However, the compiler may optimize Solidity ternary operations (i.e. `a ? b : c`) to only compute
     * one branch when needed, making this function more expensive.
     */
    function ternary(bool condition, uint256 a, uint256 b) internal pure returns (uint256) {
        unchecked {
            // branchless ternary works because:
            // b ^ (a ^ b) == a
            // b ^ 0 == b
            return b ^ ((a ^ b) * SafeCast.toUint(condition));
        }
    }

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

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return ternary(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 towards infinity instead
     * of rounding towards zero.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        if (b == 0) {
            // Guarantee the same behavior as in a regular Solidity division.
            Panic.panic(Panic.DIVISION_BY_ZERO);
        }

        // The following calculation ensures accurate ceiling division without overflow.
        // Since a is non-zero, (a - 1) / b will not overflow.
        // The largest possible result occurs when (a - 1) / b is type(uint256).max,
        // but the largest value we can obtain is type(uint256).max - 1, which happens
        // when a = type(uint256).max and b = 1.
        unchecked {
            return SafeCast.toUint(a > 0) * ((a - 1) / b + 1);
        }
    }

    /**
     * @dev Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
     * denominator == 0.
     *
     * 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 {
            (uint256 high, uint256 low) = mul512(x, y);

            // Handle non-overflow cases, 256 by 256 division.
            if (high == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return low / denominator;
            }

            // Make sure the result is less than 2²⁵⁶. Also prevents denominator == 0.
            if (denominator <= high) {
                Panic.panic(ternary(denominator == 0, Panic.DIVISION_BY_ZERO, Panic.UNDER_OVERFLOW));
            }

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

            // Make division exact by subtracting the remainder from [high low].
            uint256 remainder;
            assembly ("memory-safe") {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                high := sub(high, gt(remainder, low))
                low := sub(low, 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.

            uint256 twos = denominator & (0 - denominator);
            assembly ("memory-safe") {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [high low] by twos.
                low := div(low, twos)

                // Flip twos such that it is 2²⁵⁶ / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from high into low.
            low |= high * twos;

            // Invert denominator mod 2²⁵⁶. Now that denominator is an odd number, it has an inverse modulo 2²⁵⁶ such
            // that denominator * inv ≡ 1 mod 2²⁵⁶. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv ≡ 1 mod 2⁴.
            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 2⁸
            inverse *= 2 - denominator * inverse; // inverse mod 2¹⁶
            inverse *= 2 - denominator * inverse; // inverse mod 2³²
            inverse *= 2 - denominator * inverse; // inverse mod 2⁶⁴
            inverse *= 2 - denominator * inverse; // inverse mod 2¹²⁸
            inverse *= 2 - denominator * inverse; // inverse mod 2²⁵⁶

            // 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 2²⁵⁶. Since the preconditions guarantee that the outcome is
            // less than 2²⁵⁶, this is the final result. We don't need to compute the high bits of the result and high
            // is no longer required.
            result = low * inverse;
            return result;
        }
    }

    /**
     * @dev 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) {
        return mulDiv(x, y, denominator) + SafeCast.toUint(unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0);
    }

    /**
     * @dev Calculates floor(x * y >> n) with full precision. Throws if result overflows a uint256.
     */
    function mulShr(uint256 x, uint256 y, uint8 n) internal pure returns (uint256 result) {
        unchecked {
            (uint256 high, uint256 low) = mul512(x, y);
            if (high >= 1 << n) {
                Panic.panic(Panic.UNDER_OVERFLOW);
            }
            return (high << (256 - n)) | (low >> n);
        }
    }

    /**
     * @dev Calculates x * y >> n with full precision, following the selected rounding direction.
     */
    function mulShr(uint256 x, uint256 y, uint8 n, Rounding rounding) internal pure returns (uint256) {
        return mulShr(x, y, n) + SafeCast.toUint(unsignedRoundsUp(rounding) && mulmod(x, y, 1 << n) > 0);
    }

    /**
     * @dev Calculate the modular multiplicative inverse of a number in Z/nZ.
     *
     * If n is a prime, then Z/nZ is a field. In that case all elements are inversible, except 0.
     * If n is not a prime, then Z/nZ is not a field, and some elements might not be inversible.
     *
     * If the input value is not inversible, 0 is returned.
     *
     * NOTE: If you know for sure that n is (big) a prime, it may be cheaper to use Fermat's little theorem and get the
     * inverse using `Math.modExp(a, n - 2, n)`. See {invModPrime}.
     */
    function invMod(uint256 a, uint256 n) internal pure returns (uint256) {
        unchecked {
            if (n == 0) return 0;

            // The inverse modulo is calculated using the Extended Euclidean Algorithm (iterative version)
            // Used to compute integers x and y such that: ax + ny = gcd(a, n).
            // When the gcd is 1, then the inverse of a modulo n exists and it's x.
            // ax + ny = 1
            // ax = 1 + (-y)n
            // ax ≡ 1 (mod n) # x is the inverse of a modulo n

            // If the remainder is 0 the gcd is n right away.
            uint256 remainder = a % n;
            uint256 gcd = n;

            // Therefore the initial coefficients are:
            // ax + ny = gcd(a, n) = n
            // 0a + 1n = n
            int256 x = 0;
            int256 y = 1;

            while (remainder != 0) {
                uint256 quotient = gcd / remainder;

                (gcd, remainder) = (
                    // The old remainder is the next gcd to try.
                    remainder,
                    // Compute the next remainder.
                    // Can't overflow given that (a % gcd) * (gcd // (a % gcd)) <= gcd
                    // where gcd is at most n (capped to type(uint256).max)
                    gcd - remainder * quotient
                );

                (x, y) = (
                    // Increment the coefficient of a.
                    y,
                    // Decrement the coefficient of n.
                    // Can overflow, but the result is casted to uint256 so that the
                    // next value of y is "wrapped around" to a value between 0 and n - 1.
                    x - y * int256(quotient)
                );
            }

            if (gcd != 1) return 0; // No inverse exists.
            return ternary(x < 0, n - uint256(-x), uint256(x)); // Wrap the result if it's negative.
        }
    }

    /**
     * @dev Variant of {invMod}. More efficient, but only works if `p` is known to be a prime greater than `2`.
     *
     * From https://en.wikipedia.org/wiki/Fermat%27s_little_theorem[Fermat's little theorem], we know that if p is
     * prime, then `a**(p-1) ≡ 1 mod p`. As a consequence, we have `a * a**(p-2) ≡ 1 mod p`, which means that
     * `a**(p-2)` is the modular multiplicative inverse of a in Fp.
     *
     * NOTE: this function does NOT check that `p` is a prime greater than `2`.
     */
    function invModPrime(uint256 a, uint256 p) internal view returns (uint256) {
        unchecked {
            return Math.modExp(a, p - 2, p);
        }
    }

    /**
     * @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m)
     *
     * Requirements:
     * - modulus can't be zero
     * - underlying staticcall to precompile must succeed
     *
     * IMPORTANT: The result is only valid if the underlying call succeeds. When using this function, make
     * sure the chain you're using it on supports the precompiled contract for modular exponentiation
     * at address 0x05 as specified in https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise,
     * the underlying function will succeed given the lack of a revert, but the result may be incorrectly
     * interpreted as 0.
     */
    function modExp(uint256 b, uint256 e, uint256 m) internal view returns (uint256) {
        (bool success, uint256 result) = tryModExp(b, e, m);
        if (!success) {
            Panic.panic(Panic.DIVISION_BY_ZERO);
        }
        return result;
    }

    /**
     * @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m).
     * It includes a success flag indicating if the operation succeeded. Operation will be marked as failed if trying
     * to operate modulo 0 or if the underlying precompile reverted.
     *
     * IMPORTANT: The result is only valid if the success flag is true. When using this function, make sure the chain
     * you're using it on supports the precompiled contract for modular exponentiation at address 0x05 as specified in
     * https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise, the underlying function will succeed given the lack
     * of a revert, but the result may be incorrectly interpreted as 0.
     */
    function tryModExp(uint256 b, uint256 e, uint256 m) internal view returns (bool success, uint256 result) {
        if (m == 0) return (false, 0);
        assembly ("memory-safe") {
            let ptr := mload(0x40)
            // | Offset    | Content    | Content (Hex)                                                      |
            // |-----------|------------|--------------------------------------------------------------------|
            // | 0x00:0x1f | size of b  | 0x0000000000000000000000000000000000000000000000000000000000000020 |
            // | 0x20:0x3f | size of e  | 0x0000000000000000000000000000000000000000000000000000000000000020 |
            // | 0x40:0x5f | size of m  | 0x0000000000000000000000000000000000000000000000000000000000000020 |
            // | 0x60:0x7f | value of b | 0x<.............................................................b> |
            // | 0x80:0x9f | value of e | 0x<.............................................................e> |
            // | 0xa0:0xbf | value of m | 0x<.............................................................m> |
            mstore(ptr, 0x20)
            mstore(add(ptr, 0x20), 0x20)
            mstore(add(ptr, 0x40), 0x20)
            mstore(add(ptr, 0x60), b)
            mstore(add(ptr, 0x80), e)
            mstore(add(ptr, 0xa0), m)

            // Given the result < m, it's guaranteed to fit in 32 bytes,
            // so we can use the memory scratch space located at offset 0.
            success := staticcall(gas(), 0x05, ptr, 0xc0, 0x00, 0x20)
            result := mload(0x00)
        }
    }

    /**
     * @dev Variant of {modExp} that supports inputs of arbitrary length.
     */
    function modExp(bytes memory b, bytes memory e, bytes memory m) internal view returns (bytes memory) {
        (bool success, bytes memory result) = tryModExp(b, e, m);
        if (!success) {
            Panic.panic(Panic.DIVISION_BY_ZERO);
        }
        return result;
    }

    /**
     * @dev Variant of {tryModExp} that supports inputs of arbitrary length.
     */
    function tryModExp(
        bytes memory b,
        bytes memory e,
        bytes memory m
    ) internal view returns (bool success, bytes memory result) {
        if (_zeroBytes(m)) return (false, new bytes(0));

        uint256 mLen = m.length;

        // Encode call args in result and move the free memory pointer
        result = abi.encodePacked(b.length, e.length, mLen, b, e, m);

        assembly ("memory-safe") {
            let dataPtr := add(result, 0x20)
            // Write result on top of args to avoid allocating extra memory.
            success := staticcall(gas(), 0x05, dataPtr, mload(result), dataPtr, mLen)
            // Overwrite the length.
            // result.length > returndatasize() is guaranteed because returndatasize() == m.length
            mstore(result, mLen)
            // Set the memory pointer after the returned data.
            mstore(0x40, add(dataPtr, mLen))
        }
    }

    /**
     * @dev Returns whether the provided byte array is zero.
     */
    function _zeroBytes(bytes memory byteArray) private pure returns (bool) {
        for (uint256 i = 0; i < byteArray.length; ++i) {
            if (byteArray[i] != 0) {
                return false;
            }
        }
        return true;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
     * towards zero.
     *
     * This method is based on Newton's method for computing square roots; the algorithm is restricted to only
     * using integer operations.
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        unchecked {
            // Take care of easy edge cases when a == 0 or a == 1
            if (a <= 1) {
                return a;
            }

            // In this function, we use Newton's method to get a root of `f(x) := x² - a`. It involves building a
            // sequence x_n that converges toward sqrt(a). For each iteration x_n, we also define the error between
            // the current value as `ε_n = | x_n - sqrt(a) |`.
            //
            // For our first estimation, we consider `e` the smallest power of 2 which is bigger than the square root
            // of the target. (i.e. `2**(e-1) ≤ sqrt(a) < 2**e`). We know that `e ≤ 128` because `(2¹²⁸)² = 2²⁵⁶` is
            // bigger than any uint256.
            //
            // By noticing that
            // `2**(e-1) ≤ sqrt(a) < 2**e → (2**(e-1))² ≤ a < (2**e)² → 2**(2*e-2) ≤ a < 2**(2*e)`
            // we can deduce that `e - 1` is `log2(a) / 2`. We can thus compute `x_n = 2**(e-1)` using a method similar
            // to the msb function.
            uint256 aa = a;
            uint256 xn = 1;

            if (aa >= (1 << 128)) {
                aa >>= 128;
                xn <<= 64;
            }
            if (aa >= (1 << 64)) {
                aa >>= 64;
                xn <<= 32;
            }
            if (aa >= (1 << 32)) {
                aa >>= 32;
                xn <<= 16;
            }
            if (aa >= (1 << 16)) {
                aa >>= 16;
                xn <<= 8;
            }
            if (aa >= (1 << 8)) {
                aa >>= 8;
                xn <<= 4;
            }
            if (aa >= (1 << 4)) {
                aa >>= 4;
                xn <<= 2;
            }
            if (aa >= (1 << 2)) {
                xn <<= 1;
            }

            // We now have x_n such that `x_n = 2**(e-1) ≤ sqrt(a) < 2**e = 2 * x_n`. This implies ε_n ≤ 2**(e-1).
            //
            // We can refine our estimation by noticing that the middle of that interval minimizes the error.
            // If we move x_n to equal 2**(e-1) + 2**(e-2), then we reduce the error to ε_n ≤ 2**(e-2).
            // This is going to be our x_0 (and ε_0)
            xn = (3 * xn) >> 1; // ε_0 := | x_0 - sqrt(a) | ≤ 2**(e-2)

            // From here, Newton's method give us:
            // x_{n+1} = (x_n + a / x_n) / 2
            //
            // One should note that:
            // x_{n+1}² - a = ((x_n + a / x_n) / 2)² - a
            //              = ((x_n² + a) / (2 * x_n))² - a
            //              = (x_n⁴ + 2 * a * x_n² + a²) / (4 * x_n²) - a
            //              = (x_n⁴ + 2 * a * x_n² + a² - 4 * a * x_n²) / (4 * x_n²)
            //              = (x_n⁴ - 2 * a * x_n² + a²) / (4 * x_n²)
            //              = (x_n² - a)² / (2 * x_n)²
            //              = ((x_n² - a) / (2 * x_n))²
            //              ≥ 0
            // Which proves that for all n ≥ 1, sqrt(a) ≤ x_n
            //
            // This gives us the proof of quadratic convergence of the sequence:
            // ε_{n+1} = | x_{n+1} - sqrt(a) |
            //         = | (x_n + a / x_n) / 2 - sqrt(a) |
            //         = | (x_n² + a - 2*x_n*sqrt(a)) / (2 * x_n) |
            //         = | (x_n - sqrt(a))² / (2 * x_n) |
            //         = | ε_n² / (2 * x_n) |
            //         = ε_n² / | (2 * x_n) |
            //
            // For the first iteration, we have a special case where x_0 is known:
            // ε_1 = ε_0² / | (2 * x_0) |
            //     ≤ (2**(e-2))² / (2 * (2**(e-1) + 2**(e-2)))
            //     ≤ 2**(2*e-4) / (3 * 2**(e-1))
            //     ≤ 2**(e-3) / 3
            //     ≤ 2**(e-3-log2(3))
            //     ≤ 2**(e-4.5)
            //
            // For the following iterations, we use the fact that, 2**(e-1) ≤ sqrt(a) ≤ x_n:
            // ε_{n+1} = ε_n² / | (2 * x_n) |
            //         ≤ (2**(e-k))² / (2 * 2**(e-1))
            //         ≤ 2**(2*e-2*k) / 2**e
            //         ≤ 2**(e-2*k)
            xn = (xn + a / xn) >> 1; // ε_1 := | x_1 - sqrt(a) | ≤ 2**(e-4.5)  -- special case, see above
            xn = (xn + a / xn) >> 1; // ε_2 := | x_2 - sqrt(a) | ≤ 2**(e-9)    -- general case with k = 4.5
            xn = (xn + a / xn) >> 1; // ε_3 := | x_3 - sqrt(a) | ≤ 2**(e-18)   -- general case with k = 9
            xn = (xn + a / xn) >> 1; // ε_4 := | x_4 - sqrt(a) | ≤ 2**(e-36)   -- general case with k = 18
            xn = (xn + a / xn) >> 1; // ε_5 := | x_5 - sqrt(a) | ≤ 2**(e-72)   -- general case with k = 36
            xn = (xn + a / xn) >> 1; // ε_6 := | x_6 - sqrt(a) | ≤ 2**(e-144)  -- general case with k = 72

            // Because e ≤ 128 (as discussed during the first estimation phase), we know have reached a precision
            // ε_6 ≤ 2**(e-144) < 1. Given we're operating on integers, then we can ensure that xn is now either
            // sqrt(a) or sqrt(a) + 1.
            return xn - SafeCast.toUint(xn > a / xn);
        }
    }

    /**
     * @dev Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + SafeCast.toUint(unsignedRoundsUp(rounding) && result * result < a);
        }
    }

    /**
     * @dev Return the log in base 2 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     */
    function log2(uint256 x) internal pure returns (uint256 r) {
        // If value has upper 128 bits set, log2 result is at least 128
        r = SafeCast.toUint(x > 0xffffffffffffffffffffffffffffffff) << 7;
        // If upper 64 bits of 128-bit half set, add 64 to result
        r |= SafeCast.toUint((x >> r) > 0xffffffffffffffff) << 6;
        // If upper 32 bits of 64-bit half set, add 32 to result
        r |= SafeCast.toUint((x >> r) > 0xffffffff) << 5;
        // If upper 16 bits of 32-bit half set, add 16 to result
        r |= SafeCast.toUint((x >> r) > 0xffff) << 4;
        // If upper 8 bits of 16-bit half set, add 8 to result
        r |= SafeCast.toUint((x >> r) > 0xff) << 3;
        // If upper 4 bits of 8-bit half set, add 4 to result
        r |= SafeCast.toUint((x >> r) > 0xf) << 2;

        // Shifts value right by the current result and use it as an index into this lookup table:
        //
        // | x (4 bits) |  index  | table[index] = MSB position |
        // |------------|---------|-----------------------------|
        // |    0000    |    0    |        table[0] = 0         |
        // |    0001    |    1    |        table[1] = 0         |
        // |    0010    |    2    |        table[2] = 1         |
        // |    0011    |    3    |        table[3] = 1         |
        // |    0100    |    4    |        table[4] = 2         |
        // |    0101    |    5    |        table[5] = 2         |
        // |    0110    |    6    |        table[6] = 2         |
        // |    0111    |    7    |        table[7] = 2         |
        // |    1000    |    8    |        table[8] = 3         |
        // |    1001    |    9    |        table[9] = 3         |
        // |    1010    |   10    |        table[10] = 3        |
        // |    1011    |   11    |        table[11] = 3        |
        // |    1100    |   12    |        table[12] = 3        |
        // |    1101    |   13    |        table[13] = 3        |
        // |    1110    |   14    |        table[14] = 3        |
        // |    1111    |   15    |        table[15] = 3        |
        //
        // The lookup table is represented as a 32-byte value with the MSB positions for 0-15 in the last 16 bytes.
        assembly ("memory-safe") {
            r := or(r, byte(shr(r, x), 0x0000010102020202030303030303030300000000000000000000000000000000))
        }
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << result < value);
        }
    }

    /**
     * @dev Return the log in base 10 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 10 ** result < value);
        }
    }

    /**
     * @dev Return the log in base 256 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 x) internal pure returns (uint256 r) {
        // If value has upper 128 bits set, log2 result is at least 128
        r = SafeCast.toUint(x > 0xffffffffffffffffffffffffffffffff) << 7;
        // If upper 64 bits of 128-bit half set, add 64 to result
        r |= SafeCast.toUint((x >> r) > 0xffffffffffffffff) << 6;
        // If upper 32 bits of 64-bit half set, add 32 to result
        r |= SafeCast.toUint((x >> r) > 0xffffffff) << 5;
        // If upper 16 bits of 32-bit half set, add 16 to result
        r |= SafeCast.toUint((x >> r) > 0xffff) << 4;
        // Add 1 if upper 8 bits of 16-bit half set, and divide accumulated result by 8
        return (r >> 3) | SafeCast.toUint((x >> r) > 0xff);
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << (result << 3) < value);
        }
    }

    /**
     * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
     */
    function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
        return uint8(rounding) % 2 == 1;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/math/SafeCast.sol)
// This file was procedurally generated from scripts/generate/templates/SafeCast.js.

pragma solidity ^0.8.20;

/**
 * @dev Wrappers over Solidity's uintXX/intXX/bool casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeCast {
    /**
     * @dev Value doesn't fit in an uint of `bits` size.
     */
    error SafeCastOverflowedUintDowncast(uint8 bits, uint256 value);

    /**
     * @dev An int value doesn't fit in an uint of `bits` size.
     */
    error SafeCastOverflowedIntToUint(int256 value);

    /**
     * @dev Value doesn't fit in an int of `bits` size.
     */
    error SafeCastOverflowedIntDowncast(uint8 bits, int256 value);

    /**
     * @dev An uint value doesn't fit in an int of `bits` size.
     */
    error SafeCastOverflowedUintToInt(uint256 value);

    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     */
    function toUint248(uint256 value) internal pure returns (uint248) {
        if (value > type(uint248).max) {
            revert SafeCastOverflowedUintDowncast(248, value);
        }
        return uint248(value);
    }

    /**
     * @dev Returns the downcasted uint240 from uint256, reverting on
     * overflow (when the input is greater than largest uint240).
     *
     * Counterpart to Solidity's `uint240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     */
    function toUint240(uint256 value) internal pure returns (uint240) {
        if (value > type(uint240).max) {
            revert SafeCastOverflowedUintDowncast(240, value);
        }
        return uint240(value);
    }

    /**
     * @dev Returns the downcasted uint232 from uint256, reverting on
     * overflow (when the input is greater than largest uint232).
     *
     * Counterpart to Solidity's `uint232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     */
    function toUint232(uint256 value) internal pure returns (uint232) {
        if (value > type(uint232).max) {
            revert SafeCastOverflowedUintDowncast(232, value);
        }
        return uint232(value);
    }

    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        if (value > type(uint224).max) {
            revert SafeCastOverflowedUintDowncast(224, value);
        }
        return uint224(value);
    }

    /**
     * @dev Returns the downcasted uint216 from uint256, reverting on
     * overflow (when the input is greater than largest uint216).
     *
     * Counterpart to Solidity's `uint216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     */
    function toUint216(uint256 value) internal pure returns (uint216) {
        if (value > type(uint216).max) {
            revert SafeCastOverflowedUintDowncast(216, value);
        }
        return uint216(value);
    }

    /**
     * @dev Returns the downcasted uint208 from uint256, reverting on
     * overflow (when the input is greater than largest uint208).
     *
     * Counterpart to Solidity's `uint208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     */
    function toUint208(uint256 value) internal pure returns (uint208) {
        if (value > type(uint208).max) {
            revert SafeCastOverflowedUintDowncast(208, value);
        }
        return uint208(value);
    }

    /**
     * @dev Returns the downcasted uint200 from uint256, reverting on
     * overflow (when the input is greater than largest uint200).
     *
     * Counterpart to Solidity's `uint200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     */
    function toUint200(uint256 value) internal pure returns (uint200) {
        if (value > type(uint200).max) {
            revert SafeCastOverflowedUintDowncast(200, value);
        }
        return uint200(value);
    }

    /**
     * @dev Returns the downcasted uint192 from uint256, reverting on
     * overflow (when the input is greater than largest uint192).
     *
     * Counterpart to Solidity's `uint192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     */
    function toUint192(uint256 value) internal pure returns (uint192) {
        if (value > type(uint192).max) {
            revert SafeCastOverflowedUintDowncast(192, value);
        }
        return uint192(value);
    }

    /**
     * @dev Returns the downcasted uint184 from uint256, reverting on
     * overflow (when the input is greater than largest uint184).
     *
     * Counterpart to Solidity's `uint184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     */
    function toUint184(uint256 value) internal pure returns (uint184) {
        if (value > type(uint184).max) {
            revert SafeCastOverflowedUintDowncast(184, value);
        }
        return uint184(value);
    }

    /**
     * @dev Returns the downcasted uint176 from uint256, reverting on
     * overflow (when the input is greater than largest uint176).
     *
     * Counterpart to Solidity's `uint176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     */
    function toUint176(uint256 value) internal pure returns (uint176) {
        if (value > type(uint176).max) {
            revert SafeCastOverflowedUintDowncast(176, value);
        }
        return uint176(value);
    }

    /**
     * @dev Returns the downcasted uint168 from uint256, reverting on
     * overflow (when the input is greater than largest uint168).
     *
     * Counterpart to Solidity's `uint168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     */
    function toUint168(uint256 value) internal pure returns (uint168) {
        if (value > type(uint168).max) {
            revert SafeCastOverflowedUintDowncast(168, value);
        }
        return uint168(value);
    }

    /**
     * @dev Returns the downcasted uint160 from uint256, reverting on
     * overflow (when the input is greater than largest uint160).
     *
     * Counterpart to Solidity's `uint160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     */
    function toUint160(uint256 value) internal pure returns (uint160) {
        if (value > type(uint160).max) {
            revert SafeCastOverflowedUintDowncast(160, value);
        }
        return uint160(value);
    }

    /**
     * @dev Returns the downcasted uint152 from uint256, reverting on
     * overflow (when the input is greater than largest uint152).
     *
     * Counterpart to Solidity's `uint152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     */
    function toUint152(uint256 value) internal pure returns (uint152) {
        if (value > type(uint152).max) {
            revert SafeCastOverflowedUintDowncast(152, value);
        }
        return uint152(value);
    }

    /**
     * @dev Returns the downcasted uint144 from uint256, reverting on
     * overflow (when the input is greater than largest uint144).
     *
     * Counterpart to Solidity's `uint144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     */
    function toUint144(uint256 value) internal pure returns (uint144) {
        if (value > type(uint144).max) {
            revert SafeCastOverflowedUintDowncast(144, value);
        }
        return uint144(value);
    }

    /**
     * @dev Returns the downcasted uint136 from uint256, reverting on
     * overflow (when the input is greater than largest uint136).
     *
     * Counterpart to Solidity's `uint136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     */
    function toUint136(uint256 value) internal pure returns (uint136) {
        if (value > type(uint136).max) {
            revert SafeCastOverflowedUintDowncast(136, value);
        }
        return uint136(value);
    }

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        if (value > type(uint128).max) {
            revert SafeCastOverflowedUintDowncast(128, value);
        }
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     */
    function toUint120(uint256 value) internal pure returns (uint120) {
        if (value > type(uint120).max) {
            revert SafeCastOverflowedUintDowncast(120, value);
        }
        return uint120(value);
    }

    /**
     * @dev Returns the downcasted uint112 from uint256, reverting on
     * overflow (when the input is greater than largest uint112).
     *
     * Counterpart to Solidity's `uint112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     */
    function toUint112(uint256 value) internal pure returns (uint112) {
        if (value > type(uint112).max) {
            revert SafeCastOverflowedUintDowncast(112, value);
        }
        return uint112(value);
    }

    /**
     * @dev Returns the downcasted uint104 from uint256, reverting on
     * overflow (when the input is greater than largest uint104).
     *
     * Counterpart to Solidity's `uint104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     */
    function toUint104(uint256 value) internal pure returns (uint104) {
        if (value > type(uint104).max) {
            revert SafeCastOverflowedUintDowncast(104, value);
        }
        return uint104(value);
    }

    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        if (value > type(uint96).max) {
            revert SafeCastOverflowedUintDowncast(96, value);
        }
        return uint96(value);
    }

    /**
     * @dev Returns the downcasted uint88 from uint256, reverting on
     * overflow (when the input is greater than largest uint88).
     *
     * Counterpart to Solidity's `uint88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     */
    function toUint88(uint256 value) internal pure returns (uint88) {
        if (value > type(uint88).max) {
            revert SafeCastOverflowedUintDowncast(88, value);
        }
        return uint88(value);
    }

    /**
     * @dev Returns the downcasted uint80 from uint256, reverting on
     * overflow (when the input is greater than largest uint80).
     *
     * Counterpart to Solidity's `uint80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     */
    function toUint80(uint256 value) internal pure returns (uint80) {
        if (value > type(uint80).max) {
            revert SafeCastOverflowedUintDowncast(80, value);
        }
        return uint80(value);
    }

    /**
     * @dev Returns the downcasted uint72 from uint256, reverting on
     * overflow (when the input is greater than largest uint72).
     *
     * Counterpart to Solidity's `uint72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     */
    function toUint72(uint256 value) internal pure returns (uint72) {
        if (value > type(uint72).max) {
            revert SafeCastOverflowedUintDowncast(72, value);
        }
        return uint72(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        if (value > type(uint64).max) {
            revert SafeCastOverflowedUintDowncast(64, value);
        }
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint56 from uint256, reverting on
     * overflow (when the input is greater than largest uint56).
     *
     * Counterpart to Solidity's `uint56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     */
    function toUint56(uint256 value) internal pure returns (uint56) {
        if (value > type(uint56).max) {
            revert SafeCastOverflowedUintDowncast(56, value);
        }
        return uint56(value);
    }

    /**
     * @dev Returns the downcasted uint48 from uint256, reverting on
     * overflow (when the input is greater than largest uint48).
     *
     * Counterpart to Solidity's `uint48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     */
    function toUint48(uint256 value) internal pure returns (uint48) {
        if (value > type(uint48).max) {
            revert SafeCastOverflowedUintDowncast(48, value);
        }
        return uint48(value);
    }

    /**
     * @dev Returns the downcasted uint40 from uint256, reverting on
     * overflow (when the input is greater than largest uint40).
     *
     * Counterpart to Solidity's `uint40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     */
    function toUint40(uint256 value) internal pure returns (uint40) {
        if (value > type(uint40).max) {
            revert SafeCastOverflowedUintDowncast(40, value);
        }
        return uint40(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        if (value > type(uint32).max) {
            revert SafeCastOverflowedUintDowncast(32, value);
        }
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint24 from uint256, reverting on
     * overflow (when the input is greater than largest uint24).
     *
     * Counterpart to Solidity's `uint24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     */
    function toUint24(uint256 value) internal pure returns (uint24) {
        if (value > type(uint24).max) {
            revert SafeCastOverflowedUintDowncast(24, value);
        }
        return uint24(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        if (value > type(uint16).max) {
            revert SafeCastOverflowedUintDowncast(16, value);
        }
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        if (value > type(uint8).max) {
            revert SafeCastOverflowedUintDowncast(8, value);
        }
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        if (value < 0) {
            revert SafeCastOverflowedIntToUint(value);
        }
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int248 from int256, reverting on
     * overflow (when the input is less than smallest int248 or
     * greater than largest int248).
     *
     * Counterpart to Solidity's `int248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     */
    function toInt248(int256 value) internal pure returns (int248 downcasted) {
        downcasted = int248(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(248, value);
        }
    }

    /**
     * @dev Returns the downcasted int240 from int256, reverting on
     * overflow (when the input is less than smallest int240 or
     * greater than largest int240).
     *
     * Counterpart to Solidity's `int240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     */
    function toInt240(int256 value) internal pure returns (int240 downcasted) {
        downcasted = int240(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(240, value);
        }
    }

    /**
     * @dev Returns the downcasted int232 from int256, reverting on
     * overflow (when the input is less than smallest int232 or
     * greater than largest int232).
     *
     * Counterpart to Solidity's `int232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     */
    function toInt232(int256 value) internal pure returns (int232 downcasted) {
        downcasted = int232(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(232, value);
        }
    }

    /**
     * @dev Returns the downcasted int224 from int256, reverting on
     * overflow (when the input is less than smallest int224 or
     * greater than largest int224).
     *
     * Counterpart to Solidity's `int224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     */
    function toInt224(int256 value) internal pure returns (int224 downcasted) {
        downcasted = int224(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(224, value);
        }
    }

    /**
     * @dev Returns the downcasted int216 from int256, reverting on
     * overflow (when the input is less than smallest int216 or
     * greater than largest int216).
     *
     * Counterpart to Solidity's `int216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     */
    function toInt216(int256 value) internal pure returns (int216 downcasted) {
        downcasted = int216(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(216, value);
        }
    }

    /**
     * @dev Returns the downcasted int208 from int256, reverting on
     * overflow (when the input is less than smallest int208 or
     * greater than largest int208).
     *
     * Counterpart to Solidity's `int208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     */
    function toInt208(int256 value) internal pure returns (int208 downcasted) {
        downcasted = int208(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(208, value);
        }
    }

    /**
     * @dev Returns the downcasted int200 from int256, reverting on
     * overflow (when the input is less than smallest int200 or
     * greater than largest int200).
     *
     * Counterpart to Solidity's `int200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     */
    function toInt200(int256 value) internal pure returns (int200 downcasted) {
        downcasted = int200(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(200, value);
        }
    }

    /**
     * @dev Returns the downcasted int192 from int256, reverting on
     * overflow (when the input is less than smallest int192 or
     * greater than largest int192).
     *
     * Counterpart to Solidity's `int192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     */
    function toInt192(int256 value) internal pure returns (int192 downcasted) {
        downcasted = int192(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(192, value);
        }
    }

    /**
     * @dev Returns the downcasted int184 from int256, reverting on
     * overflow (when the input is less than smallest int184 or
     * greater than largest int184).
     *
     * Counterpart to Solidity's `int184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     */
    function toInt184(int256 value) internal pure returns (int184 downcasted) {
        downcasted = int184(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(184, value);
        }
    }

    /**
     * @dev Returns the downcasted int176 from int256, reverting on
     * overflow (when the input is less than smallest int176 or
     * greater than largest int176).
     *
     * Counterpart to Solidity's `int176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     */
    function toInt176(int256 value) internal pure returns (int176 downcasted) {
        downcasted = int176(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(176, value);
        }
    }

    /**
     * @dev Returns the downcasted int168 from int256, reverting on
     * overflow (when the input is less than smallest int168 or
     * greater than largest int168).
     *
     * Counterpart to Solidity's `int168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     */
    function toInt168(int256 value) internal pure returns (int168 downcasted) {
        downcasted = int168(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(168, value);
        }
    }

    /**
     * @dev Returns the downcasted int160 from int256, reverting on
     * overflow (when the input is less than smallest int160 or
     * greater than largest int160).
     *
     * Counterpart to Solidity's `int160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     */
    function toInt160(int256 value) internal pure returns (int160 downcasted) {
        downcasted = int160(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(160, value);
        }
    }

    /**
     * @dev Returns the downcasted int152 from int256, reverting on
     * overflow (when the input is less than smallest int152 or
     * greater than largest int152).
     *
     * Counterpart to Solidity's `int152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     */
    function toInt152(int256 value) internal pure returns (int152 downcasted) {
        downcasted = int152(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(152, value);
        }
    }

    /**
     * @dev Returns the downcasted int144 from int256, reverting on
     * overflow (when the input is less than smallest int144 or
     * greater than largest int144).
     *
     * Counterpart to Solidity's `int144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     */
    function toInt144(int256 value) internal pure returns (int144 downcasted) {
        downcasted = int144(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(144, value);
        }
    }

    /**
     * @dev Returns the downcasted int136 from int256, reverting on
     * overflow (when the input is less than smallest int136 or
     * greater than largest int136).
     *
     * Counterpart to Solidity's `int136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     */
    function toInt136(int256 value) internal pure returns (int136 downcasted) {
        downcasted = int136(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(136, value);
        }
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toInt128(int256 value) internal pure returns (int128 downcasted) {
        downcasted = int128(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(128, value);
        }
    }

    /**
     * @dev Returns the downcasted int120 from int256, reverting on
     * overflow (when the input is less than smallest int120 or
     * greater than largest int120).
     *
     * Counterpart to Solidity's `int120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     */
    function toInt120(int256 value) internal pure returns (int120 downcasted) {
        downcasted = int120(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(120, value);
        }
    }

    /**
     * @dev Returns the downcasted int112 from int256, reverting on
     * overflow (when the input is less than smallest int112 or
     * greater than largest int112).
     *
     * Counterpart to Solidity's `int112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     */
    function toInt112(int256 value) internal pure returns (int112 downcasted) {
        downcasted = int112(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(112, value);
        }
    }

    /**
     * @dev Returns the downcasted int104 from int256, reverting on
     * overflow (when the input is less than smallest int104 or
     * greater than largest int104).
     *
     * Counterpart to Solidity's `int104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     */
    function toInt104(int256 value) internal pure returns (int104 downcasted) {
        downcasted = int104(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(104, value);
        }
    }

    /**
     * @dev Returns the downcasted int96 from int256, reverting on
     * overflow (when the input is less than smallest int96 or
     * greater than largest int96).
     *
     * Counterpart to Solidity's `int96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     */
    function toInt96(int256 value) internal pure returns (int96 downcasted) {
        downcasted = int96(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(96, value);
        }
    }

    /**
     * @dev Returns the downcasted int88 from int256, reverting on
     * overflow (when the input is less than smallest int88 or
     * greater than largest int88).
     *
     * Counterpart to Solidity's `int88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     */
    function toInt88(int256 value) internal pure returns (int88 downcasted) {
        downcasted = int88(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(88, value);
        }
    }

    /**
     * @dev Returns the downcasted int80 from int256, reverting on
     * overflow (when the input is less than smallest int80 or
     * greater than largest int80).
     *
     * Counterpart to Solidity's `int80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     */
    function toInt80(int256 value) internal pure returns (int80 downcasted) {
        downcasted = int80(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(80, value);
        }
    }

    /**
     * @dev Returns the downcasted int72 from int256, reverting on
     * overflow (when the input is less than smallest int72 or
     * greater than largest int72).
     *
     * Counterpart to Solidity's `int72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     */
    function toInt72(int256 value) internal pure returns (int72 downcasted) {
        downcasted = int72(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(72, value);
        }
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toInt64(int256 value) internal pure returns (int64 downcasted) {
        downcasted = int64(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(64, value);
        }
    }

    /**
     * @dev Returns the downcasted int56 from int256, reverting on
     * overflow (when the input is less than smallest int56 or
     * greater than largest int56).
     *
     * Counterpart to Solidity's `int56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     */
    function toInt56(int256 value) internal pure returns (int56 downcasted) {
        downcasted = int56(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(56, value);
        }
    }

    /**
     * @dev Returns the downcasted int48 from int256, reverting on
     * overflow (when the input is less than smallest int48 or
     * greater than largest int48).
     *
     * Counterpart to Solidity's `int48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     */
    function toInt48(int256 value) internal pure returns (int48 downcasted) {
        downcasted = int48(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(48, value);
        }
    }

    /**
     * @dev Returns the downcasted int40 from int256, reverting on
     * overflow (when the input is less than smallest int40 or
     * greater than largest int40).
     *
     * Counterpart to Solidity's `int40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     */
    function toInt40(int256 value) internal pure returns (int40 downcasted) {
        downcasted = int40(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(40, value);
        }
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toInt32(int256 value) internal pure returns (int32 downcasted) {
        downcasted = int32(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(32, value);
        }
    }

    /**
     * @dev Returns the downcasted int24 from int256, reverting on
     * overflow (when the input is less than smallest int24 or
     * greater than largest int24).
     *
     * Counterpart to Solidity's `int24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     */
    function toInt24(int256 value) internal pure returns (int24 downcasted) {
        downcasted = int24(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(24, value);
        }
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     */
    function toInt16(int256 value) internal pure returns (int16 downcasted) {
        downcasted = int16(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(16, value);
        }
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     */
    function toInt8(int256 value) internal pure returns (int8 downcasted) {
        downcasted = int8(value);
        if (downcasted != value) {
            revert SafeCastOverflowedIntDowncast(8, value);
        }
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        if (value > uint256(type(int256).max)) {
            revert SafeCastOverflowedUintToInt(value);
        }
        return int256(value);
    }

    /**
     * @dev Cast a boolean (false or true) to a uint256 (0 or 1) with no jump.
     */
    function toUint(bool b) internal pure returns (uint256 u) {
        assembly ("memory-safe") {
            u := iszero(iszero(b))
        }
    }
}

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

pragma solidity ^0.8.20;

/**
 * @dev Helper library for emitting standardized panic codes.
 *
 * ```solidity
 * contract Example {
 *      using Panic for uint256;
 *
 *      // Use any of the declared internal constants
 *      function foo() { Panic.GENERIC.panic(); }
 *
 *      // Alternatively
 *      function foo() { Panic.panic(Panic.GENERIC); }
 * }
 * ```
 *
 * Follows the list from https://github.com/ethereum/solidity/blob/v0.8.24/libsolutil/ErrorCodes.h[libsolutil].
 *
 * _Available since v5.1._
 */
// slither-disable-next-line unused-state
library Panic {
    /// @dev generic / unspecified error
    uint256 internal constant GENERIC = 0x00;
    /// @dev used by the assert() builtin
    uint256 internal constant ASSERT = 0x01;
    /// @dev arithmetic underflow or overflow
    uint256 internal constant UNDER_OVERFLOW = 0x11;
    /// @dev division or modulo by zero
    uint256 internal constant DIVISION_BY_ZERO = 0x12;
    /// @dev enum conversion error
    uint256 internal constant ENUM_CONVERSION_ERROR = 0x21;
    /// @dev invalid encoding in storage
    uint256 internal constant STORAGE_ENCODING_ERROR = 0x22;
    /// @dev empty array pop
    uint256 internal constant EMPTY_ARRAY_POP = 0x31;
    /// @dev array out of bounds access
    uint256 internal constant ARRAY_OUT_OF_BOUNDS = 0x32;
    /// @dev resource error (too large allocation or too large array)
    uint256 internal constant RESOURCE_ERROR = 0x41;
    /// @dev calling invalid internal function
    uint256 internal constant INVALID_INTERNAL_FUNCTION = 0x51;

    /// @dev Reverts with a panic code. Recommended to use with
    /// the internal constants with predefined codes.
    function panic(uint256 code) internal pure {
        assembly ("memory-safe") {
            mstore(0x00, 0x4e487b71)
            mstore(0x20, code)
            revert(0x1c, 0x24)
        }
    }
}

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

pragma solidity ^0.8.20;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If EIP-1153 (transient storage) is available on the chain you're deploying at,
 * consider using {ReentrancyGuardTransient} instead.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant NOT_ENTERED = 1;
    uint256 private constant ENTERED = 2;

    uint256 private _status;

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    constructor() {
        _status = NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be NOT_ENTERED
        if (_status == ENTERED) {
            revert ReentrancyGuardReentrantCall();
        }

        // Any calls to nonReentrant after this point will fail
        _status = ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == ENTERED;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import {GovernanceProposal, GovernanceAction} from "./structs/GovernanceProposal.sol";

/// @title FeeGovernance
/// @notice 3-of-5 governor multisig for managing fee withdrawal addresses and pulling fees from X2Swap.
contract FeeGovernance {
    uint256 public governorCount;
    uint256 public threshold;

    address[] public governors;
    mapping(address => bool) public isGovernor;

    mapping(address => bool) public isWithdrawer;

    bool public isPaused = false;
    bool public isEmergencyPaused = false; // Permanent pause, cannot be unpaused

    uint256 public nextProposalId;
    mapping(uint256 => GovernanceProposal) public proposals;
    mapping(uint256 => mapping(address => bool)) public voted;

    // events removed

    modifier onlyGovernor() {
        require(isGovernor[msg.sender], "Not governor");
        _;
    }

    constructor(address[] memory governors_) {
        require(governors_.length >= 3, "Min 3 governors");
        uint256 governorsLength = governors_.length;
        for (uint256 i = 0; i < governorsLength; ) {
            address g = governors_[i];
            require(g != address(0), "Bad governor");
            require(!isGovernor[g], "Duplicate governor");
            governors.push(g);
            isGovernor[g] = true;
            unchecked { ++i; }
        }
        _recomputeThreshold();
    }

    function _recomputeThreshold() internal {
        governorCount = governors.length;
        require(governorCount >= 3, "Min 3 governors");
        threshold = (governorCount / 2) + 1; // more than half
    }

    function proposeAddWithdrawer(address withdrawer) external onlyGovernor returns (uint256 id) {
        require(withdrawer != address(0), "Bad withdrawer");
        require(!isWithdrawer[withdrawer], "Already withdrawer");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.AddWithdrawer,
            target: withdrawer,
            approvals: 0,
            executed: false
        });
    }

    function proposeRemoveWithdrawer(address withdrawer) external onlyGovernor returns (uint256 id) {
        require(withdrawer != address(0), "Bad withdrawer");
        require(isWithdrawer[withdrawer], "Not withdrawer");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.RemoveWithdrawer,
            target: withdrawer,
            approvals: 0,
            executed: false
        });
    }

    function proposeAddGovernor(address governor) external onlyGovernor returns (uint256 id) {
        require(governor != address(0), "Bad governor");
        require(!isGovernor[governor], "Already governor");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.AddGovernor,
            target: governor,
            approvals: 0,
            executed: false
        });
    }

    function proposeRemoveGovernor(address governor) external onlyGovernor returns (uint256 id) {
        require(governor != address(0), "Bad governor");
        require(isGovernor[governor], "Not governor");
        require(governors.length > 3, "Min 3 governors");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.RemoveGovernor,
            target: governor,
            approvals: 0,
            executed: false
        });
    }

    function proposePause() external onlyGovernor returns (uint256 id) {
        require(!isPaused, "Already paused");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.Pause,
            target: address(0),
            approvals: 0,
            executed: false
        });
    }

    function proposeUnpause() external onlyGovernor returns (uint256 id) {
        require(isPaused, "Not paused");
        require(!isEmergencyPaused, "Emergency pause cannot be reversed");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.Unpause,
            target: address(0),
            approvals: 0,
            executed: false
        });
    }

    function proposeEmergencyPause() external onlyGovernor returns (uint256 id) {
        require(!isEmergencyPaused, "Already emergency paused");
        id = ++nextProposalId;
        proposals[id] = GovernanceProposal({
            action: GovernanceAction.EmergencyPause,
            target: address(0),
            approvals: 0,
            executed: false
        });
    }

    function vote(uint256 id) external onlyGovernor {
        GovernanceProposal storage p = proposals[id];
        require(p.target != address(0) || p.action == GovernanceAction.Pause || p.action == GovernanceAction.Unpause || p.action == GovernanceAction.EmergencyPause, "No proposal");
        require(!p.executed, "Executed");
        require(!voted[id][msg.sender], "Already voted");
        voted[id][msg.sender] = true;
        p.approvals += 1;
    }

    function execute(uint256 id) external onlyGovernor {
        GovernanceProposal storage p = proposals[id];
        require(p.target != address(0) || p.action == GovernanceAction.Pause || p.action == GovernanceAction.Unpause || p.action == GovernanceAction.EmergencyPause, "No proposal");
        require(!p.executed, "Executed");
        require(p.approvals >= threshold, "Not enough votes");
        p.executed = true;

        // Pause = Temporary pause (users can only close positions and withdraw)
        if (p.action == GovernanceAction.Pause) {
            require(!isPaused, "Already paused");
            require(!isEmergencyPaused, "Already emergency paused");
            isPaused = true;
            return;
        }
        if (p.action == GovernanceAction.Unpause) {
            require(isPaused, "Not paused");
            require(!isEmergencyPaused, "Emergency pause cannot be reversed");
            isPaused = false;
            return;
        }
        // EmergencyPause = Permanent pause (cannot be unpaused, only close positions allowed)
        if (p.action == GovernanceAction.EmergencyPause) {
            require(!isEmergencyPaused, "Already emergency paused");
            isEmergencyPaused = true;
            isPaused = true; // Also set isPaused for compatibility
            return;
        }
        if (p.action == GovernanceAction.AddWithdrawer) {
            require(!isWithdrawer[p.target], "Already withdrawer");
            isWithdrawer[p.target] = true;
            return;
        }
        if (p.action == GovernanceAction.RemoveWithdrawer) {
            require(isWithdrawer[p.target], "Not withdrawer");
            isWithdrawer[p.target] = false;
            return;
        }
        if (p.action == GovernanceAction.AddGovernor) {
            require(p.target != address(0), "Bad governor");
            require(!isGovernor[p.target], "Already governor");
            governors.push(p.target);
            isGovernor[p.target] = true;
            _recomputeThreshold();
            return;
        }

        // RemoveGovernor
        require(isGovernor[p.target], "Not governor");
        require(governors.length > 3, "Min 3 governors");
        isGovernor[p.target] = false;
        uint256 len = governors.length;
        for (uint256 i = 0; i < len; ) {
            if (governors[i] == p.target) {
                address last = governors[len - 1];
                governors[i] = last;
                governors.pop();
                _recomputeThreshold();
                return;
            }
            unchecked { ++i; }
        }
        revert("Governor not found");
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/// @notice Minimal ERC20 interface with metadata.
interface IERC20Extended is IERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

/// @notice Minimal exchange interface used by the pool frontend.
interface IExchange {
    function provider() external view returns (string memory);
    function getAmountOut(address tokenIn, uint256 amountIn, bytes calldata path) external view returns (uint256);
    function swap(
        address tokenIn,
        uint256 amountIn,
        uint256 minAmountOut,
        bytes calldata path,
        uint256 deadline
    ) external returns (uint256 amountOut);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

/// @notice Minimal Chainlink-style price oracle interface.
interface IPriceOracle {
    function latestRoundData() external view returns (uint80, int256, uint256, uint256, uint80);
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

enum GovernanceAction {
    AddWithdrawer,
    RemoveWithdrawer,
    AddGovernor,
    RemoveGovernor,
    Pause,
    Unpause,
    EmergencyPause
}

struct GovernanceProposal {
    GovernanceAction action;
    address target;
    uint256 approvals;
    bool executed;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

struct Position {
    uint256 id;
    address sender;
    uint256 openAssetAmount;
    uint256 targetAmount;
    uint256 openDate;
    uint256 expireDate;
    uint256 profitSharing;
    uint256 closeDate;
    uint256 closeAssetAmount;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";

import {FeeGovernance} from "./FeeGovernance.sol";
import {IERC20Extended} from "./interfaces/IERC20Extended.sol";

/// @title X2Pool - ERC-4626 style single contract for deposits and withdrawals
/// @notice Shares represent a pro-rata claim on pool assets; conversions adjust with gains/losses.
contract X2Pool is ERC4626, ReentrancyGuard {

    using SafeERC20 for IERC20;

    FeeGovernance public immutable feeGovernance;
    address public immutable x2deployer;
    mapping(address => bool) public isSwap;
    uint256 public totalDebt;
    
    // Protection against first depositor attack (1 token minimum)
    uint256 public immutable MIN_DEPOSIT;
    
    // Protection against pool insolvency (mathematical constants)
    uint256 public constant MAX_UTILIZATION_BPS = 9500; // 95% maximum utilization
    
    // Maximum pool size (10M tokens)
    uint256 public immutable MAX_POOL_SIZE;
    
    // Minimum liquidity for borrow (10 tokens)
    uint256 public immutable MIN_BORROW_LIQUIDITY;
    
    // Events for critical operations
    event Borrow(
        address indexed swap,
        uint256 amount,
        uint256 newDebt,
        uint256 totalAssets,
        uint256 utilizationBps
    );
    
    event ReturnBorrow(
        address indexed swap,
        uint256 amountReturned,
        uint256 debtRepaid,
        uint256 newDebt,
        uint256 totalAssets,
        uint256 utilizationBps
    );
    
    event SwapRegistered(address indexed swap);
    
    event PartialWithdraw(
        address indexed owner,
        address indexed receiver,
        uint256 requested,
        uint256 actual
    );
    
    event PartialRedeem(
        address indexed owner,
        address indexed receiver,
        uint256 requestedShares,
        uint256 actualShares,
        uint256 assets
    );

    constructor(address asset_, address x2deployer_, address feeGovernance_)
        ERC4626(IERC20(asset_)) ERC20("2x Swap Liquidity Provider Token", "2xLP") {

        require(asset_ != address(0), "Asset required");
        require(x2deployer_ != address(0), "Deployer required");
        require(feeGovernance_ != address(0), "Governance required");
        
        x2deployer = x2deployer_;
        feeGovernance = FeeGovernance(feeGovernance_);
        
        // Set limits based on token decimals (adaptive to any token)
        uint8 decimals_ = IERC20Extended(asset_).decimals();
        uint256 oneToken = 10 ** decimals_;
        
        MIN_DEPOSIT = oneToken;                    // 1 token minimum deposit
        MAX_POOL_SIZE = 10_000_000 * oneToken;     // 10M tokens maximum pool size
        MIN_BORROW_LIQUIDITY = 10 * oneToken;      // 10 tokens minimum liquidity
    }

    /*//////////////////////////////////////////////////////////////
                            CORE OVERRIDES
    //////////////////////////////////////////////////////////////*/

    /// @notice Override totalAssets to include both free and borrowed funds
    /// @dev ERC4626 by default uses balanceOf, but we need to track total capital (free + debt)
    /// @return Total assets under management (balance + debt)
    function totalAssets() public view override returns (uint256) {
        return IERC20(asset()).balanceOf(address(this)) + totalDebt;
    }

    /*//////////////////////////////////////////////////////////////
                            POOL ACTIONS
    //////////////////////////////////////////////////////////////*/

    /// @notice Deposit assets with security checks
    /// @dev Includes MIN_DEPOSIT check and fee-on-transfer detection
    function deposit(uint256 assets, address receiver) public override nonReentrant returns (uint256 shares) {
        require(!feeGovernance.isPaused(), "Protocol emergency paused");
        require(assets >= MIN_DEPOSIT, "Deposit amount too small");
        
        // Check maximum pool size
        uint256 newTotalAssets = totalAssets() + assets;
        require(newTotalAssets <= MAX_POOL_SIZE, "Pool size limit exceeded");

        uint256 balanceBefore = IERC20(asset()).balanceOf(address(this));
        shares = super.deposit(assets, receiver);
        uint256 balanceAfter = IERC20(asset()).balanceOf(address(this));
        require(balanceAfter - balanceBefore == assets, "Fee detected");

        return shares;
    }

    /// @notice Mint shares with security checks
    /// @dev Includes MIN_DEPOSIT check and fee-on-transfer detection
    function mint(uint256 shares, address receiver) public override nonReentrant returns (uint256 assets) {
        require(!feeGovernance.isPaused(), "Protocol emergency paused");
        assets = previewMint(shares);
        require(assets >= MIN_DEPOSIT, "Deposit amount too small");
        
        // Check maximum pool size
        uint256 newTotalAssets = totalAssets() + assets;
        require(newTotalAssets <= MAX_POOL_SIZE, "Pool size limit exceeded");

        uint256 balanceBefore = IERC20(asset()).balanceOf(address(this));
        assets = super.mint(shares, receiver);
        uint256 balanceAfter = IERC20(asset()).balanceOf(address(this));
        require(balanceAfter - balanceBefore == assets, "Fee detected");

        return assets;
    }

    /// @notice Withdraw assets with partial fulfillment if insufficient liquidity
    /// @dev Returns available liquidity if requested amount exceeds free balance
    function withdraw(uint256 assets, address receiver, address owner) 
        public 
        override 
        nonReentrant 
        returns (uint256 shares) 
    {
        require(assets > 0, "Zero amount");
        
        // Get available liquidity (free balance)
        uint256 available = IERC20(asset()).balanceOf(address(this));
        
        // Withdraw what we can (minimum of requested and available)
        uint256 actualWithdraw = assets > available ? available : assets;
        
        // Emit event if partial withdrawal
        if (actualWithdraw < assets) {
            emit PartialWithdraw(owner, receiver, assets, actualWithdraw);
        }
        
        // Use standard ERC4626 withdraw for the actual amount
        return super.withdraw(actualWithdraw, receiver, owner);
    }

    /// @notice Redeem shares with partial fulfillment if insufficient liquidity
    /// @dev Returns available liquidity if share value exceeds free balance
    function redeem(uint256 shares, address receiver, address owner) 
        public 
        override 
        nonReentrant 
        returns (uint256 assets) 
    {
        require(shares > 0, "Zero shares");
        
        // Calculate how many assets these shares represent
        uint256 requestedAssets = previewRedeem(shares);
        
        // Get available liquidity (free balance)
        uint256 available = IERC20(asset()).balanceOf(address(this));
        
        if (requestedAssets > available) {
            // Partial redemption: calculate how many shares we can redeem
            // shares_to_redeem = (available * totalShares) / totalAssets
            uint256 totalShares = totalSupply();
            uint256 _totalAssets = totalAssets();
            uint256 sharesToRedeem = (available * totalShares) / _totalAssets;
            
            emit PartialRedeem(owner, receiver, shares, sharesToRedeem, available);
            
            // Redeem only what we can
            return super.redeem(sharesToRedeem, receiver, owner);
        }
        
        // Full redemption possible
        return super.redeem(shares, receiver, owner);
    }

    /*//////////////////////////////////////////////////////////////
                            X2SWAP ACTIONS
    //////////////////////////////////////////////////////////////*/

    /// @notice Register a new swap contract
    /// @dev Only callable by deployer
    function registerSwap(address swap) external {
        require(msg.sender == x2deployer, "Not deployer");
        require(swap != address(0), "Bad swap");
        isSwap[swap] = true;
        emit SwapRegistered(swap);
    }

    /// @notice Borrow underlying to the linked X2Swap contract with security checks
    /// @dev Only callable by the configured X2Swap, includes utilization checks
    function borrow(uint256 amount) external nonReentrant {
        require(isSwap[msg.sender], "Not swap");
        require(!feeGovernance.isPaused(), "Protocol emergency paused");
        require(amount > 0, "Zero amount");
        
        uint256 _totalAssets = totalAssets();
        uint256 newDebt = totalDebt + amount;
        
        // Check sufficient liquidity
        require(_totalAssets >= amount, "Insufficient pool liquidity");
        require(_totalAssets - amount >= MIN_BORROW_LIQUIDITY, "Below min liquidity");
        
        // Check maximum utilization
        uint256 total = _totalAssets + newDebt;
        uint256 newUtilizationBps = total > 0 ? (newDebt * 10_000) / total : 0;
        require(newUtilizationBps <= MAX_UTILIZATION_BPS, "Max utilization exceeded");
        
        totalDebt += amount;
        
        // Emit event with full information
        emit Borrow(msg.sender, amount, totalDebt, _totalAssets, newUtilizationBps);
        
        IERC20(asset()).safeTransfer(msg.sender, amount);
    }

    /// @notice Return borrowed funds to the pool with validation
    /// @dev Includes parameter consistency checks and utilization tracking
    /// @dev Allows debtRepaid > amount in loss scenarios (pool absorbs losses)
    function returnBorrow(uint256 amount, uint256 debtRepaid) external nonReentrant {
        require(isSwap[msg.sender], "Not swap");
        require(debtRepaid <= totalDebt, "Exceeds debt");

        // Transfer tokens if amount > 0
        if (amount > 0) {
            IERC20(asset()).safeTransferFrom(msg.sender, address(this), amount);
        } else {
            // H-11: Cannot clear debt without returning tokens
            require(debtRepaid == 0, "Cannot clear debt without returning tokens");
        }
        
        totalDebt -= debtRepaid;
        
        // Calculate state for event
        uint256 _totalAssets = totalAssets();
        uint256 total = _totalAssets + totalDebt;
        uint256 utilizationBps = total > 0 ? (totalDebt * 10_000) / total : 0;
        
        // Emit event with full information
        emit ReturnBorrow(msg.sender, amount, debtRepaid, totalDebt, _totalAssets, utilizationBps);
    }

    /*//////////////////////////////////////////////////////////////
                            VIEW HELPERS
    //////////////////////////////////////////////////////////////*/

    /// @notice Get current utilization rate in basis points
    /// @return Utilization rate (0-10000 = 0%-100%)
    function currentUtilizationBps() external view returns (uint256) {
        uint256 _totalAssets = totalAssets();
        uint256 total = _totalAssets + totalDebt;
        return total > 0 ? (totalDebt * 10_000) / total : 0;
    }

    /// @notice Get available liquidity (free balance not currently borrowed)
    /// @return Available assets for withdrawal or borrowing
    function availableLiquidity() external view returns (uint256) {
        return IERC20(asset()).balanceOf(address(this));
    }

    /// @notice Get maximum withdrawable amount for given shares
    /// @dev Accounts for available liquidity constraints
    /// @param shares Amount of shares to check
    /// @return Maximum assets that can be withdrawn
    function maxWithdrawForShares(uint256 shares) external view returns (uint256) {
        uint256 requestedAssets = previewRedeem(shares);
        uint256 available = IERC20(asset()).balanceOf(address(this));
        return requestedAssets > available ? available : requestedAssets;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";

import {X2Pool} from "./X2Pool.sol";
import {Position} from "./structs/Position.sol";
import {IExchange} from "./interfaces/IExchange.sol";
import {IPriceOracle} from "./interfaces/IPriceOracle.sol";
import {FeeGovernance} from "./FeeGovernance.sol";
import {IERC20Extended} from "./interfaces/IERC20Extended.sol";

/// @title X2Swap - Leveraged swap contract with comprehensive security measures
/// @notice Manages 2x leveraged positions with oracle validation and automatic protection mechanisms
/// @dev IMPORTANT: This contract is designed for pairs where:
///      - asset = stablecoin (USDC, USDT, DAI) or base currency
///      - targetToken = volatile asset with Chainlink price feed (ETH, BTC, LINK, etc.)
///      - priceOracle = Chainlink feed for targetToken/USD (e.g., ETH/USD)
///      Example: USDC (asset) ↔ WETH (targetToken) using ETH/USD Chainlink feed
contract X2Swap is ReentrancyGuard {

    using SafeERC20 for IERC20;

    X2Pool public immutable pool;
    FeeGovernance public immutable feeGovernance;
    IERC20 public immutable asset;
    IERC20 public immutable targetToken;
    uint256 public immutable positionDuration;
    uint8 public immutable assetDecimals;
    uint8 public immutable targetDecimals;
    IPriceOracle public immutable priceOracle;
    uint256 public immutable feeBps;

    uint256 public feesAccrued;

    // Oracle and deviation limits
    uint256 public constant ORACLE_MAX_DEVIATION_BPS = 500; // 5%
    uint256 public constant ORACLE_MAX_STALENESS = 3600; // 1 hour
    
    // Mathematical limits for position sizes
    uint256 public constant MAX_POSITION_SIZE_BPS = 5000; // 50% of pool (user amount only)
    uint256 public constant MAX_TOTAL_POSITIONS_BPS = 9500; // 95% of pool (matches MAX_UTILIZATION_BPS)
    
    // Minimum position amount (1 token)
    uint256 public immutable MIN_POSITION_AMOUNT;
    
    // Rate limiting
    uint256 public constant MIN_POSITION_INTERVAL = 60; // 1 minute between positions
    mapping(address => uint256) public lastPositionTime;

    uint256 public nextPositionId;
    mapping(uint256 => Position) public positions;
    mapping(address => uint256[]) public positionsOf;

    address[] public exchanges;
    mapping(address => bool) public isExchange;

    // Events
    event OpenPosition(uint256 indexed id, address indexed sender, uint256 assetAmount, uint256 targetAmount, uint256 profitSharing, uint256 feeAmount);
    event ClosePosition(uint256 indexed id, uint256 closeAssetAmount, uint256 feeAmount);

    constructor(
        address asset_,
        address targetToken_,
        address[] memory exchanges_,
        address priceOracle_,
        uint256 feeBps_,
        address pool_,
        address feeGovernance_,
        uint256 positionDuration_
    ) {
        require(asset_ != address(0), "Asset required");
        require(targetToken_ != address(0), "Target required");
        require(priceOracle_ != address(0), "Oracle required");
        require(pool_ != address(0), "Pool required");
        require(feeGovernance_ != address(0), "Fee governance required");
        require(exchanges_.length > 0, "No exchanges");
        
        pool = X2Pool(pool_);
        feeGovernance = FeeGovernance(feeGovernance_);
        asset = IERC20(asset_);
        assetDecimals = IERC20Extended(asset_).decimals();
        targetToken = IERC20(targetToken_);
        targetDecimals = IERC20Extended(targetToken_).decimals();
        
        // Register exchanges with gas optimization
        for (uint256 i = 0; i < exchanges_.length; ) {
            address ex = exchanges_[i];
            require(ex != address(0), "Bad exchange");
            require(!isExchange[ex], "Duplicate exchange");
            exchanges.push(ex);
            isExchange[ex] = true;
            unchecked { ++i; }
        }
        
        priceOracle = IPriceOracle(priceOracle_);
        
        // Validate oracle decimals are reasonable (Chainlink typically uses 8)
        uint8 oracleDecimals = priceOracle.decimals();
        require(oracleDecimals > 0 && oracleDecimals <= 18, "Invalid oracle decimals");
        
        // Verify oracle is working by checking initial price
        (, int256 answer,,,) = priceOracle.latestRoundData();
        require(answer > 0, "Oracle not working");
        
        feeBps = feeBps_;
        positionDuration = positionDuration_;
        
        // Set minimum position amount based on asset decimals
        // MIN_POSITION_AMOUNT = 1 token
        MIN_POSITION_AMOUNT = 10 ** assetDecimals;
    }

    /// @notice Open a new 2x leveraged position
    /// @dev Includes comprehensive validation and automatic pause triggers
    function openPosition(
        uint256 assetAmount,
        uint256 maxDeviationBps,
        address exchangeAddress,
        bytes calldata path,
        uint256 deadline
    ) external nonReentrant returns (uint256 id) {
        // Check emergency pause state
        require(!feeGovernance.isPaused(), "Protocol emergency paused");
        
        require(assetAmount > 0, "Zero amount");
        require(maxDeviationBps <= ORACLE_MAX_DEVIATION_BPS, "Max deviation too high");
        require(isExchange[exchangeAddress], "Bad exchange");
        
        // M-11: Comprehensive validation
        require(deadline >= block.timestamp, "Deadline expired");
        require(path.length >= 40, "Invalid path length");
        require(assetAmount >= MIN_POSITION_AMOUNT, "Amount too small");
        require(asset.balanceOf(msg.sender) >= assetAmount, "Insufficient balance");
        
        // M-8: Rate limiting
        require(block.timestamp >= lastPositionTime[msg.sender] + MIN_POSITION_INTERVAL, "Too frequent");
        lastPositionTime[msg.sender] = block.timestamp;
        
        // H-4: Limit individual position size (based on available liquidity, not total assets)
        uint256 availableLiquidity = asset.balanceOf(address(pool));
        require(assetAmount <= (availableLiquidity * MAX_POSITION_SIZE_BPS) / 10_000, "Position too large");
        
        IExchange exchange = IExchange(exchangeAddress);
        
        // Calculate opening fee (infrastructure fee)
        uint256 openFee = (assetAmount * feeBps) / 10_000;
        uint256 netUserAmount = assetAmount - openFee;
        feesAccrued += openFee;
        
        // Fee-on-transfer token protection
        uint256 balanceBefore = asset.balanceOf(address(this));
        asset.safeTransferFrom(msg.sender, address(this), assetAmount);
        uint256 balanceAfter = asset.balanceOf(address(this));
        require(balanceAfter - balanceBefore == assetAmount, "Fee detected");
        
        // H-4: Limit total positions (use total pool capital, not just free assets)
        uint256 currentDebt = pool.totalDebt();
        uint256 newDebt = currentDebt + netUserAmount;
        uint256 totalPoolCapital = pool.totalAssets();  // totalAssets = balance + debt
        require(newDebt <= (totalPoolCapital * MAX_TOTAL_POSITIONS_BPS) / 10_000, "Max positions exceeded");
        
        // H-5: Calculate profit sharing BEFORE borrow (prevents race condition)
        uint256 predictedTotal = totalPoolCapital;
        uint256 predictedUtilizationBps = predictedTotal > 0 ? (newDebt * 10_000) / predictedTotal : 0;
        uint256 profitSharing;
        if (predictedUtilizationBps <= 9000) {
            profitSharing = 20;
        } else if (predictedUtilizationBps <= 9200) {
            profitSharing = 30;
        } else if (predictedUtilizationBps <= 9400) {
            profitSharing = 40;
        } else {
            profitSharing = 50;
        }

        // Borrow from pool (with fee-on-transfer check)
        balanceBefore = asset.balanceOf(address(this));
        pool.borrow(netUserAmount);
        balanceAfter = asset.balanceOf(address(this));
        require(balanceAfter - balanceBefore == netUserAmount, "Fee detected");

        uint256 totalAmount = netUserAmount * 2;

        // Get expected output and validate
        uint256 expectedOut = exchange.getAmountOut(address(asset), totalAmount, path);
        require(expectedOut > 0, "No output");
        
        // M-2: Oracle validation
        uint256 oracleMinTargetOut = _oracleMinTargetOut(totalAmount, maxDeviationBps);
        require(expectedOut >= oracleMinTargetOut, "Oracle deviation");

        // H-2: Exact amount approval (not unlimited)
        uint256 currentAllowance = asset.allowance(address(this), exchangeAddress);
        if (currentAllowance < totalAmount) {
            asset.approve(exchangeAddress, totalAmount);
        }
        
        uint256 amountOut = exchange.swap(address(asset), totalAmount, expectedOut, path, deadline);
        
        // H-2: Revoke approval after use
        asset.approve(exchangeAddress, 0);

        // Save position
        id = ++nextPositionId; // Start from 1, not 0
        Position memory p = Position({
            id: id,
            sender: msg.sender,
            openAssetAmount: totalAmount,
            targetAmount: amountOut,
            openDate: block.timestamp,
            expireDate: block.timestamp + positionDuration,
            profitSharing: profitSharing,
            closeDate: 0,
            closeAssetAmount: 0
        });
        positions[id] = p;
        positionsOf[msg.sender].push(id);
        
        emit OpenPosition(id, msg.sender, p.openAssetAmount, p.targetAmount, p.profitSharing, openFee);
    }

    /// @notice Close an existing position
    /// @dev Owner can close anytime, anyone can close after expiration
    function closePosition(
        uint256 id,
        uint256 maxDeviationBps,
        address exchangeAddress,
        bytes calldata path,
        uint256 deadline
    ) external nonReentrant {
        // Closing is always allowed (emergency withdrawal)
        
        require(maxDeviationBps <= ORACLE_MAX_DEVIATION_BPS, "Max deviation too high");
        require(isExchange[exchangeAddress], "Bad exchange");
        
        IExchange exchange = IExchange(exchangeAddress);
        Position memory p = positions[id];

        // M-19: Position existence validation
        require(p.openDate > 0, "Position does not exist");
        require(p.sender != address(0), "Invalid position");
        require(p.targetAmount > 0, "Invalid target amount");
        require(p.closeDate == 0, "Already closed");
        
        // Access control: owner can close anytime, anyone after expiration
        if (block.timestamp < p.expireDate) {
            require(p.sender == msg.sender, "Only owner before expiration");
        }

        // Get minimum output
        uint256 amountIn = p.targetAmount;
        uint256 minOut = exchange.getAmountOut(address(targetToken), amountIn, path);
        require(minOut > 0, "No output");
        
        // M-2: Oracle validation
        uint256 oracleMinAssetOut = _oracleMinAssetOut(amountIn, maxDeviationBps);
        require(minOut >= oracleMinAssetOut, "Oracle deviation");

        // H-2: Exact amount approval
        uint256 currentAllowance = targetToken.allowance(address(this), exchangeAddress);
        if (currentAllowance < amountIn) {
            targetToken.approve(exchangeAddress, amountIn);
        }
        
        // M-18: Balance verification before swap
        uint256 assetBalanceBefore = asset.balanceOf(address(this));
        
        uint256 assetAmountOut = exchange.swap(address(targetToken), amountIn, minOut, path, deadline);
        
        // H-2: Revoke approval
        targetToken.approve(exchangeAddress, 0);
        
        // M-18: Check actual balance after swap
        uint256 assetBalanceAfter = asset.balanceOf(address(this));
        uint256 actualReceived = assetBalanceAfter - assetBalanceBefore;
        require(actualReceived >= minOut, "Actual received less than expected");
        
        assetAmountOut = actualReceived;
        
        // Calculate split between pool and borrower (includes profit sharing)
        (uint256 poolAmount, uint256 borrowerGross) = _splitClose(p.openAssetAmount, assetAmountOut, p.profitSharing);
        uint256 poolPrincipal = p.openAssetAmount / 2;
        
        // Calculate closing fee from profit only
        uint256 closeFee = 0;
        if (assetAmountOut >= p.openAssetAmount) {
            // There is profit - take fee from the profit
            uint256 profit = assetAmountOut - p.openAssetAmount;
            closeFee = (profit * feeBps) / 10_000;
            feesAccrued += closeFee;
        }
        
        uint256 borrowerNet = borrowerGross > closeFee ? borrowerGross - closeFee : 0;

        // H-2: Exact amount approval for pool return
        uint256 poolAllowance = asset.allowance(address(this), address(pool));
        if (poolAllowance < poolAmount) {
            asset.approve(address(pool), poolAmount);
        }
        
        // H-11: Return borrow with validated parameters
        pool.returnBorrow(poolAmount, poolPrincipal);
        
        // H-2: Revoke approval
        asset.approve(address(pool), 0);

        // Transfer to position owner
        if (borrowerNet > 0) {
            asset.safeTransfer(p.sender, borrowerNet);
        }

        // Update position
        positions[id].closeDate = block.timestamp;
        positions[id].closeAssetAmount = assetAmountOut;
        
        emit ClosePosition(id, assetAmountOut, closeFee);
    }

    /// @notice Preview a new position without state changes
    function previewNewPosition(
        uint256 assetAmount,
        uint256 maxDeviationBps,
        address exchangeAddress,
        bytes calldata path
    )
        external
        view
        returns (
            uint256 openFee,
            uint256 netUserAmount,
            uint256 totalAmount,
            uint256 expectedOut,
            uint256 oracleMinTargetOut,
            uint256 profitSharing
        )
    {
        require(assetAmount > 0, "Zero amount");
        require(maxDeviationBps <= ORACLE_MAX_DEVIATION_BPS, "Max deviation too high");
        require(isExchange[exchangeAddress], "Bad exchange");

        openFee = (assetAmount * feeBps) / 10_000;
        netUserAmount = assetAmount - openFee;
        totalAmount = netUserAmount * 2;

        expectedOut = IExchange(exchangeAddress).getAmountOut(address(asset), totalAmount, path);
        oracleMinTargetOut = _oracleMinTargetOutView(totalAmount, maxDeviationBps);
        profitSharing = currentProfitSharing();
    }

    /// @notice Get current profit sharing percentage based on pool utilization
    /// @dev M-6: Includes overflow protection
    function currentProfitSharing() public view returns (uint256) {
        uint256 assets = pool.totalAssets();
        uint256 debt = pool.totalDebt();
        
        // M-6: Overflow protection for addition
        if (assets > type(uint256).max - debt) {
            return 50; // Maximum profit sharing
        }
        
        uint256 total = assets + debt;
        if (total == 0) return 20;
        
        // M-6: Overflow protection for multiplication
        if (debt > type(uint256).max / 10_000) {
            return _calculateProfitSharingAlt(debt, total);
        }
        
        uint256 utilizationBps = (debt * 10_000) / total;

        if (utilizationBps <= 9000) return 20;
        if (utilizationBps <= 9200) return 30;
        if (utilizationBps <= 9400) return 40;
        return 50;
    }

    /// @notice Alternative profit sharing calculation for very large numbers
    /// @dev M-6: Prevents overflow in multiplication
    function _calculateProfitSharingAlt(uint256 debt, uint256 total) internal pure returns (uint256) {
        // Use percentage calculation to avoid overflow
        uint256 percentage = (debt / (total / 100));
        
        if (percentage <= 90) return 20;
        if (percentage <= 92) return 30;
        if (percentage <= 94) return 40;
        return 50;
    }

    /// @notice Get oracle price with validation
    /// @dev M-2: Comprehensive oracle validation with auto-pause
    function getOraclePrice() public view returns (uint256) {
        return _oraclePriceAssetPerTargetView();
    }

    /// @notice Oracle validation with state modification
    /// @dev M-2: Includes staleness checks and validation
    /// @dev Returns price of 1 targetToken in asset units (adjusted for decimals)
    /// @dev For Chainlink: ETH/USD feed with 8 decimals returns ~3000_00000000 for $3000
    ///      Adjusted to USDC (6 decimals) = 3000_000000
    function _oraclePriceAssetPerTarget() internal returns (uint256) {
        (uint80 roundId, int256 answer, , uint256 updatedAt, uint80 answeredInRound) = priceOracle.latestRoundData();
        
        // M-2: Check for invalid oracle answer
        require(answer > 0, "Invalid oracle answer");
        
        // M-2: Validate oracle data freshness and validity
        require(answeredInRound >= roundId, "Stale oracle data");
        require(updatedAt > 0, "Invalid update time");
        require(block.timestamp - updatedAt <= ORACLE_MAX_STALENESS, "Oracle data too old");
        
        // M-2: Check price reasonableness (additional protection)
        require(answer < type(int192).max, "Oracle price overflow");
        
        uint8 oracleDecimals = priceOracle.decimals();
        uint256 price = uint256(answer);
        
        // Adjust decimals to match asset decimals
        // Example: Chainlink ETH/USD (8 decimals) -> USDC (6 decimals)
        // 3000_00000000 / 100 = 3000_000000
        if (oracleDecimals < assetDecimals) {
            return price * 10 ** (assetDecimals - oracleDecimals);
        } else if (oracleDecimals > assetDecimals) {
            return price / 10 ** (oracleDecimals - assetDecimals);
        }
        return price;
    }

    /// @notice View-only oracle price (no pause trigger)
    /// @dev M-2: Oracle validation without state modification
    function _oraclePriceAssetPerTargetView() internal view returns (uint256) {
        (uint80 roundId, int256 answer, , uint256 updatedAt, uint80 answeredInRound) = priceOracle.latestRoundData();
        require(answer > 0, "Invalid oracle answer");
        
        // M-2: Validate oracle data
        require(answeredInRound >= roundId, "Stale oracle data");
        require(updatedAt > 0, "Invalid update time");
        require(block.timestamp - updatedAt <= ORACLE_MAX_STALENESS, "Oracle data too old");
        
        // M-2: Check price reasonableness
        require(answer < type(int192).max, "Oracle price overflow");
        
        uint8 oracleDecimals = priceOracle.decimals();
        uint256 price = uint256(answer);
        
        if (oracleDecimals < assetDecimals) {
            return price * 10 ** (assetDecimals - oracleDecimals);
        } else if (oracleDecimals > assetDecimals) {
            return price / 10 ** (oracleDecimals - assetDecimals);
        }
        return price;
    }

    /// @notice Calculate minimum target token output based on oracle
    /// @dev Used when opening position: asset -> targetToken
    /// @param assetAmountIn Amount of asset tokens to swap (e.g., 2000 USDC)
    /// @param maxDeviationBps Maximum acceptable deviation from oracle price (e.g., 500 = 5%)
    /// @return Minimum expected targetToken amount (e.g., 0.66 WETH)
    function _oracleMinTargetOut(uint256 assetAmountIn, uint256 maxDeviationBps) internal returns (uint256) {
        uint256 priceAssetPerTarget = _oraclePriceAssetPerTarget();
        uint256 targetOut = (assetAmountIn * (10 ** uint256(targetDecimals))) / priceAssetPerTarget;
        return (targetOut * (10_000 - maxDeviationBps)) / 10_000;
    }

    /// @notice Calculate minimum asset output based on oracle
    /// @dev Used when closing position: targetToken -> asset
    /// @param targetAmountIn Amount of target tokens to swap (e.g., 0.66 WETH)
    /// @param maxDeviationBps Maximum acceptable deviation from oracle price (e.g., 500 = 5%)
    /// @return Minimum expected asset amount (e.g., 1900 USDC with 5% deviation)
    function _oracleMinAssetOut(uint256 targetAmountIn, uint256 maxDeviationBps) internal returns (uint256) {
        uint256 priceAssetPerTarget = _oraclePriceAssetPerTarget();
        uint256 assetOut = (targetAmountIn * priceAssetPerTarget) / (10 ** uint256(targetDecimals));
        return (assetOut * (10_000 - maxDeviationBps)) / 10_000;
    }
    
    /// @notice View-only minimum target output calculation
    function _oracleMinTargetOutView(uint256 assetAmountIn, uint256 maxDeviationBps) internal view returns (uint256) {
        uint256 priceAssetPerTarget = _oraclePriceAssetPerTargetView();
        require(priceAssetPerTarget > 0, "Oracle price 0");
        uint256 targetOut = (assetAmountIn * (10 ** uint256(targetDecimals))) / priceAssetPerTarget;
        return (targetOut * (10_000 - maxDeviationBps)) / 10_000;
    }

    /// @notice View-only minimum asset output calculation
    function _oracleMinAssetOutView(uint256 targetAmountIn, uint256 maxDeviationBps) internal view returns (uint256) {
        uint256 priceAssetPerTarget = _oraclePriceAssetPerTargetView();
        require(priceAssetPerTarget > 0, "Oracle price 0");
        uint256 assetOut = (targetAmountIn * priceAssetPerTarget) / (10 ** uint256(targetDecimals));
        return (assetOut * (10_000 - maxDeviationBps)) / 10_000;
    }

    /// @notice Withdraw accrued fees (only authorized by governance)
    function withdrawFees(address to, uint256 amount) external nonReentrant returns (uint256 withdrawn) {
        require(feeGovernance.isWithdrawer(msg.sender), "Not allowed");
        require(to != address(0), "Bad recipient");
        require(amount > 0, "Zero amount");
        require(amount <= feesAccrued, "Exceeds fees");
        
        feesAccrued -= amount;
        asset.safeTransfer(to, amount);
        withdrawn = amount;
    }

    /// @notice Split closing amount between pool and borrower
    function _splitClose(uint256 openAssetAmount, uint256 assetAmountOut, uint256 profitSharing)
        internal
        pure
        returns (uint256 poolAmount, uint256 borrowerGross)
    {
        uint256 poolPrincipal = openAssetAmount / 2;

        if (assetAmountOut >= openAssetAmount) {
            // Profit scenario
            uint256 profitUint = assetAmountOut - openAssetAmount;
            uint256 poolBonus = (profitUint * profitSharing) / 100;
            poolAmount = poolPrincipal + poolBonus;
            borrowerGross = assetAmountOut - poolAmount;
        } else {
            // Loss scenario - borrower bears losses first, then pool
            uint256 loss = openAssetAmount - assetAmountOut;
            uint256 borrowerOpenAmount = openAssetAmount / 2;
            
            if (loss <= borrowerOpenAmount) {
                // Loss is within borrower's capital - pool gets principal back
                poolAmount = poolPrincipal;
                borrowerGross = borrowerOpenAmount - loss;
            } else {
                // Loss exceeds borrower's capital - pool also takes losses
                poolAmount = assetAmountOut;
                borrowerGross = 0;
            }
        }
    }

    /// @notice Get user's position IDs
    function getUserPositions(address user) external view returns (uint256[] memory) {
        return positionsOf[user];
    }

    /// @notice Get position details
    function getPosition(uint256 id) external view returns (Position memory) {
        return positions[id];
    }
}