Contract Address Details

/*
_                                                 __     _____ 
| |    __ _ _   _  ___ _ __ _____      ____ _ _ __ \ \   / ( _ )
| |   / _` | | | |/ _ \ '__/ __\ \ /\ / / _` | '_ \ \ \ / // _ \
| |__| (_| | |_| |  __/ |  \__ \\ V  V / (_| | |_) | \ V /| (_) |
|_____\__,_|\__, |\___|_|  |___/ \_/\_/ \__,_| .__/   \_/  \___/
            |___/                            |_|

*/

// SPDX-License-Identifier: MIT
pragma solidity 0.8.23;
import '@openzeppelin/contracts/utils/cryptography/ECDSA.sol';
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';

/**
 * @title Hashed Timelock contracts (HTLCs) on Ethereum ERC20 tokens.
 *
 * This contract provides a way to lock and keep HTLCs for ERC20 tokens.
 *
 * Protocol:
 *
 *  1) lock(srcReceiver, hashlock, timelock, tokenContract, amount) - a
 *      sender calls this to lock a new HTLC on a given token (tokenContract)
 *       for a given amount. A 32 byte contract id is returned
 *  2) redeem(contractId, secret) - once the srcReceiver knows the secret of
 *      the hashlock hash they can claim the tokens with this function
 *  3) refund() - after timelock has expired and if the srcReceiver did not
 *      redeem the tokens the sender / creator of the HTLC can get their tokens
 *      back with this function.
 */
struct EIP712Domain {
  string name;
  string version;
  uint256 chainId;
  address verifyingContract;
  bytes32 salt;
}

interface IMessenger {
  function notify(
    bytes32 Id,
    bytes32 hashlock,
    string memory dstChain,
    string memory dstAsset,
    string memory dstAddress,
    string memory srcAsset,
    address payable sender,
    address payable srcReceiver,
    uint256 amount,
    uint256 timelock,
    address tokenContract
  ) external;
}

contract LayerswapV8ERC20 {
  using ECDSA for bytes32;
  using Address for address;

  bytes32 private DOMAIN_SEPARATOR;
  bytes32 private constant SALT = keccak256(abi.encodePacked('Layerswap V8'));

  constructor() {
    DOMAIN_SEPARATOR = hashDomain(
      EIP712Domain({
        name: 'LayerswapV8ERC20',
        version: '1',
        chainId: block.chainid,
        verifyingContract: address(this),
        salt: SALT
      })
    );
  }

  error FundsNotSent();
  error NotFutureTimelock();
  error NotPassedTimelock();
  error LockAlreadyExists();
  error HTLCAlreadyExists();
  error HTLCNotExists();
  error HashlockNotMatch();
  error AlreadyRedeemed();
  error AlreadyRefunded();
  error NoMessenger();
  error IncorrectData();
  error InsufficientBalance();
  error NoAllowance();
  error AlreadyLocked();
  error InvalidSigniture();
  error HashlockAlreadySet();

  struct HTLC {
    string dstAddress;
    string dstChain;
    string dstAsset;
    string srcAsset;
    address payable sender;
    address payable srcReceiver;
    bytes32 hashlock;
    uint256 timelock;
    uint256 amount;
    uint256 secret;
    address tokenContract;
    address messenger;
    bool redeemed;
    bool refunded;
  }

  struct addLockMsg {
    bytes32 Id;
    bytes32 hashlock;
    uint256 timelock;
  }

  using SafeERC20 for IERC20;
  mapping(bytes32 => HTLC) contracts;
  bytes32[] contractIds;
  uint256 blockHashAsUint = uint256(blockhash(block.number - 1));
  uint256 contractNonce = 0;

  event TokenCommitted(
    bytes32 indexed Id,
    string[] hopChains,
    string[] hopAssets,
    string[] hopAddresses,
    string dstChain,
    string dstAddress,
    string dstAsset,
    address indexed sender,
    address indexed srcReceiver,
    string srcAsset,
    uint amount,
    uint timelock,
    address messenger,
    address tokenContract
  );

  event TokenLocked(
    bytes32 indexed Id,
    bytes32 hashlock,
    string dstChain,
    string dstAddress,
    string dstAsset,
    address indexed sender,
    address indexed srcReceiver,
    string srcAsset,
    uint amount,
    uint timelock,
    address messenger,
    address tokenContract
  );

  event TokenLockAdded(bytes32 Id, address messenger, bytes32 hashlock, uint256 timelock);
  event TokenRedeemed(bytes32 indexed Id, address redeemAddress);
  event TokenRefunded(bytes32 indexed Id);
  event LowLevelErrorOccurred(bytes lowLevelData);

  modifier _exists(bytes32 Id) {
    if (!hasHTLC(Id)) revert HTLCNotExists();
    _;
  }

  function commit(
    string[] memory hopChains,
    string[] memory hopAssets,
    string[] memory hopAddresses,
    string memory dstChain,
    string memory dstAsset,
    string memory dstAddress,
    string memory srcAsset,
    address srcReceiver,
    uint timelock,
    address messenger,
    uint amount,
    address tokenContract
  ) external returns (bytes32 Id) {
    if (amount == 0) {
      revert FundsNotSent();
    }
    if (timelock <= block.timestamp) {
      revert NotFutureTimelock();
    }

    IERC20 token = IERC20(tokenContract);

    if (token.balanceOf(msg.sender) < amount) {
      revert InsufficientBalance();
    }

    if (token.allowance(msg.sender, address(this)) < amount) {
      revert NoAllowance();
    }

    token.safeTransferFrom(msg.sender, address(this), amount);

    contractNonce += 1;
    Id = bytes32(blockHashAsUint ^ contractNonce);

    //Remove this check; the ID is guaranteed to be unique.
    if (hasHTLC(Id)) {
      revert HTLCAlreadyExists();
    }
    contractIds.push(Id);
    contracts[Id] = HTLC(
      dstAddress,
      dstChain,
      dstAsset,
      srcAsset,
      payable(msg.sender),
      payable(srcReceiver),
      bytes32(0),
      timelock,
      amount,
      uint256(0),
      tokenContract,
      messenger,
      false,
      false
    );

    emit TokenCommitted(
      Id,
      hopChains,
      hopAssets,
      hopAddresses,
      dstChain,
      dstAddress,
      dstAsset,
      msg.sender,
      srcReceiver,
      srcAsset,
      amount,
      timelock,
      messenger,
      tokenContract
    );
  }

  function addLock(bytes32 Id, bytes32 hashlock, uint256 timelock) external _exists(Id) returns (bytes32) {
    HTLC storage htlc = contracts[Id];
    if (htlc.refunded == true) {
      revert AlreadyRefunded();
    }
    if (timelock <= block.timestamp) {
      revert NotFutureTimelock();
    }
    if (msg.sender == htlc.sender || msg.sender == htlc.messenger || msg.sender == address(this)) {
      if (htlc.hashlock == 0) {
        htlc.hashlock = hashlock;
        htlc.timelock = timelock;
      } else {
        revert HashlockAlreadySet();
      }
      // DISCLAIMER: `tx.origin` is used in this event, but it can be misleading as it tracks the
      // original transaction sender, which could be different from the expected sender in complex
      // flows (e.g., a -> ... -> b -> c where the actual sender is b in event will be emitted a)
      emit TokenLockAdded(Id, tx.origin, hashlock, timelock);
      return Id;
    } else {
      revert NoAllowance();
    }
  }

  function addLockSig(addLockMsg memory message, uint8 v, bytes32 r, bytes32 s) external returns (bytes32) {
    if (verifyMessage(message, v, r, s)) {
      return this.addLock(message.Id, message.hashlock, message.timelock);
    } else {
      revert InvalidSigniture();
    }
  }

  /**
   * @dev Sender / Payer sets up a new hash time lock contract depositing the
   * funds and providing the reciever and terms.
   * @param srcReceiver srcReceiver of the funds.
   * @param hashlock A sha-256 hash hashlock.
   * @param timelock UNIX epoch seconds time that the lock expires at.
   *                  unlocks can be made after this time.
   * @return Id Id of the new HTLC. This is needed for subsequent
   *                    calls.
   */

  function lock(
    bytes32 Id,
    bytes32 hashlock,
    uint256 timelock,
    address srcReceiver,
    string memory srcAsset,
    string memory dstChain,
    string memory dstAddress,
    string memory dstAsset,
    address messenger,
    uint256 amount,
    address tokenContract
  ) external returns (bytes32) {
    if (timelock <= block.timestamp) {
      revert NotFutureTimelock();
    }
    if (amount == 0) {
      revert FundsNotSent();
    }
    if (hasHTLC(Id)) {
      revert HTLCAlreadyExists();
    }
    IERC20 token = IERC20(tokenContract);

    if (token.balanceOf(msg.sender) < amount) {
      revert InsufficientBalance();
    }

    if (token.allowance(msg.sender, address(this)) < amount) {
      revert NoAllowance();
    }

    token.safeTransferFrom(msg.sender, address(this), amount);
    contracts[Id] = HTLC(
      dstAddress,
      dstChain,
      dstAsset,
      srcAsset,
      payable(msg.sender),
      payable(srcReceiver),
      hashlock,
      timelock,
      amount,
      0x0,
      tokenContract,
      messenger,
      false,
      false
    );

    contractIds.push(Id);
    emit TokenLocked(
      Id,
      hashlock,
      dstChain,
      dstAddress,
      dstAsset,
      msg.sender,
      srcReceiver,
      srcAsset,
      amount,
      timelock,
      messenger,
      tokenContract
    );

    if (messenger != address(0)) {
      uint256 codeSize;
      assembly {
        codeSize := extcodesize(messenger)
      }
      if (codeSize > 0) {
        try
          IMessenger(messenger).notify(
            Id,
            hashlock,
            dstChain,
            dstAsset,
            dstAddress,
            srcAsset,
            payable(msg.sender),
            payable(srcReceiver),
            amount,
            timelock,
            tokenContract
          )
        {
          // Notify successful
        } catch Error(string memory reason) {
          revert(reason);
        } catch (bytes memory lowLevelData) {
          emit LowLevelErrorOccurred(lowLevelData);
          revert('IMessenger notify failed');
        }
      } else {
        revert NoMessenger();
      }
    }
    return Id;
  }

  /**
   * @dev Called by the srcReceiver once they know the secret of the hashlock.
   * This will transfer the locked funds to their address.
   *
   * @param Id Id of the HTLC.
   * @param secret sha256(secret) should equal the contract hashlock.
   * @return bool true on success
   */
  function redeem(bytes32 Id, uint256 secret) external _exists(Id) returns (bool) {
    HTLC storage htlc = contracts[Id];

    if (htlc.hashlock != sha256(abi.encodePacked(secret))) revert HashlockNotMatch();
    if (htlc.redeemed) revert AlreadyRedeemed();
    if (htlc.refunded) revert AlreadyRefunded();

    htlc.secret = secret;
    htlc.redeemed = true;
    IERC20(htlc.tokenContract).safeTransfer(htlc.srcReceiver, htlc.amount);
    emit TokenRedeemed(Id, msg.sender);
    return true;
  }

  /**
   * @dev Called by the sender if there was no redeem AND the time lock has
   * expired. This will refund the contract amount.
   * @param Id Id of HTLC to refund from.
   * @return bool true on success
   */
  function refund(bytes32 Id) external _exists(Id) returns (bool) {
    HTLC storage htlc = contracts[Id];

    if (htlc.refunded) revert AlreadyRefunded();
    if (htlc.redeemed) revert AlreadyRedeemed();
    if (htlc.timelock > block.timestamp) revert NotPassedTimelock();

    htlc.refunded = true;
    IERC20(htlc.tokenContract).safeTransfer(htlc.sender, htlc.amount);
    emit TokenRefunded(Id);
    return true;
  }

  /**
   * @dev Get contract details.
   * @param Id HTLC contract id
   */
  function getDetails(bytes32 Id) external view returns (HTLC memory) {
    return contracts[Id];
  }

  /**
   * @dev Check if there is a contract with a given id.
   * @param Id Id into contracts mapping.
   */
  function hasHTLC(bytes32 Id) internal view returns (bool exists) {
    exists = (contracts[Id].sender != address(0));
  }

  function getContracts(address senderAddr) public view returns (bytes32[] memory) {
    uint count = 0;

    for (uint i = 0; i < contractIds.length; i++) {
      HTLC memory htlc = contracts[contractIds[i]];
      if (htlc.sender == senderAddr) {
        count++;
      }
    }

    bytes32[] memory result = new bytes32[](count);
    uint j = 0;

    for (uint i = 0; i < contractIds.length; i++) {
      if (contracts[contractIds[i]].sender == senderAddr) {
        result[j] = contractIds[i];
        j++;
      }
    }

    return result;
  }

  function hashDomain(EIP712Domain memory domain) private pure returns (bytes32) {
    return
      keccak256(
        abi.encode(
          keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract,bytes32 salt)'),
          keccak256(bytes(domain.name)),
          keccak256(bytes(domain.version)),
          domain.chainId,
          domain.verifyingContract,
          domain.salt
        )
      );
  }

  // Hashes an EIP712 message struct
  function hashMessage(addLockMsg memory message) private pure returns (bytes32) {
    return
      keccak256(
        abi.encode(
          keccak256('addLockMsg(bytes32 Id,bytes32 hashlock,uint256 timelock)'),
          message.Id,
          message.hashlock,
          message.timelock
        )
      );
  }

  // Verifies an EIP712 message signature
  function verifyMessage(addLockMsg memory message, uint8 v, bytes32 r, bytes32 s) private view returns (bool) {
    bytes32 digest = keccak256(abi.encodePacked('\x19\x01', DOMAIN_SEPARATOR, hashMessage(message)));

    address recoveredAddress = ecrecover(digest, v, r, s);

    return (recoveredAddress == contracts[message.Id].sender);
  }
}
        

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 *
 * ==== Security Considerations
 *
 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
 * generally recommended is:
 *
 * ```solidity
 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
 *     doThing(..., value);
 * }
 *
 * function doThing(..., uint256 value) public {
 *     token.safeTransferFrom(msg.sender, address(this), value);
 *     ...
 * }
 * ```
 *
 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
 * {SafeERC20-safeTransferFrom}).
 *
 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
 * contracts should have entry points that don't rely on permit.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     *
     * CAUTION: See Security Considerations above.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC20Permit} from "../extensions/IERC20Permit.sol";
import {Address} from "../../../utils/Address.sol";

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

    /**
     * @dev An operation with an ERC20 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 Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    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.
     */
    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.
     */
    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 Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data);
        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
            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 silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
    }
}
          

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

pragma solidity ^0.8.20;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert FailedInnerCall();
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.20;

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS
    }

    /**
     * @dev The signature derives the `address(0)`.
     */
    error ECDSAInvalidSignature();

    /**
     * @dev The signature has an invalid length.
     */
    error ECDSAInvalidSignatureLength(uint256 length);

    /**
     * @dev The signature has an S value that is in the upper half order.
     */
    error ECDSAInvalidSignatureS(bytes32 s);

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with `signature` or an error. This will not
     * return address(0) without also returning an error description. Errors are documented using an enum (error type)
     * and a bytes32 providing additional information about the error.
     *
     * If no error is returned, then the address can be used for verification purposes.
     *
     * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError, bytes32) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength, bytes32(signature.length));
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, signature);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     */
    function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError, bytes32) {
        unchecked {
            bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
            // We do not check for an overflow here since the shift operation results in 0 or 1.
            uint8 v = uint8((uint256(vs) >> 255) + 27);
            return tryRecover(hash, v, r, s);
        }
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     */
    function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, r, vs);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError, bytes32) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS, s);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature, bytes32(0));
        }

        return (signer, RecoverError.NoError, bytes32(0));
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, v, r, s);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Optionally reverts with the corresponding custom error according to the `error` argument provided.
     */
    function _throwError(RecoverError error, bytes32 errorArg) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert ECDSAInvalidSignature();
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert ECDSAInvalidSignatureLength(uint256(errorArg));
        } else if (error == RecoverError.InvalidSignatureS) {
            revert ECDSAInvalidSignatureS(errorArg);
        }
    }
}