// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

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

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

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

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import {IERC1155} from "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";

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

// Notes:
// - includes common helpers useful for all marketplace/exchange modules

abstract contract BaseExchangeModule is BaseModule {
  using SafeERC20 for IERC20;

  // --- Structs ---

  // Every fill execution has the following parameters:
  // - `fillTo`: the recipient of the received items
  // - `refundTo`: the recipient of any refunds
  // - `revertIfIncomplete`: whether to revert or skip unsuccessful fills

  // The below `ETHListingParams` and `ERC20ListingParams` rely on the
  // off-chain execution encoder to ensure that the orders filled with
  // the passed in listing parameters exactly match (eg. order amounts
  // and payment tokens match).

  struct ETHListingParams {
    address fillTo;
    address refundTo;
    bool revertIfIncomplete;
    // The total amount of ETH to be provided when filling
    uint256 amount;
  }

  struct ERC20ListingParams {
    address fillTo;
    address refundTo;
    bool revertIfIncomplete;
    // The ERC20 payment token for the listings
    IERC20 token;
    // The total amount of `token` to be provided when filling
    uint256 amount;
  }

  struct OfferParams {
    address fillTo;
    address refundTo;
    bool revertIfIncomplete;
  }

  struct Fee {
    address recipient;
    uint256 amount;
  }

  // --- Fields ---

  address public immutable router;

  // --- Errors ---

  error UnsuccessfulFill();

  // --- Constructor ---

  constructor(address routerAddress) {
    router = routerAddress;
  }

  // --- Modifiers ---

  modifier refundETHLeftover(address refundTo) {
    _;

    uint256 leftover = address(this).balance;
    if (leftover > 0) {
      _sendETH(refundTo, leftover);
    }
  }

  modifier refundERC20Leftover(address refundTo, IERC20 token) {
    _;

    uint256 leftover = token.balanceOf(address(this));
    if (leftover > 0) {
      token.safeTransfer(refundTo, leftover);
    }
  }

  modifier chargeETHFees(Fee[] calldata fees, uint256 amount) {
    if (fees.length == 0) {
      _;
    } else {
      uint256 balanceBefore = address(this).balance;

      _;

      uint256 length = fees.length;
      if (length > 0) {
        uint256 balanceAfter = address(this).balance;
        uint256 actualPaid = balanceBefore - balanceAfter;

        uint256 actualFee;
        for (uint256 i = 0; i < length; ) {
          // Adjust the fee to what was actually paid
          actualFee = (fees[i].amount * actualPaid) / amount;
          if (actualFee > 0) {
            _sendETH(fees[i].recipient, actualFee);
          }

          unchecked {
            ++i;
          }
        }
      }
    }
  }

  modifier chargeERC20Fees(
    Fee[] calldata fees,
    IERC20 token,
    uint256 amount
  ) {
    if (fees.length == 0) {
      _;
    } else {
      uint256 balanceBefore = token.balanceOf(address(this));

      _;

      uint256 length = fees.length;
      if (length > 0) {
        uint256 balanceAfter = token.balanceOf(address(this));
        uint256 actualPaid = balanceBefore - balanceAfter;

        uint256 actualFee;
        for (uint256 i = 0; i < length; ) {
          // Adjust the fee to what was actually paid
          actualFee = (fees[i].amount * actualPaid) / amount;
          if (actualFee > 0) {
            token.safeTransfer(fees[i].recipient, actualFee);
          }

          unchecked {
            ++i;
          }
        }
      }
    }
  }

  // --- Helpers ---

  function _sendAllETH(address to) internal {
    _sendETH(to, address(this).balance);
  }

  function _sendAllERC20(address to, IERC20 token) internal {
    uint256 balance = token.balanceOf(address(this));
    if (balance > 0) {
      token.safeTransfer(to, balance);
    }
  }

  function _sendAllERC721(address to, IERC721 token, uint256 tokenId) internal {
    if (token.ownerOf(tokenId) == address(this)) {
      token.safeTransferFrom(address(this), to, tokenId);
    }
  }

  function _sendAllERC1155(address to, IERC1155 token, uint256 tokenId) internal {
    uint256 balance = token.balanceOf(address(this), tokenId);
    if (balance > 0) {
      token.safeTransferFrom(address(this), to, tokenId, balance, "");
    }
  }

  function _approveERC20IfNeeded(IERC20 token, address spender, uint256 amount) internal {
    uint256 allowance = token.allowance(address(this), spender);
    if (allowance < amount) {
      token.approve(spender, amount);
    }
  }

  function _approveERC721IfNeeded(IERC721 token, address operator) internal {
    bool isApproved = token.isApprovedForAll(address(this), operator);
    if (!isApproved) {
      token.setApprovalForAll(operator, true);
    }
  }

  function _approveERC1155IfNeeded(IERC1155 token, address operator) internal {
    bool isApproved = token.isApprovedForAll(address(this), operator);
    if (!isApproved) {
      token.setApprovalForAll(operator, true);
    }
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

import {TwoStepOwnable} from "../../misc/TwoStepOwnable.sol";

// Notes:
// - includes common helpers useful for all modules

abstract contract BaseModule is TwoStepOwnable, ReentrancyGuard {
  using SafeERC20 for IERC20;

  // --- Events ---

  event CallExecuted(address target, bytes data, uint256 value);

  // --- Errors ---

  error UnsuccessfulCall();
  error UnsuccessfulPayment();
  error WrongParams();

  // --- Constructor ---

  constructor(address owner) TwoStepOwnable(owner) {}

  // --- Owner ---

  // To be able to recover anything that gets stucked by mistake in the module,
  // we allow the owner to perform any arbitrary call. Since the goal is to be
  // stateless, this should only happen in case of mistakes. In addition, this
  // method is also useful for withdrawing any earned trading rewards.
  function makeCalls(
    address[] calldata targets,
    bytes[] calldata data,
    uint256[] calldata values
  ) external payable onlyOwner nonReentrant {
    uint256 length = targets.length;
    for (uint256 i = 0; i < length; ) {
      _makeCall(targets[i], data[i], values[i]);
      emit CallExecuted(targets[i], data[i], values[i]);

      unchecked {
        ++i;
      }
    }
  }

  // --- Helpers ---

  function _sendETH(address to, uint256 amount) internal {
    if (amount > 0) {
      (bool success, ) = payable(to).call{value: amount}("");
      if (!success) {
        revert UnsuccessfulPayment();
      }
    }
  }

  function _sendERC20(
    address to,
    uint256 amount,
    IERC20 token
  ) internal {
    if (amount > 0) {
      token.safeTransfer(to, amount);
    }
  }

  function _makeCall(
    address target,
    bytes memory data,
    uint256 value
  ) internal {
    (bool success, ) = payable(target).call{value: value}(data);
    if (!success) {
      revert UnsuccessfulCall();
    }
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC1155/IERC1155.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(
        address indexed operator,
        address indexed from,
        address indexed to,
        uint256[] ids,
        uint256[] values
    );

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(
        address[] calldata accounts,
        uint256[] calldata ids
    ) external view returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] calldata ids,
        uint256[] calldata amounts,
        bytes calldata data
    ) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * 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[EIP 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 v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 tokenId) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

interface ISeaport {
  enum OrderType {
    FULL_OPEN,
    PARTIAL_OPEN,
    FULL_RESTRICTED,
    PARTIAL_RESTRICTED
  }

  enum ItemType {
    NATIVE,
    ERC20,
    ERC721,
    ERC1155,
    ERC721_WITH_CRITERIA,
    ERC1155_WITH_CRITERIA
  }

  enum Side {
    OFFER,
    CONSIDERATION
  }

  struct OfferItem {
    ItemType itemType;
    address token;
    uint256 identifierOrCriteria;
    uint256 startAmount;
    uint256 endAmount;
  }

  struct ConsiderationItem {
    ItemType itemType;
    address token;
    uint256 identifierOrCriteria;
    uint256 startAmount;
    uint256 endAmount;
    address recipient;
  }

  struct SpentItem {
    ItemType itemType;
    address token;
    uint256 identifier;
    uint256 amount;
  }

  struct ReceivedItem {
    ItemType itemType;
    address token;
    uint256 identifier;
    uint256 amount;
    address recipient;
  }

  struct OrderComponents {
    address offerer;
    address zone;
    OfferItem[] offer;
    ConsiderationItem[] consideration;
    OrderType orderType;
    uint256 startTime;
    uint256 endTime;
    bytes32 zoneHash;
    uint256 salt;
    bytes32 conduitKey;
    uint256 counter;
  }

  struct OrderParameters {
    address offerer;
    address zone;
    OfferItem[] offer;
    ConsiderationItem[] consideration;
    OrderType orderType;
    uint256 startTime;
    uint256 endTime;
    bytes32 zoneHash;
    uint256 salt;
    bytes32 conduitKey;
    uint256 totalOriginalConsiderationItems;
  }

  struct Order {
    OrderParameters parameters;
    bytes signature;
  }

  struct AdvancedOrder {
    OrderParameters parameters;
    uint120 numerator;
    uint120 denominator;
    bytes signature;
    bytes extraData;
  }

  struct CriteriaResolver {
    uint256 orderIndex;
    Side side;
    uint256 index;
    uint256 identifier;
    bytes32[] criteriaProof;
  }

  struct FulfillmentComponent {
    uint256 orderIndex;
    uint256 itemIndex;
  }

  struct Fulfillment {
    FulfillmentComponent[] offerComponents;
    FulfillmentComponent[] considerationComponents;
  }

  struct Execution {
    ReceivedItem item;
    address offerer;
    bytes32 conduitKey;
  }

  struct ZoneParameters {
    bytes32 orderHash;
    address fulfiller;
    address offerer;
    SpentItem[] offer;
    ReceivedItem[] consideration;
    bytes extraData;
    bytes32[] orderHashes;
    uint256 startTime;
    uint256 endTime;
    bytes32 zoneHash;
  }

  struct Schema {
    uint256 id;
    bytes metadata;
  }

  function getOrderHash(OrderComponents calldata order) external view returns (bytes32 orderHash);

  function getOrderStatus(bytes32 orderHash)
    external
    view
    returns (
      bool isValidated,
      bool isCancelled,
      uint256 totalFilled,
      uint256 totalSize
    );

  function getCounter(address offerer) external view returns (uint256 counter);

  function fulfillAdvancedOrder(
    AdvancedOrder calldata advancedOrder,
    CriteriaResolver[] calldata criteriaResolvers,
    bytes32 fulfillerConduitKey,
    address recipient
  ) external payable returns (bool fulfilled);

  function fulfillAvailableAdvancedOrders(
    AdvancedOrder[] memory advancedOrders,
    CriteriaResolver[] calldata criteriaResolvers,
    FulfillmentComponent[][] calldata offerFulfillments,
    FulfillmentComponent[][] calldata considerationFulfillments,
    bytes32 fulfillerConduitKey,
    address recipient,
    uint256 maximumFulfilled
  ) external payable returns (bool[] memory availableOrders, Execution[] memory executions);

  function matchOrders(Order[] calldata orders, Fulfillment[] calldata fulfillments)
    external
    payable
    returns (Execution[] memory executions);

  function matchAdvancedOrders(
    AdvancedOrder[] calldata advancedOrders,
    CriteriaResolver[] calldata criteriaResolvers,
    Fulfillment[] calldata fulfillments
  ) external payable returns (Execution[] memory executions);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @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 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;

    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
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // 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
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

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

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

    /**
     * @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.encodeWithSelector(token.transfer.selector, 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.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

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

    /**
     * @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);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

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

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

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

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

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * 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.isContract(address(token));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import {IERC1155} from "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";

import {BaseExchangeModule} from "./BaseExchangeModule.sol";
import {BaseModule} from "../BaseModule.sol";
import {ISeaport} from "../../../interfaces/ISeaport.sol";

// Notes on the Seaport module:
// - supports filling listings (both ERC721/ERC1155)
// - supports filling offers (both ERC721/ERC1155)

contract SeaportV15Module is BaseExchangeModule {
  // --- Structs ---

  struct SeaportETHListingWithPrice {
    ISeaport.AdvancedOrder order;
    uint256 price;
  }

  // --- Fields ---

  ISeaport public immutable EXCHANGE;

  // --- Constructor ---

  constructor(
    address owner,
    address router,
    address exchange
  ) BaseModule(owner) BaseExchangeModule(router) {
    EXCHANGE = ISeaport(exchange);
  }

  // --- Fallback ---

  receive() external payable {}

  // --- Single ETH listing ---

  function acceptETHListing(
    ISeaport.AdvancedOrder calldata order,
    ETHListingParams calldata params,
    Fee[] calldata fees
  )
    external
    payable
    nonReentrant
    refundETHLeftover(params.refundTo)
    chargeETHFees(fees, params.amount)
  {
    // Execute the fill
    params.revertIfIncomplete
      ? _fillSingleOrderWithRevertIfIncomplete(
        order,
        new ISeaport.CriteriaResolver[](0),
        params.fillTo,
        params.amount
      )
      : _fillSingleOrder(order, new ISeaport.CriteriaResolver[](0), params.fillTo, params.amount);
  }

  // --- Single ERC20 listing ---

  function acceptERC20Listing(
    ISeaport.AdvancedOrder calldata order,
    ERC20ListingParams calldata params,
    Fee[] calldata fees
  )
    external
    nonReentrant
    refundERC20Leftover(params.refundTo, params.token)
    chargeERC20Fees(fees, params.token, params.amount)
  {
    // Approve the exchange if needed
    _approveERC20IfNeeded(params.token, address(EXCHANGE), params.amount);

    // Execute the fill
    params.revertIfIncomplete
      ? _fillSingleOrderWithRevertIfIncomplete(
        order,
        new ISeaport.CriteriaResolver[](0),
        params.fillTo,
        0
      )
      : _fillSingleOrder(order, new ISeaport.CriteriaResolver[](0), params.fillTo, 0);
  }

  // --- Multiple ETH listings ---

  function acceptETHListings(
    SeaportETHListingWithPrice[] calldata orders,
    ETHListingParams calldata params,
    Fee[] calldata fees
  )
    external
    payable
    nonReentrant
    refundETHLeftover(params.refundTo)
    chargeETHFees(fees, params.amount)
  {
    uint256 length = orders.length;
    ISeaport.CriteriaResolver[] memory criteriaResolvers = new ISeaport.CriteriaResolver[](0);

    // Execute the fills
    if (params.revertIfIncomplete) {
      for (uint256 i; i < length; ) {
        _fillSingleOrderWithRevertIfIncomplete(
          orders[i].order,
          criteriaResolvers,
          params.fillTo,
          orders[i].price
        );

        unchecked {
          ++i;
        }
      }
    } else {
      for (uint256 i; i < length; ) {
        _fillSingleOrder(orders[i].order, criteriaResolvers, params.fillTo, orders[i].price);

        unchecked {
          ++i;
        }
      }
    }
  }

  // --- Multiple ERC20 listings ---

  function acceptERC20Listings(
    ISeaport.AdvancedOrder[] calldata orders,
    ERC20ListingParams calldata params,
    Fee[] calldata fees
  )
    external
    nonReentrant
    refundERC20Leftover(params.refundTo, params.token)
    chargeERC20Fees(fees, params.token, params.amount)
  {
    // Approve the exchange if needed
    _approveERC20IfNeeded(params.token, address(EXCHANGE), params.amount);

    uint256 length = orders.length;
    ISeaport.CriteriaResolver[] memory criteriaResolvers = new ISeaport.CriteriaResolver[](0);

    // Execute the fills
    if (params.revertIfIncomplete) {
      for (uint256 i; i < length; ) {
        _fillSingleOrderWithRevertIfIncomplete(orders[i], criteriaResolvers, params.fillTo, 0);

        unchecked {
          ++i;
        }
      }
    } else {
      for (uint256 i; i < length; ) {
        _fillSingleOrder(orders[i], criteriaResolvers, params.fillTo, 0);

        unchecked {
          ++i;
        }
      }
    }
  }

  // --- Single ERC721 offer ---

  function acceptERC721Offer(
    ISeaport.AdvancedOrder calldata order,
    // Use `memory` instead of `calldata` to avoid `Stack too deep` errors
    ISeaport.CriteriaResolver[] memory criteriaResolvers,
    OfferParams calldata params,
    Fee[] calldata fees
  ) external nonReentrant {
    // Extract the ERC721 token from the consideration items
    ISeaport.ConsiderationItem calldata nftItem = order.parameters.consideration[0];
    if (
      nftItem.itemType != ISeaport.ItemType.ERC721 &&
      nftItem.itemType != ISeaport.ItemType.ERC721_WITH_CRITERIA
    ) {
      revert WrongParams();
    }
    IERC721 nftToken = IERC721(nftItem.token);

    // Extract the payment token from the offer items
    ISeaport.OfferItem calldata paymentItem = order.parameters.offer[0];
    IERC20 paymentToken = IERC20(paymentItem.token);

    // Approve the exchange if needed
    _approveERC721IfNeeded(nftToken, address(EXCHANGE));
    _approveERC20IfNeeded(paymentToken, address(EXCHANGE), type(uint256).max);

    // Execute the fill
    params.revertIfIncomplete
      ? _fillSingleOrderWithRevertIfIncomplete(order, criteriaResolvers, address(this), 0)
      : _fillSingleOrder(order, criteriaResolvers, address(this), 0);

    uint256 identifier = nftItem.itemType == ISeaport.ItemType.ERC721
      ? nftItem.identifierOrCriteria
      : criteriaResolvers[0].identifier;

    // Pay fees
    if (nftToken.ownerOf(identifier) != address(this)) {
      // Only pay fees if the fill was successful
      uint256 feesLength = fees.length;
      for (uint256 i; i < feesLength; ) {
        Fee memory fee = fees[i];
        _sendERC20(fee.recipient, fee.amount, paymentToken);

        unchecked {
          ++i;
        }
      }
    }

    // Refund any ERC721 leftover
    _sendAllERC721(params.refundTo, nftToken, identifier);

    // Forward any left payment to the specified receiver
    _sendAllERC20(params.fillTo, paymentToken);
  }

  // --- Single ERC1155 offer ---

  function acceptERC1155Offer(
    ISeaport.AdvancedOrder calldata order,
    // Use `memory` instead of `calldata` to avoid `Stack too deep` errors
    ISeaport.CriteriaResolver[] memory criteriaResolvers,
    OfferParams calldata params,
    Fee[] calldata fees
  ) external nonReentrant {
    // Extract the ERC1155 token from the consideration items
    ISeaport.ConsiderationItem calldata nftItem = order.parameters.consideration[0];
    if (
      nftItem.itemType != ISeaport.ItemType.ERC1155 &&
      nftItem.itemType != ISeaport.ItemType.ERC1155_WITH_CRITERIA
    ) {
      revert WrongParams();
    }
    IERC1155 nftToken = IERC1155(nftItem.token);

    // Extract the payment token from the offer items
    ISeaport.OfferItem calldata paymentItem = order.parameters.offer[0];
    IERC20 paymentToken = IERC20(paymentItem.token);

    // Approve the exchange if needed
    _approveERC1155IfNeeded(nftToken, address(EXCHANGE));
    _approveERC20IfNeeded(paymentToken, address(EXCHANGE), type(uint256).max);

    uint256 identifier = nftItem.itemType == ISeaport.ItemType.ERC1155
      ? nftItem.identifierOrCriteria
      : criteriaResolvers[0].identifier;

    uint256 balanceBefore = nftToken.balanceOf(address(this), identifier);

    // Execute the fill
    params.revertIfIncomplete
      ? _fillSingleOrderWithRevertIfIncomplete(order, criteriaResolvers, address(this), 0)
      : _fillSingleOrder(order, criteriaResolvers, address(this), 0);

    uint256 balanceAfter = nftToken.balanceOf(address(this), identifier);

    // Pay fees
    uint256 amountFilled = balanceBefore - balanceAfter;
    if (amountFilled > 0) {
      uint256 feesLength = fees.length;
      for (uint256 i; i < feesLength; ) {
        Fee memory fee = fees[i];
        _sendERC20(
          fee.recipient,
          // Only pay fees for the amount that was actually filled
          (fee.amount * amountFilled) / order.numerator,
          paymentToken
        );

        unchecked {
          ++i;
        }
      }
    }

    // Refund any ERC1155 leftover
    _sendAllERC1155(params.refundTo, nftToken, identifier);

    // Forward any left payment to the specified receiver
    _sendAllERC20(params.fillTo, paymentToken);
  }

  // --- Generic handler (used for Seaport-based approvals) ---

  function matchOrders(
    ISeaport.Order[] calldata orders,
    ISeaport.Fulfillment[] calldata fulfillments
  ) external nonReentrant {
    // We don't perform any kind of input or return value validation,
    // so this function should be used with precaution - the official
    // way to use it is only for Seaport-based approvals
    EXCHANGE.matchOrders(orders, fulfillments);
  }

  // --- ERC721 / ERC1155 hooks ---

  // Single token offer acceptance can be done approval-less by using the
  // standard `safeTransferFrom` method together with specifying data for
  // further contract calls. An example:
  // `safeTransferFrom(
  //      0xWALLET,
  //      0xMODULE,
  //      TOKEN_ID,
  //      0xABI_ENCODED_ROUTER_EXECUTION_CALLDATA_FOR_OFFER_ACCEPTANCE
  // )`

  function onERC721Received(
    address, // operator,
    address, // from
    uint256, // tokenId,
    bytes calldata data
  ) external returns (bytes4) {
    if (data.length > 0) {
      _makeCall(router, data, 0);
    }

    return this.onERC721Received.selector;
  }

  function onERC1155Received(
    address, // operator
    address, // from
    uint256, // tokenId
    uint256, // amount
    bytes calldata data
  ) external returns (bytes4) {
    if (data.length > 0) {
      _makeCall(router, data, 0);
    }

    return this.onERC1155Received.selector;
  }

  // --- Internal ---

  // NOTE: In lots of cases, Seaport will not revert if fills were not
  // fully executed. An example of that is partial filling, which will
  // successfully fill any amount that is still available (including a
  // zero amount). One way to ensure that we revert in case of partial
  // executions is to check the order's filled amount before and after
  // we trigger the fill (we can use Seaport's `getOrderStatus` method
  // to check). Since this can be expensive in terms of gas, we have a
  // separate method variant to be called when reverts are enabled.

  function _fillSingleOrder(
    ISeaport.AdvancedOrder calldata order,
    // Use `memory` instead of `calldata` to avoid `Stack too deep` errors
    ISeaport.CriteriaResolver[] memory criteriaResolvers,
    address receiver,
    uint256 value
  ) internal {
    // Execute the fill
    try
      EXCHANGE.fulfillAdvancedOrder{value: value}(order, criteriaResolvers, bytes32(0), receiver)
    {} catch {}
  }

  function _fillSingleOrderWithRevertIfIncomplete(
    ISeaport.AdvancedOrder calldata order,
    // Use `memory` instead of `calldata` to avoid `Stack too deep` errors
    ISeaport.CriteriaResolver[] memory criteriaResolvers,
    address receiver,
    uint256 value
  ) internal {
    // Cache the order's hash
    bytes32 orderHash = _getOrderHash(order.parameters);

    // Before filling, get the order's filled amount
    uint256 beforeFilledAmount = _getFilledAmount(orderHash, order.denominator);

    // Execute the fill
    bool success;
    try
      EXCHANGE.fulfillAdvancedOrder{value: value}(order, criteriaResolvers, bytes32(0), receiver)
    returns (bool fulfilled) {
      success = fulfilled;
    } catch {
      revert UnsuccessfulFill();
    }

    if (!success) {
      revert UnsuccessfulFill();
    } else {
      // After successfully filling, get the order's filled amount
      uint256 afterFilledAmount = _getFilledAmount(orderHash, order.denominator);

      // Make sure the amount filled as part of this call is correct
      if (afterFilledAmount - beforeFilledAmount != order.numerator) {
        revert UnsuccessfulFill();
      }
    }
  }

  function _getOrderHash(
    // Must use `memory` instead of `calldata` for the below cast
    ISeaport.OrderParameters memory orderParameters
  ) internal view returns (bytes32 orderHash) {
    // `OrderParameters` and `OrderComponents` share the exact same
    // fields, apart from the last one, so here we simply treat the
    // `orderParameters` argument as `OrderComponents` and then set
    // the last field to the correct data
    ISeaport.OrderComponents memory orderComponents;
    assembly {
      orderComponents := orderParameters
    }
    orderComponents.counter = EXCHANGE.getCounter(orderParameters.offerer);

    orderHash = EXCHANGE.getOrderHash(orderComponents);
  }

  function _getFilledAmount(
    bytes32 orderHash,
    uint256 adjustedTotalSize
  ) internal view returns (uint256 adjustedTotalFilled) {
    (, , uint256 totalFilled, uint256 totalSize) = EXCHANGE.getOrderStatus(orderHash);
    adjustedTotalFilled = totalSize > 0 ? (totalFilled * adjustedTotalSize) / totalSize : 0;
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

// Adapted from:
// https://github.com/boringcrypto/BoringSolidity/blob/e74c5b22a61bfbadd645e51a64aa1d33734d577a/contracts/BoringOwnable.sol
contract TwoStepOwnable {
  // --- Fields ---

  address public owner;
  address public pendingOwner;

  // --- Events ---

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

  // --- Errors ---

  error InvalidParams();
  error Unauthorized();

  // --- Modifiers ---

  modifier onlyOwner() {
    if (msg.sender != owner) {
      revert Unauthorized();
    }

    _;
  }

  // --- Constructor ---

  constructor(address initialOwner) {
    owner = initialOwner;
    emit OwnershipTransferred(address(0), initialOwner);
  }

  // --- Methods ---

  function transferOwnership(address newOwner) public onlyOwner {
    pendingOwner = newOwner;
  }

  function claimOwnership() public {
    address _pendingOwner = pendingOwner;
    if (msg.sender != _pendingOwner) {
      revert Unauthorized();
    }

    owner = _pendingOwner;
    pendingOwner = address(0);
    emit OwnershipTransferred(owner, _pendingOwner);
  }
}

{
  "compilationTarget": {
    "contracts/router/modules/exchanges/SeaportV15Module.sol": "SeaportV15Module"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [],
  "viaIR": true
}