ETH Price: $1,903.50 (+0.86%)

Transaction Decoder

Block:
15776907 at Oct-18-2022 06:53:35 PM +UTC
Transaction Fee:
0.00176878071694307 ETH $3.37
Gas Used:
52,109 Gas / 33.94386223 Gwei

Account State Difference:

  Address   Before After State Difference Code
0xA4D0a88a...9b9Fad8D4
0.075605172796157477 Eth
Nonce: 36
0.073836392079214407 Eth
Nonce: 37
0.00176878071694307
(Flashbots: Builder)
1.259210024972439484 Eth1.259288188472439484 Eth0.0000781635

Execution Trace

ETH 0.006 Seaport.fulfillBasicOrder( parameters=[{name:considerationToken, type:address, order:1, indexed:false, value:0x0000000000000000000000000000000000000000, valueString:0x0000000000000000000000000000000000000000}, {name:considerationIdentifier, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:considerationAmount, type:uint256, order:3, indexed:false, value:5250000000000000, valueString:5250000000000000}, {name:offerer, type:address, order:4, indexed:false, value:0x724bd8CB4c5A634DcBC27bC2A4040d1cc59cb0Ab, valueString:0x724bd8CB4c5A634DcBC27bC2A4040d1cc59cb0Ab}, {name:zone, type:address, order:5, indexed:false, value:0x004C00500000aD104D7DBd00e3ae0A5C00560C00, valueString:0x004C00500000aD104D7DBd00e3ae0A5C00560C00}, {name:offerToken, type:address, order:6, indexed:false, value:0x4B81e4d846e7E821e3ee28c12AbDA60c1d2CdA12, valueString:0x4B81e4d846e7E821e3ee28c12AbDA60c1d2CdA12}, {name:offerIdentifier, type:uint256, order:7, indexed:false, value:2776, valueString:2776}, {name:offerAmount, type:uint256, order:8, indexed:false, value:1, valueString:1}, {name:basicOrderType, type:uint8, order:9, indexed:false, value:3, valueString:3}, {name:startTime, type:uint256, order:10, indexed:false, value:1666108150, valueString:1666108150}, {name:endTime, type:uint256, order:11, indexed:false, value:1673884150, valueString:1673884150}, {name:zoneHash, type:bytes32, order:12, indexed:false, value:3100000000000000000000000000000000000000000000000000000000000000, valueString:3100000000000000000000000000000000000000000000000000000000000000}, {name:salt, type:uint256, order:13, indexed:false, value:3982331857563016413, valueString:3982331857563016413}, {name:offererConduitKey, type:bytes32, order:14, indexed:false, value:0000007B02230091A7ED01230072F7006A004D60A8D4E71D599B8104250F0000, valueString:0000007B02230091A7ED01230072F7006A004D60A8D4E71D599B8104250F0000}, {name:fulfillerConduitKey, type:bytes32, order:15, indexed:false, value:0000007B02230091A7ED01230072F7006A004D60A8D4E71D599B8104250F0000, valueString:0000007B02230091A7ED01230072F7006A004D60A8D4E71D599B8104250F0000}, {name:totalOriginalAdditionalRecipients, type:uint256, order:16, indexed:false, value:2, valueString:2}, {name:additionalRecipients, type:tuple[], order:17, indexed:false}, {name:signature, type:bytes, order:18, indexed:false, value:0xC29BEC51F53C6C3B5D376F70DAF09499BA11A94668D034A48F32E2DB8C5431E4F4BC3407184646D4DEA9214C4C5DB49748CA26D88371FD6CF373A8A37887C04A, valueString:0xC29BEC51F53C6C3B5D376F70DAF09499BA11A94668D034A48F32E2DB8C5431E4F4BC3407184646D4DEA9214C4C5DB49748CA26D88371FD6CF373A8A37887C04A}] )
  • PausableZone.isValidOrder( orderHash=3F5008B6A277EE2CEAEE8FF76D3AF2F1B7F6BA14D89004BA7F0A9D5C48827903, caller=0xA4D0a88a4B564E53879366DF456f8039b9Fad8D4, offerer=0x724bd8CB4c5A634DcBC27bC2A4040d1cc59cb0Ab, zoneHash=3100000000000000000000000000000000000000000000000000000000000000 )
    fulfillBasicOrder[Consideration (ln:9074)]
    File 1 of 2: Seaport
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { Consideration } from "./lib/Consideration.sol";
    /**
     * @title Seaport
     * @custom:version 1.1
     * @author 0age (0age.eth)
     * @custom:coauthor d1ll0n (d1ll0n.eth)
     * @custom:coauthor transmissions11 (t11s.eth)
     * @custom:contributor Kartik (slokh.eth)
     * @custom:contributor LeFevre (lefevre.eth)
     * @custom:contributor Joseph Schiarizzi (CupOJoseph.eth)
     * @custom:contributor Aspyn Palatnick (stuckinaboot.eth)
     * @custom:contributor James Wenzel (emo.eth)
     * @custom:contributor Stephan Min (stephanm.eth)
     * @custom:contributor Ryan Ghods (ralxz.eth)
     * @custom:contributor hack3r-0m (hack3r-0m.eth)
     * @custom:contributor Diego Estevez (antidiego.eth)
     * @custom:contributor Chomtana (chomtana.eth)
     * @custom:contributor Saw-mon and Natalie (sawmonandnatalie.eth)
     * @custom:contributor 0xBeans (0xBeans.eth)
     * @custom:contributor 0x4non (punkdev.eth)
     * @custom:contributor Laurence E. Day (norsefire.eth)
     * @custom:contributor vectorized.eth (vectorized.eth)
     * @custom:contributor karmacoma (karmacoma.eth)
     * @custom:contributor horsefacts (horsefacts.eth)
     * @custom:contributor UncarvedBlock (uncarvedblock.eth)
     * @custom:contributor Zoraiz Mahmood (zorz.eth)
     * @custom:contributor William Poulin (wpoulin.eth)
     * @custom:contributor Rajiv Patel-O'Connor (rajivpoc.eth)
     * @custom:contributor tserg (tserg.eth)
     * @custom:contributor cygaar (cygaar.eth)
     * @custom:contributor Meta0xNull (meta0xnull.eth)
     * @custom:contributor gpersoon (gpersoon.eth)
     * @custom:contributor Matt Solomon (msolomon.eth)
     * @custom:contributor Weikang Song (weikangs.eth)
     * @custom:contributor zer0dot (zer0dot.eth)
     * @custom:contributor Mudit Gupta (mudit.eth)
     * @custom:contributor leonardoalt (leoalt.eth)
     * @custom:contributor cmichel (cmichel.eth)
     * @custom:contributor PraneshASP (pranesh.eth)
     * @custom:contributor JasperAlexander (jasperalexander.eth)
     * @custom:contributor Ellahi (ellahi.eth)
     * @custom:contributor zaz (1zaz1.eth)
     * @custom:contributor berndartmueller (berndartmueller.eth)
     * @custom:contributor dmfxyz (dmfxyz.eth)
     * @custom:contributor daltoncoder (dontkillrobots.eth)
     * @custom:contributor 0xf4ce (0xf4ce.eth)
     * @custom:contributor phaze (phaze.eth)
     * @custom:contributor hrkrshnn (hrkrshnn.eth)
     * @custom:contributor axic (axic.eth)
     * @custom:contributor leastwood (leastwood.eth)
     * @custom:contributor 0xsanson (sanson.eth)
     * @custom:contributor blockdev (blockd3v.eth)
     * @custom:contributor fiveoutofnine (fiveoutofnine.eth)
     * @custom:contributor shuklaayush (shuklaayush.eth)
     * @custom:contributor 0xPatissier
     * @custom:contributor pcaversaccio
     * @custom:contributor David Eiber
     * @custom:contributor csanuragjain
     * @custom:contributor sach1r0
     * @custom:contributor twojoy0
     * @custom:contributor ori_dabush
     * @custom:contributor Daniel Gelfand
     * @custom:contributor okkothejawa
     * @custom:contributor FlameHorizon
     * @custom:contributor vdrg
     * @custom:contributor dmitriia
     * @custom:contributor bokeh-eth
     * @custom:contributor asutorufos
     * @custom:contributor rfart(rfa)
     * @custom:contributor Riley Holterhus
     * @custom:contributor big-tech-sux
     * @notice Seaport is a generalized ETH/ERC20/ERC721/ERC1155 marketplace. It
     *         minimizes external calls to the greatest extent possible and provides
     *         lightweight methods for common routes as well as more flexible
     *         methods for composing advanced orders or groups of orders. Each order
     *         contains an arbitrary number of items that may be spent (the "offer")
     *         along with an arbitrary number of items that must be received back by
     *         the indicated recipients (the "consideration").
     */
    contract Seaport is Consideration {
        /**
         * @notice Derive and set hashes, reference chainId, and associated domain
         *         separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) Consideration(conduitController) {}
        /**
         * @dev Internal pure function to retrieve and return the name of this
         *      contract.
         *
         * @return The name of this contract.
         */
        function _name() internal pure override returns (string memory) {
            // Return the name of the contract.
            assembly {
                mstore(0x20, 0x20)
                mstore(0x47, 0x07536561706f7274)
                return(0x20, 0x60)
            }
        }
        /**
         * @dev Internal pure function to retrieve the name of this contract as a
         *      string that will be used to derive the name hash in the constructor.
         *
         * @return The name of this contract as a string.
         */
        function _nameString() internal pure override returns (string memory) {
            // Return the name of the contract.
            return "Seaport";
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        BasicOrderParameters,
        OrderComponents,
        Fulfillment,
        FulfillmentComponent,
        Execution,
        Order,
        AdvancedOrder,
        OrderStatus,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    /**
     * @title SeaportInterface
     * @author 0age
     * @custom:version 1.1
     * @notice Seaport is a generalized ETH/ERC20/ERC721/ERC1155 marketplace. It
     *         minimizes external calls to the greatest extent possible and provides
     *         lightweight methods for common routes as well as more flexible
     *         methods for composing advanced orders.
     *
     * @dev SeaportInterface contains all external function interfaces for Seaport.
     */
    interface SeaportInterface {
        /**
         * @notice Fulfill an order offering an ERC721 token by supplying Ether (or
         *         the native token for the given chain) as consideration for the
         *         order. An arbitrary number of "additional recipients" may also be
         *         supplied which will each receive native tokens from the fulfiller
         *         as consideration.
         *
         * @param parameters Additional information on the fulfilled order. Note
         *                   that the offerer must first approve this contract (or
         *                   their preferred conduit if indicated by the order) for
         *                   their offered ERC721 token to be transferred.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillBasicOrder(BasicOrderParameters calldata parameters)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fulfill an order with an arbitrary number of items for offer and
         *         consideration. Note that this function does not support
         *         criteria-based orders or partial filling of orders (though
         *         filling the remainder of a partially-filled order is supported).
         *
         * @param order               The order to fulfill. Note that both the
         *                            offerer and the fulfiller must first approve
         *                            this contract (or the corresponding conduit if
         *                            indicated) to transfer any relevant tokens on
         *                            their behalf and that contracts must implement
         *                            `onERC1155Received` to receive ERC1155 tokens
         *                            as consideration.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Seaport.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillOrder(Order calldata order, bytes32 fulfillerConduitKey)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fill an order, fully or partially, with an arbitrary number of
         *         items for offer and consideration alongside criteria resolvers
         *         containing specific token identifiers and associated proofs.
         *
         * @param advancedOrder       The order to fulfill along with the fraction
         *                            of the order to attempt to fill. Note that
         *                            both the offerer and the fulfiller must first
         *                            approve this contract (or their preferred
         *                            conduit if indicated by the order) to transfer
         *                            any relevant tokens on their behalf and that
         *                            contracts must implement `onERC1155Received`
         *                            to receive ERC1155 tokens as consideration.
         *                            Also note that all offer and consideration
         *                            components must have no remainder after
         *                            multiplication of the respective amount with
         *                            the supplied fraction for the partial fill to
         *                            be considered valid.
         * @param criteriaResolvers   An array where each element contains a
         *                            reference to a specific offer or
         *                            consideration, a token identifier, and a proof
         *                            that the supplied token identifier is
         *                            contained in the merkle root held by the item
         *                            in question's criteria element. Note that an
         *                            empty criteria indicates that any
         *                            (transferable) token identifier on the token
         *                            in question is valid and that no associated
         *                            proof needs to be supplied.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Seaport.
         * @param recipient           The intended recipient for all received items,
         *                            with `address(0)` indicating that the caller
         *                            should receive the items.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillAdvancedOrder(
            AdvancedOrder calldata advancedOrder,
            CriteriaResolver[] calldata criteriaResolvers,
            bytes32 fulfillerConduitKey,
            address recipient
        ) external payable returns (bool fulfilled);
        /**
         * @notice Attempt to fill a group of orders, each with an arbitrary number
         *         of items for offer and consideration. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *         Note that this function does not support criteria-based orders or
         *         partial filling of orders (though filling the remainder of a
         *         partially-filled order is supported).
         *
         * @param orders                    The orders to fulfill. Note that both
         *                                  the offerer and the fulfiller must first
         *                                  approve this contract (or the
         *                                  corresponding conduit if indicated) to
         *                                  transfer any relevant tokens on their
         *                                  behalf and that contracts must implement
         *                                  `onERC1155Received` to receive ERC1155
         *                                  tokens as consideration.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableOrders(
            Order[] calldata orders,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            uint256 maximumFulfilled
        )
            external
            payable
            returns (bool[] memory availableOrders, Execution[] memory executions);
        /**
         * @notice Attempt to fill a group of orders, fully or partially, with an
         *         arbitrary number of items for offer and consideration per order
         *         alongside criteria resolvers containing specific token
         *         identifiers and associated proofs. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or their preferred conduit if
         *                                  indicated by the order) to transfer any
         *                                  relevant tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` to enable receipt of
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param criteriaResolvers         An array where each element contains a
         *                                  reference to a specific offer or
         *                                  consideration, a token identifier, and a
         *                                  proof that the supplied token identifier
         *                                  is contained in the merkle root held by
         *                                  the item in question's criteria element.
         *                                  Note that an empty criteria indicates
         *                                  that any (transferable) token
         *                                  identifier on the token in question is
         *                                  valid and that no associated proof needs
         *                                  to be supplied.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param recipient                 The intended recipient for all received
         *                                  items, with `address(0)` indicating that
         *                                  the caller should receive the items.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableAdvancedOrders(
            AdvancedOrder[] calldata 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);
        /**
         * @notice Match an arbitrary number of orders, each with an arbitrary
         *         number of items for offer and consideration along with as set of
         *         fulfillments allocating offer components to consideration
         *         components. Note that this function does not support
         *         criteria-based or partial filling of orders (though filling the
         *         remainder of a partially-filled order is supported).
         *
         * @param orders       The orders to match. Note that both the offerer and
         *                     fulfiller on each order must first approve this
         *                     contract (or their conduit if indicated by the order)
         *                     to transfer any relevant tokens on their behalf and
         *                     each consideration recipient must implement
         *                     `onERC1155Received` to enable ERC1155 token receipt.
         * @param fulfillments An array of elements allocating offer components to
         *                     consideration components. Note that each
         *                     consideration component must be fully met for the
         *                     match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchOrders(
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Match an arbitrary number of full or partial orders, each with an
         *         arbitrary number of items for offer and consideration, supplying
         *         criteria resolvers containing specific token identifiers and
         *         associated proofs as well as fulfillments allocating offer
         *         components to consideration components.
         *
         * @param orders            The advanced orders to match. Note that both the
         *                          offerer and fulfiller on each order must first
         *                          approve this contract (or a preferred conduit if
         *                          indicated by the order) to transfer any relevant
         *                          tokens on their behalf and each consideration
         *                          recipient must implement `onERC1155Received` in
         *                          order to receive ERC1155 tokens. Also note that
         *                          the offer and consideration components for each
         *                          order must have no remainder after multiplying
         *                          the respective amount with the supplied fraction
         *                          in order for the group of partial fills to be
         *                          considered valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          an empty root indicates that any (transferable)
         *                          token identifier is valid and that no associated
         *                          proof needs to be supplied.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchAdvancedOrders(
            AdvancedOrder[] calldata orders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Cancel an arbitrary number of orders. Note that only the offerer
         *         or the zone of a given order may cancel it. Callers should ensure
         *         that the intended order was cancelled by calling `getOrderStatus`
         *         and confirming that `isCancelled` returns `true`.
         *
         * @param orders The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancel(OrderComponents[] calldata orders)
            external
            returns (bool cancelled);
        /**
         * @notice Validate an arbitrary number of orders, thereby registering their
         *         signatures as valid and allowing the fulfiller to skip signature
         *         verification on fulfillment. Note that validated orders may still
         *         be unfulfillable due to invalid item amounts or other factors;
         *         callers should determine whether validated orders are fulfillable
         *         by simulating the fulfillment call prior to execution. Also note
         *         that anyone can validate a signed order, but only the offerer can
         *         validate an order without supplying a signature.
         *
         * @param orders The orders to validate.
         *
         * @return validated A boolean indicating whether the supplied orders have
         *                   been successfully validated.
         */
        function validate(Order[] calldata orders)
            external
            returns (bool validated);
        /**
         * @notice Cancel all orders from a given offerer with a given zone in bulk
         *         by incrementing a counter. Note that only the offerer may
         *         increment the counter.
         *
         * @return newCounter The new counter.
         */
        function incrementCounter() external returns (uint256 newCounter);
        /**
         * @notice Retrieve the order hash for a given order.
         *
         * @param order The components of the order.
         *
         * @return orderHash The order hash.
         */
        function getOrderHash(OrderComponents calldata order)
            external
            view
            returns (bytes32 orderHash);
        /**
         * @notice Retrieve the status of a given order by hash, including whether
         *         the order has been cancelled or validated and the fraction of the
         *         order that has been filled.
         *
         * @param orderHash The order hash in question.
         *
         * @return isValidated A boolean indicating whether the order in question
         *                     has been validated (i.e. previously approved or
         *                     partially filled).
         * @return isCancelled A boolean indicating whether the order in question
         *                     has been cancelled.
         * @return totalFilled The total portion of the order that has been filled
         *                     (i.e. the "numerator").
         * @return totalSize   The total size of the order that is either filled or
         *                     unfilled (i.e. the "denominator").
         */
        function getOrderStatus(bytes32 orderHash)
            external
            view
            returns (
                bool isValidated,
                bool isCancelled,
                uint256 totalFilled,
                uint256 totalSize
            );
        /**
         * @notice Retrieve the current counter for a given offerer.
         *
         * @param offerer The offerer in question.
         *
         * @return counter The current counter.
         */
        function getCounter(address offerer)
            external
            view
            returns (uint256 counter);
        /**
         * @notice Retrieve configuration information for this contract.
         *
         * @return version           The contract version.
         * @return domainSeparator   The domain separator for this contract.
         * @return conduitController The conduit Controller set for this contract.
         */
        function information()
            external
            view
            returns (
                string memory version,
                bytes32 domainSeparator,
                address conduitController
            );
        /**
         * @notice Retrieve the name of this contract.
         *
         * @return contractName The name of this contract.
         */
        function name() external view returns (string memory contractName);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import "./TransferHelperStructs.sol";
    import { TokenTransferrer } from "../lib/TokenTransferrer.sol";
    import { ConduitInterface } from "../interfaces/ConduitInterface.sol";
    // prettier-ignore
    import {
        ConduitControllerInterface
    } from "../interfaces/ConduitControllerInterface.sol";
    import { Conduit } from "../conduit/Conduit.sol";
    import { ConduitTransfer } from "../conduit/lib/ConduitStructs.sol";
    // prettier-ignore
    import {
        TransferHelperInterface
    } from "../interfaces/TransferHelperInterface.sol";
    /**
     * @title TransferHelper
     * @author stuckinaboot, stephankmin
     * @notice TransferHelper is a utility contract for transferring
     *         ERC20/ERC721/ERC1155 items in bulk to a specific recipient.
     */
    contract TransferHelper is TransferHelperInterface, TokenTransferrer {
        // Allow for interaction with the conduit controller.
        ConduitControllerInterface internal immutable _CONDUIT_CONTROLLER;
        // Cache the conduit creation hash used by the conduit controller.
        bytes32 internal immutable _CONDUIT_CREATION_CODE_HASH;
        /**
         * @dev Set the supplied conduit controller and retrieve its
         *      conduit creation code hash.
         *
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) {
            // Get the conduit creation code hash from the supplied conduit
            // controller and set it as an immutable.
            ConduitControllerInterface controller = ConduitControllerInterface(
                conduitController
            );
            (_CONDUIT_CREATION_CODE_HASH, ) = controller.getConduitCodeHashes();
            // Set the supplied conduit controller as an immutable.
            _CONDUIT_CONTROLLER = controller;
        }
        /**
         * @notice Transfer multiple items to a single recipient.
         *
         * @param items      The items to transfer.
         * @param recipient  The address the items should be transferred to.
         * @param conduitKey The key of the conduit through which the bulk transfer
         *                   should occur.
         *
         * @return magicValue A value indicating that the transfers were successful.
         */
        function bulkTransfer(
            TransferHelperItem[] calldata items,
            address recipient,
            bytes32 conduitKey
        ) external override returns (bytes4 magicValue) {
            // Retrieve total number of transfers and place on stack.
            uint256 totalTransfers = items.length;
            // If no conduitKey is given, use TokenTransferrer to perform transfers.
            if (conduitKey == bytes32(0)) {
                // Skip overflow checks: all for loops are indexed starting at zero.
                unchecked {
                    // Iterate over each transfer.
                    for (uint256 i = 0; i < totalTransfers; ++i) {
                        // Retrieve the transfer in question.
                        TransferHelperItem calldata item = items[i];
                        // Perform a transfer based on the transfer's item type.
                        // Revert if item being transferred is a native token.
                        if (item.itemType == ConduitItemType.NATIVE) {
                            revert InvalidItemType();
                        } else if (item.itemType == ConduitItemType.ERC20) {
                            _performERC20Transfer(
                                item.token,
                                msg.sender,
                                recipient,
                                item.amount
                            );
                        } else if (item.itemType == ConduitItemType.ERC721) {
                            _performERC721Transfer(
                                item.token,
                                msg.sender,
                                recipient,
                                item.identifier
                            );
                        } else {
                            _performERC1155Transfer(
                                item.token,
                                msg.sender,
                                recipient,
                                item.identifier,
                                item.amount
                            );
                        }
                    }
                }
            }
            // Otherwise, a conduitKey was provided.
            else {
                // Derive the conduit address from the deployer, conduit key
                // and creation code hash.
                address conduit = address(
                    uint160(
                        uint256(
                            keccak256(
                                abi.encodePacked(
                                    bytes1(0xff),
                                    address(_CONDUIT_CONTROLLER),
                                    conduitKey,
                                    _CONDUIT_CREATION_CODE_HASH
                                )
                            )
                        )
                    )
                );
                // Declare a new array to populate with each token transfer.
                ConduitTransfer[] memory conduitTransfers = new ConduitTransfer[](
                    totalTransfers
                );
                // Skip overflow checks: all for loops are indexed starting at zero.
                unchecked {
                    // Iterate over each transfer.
                    for (uint256 i = 0; i < totalTransfers; ++i) {
                        // Retrieve the transfer in question.
                        TransferHelperItem calldata item = items[i];
                        // Create a ConduitTransfer corresponding to each
                        // TransferHelperItem.
                        conduitTransfers[i] = ConduitTransfer(
                            item.itemType,
                            item.token,
                            msg.sender,
                            recipient,
                            item.identifier,
                            item.amount
                        );
                    }
                }
                // Call the conduit and execute bulk transfers.
                ConduitInterface(conduit).execute(conduitTransfers);
            }
            // Return a magic value indicating that the transfers were performed.
            magicValue = this.bulkTransfer.selector;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { ConduitItemType } from "../conduit/lib/ConduitEnums.sol";
    struct TransferHelperItem {
        ConduitItemType itemType;
        address token;
        uint256 identifier;
        uint256 amount;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import "./TokenTransferrerConstants.sol";
    // prettier-ignore
    import {
        TokenTransferrerErrors
    } from "../interfaces/TokenTransferrerErrors.sol";
    import { ConduitBatch1155Transfer } from "../conduit/lib/ConduitStructs.sol";
    /**
     * @title TokenTransferrer
     * @author 0age
     * @custom:coauthor d1ll0n
     * @custom:coauthor transmissions11
     * @notice TokenTransferrer is a library for performing optimized ERC20, ERC721,
     *         ERC1155, and batch ERC1155 transfers, used by both Seaport as well as
     *         by conduits deployed by the ConduitController. Use great caution when
     *         considering these functions for use in other codebases, as there are
     *         significant side effects and edge cases that need to be thoroughly
     *         understood and carefully addressed.
     */
    contract TokenTransferrer is TokenTransferrerErrors {
        /**
         * @dev Internal function to transfer ERC20 tokens from a given originator
         *      to a given recipient. Sufficient approvals must be set on the
         *      contract performing the transfer.
         *
         * @param token      The ERC20 token to transfer.
         * @param from       The originator of the transfer.
         * @param to         The recipient of the transfer.
         * @param amount     The amount to transfer.
         */
        function _performERC20Transfer(
            address token,
            address from,
            address to,
            uint256 amount
        ) internal {
            // Utilize assembly to perform an optimized ERC20 token transfer.
            assembly {
                // The free memory pointer memory slot will be used when populating
                // call data for the transfer; read the value and restore it later.
                let memPointer := mload(FreeMemoryPointerSlot)
                // Write call data into memory, starting with function selector.
                mstore(ERC20_transferFrom_sig_ptr, ERC20_transferFrom_signature)
                mstore(ERC20_transferFrom_from_ptr, from)
                mstore(ERC20_transferFrom_to_ptr, to)
                mstore(ERC20_transferFrom_amount_ptr, amount)
                // Make call & copy up to 32 bytes of return data to scratch space.
                // Scratch space does not need to be cleared ahead of time, as the
                // subsequent check will ensure that either at least a full word of
                // return data is received (in which case it will be overwritten) or
                // that no data is received (in which case scratch space will be
                // ignored) on a successful call to the given token.
                let callStatus := call(
                    gas(),
                    token,
                    0,
                    ERC20_transferFrom_sig_ptr,
                    ERC20_transferFrom_length,
                    0,
                    OneWord
                )
                // Determine whether transfer was successful using status & result.
                let success := and(
                    // Set success to whether the call reverted, if not check it
                    // either returned exactly 1 (can't just be non-zero data), or
                    // had no return data.
                    or(
                        and(eq(mload(0), 1), gt(returndatasize(), 31)),
                        iszero(returndatasize())
                    ),
                    callStatus
                )
                // Handle cases where either the transfer failed or no data was
                // returned. Group these, as most transfers will succeed with data.
                // Equivalent to `or(iszero(success), iszero(returndatasize()))`
                // but after it's inverted for JUMPI this expression is cheaper.
                if iszero(and(success, iszero(iszero(returndatasize())))) {
                    // If the token has no code or the transfer failed: Equivalent
                    // to `or(iszero(success), iszero(extcodesize(token)))` but
                    // after it's inverted for JUMPI this expression is cheaper.
                    if iszero(and(iszero(iszero(extcodesize(token))), success)) {
                        // If the transfer failed:
                        if iszero(success) {
                            // If it was due to a revert:
                            if iszero(callStatus) {
                                // If it returned a message, bubble it up as long as
                                // sufficient gas remains to do so:
                                if returndatasize() {
                                    // Ensure that sufficient gas is available to
                                    // copy returndata while expanding memory where
                                    // necessary. Start by computing the word size
                                    // of returndata and allocated memory. Round up
                                    // to the nearest full word.
                                    let returnDataWords := div(
                                        add(returndatasize(), AlmostOneWord),
                                        OneWord
                                    )
                                    // Note: use the free memory pointer in place of
                                    // msize() to work around a Yul warning that
                                    // prevents accessing msize directly when the IR
                                    // pipeline is activated.
                                    let msizeWords := div(memPointer, OneWord)
                                    // Next, compute the cost of the returndatacopy.
                                    let cost := mul(CostPerWord, returnDataWords)
                                    // Then, compute cost of new memory allocation.
                                    if gt(returnDataWords, msizeWords) {
                                        cost := add(
                                            cost,
                                            add(
                                                mul(
                                                    sub(
                                                        returnDataWords,
                                                        msizeWords
                                                    ),
                                                    CostPerWord
                                                ),
                                                div(
                                                    sub(
                                                        mul(
                                                            returnDataWords,
                                                            returnDataWords
                                                        ),
                                                        mul(msizeWords, msizeWords)
                                                    ),
                                                    MemoryExpansionCoefficient
                                                )
                                            )
                                        )
                                    }
                                    // Finally, add a small constant and compare to
                                    // gas remaining; bubble up the revert data if
                                    // enough gas is still available.
                                    if lt(add(cost, ExtraGasBuffer), gas()) {
                                        // Copy returndata to memory; overwrite
                                        // existing memory.
                                        returndatacopy(0, 0, returndatasize())
                                        // Revert, specifying memory region with
                                        // copied returndata.
                                        revert(0, returndatasize())
                                    }
                                }
                                // Otherwise revert with a generic error message.
                                mstore(
                                    TokenTransferGenericFailure_error_sig_ptr,
                                    TokenTransferGenericFailure_error_signature
                                )
                                mstore(
                                    TokenTransferGenericFailure_error_token_ptr,
                                    token
                                )
                                mstore(
                                    TokenTransferGenericFailure_error_from_ptr,
                                    from
                                )
                                mstore(TokenTransferGenericFailure_error_to_ptr, to)
                                mstore(TokenTransferGenericFailure_error_id_ptr, 0)
                                mstore(
                                    TokenTransferGenericFailure_error_amount_ptr,
                                    amount
                                )
                                revert(
                                    TokenTransferGenericFailure_error_sig_ptr,
                                    TokenTransferGenericFailure_error_length
                                )
                            }
                            // Otherwise revert with a message about the token
                            // returning false or non-compliant return values.
                            mstore(
                                BadReturnValueFromERC20OnTransfer_error_sig_ptr,
                                BadReturnValueFromERC20OnTransfer_error_signature
                            )
                            mstore(
                                BadReturnValueFromERC20OnTransfer_error_token_ptr,
                                token
                            )
                            mstore(
                                BadReturnValueFromERC20OnTransfer_error_from_ptr,
                                from
                            )
                            mstore(
                                BadReturnValueFromERC20OnTransfer_error_to_ptr,
                                to
                            )
                            mstore(
                                BadReturnValueFromERC20OnTransfer_error_amount_ptr,
                                amount
                            )
                            revert(
                                BadReturnValueFromERC20OnTransfer_error_sig_ptr,
                                BadReturnValueFromERC20OnTransfer_error_length
                            )
                        }
                        // Otherwise, revert with error about token not having code:
                        mstore(NoContract_error_sig_ptr, NoContract_error_signature)
                        mstore(NoContract_error_token_ptr, token)
                        revert(NoContract_error_sig_ptr, NoContract_error_length)
                    }
                    // Otherwise, the token just returned no data despite the call
                    // having succeeded; no need to optimize for this as it's not
                    // technically ERC20 compliant.
                }
                // Restore the original free memory pointer.
                mstore(FreeMemoryPointerSlot, memPointer)
                // Restore the zero slot to zero.
                mstore(ZeroSlot, 0)
            }
        }
        /**
         * @dev Internal function to transfer an ERC721 token from a given
         *      originator to a given recipient. Sufficient approvals must be set on
         *      the contract performing the transfer. Note that this function does
         *      not check whether the receiver can accept the ERC721 token (i.e. it
         *      does not use `safeTransferFrom`).
         *
         * @param token      The ERC721 token to transfer.
         * @param from       The originator of the transfer.
         * @param to         The recipient of the transfer.
         * @param identifier The tokenId to transfer.
         */
        function _performERC721Transfer(
            address token,
            address from,
            address to,
            uint256 identifier
        ) internal {
            // Utilize assembly to perform an optimized ERC721 token transfer.
            assembly {
                // If the token has no code, revert.
                if iszero(extcodesize(token)) {
                    mstore(NoContract_error_sig_ptr, NoContract_error_signature)
                    mstore(NoContract_error_token_ptr, token)
                    revert(NoContract_error_sig_ptr, NoContract_error_length)
                }
                // The free memory pointer memory slot will be used when populating
                // call data for the transfer; read the value and restore it later.
                let memPointer := mload(FreeMemoryPointerSlot)
                // Write call data to memory starting with function selector.
                mstore(ERC721_transferFrom_sig_ptr, ERC721_transferFrom_signature)
                mstore(ERC721_transferFrom_from_ptr, from)
                mstore(ERC721_transferFrom_to_ptr, to)
                mstore(ERC721_transferFrom_id_ptr, identifier)
                // Perform the call, ignoring return data.
                let success := call(
                    gas(),
                    token,
                    0,
                    ERC721_transferFrom_sig_ptr,
                    ERC721_transferFrom_length,
                    0,
                    0
                )
                // If the transfer reverted:
                if iszero(success) {
                    // If it returned a message, bubble it up as long as sufficient
                    // gas remains to do so:
                    if returndatasize() {
                        // Ensure that sufficient gas is available to copy
                        // returndata while expanding memory where necessary. Start
                        // by computing word size of returndata & allocated memory.
                        // Round up to the nearest full word.
                        let returnDataWords := div(
                            add(returndatasize(), AlmostOneWord),
                            OneWord
                        )
                        // Note: use the free memory pointer in place of msize() to
                        // work around a Yul warning that prevents accessing msize
                        // directly when the IR pipeline is activated.
                        let msizeWords := div(memPointer, OneWord)
                        // Next, compute the cost of the returndatacopy.
                        let cost := mul(CostPerWord, returnDataWords)
                        // Then, compute cost of new memory allocation.
                        if gt(returnDataWords, msizeWords) {
                            cost := add(
                                cost,
                                add(
                                    mul(
                                        sub(returnDataWords, msizeWords),
                                        CostPerWord
                                    ),
                                    div(
                                        sub(
                                            mul(returnDataWords, returnDataWords),
                                            mul(msizeWords, msizeWords)
                                        ),
                                        MemoryExpansionCoefficient
                                    )
                                )
                            )
                        }
                        // Finally, add a small constant and compare to gas
                        // remaining; bubble up the revert data if enough gas is
                        // still available.
                        if lt(add(cost, ExtraGasBuffer), gas()) {
                            // Copy returndata to memory; overwrite existing memory.
                            returndatacopy(0, 0, returndatasize())
                            // Revert, giving memory region with copied returndata.
                            revert(0, returndatasize())
                        }
                    }
                    // Otherwise revert with a generic error message.
                    mstore(
                        TokenTransferGenericFailure_error_sig_ptr,
                        TokenTransferGenericFailure_error_signature
                    )
                    mstore(TokenTransferGenericFailure_error_token_ptr, token)
                    mstore(TokenTransferGenericFailure_error_from_ptr, from)
                    mstore(TokenTransferGenericFailure_error_to_ptr, to)
                    mstore(TokenTransferGenericFailure_error_id_ptr, identifier)
                    mstore(TokenTransferGenericFailure_error_amount_ptr, 1)
                    revert(
                        TokenTransferGenericFailure_error_sig_ptr,
                        TokenTransferGenericFailure_error_length
                    )
                }
                // Restore the original free memory pointer.
                mstore(FreeMemoryPointerSlot, memPointer)
                // Restore the zero slot to zero.
                mstore(ZeroSlot, 0)
            }
        }
        /**
         * @dev Internal function to transfer ERC1155 tokens from a given
         *      originator to a given recipient. Sufficient approvals must be set on
         *      the contract performing the transfer and contract recipients must
         *      implement the ERC1155TokenReceiver interface to indicate that they
         *      are willing to accept the transfer.
         *
         * @param token      The ERC1155 token to transfer.
         * @param from       The originator of the transfer.
         * @param to         The recipient of the transfer.
         * @param identifier The id to transfer.
         * @param amount     The amount to transfer.
         */
        function _performERC1155Transfer(
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount
        ) internal {
            // Utilize assembly to perform an optimized ERC1155 token transfer.
            assembly {
                // If the token has no code, revert.
                if iszero(extcodesize(token)) {
                    mstore(NoContract_error_sig_ptr, NoContract_error_signature)
                    mstore(NoContract_error_token_ptr, token)
                    revert(NoContract_error_sig_ptr, NoContract_error_length)
                }
                // The following memory slots will be used when populating call data
                // for the transfer; read the values and restore them later.
                let memPointer := mload(FreeMemoryPointerSlot)
                let slot0x80 := mload(Slot0x80)
                let slot0xA0 := mload(Slot0xA0)
                let slot0xC0 := mload(Slot0xC0)
                // Write call data into memory, beginning with function selector.
                mstore(
                    ERC1155_safeTransferFrom_sig_ptr,
                    ERC1155_safeTransferFrom_signature
                )
                mstore(ERC1155_safeTransferFrom_from_ptr, from)
                mstore(ERC1155_safeTransferFrom_to_ptr, to)
                mstore(ERC1155_safeTransferFrom_id_ptr, identifier)
                mstore(ERC1155_safeTransferFrom_amount_ptr, amount)
                mstore(
                    ERC1155_safeTransferFrom_data_offset_ptr,
                    ERC1155_safeTransferFrom_data_length_offset
                )
                mstore(ERC1155_safeTransferFrom_data_length_ptr, 0)
                // Perform the call, ignoring return data.
                let success := call(
                    gas(),
                    token,
                    0,
                    ERC1155_safeTransferFrom_sig_ptr,
                    ERC1155_safeTransferFrom_length,
                    0,
                    0
                )
                // If the transfer reverted:
                if iszero(success) {
                    // If it returned a message, bubble it up as long as sufficient
                    // gas remains to do so:
                    if returndatasize() {
                        // Ensure that sufficient gas is available to copy
                        // returndata while expanding memory where necessary. Start
                        // by computing word size of returndata & allocated memory.
                        // Round up to the nearest full word.
                        let returnDataWords := div(
                            add(returndatasize(), AlmostOneWord),
                            OneWord
                        )
                        // Note: use the free memory pointer in place of msize() to
                        // work around a Yul warning that prevents accessing msize
                        // directly when the IR pipeline is activated.
                        let msizeWords := div(memPointer, OneWord)
                        // Next, compute the cost of the returndatacopy.
                        let cost := mul(CostPerWord, returnDataWords)
                        // Then, compute cost of new memory allocation.
                        if gt(returnDataWords, msizeWords) {
                            cost := add(
                                cost,
                                add(
                                    mul(
                                        sub(returnDataWords, msizeWords),
                                        CostPerWord
                                    ),
                                    div(
                                        sub(
                                            mul(returnDataWords, returnDataWords),
                                            mul(msizeWords, msizeWords)
                                        ),
                                        MemoryExpansionCoefficient
                                    )
                                )
                            )
                        }
                        // Finally, add a small constant and compare to gas
                        // remaining; bubble up the revert data if enough gas is
                        // still available.
                        if lt(add(cost, ExtraGasBuffer), gas()) {
                            // Copy returndata to memory; overwrite existing memory.
                            returndatacopy(0, 0, returndatasize())
                            // Revert, giving memory region with copied returndata.
                            revert(0, returndatasize())
                        }
                    }
                    // Otherwise revert with a generic error message.
                    mstore(
                        TokenTransferGenericFailure_error_sig_ptr,
                        TokenTransferGenericFailure_error_signature
                    )
                    mstore(TokenTransferGenericFailure_error_token_ptr, token)
                    mstore(TokenTransferGenericFailure_error_from_ptr, from)
                    mstore(TokenTransferGenericFailure_error_to_ptr, to)
                    mstore(TokenTransferGenericFailure_error_id_ptr, identifier)
                    mstore(TokenTransferGenericFailure_error_amount_ptr, amount)
                    revert(
                        TokenTransferGenericFailure_error_sig_ptr,
                        TokenTransferGenericFailure_error_length
                    )
                }
                mstore(Slot0x80, slot0x80) // Restore slot 0x80.
                mstore(Slot0xA0, slot0xA0) // Restore slot 0xA0.
                mstore(Slot0xC0, slot0xC0) // Restore slot 0xC0.
                // Restore the original free memory pointer.
                mstore(FreeMemoryPointerSlot, memPointer)
                // Restore the zero slot to zero.
                mstore(ZeroSlot, 0)
            }
        }
        /**
         * @dev Internal function to transfer ERC1155 tokens from a given
         *      originator to a given recipient. Sufficient approvals must be set on
         *      the contract performing the transfer and contract recipients must
         *      implement the ERC1155TokenReceiver interface to indicate that they
         *      are willing to accept the transfer. NOTE: this function is not
         *      memory-safe; it will overwrite existing memory, restore the free
         *      memory pointer to the default value, and overwrite the zero slot.
         *      This function should only be called once memory is no longer
         *      required and when uninitialized arrays are not utilized, and memory
         *      should be considered fully corrupted (aside from the existence of a
         *      default-value free memory pointer) after calling this function.
         *
         * @param batchTransfers The group of 1155 batch transfers to perform.
         */
        function _performERC1155BatchTransfers(
            ConduitBatch1155Transfer[] calldata batchTransfers
        ) internal {
            // Utilize assembly to perform optimized batch 1155 transfers.
            assembly {
                let len := batchTransfers.length
                // Pointer to first head in the array, which is offset to the struct
                // at each index. This gets incremented after each loop to avoid
                // multiplying by 32 to get the offset for each element.
                let nextElementHeadPtr := batchTransfers.offset
                // Pointer to beginning of the head of the array. This is the
                // reference position each offset references. It's held static to
                // let each loop calculate the data position for an element.
                let arrayHeadPtr := nextElementHeadPtr
                // Write the function selector, which will be reused for each call:
                // safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)
                mstore(
                    ConduitBatch1155Transfer_from_offset,
                    ERC1155_safeBatchTransferFrom_signature
                )
                // Iterate over each batch transfer.
                for {
                    let i := 0
                } lt(i, len) {
                    i := add(i, 1)
                } {
                    // Read the offset to the beginning of the element and add
                    // it to pointer to the beginning of the array head to get
                    // the absolute position of the element in calldata.
                    let elementPtr := add(
                        arrayHeadPtr,
                        calldataload(nextElementHeadPtr)
                    )
                    // Retrieve the token from calldata.
                    let token := calldataload(elementPtr)
                    // If the token has no code, revert.
                    if iszero(extcodesize(token)) {
                        mstore(NoContract_error_sig_ptr, NoContract_error_signature)
                        mstore(NoContract_error_token_ptr, token)
                        revert(NoContract_error_sig_ptr, NoContract_error_length)
                    }
                    // Get the total number of supplied ids.
                    let idsLength := calldataload(
                        add(elementPtr, ConduitBatch1155Transfer_ids_length_offset)
                    )
                    // Determine the expected offset for the amounts array.
                    let expectedAmountsOffset := add(
                        ConduitBatch1155Transfer_amounts_length_baseOffset,
                        mul(idsLength, OneWord)
                    )
                    // Validate struct encoding.
                    let invalidEncoding := iszero(
                        and(
                            // ids.length == amounts.length
                            eq(
                                idsLength,
                                calldataload(add(elementPtr, expectedAmountsOffset))
                            ),
                            and(
                                // ids_offset == 0xa0
                                eq(
                                    calldataload(
                                        add(
                                            elementPtr,
                                            ConduitBatch1155Transfer_ids_head_offset
                                        )
                                    ),
                                    ConduitBatch1155Transfer_ids_length_offset
                                ),
                                // amounts_offset == 0xc0 + ids.length*32
                                eq(
                                    calldataload(
                                        add(
                                            elementPtr,
                                            ConduitBatchTransfer_amounts_head_offset
                                        )
                                    ),
                                    expectedAmountsOffset
                                )
                            )
                        )
                    )
                    // Revert with an error if the encoding is not valid.
                    if invalidEncoding {
                        mstore(
                            Invalid1155BatchTransferEncoding_ptr,
                            Invalid1155BatchTransferEncoding_selector
                        )
                        revert(
                            Invalid1155BatchTransferEncoding_ptr,
                            Invalid1155BatchTransferEncoding_length
                        )
                    }
                    // Update the offset position for the next loop
                    nextElementHeadPtr := add(nextElementHeadPtr, OneWord)
                    // Copy the first section of calldata (before dynamic values).
                    calldatacopy(
                        BatchTransfer1155Params_ptr,
                        add(elementPtr, ConduitBatch1155Transfer_from_offset),
                        ConduitBatch1155Transfer_usable_head_size
                    )
                    // Determine size of calldata required for ids and amounts. Note
                    // that the size includes both lengths as well as the data.
                    let idsAndAmountsSize := add(TwoWords, mul(idsLength, TwoWords))
                    // Update the offset for the data array in memory.
                    mstore(
                        BatchTransfer1155Params_data_head_ptr,
                        add(
                            BatchTransfer1155Params_ids_length_offset,
                            idsAndAmountsSize
                        )
                    )
                    // Set the length of the data array in memory to zero.
                    mstore(
                        add(
                            BatchTransfer1155Params_data_length_basePtr,
                            idsAndAmountsSize
                        ),
                        0
                    )
                    // Determine the total calldata size for the call to transfer.
                    let transferDataSize := add(
                        BatchTransfer1155Params_calldata_baseSize,
                        idsAndAmountsSize
                    )
                    // Copy second section of calldata (including dynamic values).
                    calldatacopy(
                        BatchTransfer1155Params_ids_length_ptr,
                        add(elementPtr, ConduitBatch1155Transfer_ids_length_offset),
                        idsAndAmountsSize
                    )
                    // Perform the call to transfer 1155 tokens.
                    let success := call(
                        gas(),
                        token,
                        0,
                        ConduitBatch1155Transfer_from_offset, // Data portion start.
                        transferDataSize, // Location of the length of callData.
                        0,
                        0
                    )
                    // If the transfer reverted:
                    if iszero(success) {
                        // If it returned a message, bubble it up as long as
                        // sufficient gas remains to do so:
                        if returndatasize() {
                            // Ensure that sufficient gas is available to copy
                            // returndata while expanding memory where necessary.
                            // Start by computing word size of returndata and
                            // allocated memory. Round up to the nearest full word.
                            let returnDataWords := div(
                                add(returndatasize(), AlmostOneWord),
                                OneWord
                            )
                            // Note: use transferDataSize in place of msize() to
                            // work around a Yul warning that prevents accessing
                            // msize directly when the IR pipeline is activated.
                            // The free memory pointer is not used here because
                            // this function does almost all memory management
                            // manually and does not update it, and transferDataSize
                            // should be the largest memory value used (unless a
                            // previous batch was larger).
                            let msizeWords := div(transferDataSize, OneWord)
                            // Next, compute the cost of the returndatacopy.
                            let cost := mul(CostPerWord, returnDataWords)
                            // Then, compute cost of new memory allocation.
                            if gt(returnDataWords, msizeWords) {
                                cost := add(
                                    cost,
                                    add(
                                        mul(
                                            sub(returnDataWords, msizeWords),
                                            CostPerWord
                                        ),
                                        div(
                                            sub(
                                                mul(
                                                    returnDataWords,
                                                    returnDataWords
                                                ),
                                                mul(msizeWords, msizeWords)
                                            ),
                                            MemoryExpansionCoefficient
                                        )
                                    )
                                )
                            }
                            // Finally, add a small constant and compare to gas
                            // remaining; bubble up the revert data if enough gas is
                            // still available.
                            if lt(add(cost, ExtraGasBuffer), gas()) {
                                // Copy returndata to memory; overwrite existing.
                                returndatacopy(0, 0, returndatasize())
                                // Revert with memory region containing returndata.
                                revert(0, returndatasize())
                            }
                        }
                        // Set the error signature.
                        mstore(
                            0,
                            ERC1155BatchTransferGenericFailure_error_signature
                        )
                        // Write the token.
                        mstore(ERC1155BatchTransferGenericFailure_token_ptr, token)
                        // Increase the offset to ids by 32.
                        mstore(
                            BatchTransfer1155Params_ids_head_ptr,
                            ERC1155BatchTransferGenericFailure_ids_offset
                        )
                        // Increase the offset to amounts by 32.
                        mstore(
                            BatchTransfer1155Params_amounts_head_ptr,
                            add(
                                OneWord,
                                mload(BatchTransfer1155Params_amounts_head_ptr)
                            )
                        )
                        // Return modified region. The total size stays the same as
                        // `token` uses the same number of bytes as `data.length`.
                        revert(0, transferDataSize)
                    }
                }
                // Reset the free memory pointer to the default value; memory must
                // be assumed to be dirtied and not reused from this point forward.
                // Also note that the zero slot is not reset to zero, meaning empty
                // arrays cannot be safely created or utilized until it is restored.
                mstore(FreeMemoryPointerSlot, DefaultFreeMemoryPointer)
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        ConduitTransfer,
        ConduitBatch1155Transfer
    } from "../conduit/lib/ConduitStructs.sol";
    /**
     * @title ConduitInterface
     * @author 0age
     * @notice ConduitInterface contains all external function interfaces, events,
     *         and errors for conduit contracts.
     */
    interface ConduitInterface {
        /**
         * @dev Revert with an error when attempting to execute transfers using a
         *      caller that does not have an open channel.
         */
        error ChannelClosed(address channel);
        /**
         * @dev Revert with an error when attempting to update a channel to the
         *      current status of that channel.
         */
        error ChannelStatusAlreadySet(address channel, bool isOpen);
        /**
         * @dev Revert with an error when attempting to execute a transfer for an
         *      item that does not have an ERC20/721/1155 item type.
         */
        error InvalidItemType();
        /**
         * @dev Revert with an error when attempting to update the status of a
         *      channel from a caller that is not the conduit controller.
         */
        error InvalidController();
        /**
         * @dev Emit an event whenever a channel is opened or closed.
         *
         * @param channel The channel that has been updated.
         * @param open    A boolean indicating whether the conduit is open or not.
         */
        event ChannelUpdated(address indexed channel, bool open);
        /**
         * @notice Execute a sequence of ERC20/721/1155 transfers. Only a caller
         *         with an open channel can call this function.
         *
         * @param transfers The ERC20/721/1155 transfers to perform.
         *
         * @return magicValue A magic value indicating that the transfers were
         *                    performed successfully.
         */
        function execute(ConduitTransfer[] calldata transfers)
            external
            returns (bytes4 magicValue);
        /**
         * @notice Execute a sequence of batch 1155 transfers. Only a caller with an
         *         open channel can call this function.
         *
         * @param batch1155Transfers The 1155 batch transfers to perform.
         *
         * @return magicValue A magic value indicating that the transfers were
         *                    performed successfully.
         */
        function executeBatch1155(
            ConduitBatch1155Transfer[] calldata batch1155Transfers
        ) external returns (bytes4 magicValue);
        /**
         * @notice Execute a sequence of transfers, both single and batch 1155. Only
         *         a caller with an open channel can call this function.
         *
         * @param standardTransfers  The ERC20/721/1155 transfers to perform.
         * @param batch1155Transfers The 1155 batch transfers to perform.
         *
         * @return magicValue A magic value indicating that the transfers were
         *                    performed successfully.
         */
        function executeWithBatch1155(
            ConduitTransfer[] calldata standardTransfers,
            ConduitBatch1155Transfer[] calldata batch1155Transfers
        ) external returns (bytes4 magicValue);
        /**
         * @notice Open or close a given channel. Only callable by the controller.
         *
         * @param channel The channel to open or close.
         * @param isOpen  The status of the channel (either open or closed).
         */
        function updateChannel(address channel, bool isOpen) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title ConduitControllerInterface
     * @author 0age
     * @notice ConduitControllerInterface contains all external function interfaces,
     *         structs, events, and errors for the conduit controller.
     */
    interface ConduitControllerInterface {
        /**
         * @dev Track the conduit key, current owner, new potential owner, and open
         *      channels for each deployed conduit.
         */
        struct ConduitProperties {
            bytes32 key;
            address owner;
            address potentialOwner;
            address[] channels;
            mapping(address => uint256) channelIndexesPlusOne;
        }
        /**
         * @dev Emit an event whenever a new conduit is created.
         *
         * @param conduit    The newly created conduit.
         * @param conduitKey The conduit key used to create the new conduit.
         */
        event NewConduit(address conduit, bytes32 conduitKey);
        /**
         * @dev Emit an event whenever conduit ownership is transferred.
         *
         * @param conduit       The conduit for which ownership has been
         *                      transferred.
         * @param previousOwner The previous owner of the conduit.
         * @param newOwner      The new owner of the conduit.
         */
        event OwnershipTransferred(
            address indexed conduit,
            address indexed previousOwner,
            address indexed newOwner
        );
        /**
         * @dev Emit an event whenever a conduit owner registers a new potential
         *      owner for that conduit.
         *
         * @param newPotentialOwner The new potential owner of the conduit.
         */
        event PotentialOwnerUpdated(address indexed newPotentialOwner);
        /**
         * @dev Revert with an error when attempting to create a new conduit using a
         *      conduit key where the first twenty bytes of the key do not match the
         *      address of the caller.
         */
        error InvalidCreator();
        /**
         * @dev Revert with an error when attempting to create a new conduit when no
         *      initial owner address is supplied.
         */
        error InvalidInitialOwner();
        /**
         * @dev Revert with an error when attempting to set a new potential owner
         *      that is already set.
         */
        error NewPotentialOwnerAlreadySet(
            address conduit,
            address newPotentialOwner
        );
        /**
         * @dev Revert with an error when attempting to cancel ownership transfer
         *      when no new potential owner is currently set.
         */
        error NoPotentialOwnerCurrentlySet(address conduit);
        /**
         * @dev Revert with an error when attempting to interact with a conduit that
         *      does not yet exist.
         */
        error NoConduit();
        /**
         * @dev Revert with an error when attempting to create a conduit that
         *      already exists.
         */
        error ConduitAlreadyExists(address conduit);
        /**
         * @dev Revert with an error when attempting to update channels or transfer
         *      ownership of a conduit when the caller is not the owner of the
         *      conduit in question.
         */
        error CallerIsNotOwner(address conduit);
        /**
         * @dev Revert with an error when attempting to register a new potential
         *      owner and supplying the null address.
         */
        error NewPotentialOwnerIsZeroAddress(address conduit);
        /**
         * @dev Revert with an error when attempting to claim ownership of a conduit
         *      with a caller that is not the current potential owner for the
         *      conduit in question.
         */
        error CallerIsNotNewPotentialOwner(address conduit);
        /**
         * @dev Revert with an error when attempting to retrieve a channel using an
         *      index that is out of range.
         */
        error ChannelOutOfRange(address conduit);
        /**
         * @notice Deploy a new conduit using a supplied conduit key and assigning
         *         an initial owner for the deployed conduit. Note that the first
         *         twenty bytes of the supplied conduit key must match the caller
         *         and that a new conduit cannot be created if one has already been
         *         deployed using the same conduit key.
         *
         * @param conduitKey   The conduit key used to deploy the conduit. Note that
         *                     the first twenty bytes of the conduit key must match
         *                     the caller of this contract.
         * @param initialOwner The initial owner to set for the new conduit.
         *
         * @return conduit The address of the newly deployed conduit.
         */
        function createConduit(bytes32 conduitKey, address initialOwner)
            external
            returns (address conduit);
        /**
         * @notice Open or close a channel on a given conduit, thereby allowing the
         *         specified account to execute transfers against that conduit.
         *         Extreme care must be taken when updating channels, as malicious
         *         or vulnerable channels can transfer any ERC20, ERC721 and ERC1155
         *         tokens where the token holder has granted the conduit approval.
         *         Only the owner of the conduit in question may call this function.
         *
         * @param conduit The conduit for which to open or close the channel.
         * @param channel The channel to open or close on the conduit.
         * @param isOpen  A boolean indicating whether to open or close the channel.
         */
        function updateChannel(
            address conduit,
            address channel,
            bool isOpen
        ) external;
        /**
         * @notice Initiate conduit ownership transfer by assigning a new potential
         *         owner for the given conduit. Once set, the new potential owner
         *         may call `acceptOwnership` to claim ownership of the conduit.
         *         Only the owner of the conduit in question may call this function.
         *
         * @param conduit The conduit for which to initiate ownership transfer.
         * @param newPotentialOwner The new potential owner of the conduit.
         */
        function transferOwnership(address conduit, address newPotentialOwner)
            external;
        /**
         * @notice Clear the currently set potential owner, if any, from a conduit.
         *         Only the owner of the conduit in question may call this function.
         *
         * @param conduit The conduit for which to cancel ownership transfer.
         */
        function cancelOwnershipTransfer(address conduit) external;
        /**
         * @notice Accept ownership of a supplied conduit. Only accounts that the
         *         current owner has set as the new potential owner may call this
         *         function.
         *
         * @param conduit The conduit for which to accept ownership.
         */
        function acceptOwnership(address conduit) external;
        /**
         * @notice Retrieve the current owner of a deployed conduit.
         *
         * @param conduit The conduit for which to retrieve the associated owner.
         *
         * @return owner The owner of the supplied conduit.
         */
        function ownerOf(address conduit) external view returns (address owner);
        /**
         * @notice Retrieve the conduit key for a deployed conduit via reverse
         *         lookup.
         *
         * @param conduit The conduit for which to retrieve the associated conduit
         *                key.
         *
         * @return conduitKey The conduit key used to deploy the supplied conduit.
         */
        function getKey(address conduit) external view returns (bytes32 conduitKey);
        /**
         * @notice Derive the conduit associated with a given conduit key and
         *         determine whether that conduit exists (i.e. whether it has been
         *         deployed).
         *
         * @param conduitKey The conduit key used to derive the conduit.
         *
         * @return conduit The derived address of the conduit.
         * @return exists  A boolean indicating whether the derived conduit has been
         *                 deployed or not.
         */
        function getConduit(bytes32 conduitKey)
            external
            view
            returns (address conduit, bool exists);
        /**
         * @notice Retrieve the potential owner, if any, for a given conduit. The
         *         current owner may set a new potential owner via
         *         `transferOwnership` and that owner may then accept ownership of
         *         the conduit in question via `acceptOwnership`.
         *
         * @param conduit The conduit for which to retrieve the potential owner.
         *
         * @return potentialOwner The potential owner, if any, for the conduit.
         */
        function getPotentialOwner(address conduit)
            external
            view
            returns (address potentialOwner);
        /**
         * @notice Retrieve the status (either open or closed) of a given channel on
         *         a conduit.
         *
         * @param conduit The conduit for which to retrieve the channel status.
         * @param channel The channel for which to retrieve the status.
         *
         * @return isOpen The status of the channel on the given conduit.
         */
        function getChannelStatus(address conduit, address channel)
            external
            view
            returns (bool isOpen);
        /**
         * @notice Retrieve the total number of open channels for a given conduit.
         *
         * @param conduit The conduit for which to retrieve the total channel count.
         *
         * @return totalChannels The total number of open channels for the conduit.
         */
        function getTotalChannels(address conduit)
            external
            view
            returns (uint256 totalChannels);
        /**
         * @notice Retrieve an open channel at a specific index for a given conduit.
         *         Note that the index of a channel can change as a result of other
         *         channels being closed on the conduit.
         *
         * @param conduit      The conduit for which to retrieve the open channel.
         * @param channelIndex The index of the channel in question.
         *
         * @return channel The open channel, if any, at the specified channel index.
         */
        function getChannel(address conduit, uint256 channelIndex)
            external
            view
            returns (address channel);
        /**
         * @notice Retrieve all open channels for a given conduit. Note that calling
         *         this function for a conduit with many channels will revert with
         *         an out-of-gas error.
         *
         * @param conduit The conduit for which to retrieve open channels.
         *
         * @return channels An array of open channels on the given conduit.
         */
        function getChannels(address conduit)
            external
            view
            returns (address[] memory channels);
        /**
         * @dev Retrieve the conduit creation code and runtime code hashes.
         */
        function getConduitCodeHashes()
            external
            view
            returns (bytes32 creationCodeHash, bytes32 runtimeCodeHash);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { ConduitInterface } from "../interfaces/ConduitInterface.sol";
    import { ConduitItemType } from "./lib/ConduitEnums.sol";
    import { TokenTransferrer } from "../lib/TokenTransferrer.sol";
    // prettier-ignore
    import {
        ConduitTransfer,
        ConduitBatch1155Transfer
    } from "./lib/ConduitStructs.sol";
    import "./lib/ConduitConstants.sol";
    /**
     * @title Conduit
     * @author 0age
     * @notice This contract serves as an originator for "proxied" transfers. Each
     *         conduit is deployed and controlled by a "conduit controller" that can
     *         add and remove "channels" or contracts that can instruct the conduit
     *         to transfer approved ERC20/721/1155 tokens. *IMPORTANT NOTE: each
     *         conduit has an owner that can arbitrarily add or remove channels, and
     *         a malicious or negligent owner can add a channel that allows for any
     *         approved ERC20/721/1155 tokens to be taken immediately — be extremely
     *         cautious with what conduits you give token approvals to!*
     */
    contract Conduit is ConduitInterface, TokenTransferrer {
        // Set deployer as an immutable controller that can update channel statuses.
        address private immutable _controller;
        // Track the status of each channel.
        mapping(address => bool) private _channels;
        /**
         * @notice Ensure that the caller is currently registered as an open channel
         *         on the conduit.
         */
        modifier onlyOpenChannel() {
            // Utilize assembly to access channel storage mapping directly.
            assembly {
                // Write the caller to scratch space.
                mstore(ChannelKey_channel_ptr, caller())
                // Write the storage slot for _channels to scratch space.
                mstore(ChannelKey_slot_ptr, _channels.slot)
                // Derive the position in storage of _channels[msg.sender]
                // and check if the stored value is zero.
                if iszero(
                    sload(keccak256(ChannelKey_channel_ptr, ChannelKey_length))
                ) {
                    // The caller is not an open channel; revert with
                    // ChannelClosed(caller). First, set error signature in memory.
                    mstore(ChannelClosed_error_ptr, ChannelClosed_error_signature)
                    // Next, set the caller as the argument.
                    mstore(ChannelClosed_channel_ptr, caller())
                    // Finally, revert, returning full custom error with argument.
                    revert(ChannelClosed_error_ptr, ChannelClosed_error_length)
                }
            }
            // Continue with function execution.
            _;
        }
        /**
         * @notice In the constructor, set the deployer as the controller.
         */
        constructor() {
            // Set the deployer as the controller.
            _controller = msg.sender;
        }
        /**
         * @notice Execute a sequence of ERC20/721/1155 transfers. Only a caller
         *         with an open channel can call this function. Note that channels
         *         are expected to implement reentrancy protection if desired, and
         *         that cross-channel reentrancy may be possible if the conduit has
         *         multiple open channels at once. Also note that channels are
         *         expected to implement checks against transferring any zero-amount
         *         items if that constraint is desired.
         *
         * @param transfers The ERC20/721/1155 transfers to perform.
         *
         * @return magicValue A magic value indicating that the transfers were
         *                    performed successfully.
         */
        function execute(ConduitTransfer[] calldata transfers)
            external
            override
            onlyOpenChannel
            returns (bytes4 magicValue)
        {
            // Retrieve the total number of transfers and place on the stack.
            uint256 totalStandardTransfers = transfers.length;
            // Iterate over each transfer.
            for (uint256 i = 0; i < totalStandardTransfers; ) {
                // Retrieve the transfer in question and perform the transfer.
                _transfer(transfers[i]);
                // Skip overflow check as for loop is indexed starting at zero.
                unchecked {
                    ++i;
                }
            }
            // Return a magic value indicating that the transfers were performed.
            magicValue = this.execute.selector;
        }
        /**
         * @notice Execute a sequence of batch 1155 item transfers. Only a caller
         *         with an open channel can call this function. Note that channels
         *         are expected to implement reentrancy protection if desired, and
         *         that cross-channel reentrancy may be possible if the conduit has
         *         multiple open channels at once. Also note that channels are
         *         expected to implement checks against transferring any zero-amount
         *         items if that constraint is desired.
         *
         * @param batchTransfers The 1155 batch item transfers to perform.
         *
         * @return magicValue A magic value indicating that the item transfers were
         *                    performed successfully.
         */
        function executeBatch1155(
            ConduitBatch1155Transfer[] calldata batchTransfers
        ) external override onlyOpenChannel returns (bytes4 magicValue) {
            // Perform 1155 batch transfers. Note that memory should be considered
            // entirely corrupted from this point forward.
            _performERC1155BatchTransfers(batchTransfers);
            // Return a magic value indicating that the transfers were performed.
            magicValue = this.executeBatch1155.selector;
        }
        /**
         * @notice Execute a sequence of transfers, both single ERC20/721/1155 item
         *         transfers as well as batch 1155 item transfers. Only a caller
         *         with an open channel can call this function. Note that channels
         *         are expected to implement reentrancy protection if desired, and
         *         that cross-channel reentrancy may be possible if the conduit has
         *         multiple open channels at once. Also note that channels are
         *         expected to implement checks against transferring any zero-amount
         *         items if that constraint is desired.
         *
         * @param standardTransfers The ERC20/721/1155 item transfers to perform.
         * @param batchTransfers    The 1155 batch item transfers to perform.
         *
         * @return magicValue A magic value indicating that the item transfers were
         *                    performed successfully.
         */
        function executeWithBatch1155(
            ConduitTransfer[] calldata standardTransfers,
            ConduitBatch1155Transfer[] calldata batchTransfers
        ) external override onlyOpenChannel returns (bytes4 magicValue) {
            // Retrieve the total number of transfers and place on the stack.
            uint256 totalStandardTransfers = standardTransfers.length;
            // Iterate over each standard transfer.
            for (uint256 i = 0; i < totalStandardTransfers; ) {
                // Retrieve the transfer in question and perform the transfer.
                _transfer(standardTransfers[i]);
                // Skip overflow check as for loop is indexed starting at zero.
                unchecked {
                    ++i;
                }
            }
            // Perform 1155 batch transfers. Note that memory should be considered
            // entirely corrupted from this point forward aside from the free memory
            // pointer having the default value.
            _performERC1155BatchTransfers(batchTransfers);
            // Return a magic value indicating that the transfers were performed.
            magicValue = this.executeWithBatch1155.selector;
        }
        /**
         * @notice Open or close a given channel. Only callable by the controller.
         *
         * @param channel The channel to open or close.
         * @param isOpen  The status of the channel (either open or closed).
         */
        function updateChannel(address channel, bool isOpen) external override {
            // Ensure that the caller is the controller of this contract.
            if (msg.sender != _controller) {
                revert InvalidController();
            }
            // Ensure that the channel does not already have the indicated status.
            if (_channels[channel] == isOpen) {
                revert ChannelStatusAlreadySet(channel, isOpen);
            }
            // Update the status of the channel.
            _channels[channel] = isOpen;
            // Emit a corresponding event.
            emit ChannelUpdated(channel, isOpen);
        }
        /**
         * @dev Internal function to transfer a given ERC20/721/1155 item. Note that
         *      channels are expected to implement checks against transferring any
         *      zero-amount items if that constraint is desired.
         *
         * @param item The ERC20/721/1155 item to transfer.
         */
        function _transfer(ConduitTransfer calldata item) internal {
            // Determine the transfer method based on the respective item type.
            if (item.itemType == ConduitItemType.ERC20) {
                // Transfer ERC20 token. Note that item.identifier is ignored and
                // therefore ERC20 transfer items are potentially malleable — this
                // check should be performed by the calling channel if a constraint
                // on item malleability is desired.
                _performERC20Transfer(item.token, item.from, item.to, item.amount);
            } else if (item.itemType == ConduitItemType.ERC721) {
                // Ensure that exactly one 721 item is being transferred.
                if (item.amount != 1) {
                    revert InvalidERC721TransferAmount();
                }
                // Transfer ERC721 token.
                _performERC721Transfer(
                    item.token,
                    item.from,
                    item.to,
                    item.identifier
                );
            } else if (item.itemType == ConduitItemType.ERC1155) {
                // Transfer ERC1155 token.
                _performERC1155Transfer(
                    item.token,
                    item.from,
                    item.to,
                    item.identifier,
                    item.amount
                );
            } else {
                // Throw with an error.
                revert InvalidItemType();
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { ConduitItemType } from "./ConduitEnums.sol";
    struct ConduitTransfer {
        ConduitItemType itemType;
        address token;
        address from;
        address to;
        uint256 identifier;
        uint256 amount;
    }
    struct ConduitBatch1155Transfer {
        address token;
        address from;
        address to;
        uint256[] ids;
        uint256[] amounts;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { TransferHelperItem } from "../helpers/TransferHelperStructs.sol";
    interface TransferHelperInterface {
        /**
         * @dev Revert with an error when attempting to execute transfers with a
         *      NATIVE itemType.
         */
        error InvalidItemType();
        /**
         * @notice Transfer multiple items to a single recipient.
         *
         * @param items The items to transfer.
         * @param recipient  The address the items should be transferred to.
         * @param conduitKey  The key of the conduit performing the bulk transfer.
         */
        function bulkTransfer(
            TransferHelperItem[] calldata items,
            address recipient,
            bytes32 conduitKey
        ) external returns (bytes4);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    enum ConduitItemType {
        NATIVE, // unused
        ERC20,
        ERC721,
        ERC1155
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /*
     * -------------------------- Disambiguation & Other Notes ---------------------
     *    - The term "head" is used as it is in the documentation for ABI encoding,
     *      but only in reference to dynamic types, i.e. it always refers to the
     *      offset or pointer to the body of a dynamic type. In calldata, the head
     *      is always an offset (relative to the parent object), while in memory,
     *      the head is always the pointer to the body. More information found here:
     *      https://docs.soliditylang.org/en/v0.8.14/abi-spec.html#argument-encoding
     *        - Note that the length of an array is separate from and precedes the
     *          head of the array.
     *
     *    - The term "body" is used in place of the term "head" used in the ABI
     *      documentation. It refers to the start of the data for a dynamic type,
     *      e.g. the first word of a struct or the first word of the first element
     *      in an array.
     *
     *    - The term "pointer" is used to describe the absolute position of a value
     *      and never an offset relative to another value.
     *        - The suffix "_ptr" refers to a memory pointer.
     *        - The suffix "_cdPtr" refers to a calldata pointer.
     *
     *    - The term "offset" is used to describe the position of a value relative
     *      to some parent value. For example, OrderParameters_conduit_offset is the
     *      offset to the "conduit" value in the OrderParameters struct relative to
     *      the start of the body.
     *        - Note: Offsets are used to derive pointers.
     *
     *    - Some structs have pointers defined for all of their fields in this file.
     *      Lines which are commented out are fields that are not used in the
     *      codebase but have been left in for readability.
     */
    uint256 constant AlmostOneWord = 0x1f;
    uint256 constant OneWord = 0x20;
    uint256 constant TwoWords = 0x40;
    uint256 constant ThreeWords = 0x60;
    uint256 constant FreeMemoryPointerSlot = 0x40;
    uint256 constant ZeroSlot = 0x60;
    uint256 constant DefaultFreeMemoryPointer = 0x80;
    uint256 constant Slot0x80 = 0x80;
    uint256 constant Slot0xA0 = 0xa0;
    uint256 constant Slot0xC0 = 0xc0;
    // abi.encodeWithSignature("transferFrom(address,address,uint256)")
    uint256 constant ERC20_transferFrom_signature = (
        0x23b872dd00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ERC20_transferFrom_sig_ptr = 0x0;
    uint256 constant ERC20_transferFrom_from_ptr = 0x04;
    uint256 constant ERC20_transferFrom_to_ptr = 0x24;
    uint256 constant ERC20_transferFrom_amount_ptr = 0x44;
    uint256 constant ERC20_transferFrom_length = 0x64; // 4 + 32 * 3 == 100
    // abi.encodeWithSignature(
    //     "safeTransferFrom(address,address,uint256,uint256,bytes)"
    // )
    uint256 constant ERC1155_safeTransferFrom_signature = (
        0xf242432a00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ERC1155_safeTransferFrom_sig_ptr = 0x0;
    uint256 constant ERC1155_safeTransferFrom_from_ptr = 0x04;
    uint256 constant ERC1155_safeTransferFrom_to_ptr = 0x24;
    uint256 constant ERC1155_safeTransferFrom_id_ptr = 0x44;
    uint256 constant ERC1155_safeTransferFrom_amount_ptr = 0x64;
    uint256 constant ERC1155_safeTransferFrom_data_offset_ptr = 0x84;
    uint256 constant ERC1155_safeTransferFrom_data_length_ptr = 0xa4;
    uint256 constant ERC1155_safeTransferFrom_length = 0xc4; // 4 + 32 * 6 == 196
    uint256 constant ERC1155_safeTransferFrom_data_length_offset = 0xa0;
    // abi.encodeWithSignature(
    //     "safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)"
    // )
    uint256 constant ERC1155_safeBatchTransferFrom_signature = (
        0x2eb2c2d600000000000000000000000000000000000000000000000000000000
    );
    bytes4 constant ERC1155_safeBatchTransferFrom_selector = bytes4(
        bytes32(ERC1155_safeBatchTransferFrom_signature)
    );
    uint256 constant ERC721_transferFrom_signature = ERC20_transferFrom_signature;
    uint256 constant ERC721_transferFrom_sig_ptr = 0x0;
    uint256 constant ERC721_transferFrom_from_ptr = 0x04;
    uint256 constant ERC721_transferFrom_to_ptr = 0x24;
    uint256 constant ERC721_transferFrom_id_ptr = 0x44;
    uint256 constant ERC721_transferFrom_length = 0x64; // 4 + 32 * 3 == 100
    // abi.encodeWithSignature("NoContract(address)")
    uint256 constant NoContract_error_signature = (
        0x5f15d67200000000000000000000000000000000000000000000000000000000
    );
    uint256 constant NoContract_error_sig_ptr = 0x0;
    uint256 constant NoContract_error_token_ptr = 0x4;
    uint256 constant NoContract_error_length = 0x24; // 4 + 32 == 36
    // abi.encodeWithSignature(
    //     "TokenTransferGenericFailure(address,address,address,uint256,uint256)"
    // )
    uint256 constant TokenTransferGenericFailure_error_signature = (
        0xf486bc8700000000000000000000000000000000000000000000000000000000
    );
    uint256 constant TokenTransferGenericFailure_error_sig_ptr = 0x0;
    uint256 constant TokenTransferGenericFailure_error_token_ptr = 0x4;
    uint256 constant TokenTransferGenericFailure_error_from_ptr = 0x24;
    uint256 constant TokenTransferGenericFailure_error_to_ptr = 0x44;
    uint256 constant TokenTransferGenericFailure_error_id_ptr = 0x64;
    uint256 constant TokenTransferGenericFailure_error_amount_ptr = 0x84;
    // 4 + 32 * 5 == 164
    uint256 constant TokenTransferGenericFailure_error_length = 0xa4;
    // abi.encodeWithSignature(
    //     "BadReturnValueFromERC20OnTransfer(address,address,address,uint256)"
    // )
    uint256 constant BadReturnValueFromERC20OnTransfer_error_signature = (
        0x9889192300000000000000000000000000000000000000000000000000000000
    );
    uint256 constant BadReturnValueFromERC20OnTransfer_error_sig_ptr = 0x0;
    uint256 constant BadReturnValueFromERC20OnTransfer_error_token_ptr = 0x4;
    uint256 constant BadReturnValueFromERC20OnTransfer_error_from_ptr = 0x24;
    uint256 constant BadReturnValueFromERC20OnTransfer_error_to_ptr = 0x44;
    uint256 constant BadReturnValueFromERC20OnTransfer_error_amount_ptr = 0x64;
    // 4 + 32 * 4 == 132
    uint256 constant BadReturnValueFromERC20OnTransfer_error_length = 0x84;
    uint256 constant ExtraGasBuffer = 0x20;
    uint256 constant CostPerWord = 3;
    uint256 constant MemoryExpansionCoefficient = 0x200;
    // Values are offset by 32 bytes in order to write the token to the beginning
    // in the event of a revert
    uint256 constant BatchTransfer1155Params_ptr = 0x24;
    uint256 constant BatchTransfer1155Params_ids_head_ptr = 0x64;
    uint256 constant BatchTransfer1155Params_amounts_head_ptr = 0x84;
    uint256 constant BatchTransfer1155Params_data_head_ptr = 0xa4;
    uint256 constant BatchTransfer1155Params_data_length_basePtr = 0xc4;
    uint256 constant BatchTransfer1155Params_calldata_baseSize = 0xc4;
    uint256 constant BatchTransfer1155Params_ids_length_ptr = 0xc4;
    uint256 constant BatchTransfer1155Params_ids_length_offset = 0xa0;
    uint256 constant BatchTransfer1155Params_amounts_length_baseOffset = 0xc0;
    uint256 constant BatchTransfer1155Params_data_length_baseOffset = 0xe0;
    uint256 constant ConduitBatch1155Transfer_usable_head_size = 0x80;
    uint256 constant ConduitBatch1155Transfer_from_offset = 0x20;
    uint256 constant ConduitBatch1155Transfer_ids_head_offset = 0x60;
    uint256 constant ConduitBatch1155Transfer_amounts_head_offset = 0x80;
    uint256 constant ConduitBatch1155Transfer_ids_length_offset = 0xa0;
    uint256 constant ConduitBatch1155Transfer_amounts_length_baseOffset = 0xc0;
    uint256 constant ConduitBatch1155Transfer_calldata_baseSize = 0xc0;
    // Note: abbreviated version of above constant to adhere to line length limit.
    uint256 constant ConduitBatchTransfer_amounts_head_offset = 0x80;
    uint256 constant Invalid1155BatchTransferEncoding_ptr = 0x00;
    uint256 constant Invalid1155BatchTransferEncoding_length = 0x04;
    uint256 constant Invalid1155BatchTransferEncoding_selector = (
        0xeba2084c00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ERC1155BatchTransferGenericFailure_error_signature = (
        0xafc445e200000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ERC1155BatchTransferGenericFailure_token_ptr = 0x04;
    uint256 constant ERC1155BatchTransferGenericFailure_ids_offset = 0xc0;
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title TokenTransferrerErrors
     */
    interface TokenTransferrerErrors {
        /**
         * @dev Revert with an error when an ERC721 transfer with amount other than
         *      one is attempted.
         */
        error InvalidERC721TransferAmount();
        /**
         * @dev Revert with an error when attempting to fulfill an order where an
         *      item has an amount of zero.
         */
        error MissingItemAmount();
        /**
         * @dev Revert with an error when attempting to fulfill an order where an
         *      item has unused parameters. This includes both the token and the
         *      identifier parameters for native transfers as well as the identifier
         *      parameter for ERC20 transfers. Note that the conduit does not
         *      perform this check, leaving it up to the calling channel to enforce
         *      when desired.
         */
        error UnusedItemParameters();
        /**
         * @dev Revert with an error when an ERC20, ERC721, or ERC1155 token
         *      transfer reverts.
         *
         * @param token      The token for which the transfer was attempted.
         * @param from       The source of the attempted transfer.
         * @param to         The recipient of the attempted transfer.
         * @param identifier The identifier for the attempted transfer.
         * @param amount     The amount for the attempted transfer.
         */
        error TokenTransferGenericFailure(
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount
        );
        /**
         * @dev Revert with an error when a batch ERC1155 token transfer reverts.
         *
         * @param token       The token for which the transfer was attempted.
         * @param from        The source of the attempted transfer.
         * @param to          The recipient of the attempted transfer.
         * @param identifiers The identifiers for the attempted transfer.
         * @param amounts     The amounts for the attempted transfer.
         */
        error ERC1155BatchTransferGenericFailure(
            address token,
            address from,
            address to,
            uint256[] identifiers,
            uint256[] amounts
        );
        /**
         * @dev Revert with an error when an ERC20 token transfer returns a falsey
         *      value.
         *
         * @param token      The token for which the ERC20 transfer was attempted.
         * @param from       The source of the attempted ERC20 transfer.
         * @param to         The recipient of the attempted ERC20 transfer.
         * @param amount     The amount for the attempted ERC20 transfer.
         */
        error BadReturnValueFromERC20OnTransfer(
            address token,
            address from,
            address to,
            uint256 amount
        );
        /**
         * @dev Revert with an error when an account being called as an assumed
         *      contract does not have code and returns no data.
         *
         * @param account The account that should contain code.
         */
        error NoContract(address account);
        /**
         * @dev Revert with an error when attempting to execute an 1155 batch
         *      transfer using calldata not produced by default ABI encoding or with
         *      different lengths for ids and amounts arrays.
         */
        error Invalid1155BatchTransferEncoding();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // error ChannelClosed(address channel)
    uint256 constant ChannelClosed_error_signature = (
        0x93daadf200000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ChannelClosed_error_ptr = 0x00;
    uint256 constant ChannelClosed_channel_ptr = 0x4;
    uint256 constant ChannelClosed_error_length = 0x24;
    // For the mapping:
    // mapping(address => bool) channels
    // The position in storage for a particular account is:
    // keccak256(abi.encode(account, channels.slot))
    uint256 constant ChannelKey_channel_ptr = 0x00;
    uint256 constant ChannelKey_slot_ptr = 0x20;
    uint256 constant ChannelKey_length = 0x40;
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ConduitInterface } from "../interfaces/ConduitInterface.sol";
    import { ConduitItemType } from "../conduit/lib/ConduitEnums.sol";
    import { ItemType } from "./ConsiderationEnums.sol";
    import { ReceivedItem } from "./ConsiderationStructs.sol";
    import { Verifiers } from "./Verifiers.sol";
    import { TokenTransferrer } from "./TokenTransferrer.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title Executor
     * @author 0age
     * @notice Executor contains functions related to processing executions (i.e.
     *         transferring items, either directly or via conduits).
     */
    contract Executor is Verifiers, TokenTransferrer {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) Verifiers(conduitController) {}
        /**
         * @dev Internal function to transfer a given item, either directly or via
         *      a corresponding conduit.
         *
         * @param item        The item to transfer, including an amount and a
         *                    recipient.
         * @param from        The account supplying the item.
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _transfer(
            ReceivedItem memory item,
            address from,
            bytes32 conduitKey,
            bytes memory accumulator
        ) internal {
            // If the item type indicates Ether or a native token...
            if (item.itemType == ItemType.NATIVE) {
                // Ensure neither the token nor the identifier parameters are set.
                if ((uint160(item.token) | item.identifier) != 0) {
                    revert UnusedItemParameters();
                }
                // transfer the native tokens to the recipient.
                _transferEth(item.recipient, item.amount);
            } else if (item.itemType == ItemType.ERC20) {
                // Ensure that no identifier is supplied.
                if (item.identifier != 0) {
                    revert UnusedItemParameters();
                }
                // Transfer ERC20 tokens from the source to the recipient.
                _transferERC20(
                    item.token,
                    from,
                    item.recipient,
                    item.amount,
                    conduitKey,
                    accumulator
                );
            } else if (item.itemType == ItemType.ERC721) {
                // Transfer ERC721 token from the source to the recipient.
                _transferERC721(
                    item.token,
                    from,
                    item.recipient,
                    item.identifier,
                    item.amount,
                    conduitKey,
                    accumulator
                );
            } else {
                // Transfer ERC1155 token from the source to the recipient.
                _transferERC1155(
                    item.token,
                    from,
                    item.recipient,
                    item.identifier,
                    item.amount,
                    conduitKey,
                    accumulator
                );
            }
        }
        /**
         * @dev Internal function to transfer an individual ERC721 or ERC1155 item
         *      from a given originator to a given recipient. The accumulator will
         *      be bypassed, meaning that this function should be utilized in cases
         *      where multiple item transfers can be accumulated into a single
         *      conduit call. Sufficient approvals must be set, either on the
         *      respective conduit or on this contract itself.
         *
         * @param itemType   The type of item to transfer, either ERC721 or ERC1155.
         * @param token      The token to transfer.
         * @param from       The originator of the transfer.
         * @param to         The recipient of the transfer.
         * @param identifier The tokenId to transfer.
         * @param amount     The amount to transfer.
         * @param conduitKey A bytes32 value indicating what corresponding conduit,
         *                   if any, to source token approvals from. The zero hash
         *                   signifies that no conduit should be used, with direct
         *                   approvals set on this contract.
         */
        function _transferIndividual721Or1155Item(
            ItemType itemType,
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount,
            bytes32 conduitKey
        ) internal {
            // Determine if the transfer is to be performed via a conduit.
            if (conduitKey != bytes32(0)) {
                // Use free memory pointer as calldata offset for the conduit call.
                uint256 callDataOffset;
                // Utilize assembly to place each argument in free memory.
                assembly {
                    // Retrieve the free memory pointer and use it as the offset.
                    callDataOffset := mload(FreeMemoryPointerSlot)
                    // Write ConduitInterface.execute.selector to memory.
                    mstore(callDataOffset, Conduit_execute_signature)
                    // Write the offset to the ConduitTransfer array in memory.
                    mstore(
                        add(
                            callDataOffset,
                            Conduit_execute_ConduitTransfer_offset_ptr
                        ),
                        Conduit_execute_ConduitTransfer_ptr
                    )
                    // Write the length of the ConduitTransfer array to memory.
                    mstore(
                        add(
                            callDataOffset,
                            Conduit_execute_ConduitTransfer_length_ptr
                        ),
                        Conduit_execute_ConduitTransfer_length
                    )
                    // Write the item type to memory.
                    mstore(
                        add(callDataOffset, Conduit_execute_transferItemType_ptr),
                        itemType
                    )
                    // Write the token to memory.
                    mstore(
                        add(callDataOffset, Conduit_execute_transferToken_ptr),
                        token
                    )
                    // Write the transfer source to memory.
                    mstore(
                        add(callDataOffset, Conduit_execute_transferFrom_ptr),
                        from
                    )
                    // Write the transfer recipient to memory.
                    mstore(add(callDataOffset, Conduit_execute_transferTo_ptr), to)
                    // Write the token identifier to memory.
                    mstore(
                        add(callDataOffset, Conduit_execute_transferIdentifier_ptr),
                        identifier
                    )
                    // Write the transfer amount to memory.
                    mstore(
                        add(callDataOffset, Conduit_execute_transferAmount_ptr),
                        amount
                    )
                }
                // Perform the call to the conduit.
                _callConduitUsingOffsets(
                    conduitKey,
                    callDataOffset,
                    OneConduitExecute_size
                );
            } else {
                // Otherwise, determine whether it is an ERC721 or ERC1155 item.
                if (itemType == ItemType.ERC721) {
                    // Ensure that exactly one 721 item is being transferred.
                    if (amount != 1) {
                        revert InvalidERC721TransferAmount();
                    }
                    // Perform transfer via the token contract directly.
                    _performERC721Transfer(token, from, to, identifier);
                } else {
                    // Perform transfer via the token contract directly.
                    _performERC1155Transfer(token, from, to, identifier, amount);
                }
            }
        }
        /**
         * @dev Internal function to transfer Ether or other native tokens to a
         *      given recipient.
         *
         * @param to     The recipient of the transfer.
         * @param amount The amount to transfer.
         */
        function _transferEth(address payable to, uint256 amount) internal {
            // Ensure that the supplied amount is non-zero.
            _assertNonZeroAmount(amount);
            // Declare a variable indicating whether the call was successful or not.
            bool success;
            assembly {
                // Transfer the ETH and store if it succeeded or not.
                success := call(gas(), to, amount, 0, 0, 0, 0)
            }
            // If the call fails...
            if (!success) {
                // Revert and pass the revert reason along if one was returned.
                _revertWithReasonIfOneIsReturned();
                // Otherwise, revert with a generic error message.
                revert EtherTransferGenericFailure(to, amount);
            }
        }
        /**
         * @dev Internal function to transfer ERC20 tokens from a given originator
         *      to a given recipient using a given conduit if applicable. Sufficient
         *      approvals must be set on this contract or on a respective conduit.
         *
         * @param token       The ERC20 token to transfer.
         * @param from        The originator of the transfer.
         * @param to          The recipient of the transfer.
         * @param amount      The amount to transfer.
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _transferERC20(
            address token,
            address from,
            address to,
            uint256 amount,
            bytes32 conduitKey,
            bytes memory accumulator
        ) internal {
            // Ensure that the supplied amount is non-zero.
            _assertNonZeroAmount(amount);
            // Trigger accumulated transfers if the conduits differ.
            _triggerIfArmedAndNotAccumulatable(accumulator, conduitKey);
            // If no conduit has been specified...
            if (conduitKey == bytes32(0)) {
                // Perform the token transfer directly.
                _performERC20Transfer(token, from, to, amount);
            } else {
                // Insert the call to the conduit into the accumulator.
                _insert(
                    conduitKey,
                    accumulator,
                    ConduitItemType.ERC20,
                    token,
                    from,
                    to,
                    uint256(0),
                    amount
                );
            }
        }
        /**
         * @dev Internal function to transfer a single ERC721 token from a given
         *      originator to a given recipient. Sufficient approvals must be set,
         *      either on the respective conduit or on this contract itself.
         *
         * @param token       The ERC721 token to transfer.
         * @param from        The originator of the transfer.
         * @param to          The recipient of the transfer.
         * @param identifier  The tokenId to transfer (must be 1 for ERC721).
         * @param amount      The amount to transfer.
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _transferERC721(
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount,
            bytes32 conduitKey,
            bytes memory accumulator
        ) internal {
            // Trigger accumulated transfers if the conduits differ.
            _triggerIfArmedAndNotAccumulatable(accumulator, conduitKey);
            // If no conduit has been specified...
            if (conduitKey == bytes32(0)) {
                // Ensure that exactly one 721 item is being transferred.
                if (amount != 1) {
                    revert InvalidERC721TransferAmount();
                }
                // Perform transfer via the token contract directly.
                _performERC721Transfer(token, from, to, identifier);
            } else {
                // Insert the call to the conduit into the accumulator.
                _insert(
                    conduitKey,
                    accumulator,
                    ConduitItemType.ERC721,
                    token,
                    from,
                    to,
                    identifier,
                    amount
                );
            }
        }
        /**
         * @dev Internal function to transfer ERC1155 tokens from a given originator
         *      to a given recipient. Sufficient approvals must be set, either on
         *      the respective conduit or on this contract itself.
         *
         * @param token       The ERC1155 token to transfer.
         * @param from        The originator of the transfer.
         * @param to          The recipient of the transfer.
         * @param identifier  The id to transfer.
         * @param amount      The amount to transfer.
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _transferERC1155(
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount,
            bytes32 conduitKey,
            bytes memory accumulator
        ) internal {
            // Ensure that the supplied amount is non-zero.
            _assertNonZeroAmount(amount);
            // Trigger accumulated transfers if the conduits differ.
            _triggerIfArmedAndNotAccumulatable(accumulator, conduitKey);
            // If no conduit has been specified...
            if (conduitKey == bytes32(0)) {
                // Perform transfer via the token contract directly.
                _performERC1155Transfer(token, from, to, identifier, amount);
            } else {
                // Insert the call to the conduit into the accumulator.
                _insert(
                    conduitKey,
                    accumulator,
                    ConduitItemType.ERC1155,
                    token,
                    from,
                    to,
                    identifier,
                    amount
                );
            }
        }
        /**
         * @dev Internal function to trigger a call to the conduit currently held by
         *      the accumulator if the accumulator contains item transfers (i.e. it
         *      is "armed") and the supplied conduit key does not match the key held
         *      by the accumulator.
         *
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         */
        function _triggerIfArmedAndNotAccumulatable(
            bytes memory accumulator,
            bytes32 conduitKey
        ) internal {
            // Retrieve the current conduit key from the accumulator.
            bytes32 accumulatorConduitKey = _getAccumulatorConduitKey(accumulator);
            // Perform conduit call if the set key does not match the supplied key.
            if (accumulatorConduitKey != conduitKey) {
                _triggerIfArmed(accumulator);
            }
        }
        /**
         * @dev Internal function to trigger a call to the conduit currently held by
         *      the accumulator if the accumulator contains item transfers (i.e. it
         *      is "armed").
         *
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _triggerIfArmed(bytes memory accumulator) internal {
            // Exit if the accumulator is not "armed".
            if (accumulator.length != AccumulatorArmed) {
                return;
            }
            // Retrieve the current conduit key from the accumulator.
            bytes32 accumulatorConduitKey = _getAccumulatorConduitKey(accumulator);
            // Perform conduit call.
            _trigger(accumulatorConduitKey, accumulator);
        }
        /**
         * @dev Internal function to trigger a call to the conduit corresponding to
         *      a given conduit key, supplying all accumulated item transfers. The
         *      accumulator will be "disarmed" and reset in the process.
         *
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _trigger(bytes32 conduitKey, bytes memory accumulator) internal {
            // Declare variables for offset in memory & size of calldata to conduit.
            uint256 callDataOffset;
            uint256 callDataSize;
            // Call the conduit with all the accumulated transfers.
            assembly {
                // Call begins at third word; the first is length or "armed" status,
                // and the second is the current conduit key.
                callDataOffset := add(accumulator, TwoWords)
                // 68 + items * 192
                callDataSize := add(
                    Accumulator_array_offset_ptr,
                    mul(
                        mload(add(accumulator, Accumulator_array_length_ptr)),
                        Conduit_transferItem_size
                    )
                )
            }
            // Call conduit derived from conduit key & supply accumulated transfers.
            _callConduitUsingOffsets(conduitKey, callDataOffset, callDataSize);
            // Reset accumulator length to signal that it is now "disarmed".
            assembly {
                mstore(accumulator, AccumulatorDisarmed)
            }
        }
        /**
         * @dev Internal function to perform a call to the conduit corresponding to
         *      a given conduit key based on the offset and size of the calldata in
         *      question in memory.
         *
         * @param conduitKey     A bytes32 value indicating what corresponding
         *                       conduit, if any, to source token approvals from.
         *                       The zero hash signifies that no conduit should be
         *                       used, with direct approvals set on this contract.
         * @param callDataOffset The memory pointer where calldata is contained.
         * @param callDataSize   The size of calldata in memory.
         */
        function _callConduitUsingOffsets(
            bytes32 conduitKey,
            uint256 callDataOffset,
            uint256 callDataSize
        ) internal {
            // Derive the address of the conduit using the conduit key.
            address conduit = _deriveConduit(conduitKey);
            bool success;
            bytes4 result;
            // call the conduit.
            assembly {
                // Ensure first word of scratch space is empty.
                mstore(0, 0)
                // Perform call, placing first word of return data in scratch space.
                success := call(
                    gas(),
                    conduit,
                    0,
                    callDataOffset,
                    callDataSize,
                    0,
                    OneWord
                )
                // Take value from scratch space and place it on the stack.
                result := mload(0)
            }
            // If the call failed...
            if (!success) {
                // Pass along whatever revert reason was given by the conduit.
                _revertWithReasonIfOneIsReturned();
                // Otherwise, revert with a generic error.
                revert InvalidCallToConduit(conduit);
            }
            // Ensure result was extracted and matches EIP-1271 magic value.
            if (result != ConduitInterface.execute.selector) {
                revert InvalidConduit(conduitKey, conduit);
            }
        }
        /**
         * @dev Internal pure function to retrieve the current conduit key set for
         *      the accumulator.
         *
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         *
         * @return accumulatorConduitKey The conduit key currently set for the
         *                               accumulator.
         */
        function _getAccumulatorConduitKey(bytes memory accumulator)
            internal
            pure
            returns (bytes32 accumulatorConduitKey)
        {
            // Retrieve the current conduit key from the accumulator.
            assembly {
                accumulatorConduitKey := mload(
                    add(accumulator, Accumulator_conduitKey_ptr)
                )
            }
        }
        /**
         * @dev Internal pure function to place an item transfer into an accumulator
         *      that collects a series of transfers to execute against a given
         *      conduit in a single call.
         *
         * @param conduitKey  A bytes32 value indicating what corresponding conduit,
         *                    if any, to source token approvals from. The zero hash
         *                    signifies that no conduit should be used, with direct
         *                    approvals set on this contract.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         * @param itemType    The type of the item to transfer.
         * @param token       The token to transfer.
         * @param from        The originator of the transfer.
         * @param to          The recipient of the transfer.
         * @param identifier  The tokenId to transfer.
         * @param amount      The amount to transfer.
         */
        function _insert(
            bytes32 conduitKey,
            bytes memory accumulator,
            ConduitItemType itemType,
            address token,
            address from,
            address to,
            uint256 identifier,
            uint256 amount
        ) internal pure {
            uint256 elements;
            // "Arm" and prime accumulator if it's not already armed. The sentinel
            // value is held in the length of the accumulator array.
            if (accumulator.length == AccumulatorDisarmed) {
                elements = 1;
                bytes4 selector = ConduitInterface.execute.selector;
                assembly {
                    mstore(accumulator, AccumulatorArmed) // "arm" the accumulator.
                    mstore(add(accumulator, Accumulator_conduitKey_ptr), conduitKey)
                    mstore(add(accumulator, Accumulator_selector_ptr), selector)
                    mstore(
                        add(accumulator, Accumulator_array_offset_ptr),
                        Accumulator_array_offset
                    )
                    mstore(add(accumulator, Accumulator_array_length_ptr), elements)
                }
            } else {
                // Otherwise, increase the number of elements by one.
                assembly {
                    elements := add(
                        mload(add(accumulator, Accumulator_array_length_ptr)),
                        1
                    )
                    mstore(add(accumulator, Accumulator_array_length_ptr), elements)
                }
            }
            // Insert the item.
            assembly {
                let itemPointer := sub(
                    add(accumulator, mul(elements, Conduit_transferItem_size)),
                    Accumulator_itemSizeOffsetDifference
                )
                mstore(itemPointer, itemType)
                mstore(add(itemPointer, Conduit_transferItem_token_ptr), token)
                mstore(add(itemPointer, Conduit_transferItem_from_ptr), from)
                mstore(add(itemPointer, Conduit_transferItem_to_ptr), to)
                mstore(
                    add(itemPointer, Conduit_transferItem_identifier_ptr),
                    identifier
                )
                mstore(add(itemPointer, Conduit_transferItem_amount_ptr), amount)
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    enum OrderType {
        // 0: no partial fills, anyone can execute
        FULL_OPEN,
        // 1: partial fills supported, anyone can execute
        PARTIAL_OPEN,
        // 2: no partial fills, only offerer or zone can execute
        FULL_RESTRICTED,
        // 3: partial fills supported, only offerer or zone can execute
        PARTIAL_RESTRICTED
    }
    // prettier-ignore
    enum BasicOrderType {
        // 0: no partial fills, anyone can execute
        ETH_TO_ERC721_FULL_OPEN,
        // 1: partial fills supported, anyone can execute
        ETH_TO_ERC721_PARTIAL_OPEN,
        // 2: no partial fills, only offerer or zone can execute
        ETH_TO_ERC721_FULL_RESTRICTED,
        // 3: partial fills supported, only offerer or zone can execute
        ETH_TO_ERC721_PARTIAL_RESTRICTED,
        // 4: no partial fills, anyone can execute
        ETH_TO_ERC1155_FULL_OPEN,
        // 5: partial fills supported, anyone can execute
        ETH_TO_ERC1155_PARTIAL_OPEN,
        // 6: no partial fills, only offerer or zone can execute
        ETH_TO_ERC1155_FULL_RESTRICTED,
        // 7: partial fills supported, only offerer or zone can execute
        ETH_TO_ERC1155_PARTIAL_RESTRICTED,
        // 8: no partial fills, anyone can execute
        ERC20_TO_ERC721_FULL_OPEN,
        // 9: partial fills supported, anyone can execute
        ERC20_TO_ERC721_PARTIAL_OPEN,
        // 10: no partial fills, only offerer or zone can execute
        ERC20_TO_ERC721_FULL_RESTRICTED,
        // 11: partial fills supported, only offerer or zone can execute
        ERC20_TO_ERC721_PARTIAL_RESTRICTED,
        // 12: no partial fills, anyone can execute
        ERC20_TO_ERC1155_FULL_OPEN,
        // 13: partial fills supported, anyone can execute
        ERC20_TO_ERC1155_PARTIAL_OPEN,
        // 14: no partial fills, only offerer or zone can execute
        ERC20_TO_ERC1155_FULL_RESTRICTED,
        // 15: partial fills supported, only offerer or zone can execute
        ERC20_TO_ERC1155_PARTIAL_RESTRICTED,
        // 16: no partial fills, anyone can execute
        ERC721_TO_ERC20_FULL_OPEN,
        // 17: partial fills supported, anyone can execute
        ERC721_TO_ERC20_PARTIAL_OPEN,
        // 18: no partial fills, only offerer or zone can execute
        ERC721_TO_ERC20_FULL_RESTRICTED,
        // 19: partial fills supported, only offerer or zone can execute
        ERC721_TO_ERC20_PARTIAL_RESTRICTED,
        // 20: no partial fills, anyone can execute
        ERC1155_TO_ERC20_FULL_OPEN,
        // 21: partial fills supported, anyone can execute
        ERC1155_TO_ERC20_PARTIAL_OPEN,
        // 22: no partial fills, only offerer or zone can execute
        ERC1155_TO_ERC20_FULL_RESTRICTED,
        // 23: partial fills supported, only offerer or zone can execute
        ERC1155_TO_ERC20_PARTIAL_RESTRICTED
    }
    // prettier-ignore
    enum BasicOrderRouteType {
        // 0: provide Ether (or other native token) to receive offered ERC721 item.
        ETH_TO_ERC721,
        // 1: provide Ether (or other native token) to receive offered ERC1155 item.
        ETH_TO_ERC1155,
        // 2: provide ERC20 item to receive offered ERC721 item.
        ERC20_TO_ERC721,
        // 3: provide ERC20 item to receive offered ERC1155 item.
        ERC20_TO_ERC1155,
        // 4: provide ERC721 item to receive offered ERC20 item.
        ERC721_TO_ERC20,
        // 5: provide ERC1155 item to receive offered ERC20 item.
        ERC1155_TO_ERC20
    }
    // prettier-ignore
    enum ItemType {
        // 0: ETH on mainnet, MATIC on polygon, etc.
        NATIVE,
        // 1: ERC20 items (ERC777 and ERC20 analogues could also technically work)
        ERC20,
        // 2: ERC721 items
        ERC721,
        // 3: ERC1155 items
        ERC1155,
        // 4: ERC721 items where a number of tokenIds are supported
        ERC721_WITH_CRITERIA,
        // 5: ERC1155 items where a number of ids are supported
        ERC1155_WITH_CRITERIA
    }
    // prettier-ignore
    enum Side {
        // 0: Items that can be spent
        OFFER,
        // 1: Items that must be received
        CONSIDERATION
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        OrderType,
        BasicOrderType,
        ItemType,
        Side
    } from "./ConsiderationEnums.sol";
    /**
     * @dev An order contains eleven components: an offerer, a zone (or account that
     *      can cancel the order or restrict who can fulfill the order depending on
     *      the type), the order type (specifying partial fill support as well as
     *      restricted order status), the start and end time, a hash that will be
     *      provided to the zone when validating restricted orders, a salt, a key
     *      corresponding to a given conduit, a counter, and an arbitrary number of
     *      offer items that can be spent along with consideration items that must
     *      be received by their respective 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;
    }
    /**
     * @dev An offer item has five components: an item type (ETH or other native
     *      tokens, ERC20, ERC721, and ERC1155, as well as criteria-based ERC721 and
     *      ERC1155), a token address, a dual-purpose "identifierOrCriteria"
     *      component that will either represent a tokenId or a merkle root
     *      depending on the item type, and a start and end amount that support
     *      increasing or decreasing amounts over the duration of the respective
     *      order.
     */
    struct OfferItem {
        ItemType itemType;
        address token;
        uint256 identifierOrCriteria;
        uint256 startAmount;
        uint256 endAmount;
    }
    /**
     * @dev A consideration item has the same five components as an offer item and
     *      an additional sixth component designating the required recipient of the
     *      item.
     */
    struct ConsiderationItem {
        ItemType itemType;
        address token;
        uint256 identifierOrCriteria;
        uint256 startAmount;
        uint256 endAmount;
        address payable recipient;
    }
    /**
     * @dev A spent item is translated from a utilized offer item and has four
     *      components: an item type (ETH or other native tokens, ERC20, ERC721, and
     *      ERC1155), a token address, a tokenId, and an amount.
     */
    struct SpentItem {
        ItemType itemType;
        address token;
        uint256 identifier;
        uint256 amount;
    }
    /**
     * @dev A received item is translated from a utilized consideration item and has
     *      the same four components as a spent item, as well as an additional fifth
     *      component designating the required recipient of the item.
     */
    struct ReceivedItem {
        ItemType itemType;
        address token;
        uint256 identifier;
        uint256 amount;
        address payable recipient;
    }
    /**
     * @dev For basic orders involving ETH / native / ERC20 <=> ERC721 / ERC1155
     *      matching, a group of six functions may be called that only requires a
     *      subset of the usual order arguments. Note the use of a "basicOrderType"
     *      enum; this represents both the usual order type as well as the "route"
     *      of the basic order (a simple derivation function for the basic order
     *      type is `basicOrderType = orderType + (4 * basicOrderRoute)`.)
     */
    struct BasicOrderParameters {
        // calldata offset
        address considerationToken; // 0x24
        uint256 considerationIdentifier; // 0x44
        uint256 considerationAmount; // 0x64
        address payable offerer; // 0x84
        address zone; // 0xa4
        address offerToken; // 0xc4
        uint256 offerIdentifier; // 0xe4
        uint256 offerAmount; // 0x104
        BasicOrderType basicOrderType; // 0x124
        uint256 startTime; // 0x144
        uint256 endTime; // 0x164
        bytes32 zoneHash; // 0x184
        uint256 salt; // 0x1a4
        bytes32 offererConduitKey; // 0x1c4
        bytes32 fulfillerConduitKey; // 0x1e4
        uint256 totalOriginalAdditionalRecipients; // 0x204
        AdditionalRecipient[] additionalRecipients; // 0x224
        bytes signature; // 0x244
        // Total length, excluding dynamic array data: 0x264 (580)
    }
    /**
     * @dev Basic orders can supply any number of additional recipients, with the
     *      implied assumption that they are supplied from the offered ETH (or other
     *      native token) or ERC20 token for the order.
     */
    struct AdditionalRecipient {
        uint256 amount;
        address payable recipient;
    }
    /**
     * @dev The full set of order components, with the exception of the counter,
     *      must be supplied when fulfilling more sophisticated orders or groups of
     *      orders. The total number of original consideration items must also be
     *      supplied, as the caller may specify additional consideration items.
     */
    struct OrderParameters {
        address offerer; // 0x00
        address zone; // 0x20
        OfferItem[] offer; // 0x40
        ConsiderationItem[] consideration; // 0x60
        OrderType orderType; // 0x80
        uint256 startTime; // 0xa0
        uint256 endTime; // 0xc0
        bytes32 zoneHash; // 0xe0
        uint256 salt; // 0x100
        bytes32 conduitKey; // 0x120
        uint256 totalOriginalConsiderationItems; // 0x140
        // offer.length                          // 0x160
    }
    /**
     * @dev Orders require a signature in addition to the other order parameters.
     */
    struct Order {
        OrderParameters parameters;
        bytes signature;
    }
    /**
     * @dev Advanced orders include a numerator (i.e. a fraction to attempt to fill)
     *      and a denominator (the total size of the order) in addition to the
     *      signature and other order parameters. It also supports an optional field
     *      for supplying extra data; this data will be included in a staticcall to
     *      `isValidOrderIncludingExtraData` on the zone for the order if the order
     *      type is restricted and the offerer or zone are not the caller.
     */
    struct AdvancedOrder {
        OrderParameters parameters;
        uint120 numerator;
        uint120 denominator;
        bytes signature;
        bytes extraData;
    }
    /**
     * @dev Orders can be validated (either explicitly via `validate`, or as a
     *      consequence of a full or partial fill), specifically cancelled (they can
     *      also be cancelled in bulk via incrementing a per-zone counter), and
     *      partially or fully filled (with the fraction filled represented by a
     *      numerator and denominator).
     */
    struct OrderStatus {
        bool isValidated;
        bool isCancelled;
        uint120 numerator;
        uint120 denominator;
    }
    /**
     * @dev A criteria resolver specifies an order, side (offer vs. consideration),
     *      and item index. It then provides a chosen identifier (i.e. tokenId)
     *      alongside a merkle proof demonstrating the identifier meets the required
     *      criteria.
     */
    struct CriteriaResolver {
        uint256 orderIndex;
        Side side;
        uint256 index;
        uint256 identifier;
        bytes32[] criteriaProof;
    }
    /**
     * @dev A fulfillment is applied to a group of orders. It decrements a series of
     *      offer and consideration items, then generates a single execution
     *      element. A given fulfillment can be applied to as many offer and
     *      consideration items as desired, but must contain at least one offer and
     *      at least one consideration that match. The fulfillment must also remain
     *      consistent on all key parameters across all offer items (same offerer,
     *      token, type, tokenId, and conduit preference) as well as across all
     *      consideration items (token, type, tokenId, and recipient).
     */
    struct Fulfillment {
        FulfillmentComponent[] offerComponents;
        FulfillmentComponent[] considerationComponents;
    }
    /**
     * @dev Each fulfillment component contains one index referencing a specific
     *      order and another referencing a specific offer or consideration item.
     */
    struct FulfillmentComponent {
        uint256 orderIndex;
        uint256 itemIndex;
    }
    /**
     * @dev An execution is triggered once all consideration items have been zeroed
     *      out. It sends the item in question from the offerer to the item's
     *      recipient, optionally sourcing approvals from either this contract
     *      directly or from the offerer's chosen conduit if one is specified. An
     *      execution is not provided as an argument, but rather is derived via
     *      orders, criteria resolvers, and fulfillments (where the total number of
     *      executions will be less than or equal to the total number of indicated
     *      fulfillments) and returned as part of `matchOrders`.
     */
    struct Execution {
        ReceivedItem item;
        address offerer;
        bytes32 conduitKey;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { OrderStatus } from "./ConsiderationStructs.sol";
    import { Assertions } from "./Assertions.sol";
    import { SignatureVerification } from "./SignatureVerification.sol";
    /**
     * @title Verifiers
     * @author 0age
     * @notice Verifiers contains functions for performing verifications.
     */
    contract Verifiers is Assertions, SignatureVerification {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) Assertions(conduitController) {}
        /**
         * @dev Internal view function to ensure that the current time falls within
         *      an order's valid timespan.
         *
         * @param startTime       The time at which the order becomes active.
         * @param endTime         The time at which the order becomes inactive.
         * @param revertOnInvalid A boolean indicating whether to revert if the
         *                        order is not active.
         *
         * @return valid A boolean indicating whether the order is active.
         */
        function _verifyTime(
            uint256 startTime,
            uint256 endTime,
            bool revertOnInvalid
        ) internal view returns (bool valid) {
            // Revert if order's timespan hasn't started yet or has already ended.
            if (startTime > block.timestamp || endTime <= block.timestamp) {
                // Only revert if revertOnInvalid has been supplied as true.
                if (revertOnInvalid) {
                    revert InvalidTime();
                }
                // Return false as the order is invalid.
                return false;
            }
            // Return true as the order time is valid.
            valid = true;
        }
        /**
         * @dev Internal view function to verify the signature of an order. An
         *      ERC-1271 fallback will be attempted if either the signature length
         *      is not 32 or 33 bytes or if the recovered signer does not match the
         *      supplied offerer. Note that in cases where a 32 or 33 byte signature
         *      is supplied, only standard ECDSA signatures that recover to a
         *      non-zero address are supported.
         *
         * @param offerer   The offerer for the order.
         * @param orderHash The order hash.
         * @param signature A signature from the offerer indicating that the order
         *                  has been approved.
         */
        function _verifySignature(
            address offerer,
            bytes32 orderHash,
            bytes memory signature
        ) internal view {
            // Skip signature verification if the offerer is the caller.
            if (offerer == msg.sender) {
                return;
            }
            // Derive EIP-712 digest using the domain separator and the order hash.
            bytes32 digest = _deriveEIP712Digest(_domainSeparator(), orderHash);
            // Ensure that the signature for the digest is valid for the offerer.
            _assertValidSignature(offerer, digest, signature);
        }
        /**
         * @dev Internal view function to validate that a given order is fillable
         *      and not cancelled based on the order status.
         *
         * @param orderHash       The order hash.
         * @param orderStatus     The status of the order, including whether it has
         *                        been cancelled and the fraction filled.
         * @param onlyAllowUnused A boolean flag indicating whether partial fills
         *                        are supported by the calling function.
         * @param revertOnInvalid A boolean indicating whether to revert if the
         *                        order has been cancelled or filled beyond the
         *                        allowable amount.
         *
         * @return valid A boolean indicating whether the order is valid.
         */
        function _verifyOrderStatus(
            bytes32 orderHash,
            OrderStatus storage orderStatus,
            bool onlyAllowUnused,
            bool revertOnInvalid
        ) internal view returns (bool valid) {
            // Ensure that the order has not been cancelled.
            if (orderStatus.isCancelled) {
                // Only revert if revertOnInvalid has been supplied as true.
                if (revertOnInvalid) {
                    revert OrderIsCancelled(orderHash);
                }
                // Return false as the order status is invalid.
                return false;
            }
            // Read order status numerator from storage and place on stack.
            uint256 orderStatusNumerator = orderStatus.numerator;
            // If the order is not entirely unused...
            if (orderStatusNumerator != 0) {
                // ensure the order has not been partially filled when not allowed.
                if (onlyAllowUnused) {
                    // Always revert on partial fills when onlyAllowUnused is true.
                    revert OrderPartiallyFilled(orderHash);
                }
                // Otherwise, ensure that order has not been entirely filled.
                else if (orderStatusNumerator >= orderStatus.denominator) {
                    // Only revert if revertOnInvalid has been supplied as true.
                    if (revertOnInvalid) {
                        revert OrderAlreadyFilled(orderHash);
                    }
                    // Return false as the order status is invalid.
                    return false;
                }
            }
            // Return true as the order status is valid.
            valid = true;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /*
     * -------------------------- Disambiguation & Other Notes ---------------------
     *    - The term "head" is used as it is in the documentation for ABI encoding,
     *      but only in reference to dynamic types, i.e. it always refers to the
     *      offset or pointer to the body of a dynamic type. In calldata, the head
     *      is always an offset (relative to the parent object), while in memory,
     *      the head is always the pointer to the body. More information found here:
     *      https://docs.soliditylang.org/en/v0.8.14/abi-spec.html#argument-encoding
     *        - Note that the length of an array is separate from and precedes the
     *          head of the array.
     *
     *    - The term "body" is used in place of the term "head" used in the ABI
     *      documentation. It refers to the start of the data for a dynamic type,
     *      e.g. the first word of a struct or the first word of the first element
     *      in an array.
     *
     *    - The term "pointer" is used to describe the absolute position of a value
     *      and never an offset relative to another value.
     *        - The suffix "_ptr" refers to a memory pointer.
     *        - The suffix "_cdPtr" refers to a calldata pointer.
     *
     *    - The term "offset" is used to describe the position of a value relative
     *      to some parent value. For example, OrderParameters_conduit_offset is the
     *      offset to the "conduit" value in the OrderParameters struct relative to
     *      the start of the body.
     *        - Note: Offsets are used to derive pointers.
     *
     *    - Some structs have pointers defined for all of their fields in this file.
     *      Lines which are commented out are fields that are not used in the
     *      codebase but have been left in for readability.
     */
    // Declare constants for name, version, and reentrancy sentinel values.
    // Name is right padded, so it touches the length which is left padded. This
    // enables writing both values at once. Length goes at byte 95 in memory, and
    // name fills bytes 96-109, so both values can be written left-padded to 77.
    uint256 constant NameLengthPtr = 77;
    uint256 constant NameWithLength = 0x0d436F6E73696465726174696F6E;
    uint256 constant Version = 0x312e31;
    uint256 constant Version_length = 3;
    uint256 constant Version_shift = 0xe8;
    uint256 constant _NOT_ENTERED = 1;
    uint256 constant _ENTERED = 2;
    // Common Offsets
    // Offsets for identically positioned fields shared by:
    // OfferItem, ConsiderationItem, SpentItem, ReceivedItem
    uint256 constant Common_token_offset = 0x20;
    uint256 constant Common_identifier_offset = 0x40;
    uint256 constant Common_amount_offset = 0x60;
    uint256 constant ReceivedItem_size = 0xa0;
    uint256 constant ReceivedItem_amount_offset = 0x60;
    uint256 constant ReceivedItem_recipient_offset = 0x80;
    uint256 constant ReceivedItem_CommonParams_size = 0x60;
    uint256 constant ConsiderationItem_recipient_offset = 0xa0;
    // Store the same constant in an abbreviated format for a line length fix.
    uint256 constant ConsiderItem_recipient_offset = 0xa0;
    uint256 constant Execution_offerer_offset = 0x20;
    uint256 constant Execution_conduit_offset = 0x40;
    uint256 constant InvalidFulfillmentComponentData_error_signature = (
        0x7fda727900000000000000000000000000000000000000000000000000000000
    );
    uint256 constant InvalidFulfillmentComponentData_error_len = 0x04;
    uint256 constant Panic_error_signature = (
        0x4e487b7100000000000000000000000000000000000000000000000000000000
    );
    uint256 constant Panic_error_offset = 0x04;
    uint256 constant Panic_error_length = 0x24;
    uint256 constant Panic_arithmetic = 0x11;
    uint256 constant MissingItemAmount_error_signature = (
        0x91b3e51400000000000000000000000000000000000000000000000000000000
    );
    uint256 constant MissingItemAmount_error_len = 0x04;
    uint256 constant OrderParameters_offer_head_offset = 0x40;
    uint256 constant OrderParameters_consideration_head_offset = 0x60;
    uint256 constant OrderParameters_conduit_offset = 0x120;
    uint256 constant OrderParameters_counter_offset = 0x140;
    uint256 constant Fulfillment_itemIndex_offset = 0x20;
    uint256 constant AdvancedOrder_numerator_offset = 0x20;
    uint256 constant AlmostOneWord = 0x1f;
    uint256 constant OneWord = 0x20;
    uint256 constant TwoWords = 0x40;
    uint256 constant ThreeWords = 0x60;
    uint256 constant FourWords = 0x80;
    uint256 constant FiveWords = 0xa0;
    uint256 constant FreeMemoryPointerSlot = 0x40;
    uint256 constant ZeroSlot = 0x60;
    uint256 constant DefaultFreeMemoryPointer = 0x80;
    uint256 constant Slot0x80 = 0x80;
    uint256 constant Slot0xA0 = 0xa0;
    uint256 constant BasicOrder_endAmount_cdPtr = 0x104;
    uint256 constant BasicOrder_common_params_size = 0xa0;
    uint256 constant BasicOrder_considerationHashesArray_ptr = 0x160;
    uint256 constant EIP712_Order_size = 0x180;
    uint256 constant EIP712_OfferItem_size = 0xc0;
    uint256 constant EIP712_ConsiderationItem_size = 0xe0;
    uint256 constant AdditionalRecipients_size = 0x40;
    uint256 constant EIP712_DomainSeparator_offset = 0x02;
    uint256 constant EIP712_OrderHash_offset = 0x22;
    uint256 constant EIP712_DigestPayload_size = 0x42;
    uint256 constant receivedItemsHash_ptr = 0x60;
    /*
     *  Memory layout in _prepareBasicFulfillmentFromCalldata of
     *  data for OrderFulfilled
     *
     *   event OrderFulfilled(
     *     bytes32 orderHash,
     *     address indexed offerer,
     *     address indexed zone,
     *     address fulfiller,
     *     SpentItem[] offer,
     *       > (itemType, token, id, amount)
     *     ReceivedItem[] consideration
     *       > (itemType, token, id, amount, recipient)
     *   )
     *
     *  - 0x00: orderHash
     *  - 0x20: fulfiller
     *  - 0x40: offer offset (0x80)
     *  - 0x60: consideration offset (0x120)
     *  - 0x80: offer.length (1)
     *  - 0xa0: offerItemType
     *  - 0xc0: offerToken
     *  - 0xe0: offerIdentifier
     *  - 0x100: offerAmount
     *  - 0x120: consideration.length (1 + additionalRecipients.length)
     *  - 0x140: considerationItemType
     *  - 0x160: considerationToken
     *  - 0x180: considerationIdentifier
     *  - 0x1a0: considerationAmount
     *  - 0x1c0: considerationRecipient
     *  - ...
     */
    // Minimum length of the OrderFulfilled event data.
    // Must be added to the size of the ReceivedItem array for additionalRecipients
    // (0xa0 * additionalRecipients.length) to calculate full size of the buffer.
    uint256 constant OrderFulfilled_baseSize = 0x1e0;
    uint256 constant OrderFulfilled_selector = (
        0x9d9af8e38d66c62e2c12f0225249fd9d721c54b83f48d9352c97c6cacdcb6f31
    );
    // Minimum offset in memory to OrderFulfilled event data.
    // Must be added to the size of the EIP712 hash array for additionalRecipients
    // (32 * additionalRecipients.length) to calculate the pointer to event data.
    uint256 constant OrderFulfilled_baseOffset = 0x180;
    uint256 constant OrderFulfilled_consideration_length_baseOffset = 0x2a0;
    uint256 constant OrderFulfilled_offer_length_baseOffset = 0x200;
    // uint256 constant OrderFulfilled_orderHash_offset = 0x00;
    uint256 constant OrderFulfilled_fulfiller_offset = 0x20;
    uint256 constant OrderFulfilled_offer_head_offset = 0x40;
    uint256 constant OrderFulfilled_offer_body_offset = 0x80;
    uint256 constant OrderFulfilled_consideration_head_offset = 0x60;
    uint256 constant OrderFulfilled_consideration_body_offset = 0x120;
    // BasicOrderParameters
    uint256 constant BasicOrder_parameters_cdPtr = 0x04;
    uint256 constant BasicOrder_considerationToken_cdPtr = 0x24;
    // uint256 constant BasicOrder_considerationIdentifier_cdPtr = 0x44;
    uint256 constant BasicOrder_considerationAmount_cdPtr = 0x64;
    uint256 constant BasicOrder_offerer_cdPtr = 0x84;
    uint256 constant BasicOrder_zone_cdPtr = 0xa4;
    uint256 constant BasicOrder_offerToken_cdPtr = 0xc4;
    // uint256 constant BasicOrder_offerIdentifier_cdPtr = 0xe4;
    uint256 constant BasicOrder_offerAmount_cdPtr = 0x104;
    uint256 constant BasicOrder_basicOrderType_cdPtr = 0x124;
    uint256 constant BasicOrder_startTime_cdPtr = 0x144;
    // uint256 constant BasicOrder_endTime_cdPtr = 0x164;
    // uint256 constant BasicOrder_zoneHash_cdPtr = 0x184;
    // uint256 constant BasicOrder_salt_cdPtr = 0x1a4;
    uint256 constant BasicOrder_offererConduit_cdPtr = 0x1c4;
    uint256 constant BasicOrder_fulfillerConduit_cdPtr = 0x1e4;
    uint256 constant BasicOrder_totalOriginalAdditionalRecipients_cdPtr = 0x204;
    uint256 constant BasicOrder_additionalRecipients_head_cdPtr = 0x224;
    uint256 constant BasicOrder_signature_cdPtr = 0x244;
    uint256 constant BasicOrder_additionalRecipients_length_cdPtr = 0x264;
    uint256 constant BasicOrder_additionalRecipients_data_cdPtr = 0x284;
    uint256 constant BasicOrder_parameters_ptr = 0x20;
    uint256 constant BasicOrder_basicOrderType_range = 0x18; // 24 values
    /*
     *  Memory layout in _prepareBasicFulfillmentFromCalldata of
     *  EIP712 data for ConsiderationItem
     *   - 0x80: ConsiderationItem EIP-712 typehash (constant)
     *   - 0xa0: itemType
     *   - 0xc0: token
     *   - 0xe0: identifier
     *   - 0x100: startAmount
     *   - 0x120: endAmount
     *   - 0x140: recipient
     */
    uint256 constant BasicOrder_considerationItem_typeHash_ptr = 0x80; // memoryPtr
    uint256 constant BasicOrder_considerationItem_itemType_ptr = 0xa0;
    uint256 constant BasicOrder_considerationItem_token_ptr = 0xc0;
    uint256 constant BasicOrder_considerationItem_identifier_ptr = 0xe0;
    uint256 constant BasicOrder_considerationItem_startAmount_ptr = 0x100;
    uint256 constant BasicOrder_considerationItem_endAmount_ptr = 0x120;
    // uint256 constant BasicOrder_considerationItem_recipient_ptr = 0x140;
    /*
     *  Memory layout in _prepareBasicFulfillmentFromCalldata of
     *  EIP712 data for OfferItem
     *   - 0x80:  OfferItem EIP-712 typehash (constant)
     *   - 0xa0:  itemType
     *   - 0xc0:  token
     *   - 0xe0:  identifier (reused for offeredItemsHash)
     *   - 0x100: startAmount
     *   - 0x120: endAmount
     */
    uint256 constant BasicOrder_offerItem_typeHash_ptr = DefaultFreeMemoryPointer;
    uint256 constant BasicOrder_offerItem_itemType_ptr = 0xa0;
    uint256 constant BasicOrder_offerItem_token_ptr = 0xc0;
    // uint256 constant BasicOrder_offerItem_identifier_ptr = 0xe0;
    // uint256 constant BasicOrder_offerItem_startAmount_ptr = 0x100;
    uint256 constant BasicOrder_offerItem_endAmount_ptr = 0x120;
    /*
     *  Memory layout in _prepareBasicFulfillmentFromCalldata of
     *  EIP712 data for Order
     *   - 0x80:   Order EIP-712 typehash (constant)
     *   - 0xa0:   orderParameters.offerer
     *   - 0xc0:   orderParameters.zone
     *   - 0xe0:   keccak256(abi.encodePacked(offerHashes))
     *   - 0x100:  keccak256(abi.encodePacked(considerationHashes))
     *   - 0x120:  orderType
     *   - 0x140:  startTime
     *   - 0x160:  endTime
     *   - 0x180:  zoneHash
     *   - 0x1a0:  salt
     *   - 0x1c0:  conduit
     *   - 0x1e0:  _counters[orderParameters.offerer] (from storage)
     */
    uint256 constant BasicOrder_order_typeHash_ptr = 0x80;
    uint256 constant BasicOrder_order_offerer_ptr = 0xa0;
    // uint256 constant BasicOrder_order_zone_ptr = 0xc0;
    uint256 constant BasicOrder_order_offerHashes_ptr = 0xe0;
    uint256 constant BasicOrder_order_considerationHashes_ptr = 0x100;
    uint256 constant BasicOrder_order_orderType_ptr = 0x120;
    uint256 constant BasicOrder_order_startTime_ptr = 0x140;
    // uint256 constant BasicOrder_order_endTime_ptr = 0x160;
    // uint256 constant BasicOrder_order_zoneHash_ptr = 0x180;
    // uint256 constant BasicOrder_order_salt_ptr = 0x1a0;
    // uint256 constant BasicOrder_order_conduitKey_ptr = 0x1c0;
    uint256 constant BasicOrder_order_counter_ptr = 0x1e0;
    uint256 constant BasicOrder_additionalRecipients_head_ptr = 0x240;
    uint256 constant BasicOrder_signature_ptr = 0x260;
    // Signature-related
    bytes32 constant EIP2098_allButHighestBitMask = (
        0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
    );
    bytes32 constant ECDSA_twentySeventhAndTwentyEighthBytesSet = (
        0x0000000000000000000000000000000000000000000000000000000101000000
    );
    uint256 constant ECDSA_MaxLength = 65;
    uint256 constant ECDSA_signature_s_offset = 0x40;
    uint256 constant ECDSA_signature_v_offset = 0x60;
    bytes32 constant EIP1271_isValidSignature_selector = (
        0x1626ba7e00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant EIP1271_isValidSignature_signatureHead_negativeOffset = 0x20;
    uint256 constant EIP1271_isValidSignature_digest_negativeOffset = 0x40;
    uint256 constant EIP1271_isValidSignature_selector_negativeOffset = 0x44;
    uint256 constant EIP1271_isValidSignature_calldata_baseLength = 0x64;
    uint256 constant EIP1271_isValidSignature_signature_head_offset = 0x40;
    // abi.encodeWithSignature("NoContract(address)")
    uint256 constant NoContract_error_signature = (
        0x5f15d67200000000000000000000000000000000000000000000000000000000
    );
    uint256 constant NoContract_error_sig_ptr = 0x0;
    uint256 constant NoContract_error_token_ptr = 0x4;
    uint256 constant NoContract_error_length = 0x24; // 4 + 32 == 36
    uint256 constant EIP_712_PREFIX = (
        0x1901000000000000000000000000000000000000000000000000000000000000
    );
    uint256 constant ExtraGasBuffer = 0x20;
    uint256 constant CostPerWord = 3;
    uint256 constant MemoryExpansionCoefficient = 0x200; // 512
    uint256 constant Create2AddressDerivation_ptr = 0x0b;
    uint256 constant Create2AddressDerivation_length = 0x55;
    uint256 constant MaskOverByteTwelve = (
        0x0000000000000000000000ff0000000000000000000000000000000000000000
    );
    uint256 constant MaskOverLastTwentyBytes = (
        0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff
    );
    uint256 constant MaskOverFirstFourBytes = (
        0xffffffff00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant Conduit_execute_signature = (
        0x4ce34aa200000000000000000000000000000000000000000000000000000000
    );
    uint256 constant MaxUint8 = 0xff;
    uint256 constant MaxUint120 = 0xffffffffffffffffffffffffffffff;
    uint256 constant Conduit_execute_ConduitTransfer_ptr = 0x20;
    uint256 constant Conduit_execute_ConduitTransfer_length = 0x01;
    uint256 constant Conduit_execute_ConduitTransfer_offset_ptr = 0x04;
    uint256 constant Conduit_execute_ConduitTransfer_length_ptr = 0x24;
    uint256 constant Conduit_execute_transferItemType_ptr = 0x44;
    uint256 constant Conduit_execute_transferToken_ptr = 0x64;
    uint256 constant Conduit_execute_transferFrom_ptr = 0x84;
    uint256 constant Conduit_execute_transferTo_ptr = 0xa4;
    uint256 constant Conduit_execute_transferIdentifier_ptr = 0xc4;
    uint256 constant Conduit_execute_transferAmount_ptr = 0xe4;
    uint256 constant OneConduitExecute_size = 0x104;
    // Sentinel value to indicate that the conduit accumulator is not armed.
    uint256 constant AccumulatorDisarmed = 0x20;
    uint256 constant AccumulatorArmed = 0x40;
    uint256 constant Accumulator_conduitKey_ptr = 0x20;
    uint256 constant Accumulator_selector_ptr = 0x40;
    uint256 constant Accumulator_array_offset_ptr = 0x44;
    uint256 constant Accumulator_array_length_ptr = 0x64;
    uint256 constant Accumulator_itemSizeOffsetDifference = 0x3c;
    uint256 constant Accumulator_array_offset = 0x20;
    uint256 constant Conduit_transferItem_size = 0xc0;
    uint256 constant Conduit_transferItem_token_ptr = 0x20;
    uint256 constant Conduit_transferItem_from_ptr = 0x40;
    uint256 constant Conduit_transferItem_to_ptr = 0x60;
    uint256 constant Conduit_transferItem_identifier_ptr = 0x80;
    uint256 constant Conduit_transferItem_amount_ptr = 0xa0;
    // Declare constant for errors related to amount derivation.
    // error InexactFraction() @ AmountDerivationErrors.sol
    uint256 constant InexactFraction_error_signature = (
        0xc63cf08900000000000000000000000000000000000000000000000000000000
    );
    uint256 constant InexactFraction_error_len = 0x04;
    // Declare constant for errors related to signature verification.
    uint256 constant Ecrecover_precompile = 1;
    uint256 constant Ecrecover_args_size = 0x80;
    uint256 constant Signature_lower_v = 27;
    // error BadSignatureV(uint8) @ SignatureVerificationErrors.sol
    uint256 constant BadSignatureV_error_signature = (
        0x1f003d0a00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant BadSignatureV_error_offset = 0x04;
    uint256 constant BadSignatureV_error_length = 0x24;
    // error InvalidSigner() @ SignatureVerificationErrors.sol
    uint256 constant InvalidSigner_error_signature = (
        0x815e1d6400000000000000000000000000000000000000000000000000000000
    );
    uint256 constant InvalidSigner_error_length = 0x04;
    // error InvalidSignature() @ SignatureVerificationErrors.sol
    uint256 constant InvalidSignature_error_signature = (
        0x8baa579f00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant InvalidSignature_error_length = 0x04;
    // error BadContractSignature() @ SignatureVerificationErrors.sol
    uint256 constant BadContractSignature_error_signature = (
        0x4f7fb80d00000000000000000000000000000000000000000000000000000000
    );
    uint256 constant BadContractSignature_error_length = 0x04;
    uint256 constant NumBitsAfterSelector = 0xe0;
    // 69 is the lowest modulus for which the remainder
    // of every selector other than the two match functions
    // is greater than those of the match functions.
    uint256 constant NonMatchSelector_MagicModulus = 69;
    // Of the two match function selectors, the highest
    // remainder modulo 69 is 29.
    uint256 constant NonMatchSelector_MagicRemainder = 0x1d;
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { OrderParameters } from "./ConsiderationStructs.sol";
    import { GettersAndDerivers } from "./GettersAndDerivers.sol";
    // prettier-ignore
    import {
        TokenTransferrerErrors
    } from "../interfaces/TokenTransferrerErrors.sol";
    import { CounterManager } from "./CounterManager.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title Assertions
     * @author 0age
     * @notice Assertions contains logic for making various assertions that do not
     *         fit neatly within a dedicated semantic scope.
     */
    contract Assertions is
        GettersAndDerivers,
        CounterManager,
        TokenTransferrerErrors
    {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController)
            GettersAndDerivers(conduitController)
        {}
        /**
         * @dev Internal view function to ensure that the supplied consideration
         *      array length on a given set of order parameters is not less than the
         *      original consideration array length for that order and to retrieve
         *      the current counter for a given order's offerer and zone and use it
         *      to derive the order hash.
         *
         * @param orderParameters The parameters of the order to hash.
         *
         * @return The hash.
         */
        function _assertConsiderationLengthAndGetOrderHash(
            OrderParameters memory orderParameters
        ) internal view returns (bytes32) {
            // Ensure supplied consideration array length is not less than original.
            _assertConsiderationLengthIsNotLessThanOriginalConsiderationLength(
                orderParameters.consideration.length,
                orderParameters.totalOriginalConsiderationItems
            );
            // Derive and return order hash using current counter for the offerer.
            return
                _deriveOrderHash(
                    orderParameters,
                    _getCounter(orderParameters.offerer)
                );
        }
        /**
         * @dev Internal pure function to ensure that the supplied consideration
         *      array length for an order to be fulfilled is not less than the
         *      original consideration array length for that order.
         *
         * @param suppliedConsiderationItemTotal The number of consideration items
         *                                       supplied when fulfilling the order.
         * @param originalConsiderationItemTotal The number of consideration items
         *                                       supplied on initial order creation.
         */
        function _assertConsiderationLengthIsNotLessThanOriginalConsiderationLength(
            uint256 suppliedConsiderationItemTotal,
            uint256 originalConsiderationItemTotal
        ) internal pure {
            // Ensure supplied consideration array length is not less than original.
            if (suppliedConsiderationItemTotal < originalConsiderationItemTotal) {
                revert MissingOriginalConsiderationItems();
            }
        }
        /**
         * @dev Internal pure function to ensure that a given item amount is not
         *      zero.
         *
         * @param amount The amount to check.
         */
        function _assertNonZeroAmount(uint256 amount) internal pure {
            // Revert if the supplied amount is equal to zero.
            if (amount == 0) {
                revert MissingItemAmount();
            }
        }
        /**
         * @dev Internal pure function to validate calldata offsets for dynamic
         *      types in BasicOrderParameters and other parameters. This ensures
         *      that functions using the calldata object normally will be using the
         *      same data as the assembly functions and that values that are bound
         *      to a given range are within that range. Note that no parameters are
         *      supplied as all basic order functions use the same calldata
         *      encoding.
         */
        function _assertValidBasicOrderParameters() internal pure {
            // Declare a boolean designating basic order parameter offset validity.
            bool validOffsets;
            // Utilize assembly in order to read offset data directly from calldata.
            assembly {
                /*
                 * Checks:
                 * 1. Order parameters struct offset == 0x20
                 * 2. Additional recipients arr offset == 0x240
                 * 3. Signature offset == 0x260 + (recipients.length * 0x40)
                 * 4. BasicOrderType between 0 and 23 (i.e. < 24)
                 */
                validOffsets := and(
                    // Order parameters at calldata 0x04 must have offset of 0x20.
                    eq(
                        calldataload(BasicOrder_parameters_cdPtr),
                        BasicOrder_parameters_ptr
                    ),
                    // Additional recipients at cd 0x224 must have offset of 0x240.
                    eq(
                        calldataload(BasicOrder_additionalRecipients_head_cdPtr),
                        BasicOrder_additionalRecipients_head_ptr
                    )
                )
                validOffsets := and(
                    validOffsets,
                    eq(
                        // Load signature offset from calldata 0x244.
                        calldataload(BasicOrder_signature_cdPtr),
                        // Derive expected offset as start of recipients + len * 64.
                        add(
                            BasicOrder_signature_ptr,
                            mul(
                                // Additional recipients length at calldata 0x264.
                                calldataload(
                                    BasicOrder_additionalRecipients_length_cdPtr
                                ),
                                // Each additional recipient has a length of 0x40.
                                AdditionalRecipients_size
                            )
                        )
                    )
                )
                validOffsets := and(
                    validOffsets,
                    lt(
                        // BasicOrderType parameter at calldata offset 0x124.
                        calldataload(BasicOrder_basicOrderType_cdPtr),
                        // Value should be less than 24.
                        BasicOrder_basicOrderType_range
                    )
                )
            }
            // Revert with an error if basic order parameter offsets are invalid.
            if (!validOffsets) {
                revert InvalidBasicOrderParameterEncoding();
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { EIP1271Interface } from "../interfaces/EIP1271Interface.sol";
    // prettier-ignore
    import {
        SignatureVerificationErrors
    } from "../interfaces/SignatureVerificationErrors.sol";
    import { LowLevelHelpers } from "./LowLevelHelpers.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title SignatureVerification
     * @author 0age
     * @notice SignatureVerification contains logic for verifying signatures.
     */
    contract SignatureVerification is SignatureVerificationErrors, LowLevelHelpers {
        /**
         * @dev Internal view function to verify the signature of an order. An
         *      ERC-1271 fallback will be attempted if either the signature length
         *      is not 64 or 65 bytes or if the recovered signer does not match the
         *      supplied signer.
         *
         * @param signer    The signer for the order.
         * @param digest    The digest to verify the signature against.
         * @param signature A signature from the signer indicating that the order
         *                  has been approved.
         */
        function _assertValidSignature(
            address signer,
            bytes32 digest,
            bytes memory signature
        ) internal view {
            // Declare value for ecrecover equality or 1271 call success status.
            bool success;
            // Utilize assembly to perform optimized signature verification check.
            assembly {
                // Ensure that first word of scratch space is empty.
                mstore(0, 0)
                // Declare value for v signature parameter.
                let v
                // Get the length of the signature.
                let signatureLength := mload(signature)
                // Get the pointer to the value preceding the signature length.
                // This will be used for temporary memory overrides - either the
                // signature head for isValidSignature or the digest for ecrecover.
                let wordBeforeSignaturePtr := sub(signature, OneWord)
                // Cache the current value behind the signature to restore it later.
                let cachedWordBeforeSignature := mload(wordBeforeSignaturePtr)
                // Declare lenDiff + recoveredSigner scope to manage stack pressure.
                {
                    // Take the difference between the max ECDSA signature length
                    // and the actual signature length. Overflow desired for any
                    // values > 65. If the diff is not 0 or 1, it is not a valid
                    // ECDSA signature - move on to EIP1271 check.
                    let lenDiff := sub(ECDSA_MaxLength, signatureLength)
                    // Declare variable for recovered signer.
                    let recoveredSigner
                    // If diff is 0 or 1, it may be an ECDSA signature.
                    // Try to recover signer.
                    if iszero(gt(lenDiff, 1)) {
                        // Read the signature `s` value.
                        let originalSignatureS := mload(
                            add(signature, ECDSA_signature_s_offset)
                        )
                        // Read the first byte of the word after `s`. If the
                        // signature is 65 bytes, this will be the real `v` value.
                        // If not, it will need to be modified - doing it this way
                        // saves an extra condition.
                        v := byte(
                            0,
                            mload(add(signature, ECDSA_signature_v_offset))
                        )
                        // If lenDiff is 1, parse 64-byte signature as ECDSA.
                        if lenDiff {
                            // Extract yParity from highest bit of vs and add 27 to
                            // get v.
                            v := add(
                                shr(MaxUint8, originalSignatureS),
                                Signature_lower_v
                            )
                            // Extract canonical s from vs, all but the highest bit.
                            // Temporarily overwrite the original `s` value in the
                            // signature.
                            mstore(
                                add(signature, ECDSA_signature_s_offset),
                                and(
                                    originalSignatureS,
                                    EIP2098_allButHighestBitMask
                                )
                            )
                        }
                        // Temporarily overwrite the signature length with `v` to
                        // conform to the expected input for ecrecover.
                        mstore(signature, v)
                        // Temporarily overwrite the word before the length with
                        // `digest` to conform to the expected input for ecrecover.
                        mstore(wordBeforeSignaturePtr, digest)
                        // Attempt to recover the signer for the given signature. Do
                        // not check the call status as ecrecover will return a null
                        // address if the signature is invalid.
                        pop(
                            staticcall(
                                gas(),
                                Ecrecover_precompile, // Call ecrecover precompile.
                                wordBeforeSignaturePtr, // Use data memory location.
                                Ecrecover_args_size, // Size of digest, v, r, and s.
                                0, // Write result to scratch space.
                                OneWord // Provide size of returned result.
                            )
                        )
                        // Restore cached word before signature.
                        mstore(wordBeforeSignaturePtr, cachedWordBeforeSignature)
                        // Restore cached signature length.
                        mstore(signature, signatureLength)
                        // Restore cached signature `s` value.
                        mstore(
                            add(signature, ECDSA_signature_s_offset),
                            originalSignatureS
                        )
                        // Read the recovered signer from the buffer given as return
                        // space for ecrecover.
                        recoveredSigner := mload(0)
                    }
                    // Set success to true if the signature provided was a valid
                    // ECDSA signature and the signer is not the null address. Use
                    // gt instead of direct as success is used outside of assembly.
                    success := and(eq(signer, recoveredSigner), gt(signer, 0))
                }
                // If the signature was not verified with ecrecover, try EIP1271.
                if iszero(success) {
                    // Temporarily overwrite the word before the signature length
                    // and use it as the head of the signature input to
                    // `isValidSignature`, which has a value of 64.
                    mstore(
                        wordBeforeSignaturePtr,
                        EIP1271_isValidSignature_signature_head_offset
                    )
                    // Get pointer to use for the selector of `isValidSignature`.
                    let selectorPtr := sub(
                        signature,
                        EIP1271_isValidSignature_selector_negativeOffset
                    )
                    // Cache the value currently stored at the selector pointer.
                    let cachedWordOverwrittenBySelector := mload(selectorPtr)
                    // Get pointer to use for `digest` input to `isValidSignature`.
                    let digestPtr := sub(
                        signature,
                        EIP1271_isValidSignature_digest_negativeOffset
                    )
                    // Cache the value currently stored at the digest pointer.
                    let cachedWordOverwrittenByDigest := mload(digestPtr)
                    // Write the selector first, since it overlaps the digest.
                    mstore(selectorPtr, EIP1271_isValidSignature_selector)
                    // Next, write the digest.
                    mstore(digestPtr, digest)
                    // Call signer with `isValidSignature` to validate signature.
                    success := staticcall(
                        gas(),
                        signer,
                        selectorPtr,
                        add(
                            signatureLength,
                            EIP1271_isValidSignature_calldata_baseLength
                        ),
                        0,
                        OneWord
                    )
                    // Determine if the signature is valid on successful calls.
                    if success {
                        // If first word of scratch space does not contain EIP-1271
                        // signature selector, revert.
                        if iszero(eq(mload(0), EIP1271_isValidSignature_selector)) {
                            // Revert with bad 1271 signature if signer has code.
                            if extcodesize(signer) {
                                // Bad contract signature.
                                mstore(0, BadContractSignature_error_signature)
                                revert(0, BadContractSignature_error_length)
                            }
                            // Check if signature length was invalid.
                            if gt(sub(ECDSA_MaxLength, signatureLength), 1) {
                                // Revert with generic invalid signature error.
                                mstore(0, InvalidSignature_error_signature)
                                revert(0, InvalidSignature_error_length)
                            }
                            // Check if v was invalid.
                            if iszero(
                                byte(v, ECDSA_twentySeventhAndTwentyEighthBytesSet)
                            ) {
                                // Revert with invalid v value.
                                mstore(0, BadSignatureV_error_signature)
                                mstore(BadSignatureV_error_offset, v)
                                revert(0, BadSignatureV_error_length)
                            }
                            // Revert with generic invalid signer error message.
                            mstore(0, InvalidSigner_error_signature)
                            revert(0, InvalidSigner_error_length)
                        }
                    }
                    // Restore the cached values overwritten by selector, digest and
                    // signature head.
                    mstore(wordBeforeSignaturePtr, cachedWordBeforeSignature)
                    mstore(selectorPtr, cachedWordOverwrittenBySelector)
                    mstore(digestPtr, cachedWordOverwrittenByDigest)
                }
            }
            // If the call failed...
            if (!success) {
                // Revert and pass reason along if one was returned.
                _revertWithReasonIfOneIsReturned();
                // Otherwise, revert with error indicating bad contract signature.
                assembly {
                    mstore(0, BadContractSignature_error_signature)
                    revert(0, BadContractSignature_error_length)
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { OrderParameters } from "./ConsiderationStructs.sol";
    import { ConsiderationBase } from "./ConsiderationBase.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title GettersAndDerivers
     * @author 0age
     * @notice ConsiderationInternal contains pure and internal view functions
     *         related to getting or deriving various values.
     */
    contract GettersAndDerivers is ConsiderationBase {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController)
            ConsiderationBase(conduitController)
        {}
        /**
         * @dev Internal view function to derive the order hash for a given order.
         *      Note that only the original consideration items are included in the
         *      order hash, as additional consideration items may be supplied by the
         *      caller.
         *
         * @param orderParameters The parameters of the order to hash.
         * @param counter           The counter of the order to hash.
         *
         * @return orderHash The hash.
         */
        function _deriveOrderHash(
            OrderParameters memory orderParameters,
            uint256 counter
        ) internal view returns (bytes32 orderHash) {
            // Get length of original consideration array and place it on the stack.
            uint256 originalConsiderationLength = (
                orderParameters.totalOriginalConsiderationItems
            );
            /*
             * Memory layout for an array of structs (dynamic or not) is similar
             * to ABI encoding of dynamic types, with a head segment followed by
             * a data segment. The main difference is that the head of an element
             * is a memory pointer rather than an offset.
             */
            // Declare a variable for the derived hash of the offer array.
            bytes32 offerHash;
            // Read offer item EIP-712 typehash from runtime code & place on stack.
            bytes32 typeHash = _OFFER_ITEM_TYPEHASH;
            // Utilize assembly so that memory regions can be reused across hashes.
            assembly {
                // Retrieve the free memory pointer and place on the stack.
                let hashArrPtr := mload(FreeMemoryPointerSlot)
                // Get the pointer to the offers array.
                let offerArrPtr := mload(
                    add(orderParameters, OrderParameters_offer_head_offset)
                )
                // Load the length.
                let offerLength := mload(offerArrPtr)
                // Set the pointer to the first offer's head.
                offerArrPtr := add(offerArrPtr, OneWord)
                // Iterate over the offer items.
                // prettier-ignore
                for { let i := 0 } lt(i, offerLength) {
                    i := add(i, 1)
                } {
                    // Read the pointer to the offer data and subtract one word
                    // to get typeHash pointer.
                    let ptr := sub(mload(offerArrPtr), OneWord)
                    // Read the current value before the offer data.
                    let value := mload(ptr)
                    // Write the type hash to the previous word.
                    mstore(ptr, typeHash)
                    // Take the EIP712 hash and store it in the hash array.
                    mstore(hashArrPtr, keccak256(ptr, EIP712_OfferItem_size))
                    // Restore the previous word.
                    mstore(ptr, value)
                    // Increment the array pointers by one word.
                    offerArrPtr := add(offerArrPtr, OneWord)
                    hashArrPtr := add(hashArrPtr, OneWord)
                }
                // Derive the offer hash using the hashes of each item.
                offerHash := keccak256(
                    mload(FreeMemoryPointerSlot),
                    mul(offerLength, OneWord)
                )
            }
            // Declare a variable for the derived hash of the consideration array.
            bytes32 considerationHash;
            // Read consideration item typehash from runtime code & place on stack.
            typeHash = _CONSIDERATION_ITEM_TYPEHASH;
            // Utilize assembly so that memory regions can be reused across hashes.
            assembly {
                // Retrieve the free memory pointer and place on the stack.
                let hashArrPtr := mload(FreeMemoryPointerSlot)
                // Get the pointer to the consideration array.
                let considerationArrPtr := add(
                    mload(
                        add(
                            orderParameters,
                            OrderParameters_consideration_head_offset
                        )
                    ),
                    OneWord
                )
                // Iterate over the consideration items (not including tips).
                // prettier-ignore
                for { let i := 0 } lt(i, originalConsiderationLength) {
                    i := add(i, 1)
                } {
                    // Read the pointer to the consideration data and subtract one
                    // word to get typeHash pointer.
                    let ptr := sub(mload(considerationArrPtr), OneWord)
                    // Read the current value before the consideration data.
                    let value := mload(ptr)
                    // Write the type hash to the previous word.
                    mstore(ptr, typeHash)
                    // Take the EIP712 hash and store it in the hash array.
                    mstore(
                        hashArrPtr,
                        keccak256(ptr, EIP712_ConsiderationItem_size)
                    )
                    // Restore the previous word.
                    mstore(ptr, value)
                    // Increment the array pointers by one word.
                    considerationArrPtr := add(considerationArrPtr, OneWord)
                    hashArrPtr := add(hashArrPtr, OneWord)
                }
                // Derive the consideration hash using the hashes of each item.
                considerationHash := keccak256(
                    mload(FreeMemoryPointerSlot),
                    mul(originalConsiderationLength, OneWord)
                )
            }
            // Read order item EIP-712 typehash from runtime code & place on stack.
            typeHash = _ORDER_TYPEHASH;
            // Utilize assembly to access derived hashes & other arguments directly.
            assembly {
                // Retrieve pointer to the region located just behind parameters.
                let typeHashPtr := sub(orderParameters, OneWord)
                // Store the value at that pointer location to restore later.
                let previousValue := mload(typeHashPtr)
                // Store the order item EIP-712 typehash at the typehash location.
                mstore(typeHashPtr, typeHash)
                // Retrieve the pointer for the offer array head.
                let offerHeadPtr := add(
                    orderParameters,
                    OrderParameters_offer_head_offset
                )
                // Retrieve the data pointer referenced by the offer head.
                let offerDataPtr := mload(offerHeadPtr)
                // Store the offer hash at the retrieved memory location.
                mstore(offerHeadPtr, offerHash)
                // Retrieve the pointer for the consideration array head.
                let considerationHeadPtr := add(
                    orderParameters,
                    OrderParameters_consideration_head_offset
                )
                // Retrieve the data pointer referenced by the consideration head.
                let considerationDataPtr := mload(considerationHeadPtr)
                // Store the consideration hash at the retrieved memory location.
                mstore(considerationHeadPtr, considerationHash)
                // Retrieve the pointer for the counter.
                let counterPtr := add(
                    orderParameters,
                    OrderParameters_counter_offset
                )
                // Store the counter at the retrieved memory location.
                mstore(counterPtr, counter)
                // Derive the order hash using the full range of order parameters.
                orderHash := keccak256(typeHashPtr, EIP712_Order_size)
                // Restore the value previously held at typehash pointer location.
                mstore(typeHashPtr, previousValue)
                // Restore offer data pointer at the offer head pointer location.
                mstore(offerHeadPtr, offerDataPtr)
                // Restore consideration data pointer at the consideration head ptr.
                mstore(considerationHeadPtr, considerationDataPtr)
                // Restore consideration item length at the counter pointer.
                mstore(counterPtr, originalConsiderationLength)
            }
        }
        /**
         * @dev Internal view function to derive the address of a given conduit
         *      using a corresponding conduit key.
         *
         * @param conduitKey A bytes32 value indicating what corresponding conduit,
         *                   if any, to source token approvals from. This value is
         *                   the "salt" parameter supplied by the deployer (i.e. the
         *                   conduit controller) when deploying the given conduit.
         *
         * @return conduit The address of the conduit associated with the given
         *                 conduit key.
         */
        function _deriveConduit(bytes32 conduitKey)
            internal
            view
            returns (address conduit)
        {
            // Read conduit controller address from runtime and place on the stack.
            address conduitController = address(_CONDUIT_CONTROLLER);
            // Read conduit creation code hash from runtime and place on the stack.
            bytes32 conduitCreationCodeHash = _CONDUIT_CREATION_CODE_HASH;
            // Leverage scratch space to perform an efficient hash.
            assembly {
                // Retrieve the free memory pointer; it will be replaced afterwards.
                let freeMemoryPointer := mload(FreeMemoryPointerSlot)
                // Place the control character and the conduit controller in scratch
                // space; note that eleven bytes at the beginning are left unused.
                mstore(0, or(MaskOverByteTwelve, conduitController))
                // Place the conduit key in the next region of scratch space.
                mstore(OneWord, conduitKey)
                // Place conduit creation code hash in free memory pointer location.
                mstore(TwoWords, conduitCreationCodeHash)
                // Derive conduit by hashing and applying a mask over last 20 bytes.
                conduit := and(
                    // Hash the relevant region.
                    keccak256(
                        // The region starts at memory pointer 11.
                        Create2AddressDerivation_ptr,
                        // The region is 85 bytes long (1 + 20 + 32 + 32).
                        Create2AddressDerivation_length
                    ),
                    // The address equals the last twenty bytes of the hash.
                    MaskOverLastTwentyBytes
                )
                // Restore the free memory pointer.
                mstore(FreeMemoryPointerSlot, freeMemoryPointer)
            }
        }
        /**
         * @dev Internal view function to get the EIP-712 domain separator. If the
         *      chainId matches the chainId set on deployment, the cached domain
         *      separator will be returned; otherwise, it will be derived from
         *      scratch.
         *
         * @return The domain separator.
         */
        function _domainSeparator() internal view returns (bytes32) {
            // prettier-ignore
            return block.chainid == _CHAIN_ID
                ? _DOMAIN_SEPARATOR
                : _deriveDomainSeparator();
        }
        /**
         * @dev Internal view function to retrieve configuration information for
         *      this contract.
         *
         * @return version           The contract version.
         * @return domainSeparator   The domain separator for this contract.
         * @return conduitController The conduit Controller set for this contract.
         */
        function _information()
            internal
            view
            returns (
                string memory version,
                bytes32 domainSeparator,
                address conduitController
            )
        {
            // Derive the domain separator.
            domainSeparator = _domainSeparator();
            // Declare variable as immutables cannot be accessed within assembly.
            conduitController = address(_CONDUIT_CONTROLLER);
            // Allocate a string with the intended length.
            version = new string(Version_length);
            // Set the version as data on the newly allocated string.
            assembly {
                mstore(add(version, OneWord), shl(Version_shift, Version))
            }
        }
        /**
         * @dev Internal pure function to efficiently derive an digest to sign for
         *      an order in accordance with EIP-712.
         *
         * @param domainSeparator The domain separator.
         * @param orderHash       The order hash.
         *
         * @return value The hash.
         */
        function _deriveEIP712Digest(bytes32 domainSeparator, bytes32 orderHash)
            internal
            pure
            returns (bytes32 value)
        {
            // Leverage scratch space to perform an efficient hash.
            assembly {
                // Place the EIP-712 prefix at the start of scratch space.
                mstore(0, EIP_712_PREFIX)
                // Place the domain separator in the next region of scratch space.
                mstore(EIP712_DomainSeparator_offset, domainSeparator)
                // Place the order hash in scratch space, spilling into the first
                // two bytes of the free memory pointer — this should never be set
                // as memory cannot be expanded to that size, and will be zeroed out
                // after the hash is performed.
                mstore(EIP712_OrderHash_offset, orderHash)
                // Hash the relevant region (65 bytes).
                value := keccak256(0, EIP712_DigestPayload_size)
                // Clear out the dirtied bits in the memory pointer.
                mstore(EIP712_OrderHash_offset, 0)
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    // prettier-ignore
    import {
        ConsiderationEventsAndErrors
    } from "../interfaces/ConsiderationEventsAndErrors.sol";
    import { ReentrancyGuard } from "./ReentrancyGuard.sol";
    /**
     * @title CounterManager
     * @author 0age
     * @notice CounterManager contains a storage mapping and related functionality
     *         for retrieving and incrementing a per-offerer counter.
     */
    contract CounterManager is ConsiderationEventsAndErrors, ReentrancyGuard {
        // Only orders signed using an offerer's current counter are fulfillable.
        mapping(address => uint256) private _counters;
        /**
         * @dev Internal function to cancel all orders from a given offerer with a
         *      given zone in bulk by incrementing a counter. Note that only the
         *      offerer may increment the counter.
         *
         * @return newCounter The new counter.
         */
        function _incrementCounter() internal returns (uint256 newCounter) {
            // Ensure that the reentrancy guard is not currently set.
            _assertNonReentrant();
            // Skip overflow check as counter cannot be incremented that far.
            unchecked {
                // Increment current counter for the supplied offerer.
                newCounter = ++_counters[msg.sender];
            }
            // Emit an event containing the new counter.
            emit CounterIncremented(newCounter, msg.sender);
        }
        /**
         * @dev Internal view function to retrieve the current counter for a given
         *      offerer.
         *
         * @param offerer The offerer in question.
         *
         * @return currentCounter The current counter.
         */
        function _getCounter(address offerer)
            internal
            view
            returns (uint256 currentCounter)
        {
            // Return the counter for the supplied offerer.
            currentCounter = _counters[offerer];
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    // prettier-ignore
    import {
        ConduitControllerInterface
    } from "../interfaces/ConduitControllerInterface.sol";
    // prettier-ignore
    import {
        ConsiderationEventsAndErrors
    } from "../interfaces/ConsiderationEventsAndErrors.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title ConsiderationBase
     * @author 0age
     * @notice ConsiderationBase contains immutable constants and constructor logic.
     */
    contract ConsiderationBase is ConsiderationEventsAndErrors {
        // Precompute hashes, original chainId, and domain separator on deployment.
        bytes32 internal immutable _NAME_HASH;
        bytes32 internal immutable _VERSION_HASH;
        bytes32 internal immutable _EIP_712_DOMAIN_TYPEHASH;
        bytes32 internal immutable _OFFER_ITEM_TYPEHASH;
        bytes32 internal immutable _CONSIDERATION_ITEM_TYPEHASH;
        bytes32 internal immutable _ORDER_TYPEHASH;
        uint256 internal immutable _CHAIN_ID;
        bytes32 internal immutable _DOMAIN_SEPARATOR;
        // Allow for interaction with the conduit controller.
        ConduitControllerInterface internal immutable _CONDUIT_CONTROLLER;
        // Cache the conduit creation code hash used by the conduit controller.
        bytes32 internal immutable _CONDUIT_CREATION_CODE_HASH;
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) {
            // Derive name and version hashes alongside required EIP-712 typehashes.
            (
                _NAME_HASH,
                _VERSION_HASH,
                _EIP_712_DOMAIN_TYPEHASH,
                _OFFER_ITEM_TYPEHASH,
                _CONSIDERATION_ITEM_TYPEHASH,
                _ORDER_TYPEHASH
            ) = _deriveTypehashes();
            // Store the current chainId and derive the current domain separator.
            _CHAIN_ID = block.chainid;
            _DOMAIN_SEPARATOR = _deriveDomainSeparator();
            // Set the supplied conduit controller.
            _CONDUIT_CONTROLLER = ConduitControllerInterface(conduitController);
            // Retrieve the conduit creation code hash from the supplied controller.
            (_CONDUIT_CREATION_CODE_HASH, ) = (
                _CONDUIT_CONTROLLER.getConduitCodeHashes()
            );
        }
        /**
         * @dev Internal view function to derive the EIP-712 domain separator.
         *
         * @return The derived domain separator.
         */
        function _deriveDomainSeparator() internal view returns (bytes32) {
            // prettier-ignore
            return keccak256(
                abi.encode(
                    _EIP_712_DOMAIN_TYPEHASH,
                    _NAME_HASH,
                    _VERSION_HASH,
                    block.chainid,
                    address(this)
                )
            );
        }
        /**
         * @dev Internal pure function to retrieve the default name of this
         *      contract and return.
         *
         * @return The name of this contract.
         */
        function _name() internal pure virtual returns (string memory) {
            // Return the name of the contract.
            assembly {
                // First element is the offset for the returned string. Offset the
                // value in memory by one word so that the free memory pointer will
                // be overwritten by the next write.
                mstore(OneWord, OneWord)
                // Name is right padded, so it touches the length which is left
                // padded. This enables writing both values at once. The free memory
                // pointer will be overwritten in the process.
                mstore(NameLengthPtr, NameWithLength)
                // Standard ABI encoding pads returned data to the nearest word. Use
                // the already empty zero slot memory region for this purpose and
                // return the final name string, offset by the original single word.
                return(OneWord, ThreeWords)
            }
        }
        /**
         * @dev Internal pure function to retrieve the default name of this contract
         *      as a string that can be used internally.
         *
         * @return The name of this contract.
         */
        function _nameString() internal pure virtual returns (string memory) {
            // Return the name of the contract.
            return "Consideration";
        }
        /**
         * @dev Internal pure function to derive required EIP-712 typehashes and
         *      other hashes during contract creation.
         *
         * @return nameHash                  The hash of the name of the contract.
         * @return versionHash               The hash of the version string of the
         *                                   contract.
         * @return eip712DomainTypehash      The primary EIP-712 domain typehash.
         * @return offerItemTypehash         The EIP-712 typehash for OfferItem
         *                                   types.
         * @return considerationItemTypehash The EIP-712 typehash for
         *                                   ConsiderationItem types.
         * @return orderTypehash             The EIP-712 typehash for Order types.
         */
        function _deriveTypehashes()
            internal
            pure
            returns (
                bytes32 nameHash,
                bytes32 versionHash,
                bytes32 eip712DomainTypehash,
                bytes32 offerItemTypehash,
                bytes32 considerationItemTypehash,
                bytes32 orderTypehash
            )
        {
            // Derive hash of the name of the contract.
            nameHash = keccak256(bytes(_nameString()));
            // Derive hash of the version string of the contract.
            versionHash = keccak256(bytes("1.1"));
            // Construct the OfferItem type string.
            // prettier-ignore
            bytes memory offerItemTypeString = abi.encodePacked(
                "OfferItem(",
                    "uint8 itemType,",
                    "address token,",
                    "uint256 identifierOrCriteria,",
                    "uint256 startAmount,",
                    "uint256 endAmount",
                ")"
            );
            // Construct the ConsiderationItem type string.
            // prettier-ignore
            bytes memory considerationItemTypeString = abi.encodePacked(
                "ConsiderationItem(",
                    "uint8 itemType,",
                    "address token,",
                    "uint256 identifierOrCriteria,",
                    "uint256 startAmount,",
                    "uint256 endAmount,",
                    "address recipient",
                ")"
            );
            // Construct the OrderComponents type string, not including the above.
            // prettier-ignore
            bytes memory orderComponentsPartialTypeString = abi.encodePacked(
                "OrderComponents(",
                    "address offerer,",
                    "address zone,",
                    "OfferItem[] offer,",
                    "ConsiderationItem[] consideration,",
                    "uint8 orderType,",
                    "uint256 startTime,",
                    "uint256 endTime,",
                    "bytes32 zoneHash,",
                    "uint256 salt,",
                    "bytes32 conduitKey,",
                    "uint256 counter",
                ")"
            );
            // Construct the primary EIP-712 domain type string.
            // prettier-ignore
            eip712DomainTypehash = keccak256(
                abi.encodePacked(
                    "EIP712Domain(",
                        "string name,",
                        "string version,",
                        "uint256 chainId,",
                        "address verifyingContract",
                    ")"
                )
            );
            // Derive the OfferItem type hash using the corresponding type string.
            offerItemTypehash = keccak256(offerItemTypeString);
            // Derive ConsiderationItem type hash using corresponding type string.
            considerationItemTypehash = keccak256(considerationItemTypeString);
            // Derive OrderItem type hash via combination of relevant type strings.
            orderTypehash = keccak256(
                abi.encodePacked(
                    orderComponentsPartialTypeString,
                    considerationItemTypeString,
                    offerItemTypeString
                )
            );
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { SpentItem, ReceivedItem } from "../lib/ConsiderationStructs.sol";
    /**
     * @title ConsiderationEventsAndErrors
     * @author 0age
     * @notice ConsiderationEventsAndErrors contains all events and errors.
     */
    interface ConsiderationEventsAndErrors {
        /**
         * @dev Emit an event whenever an order is successfully fulfilled.
         *
         * @param orderHash     The hash of the fulfilled order.
         * @param offerer       The offerer of the fulfilled order.
         * @param zone          The zone of the fulfilled order.
         * @param recipient     The recipient of each spent item on the fulfilled
         *                      order, or the null address if there is no specific
         *                      fulfiller (i.e. the order is part of a group of
         *                      orders). Defaults to the caller unless explicitly
         *                      specified otherwise by the fulfiller.
         * @param offer         The offer items spent as part of the order.
         * @param consideration The consideration items received as part of the
         *                      order along with the recipients of each item.
         */
        event OrderFulfilled(
            bytes32 orderHash,
            address indexed offerer,
            address indexed zone,
            address recipient,
            SpentItem[] offer,
            ReceivedItem[] consideration
        );
        /**
         * @dev Emit an event whenever an order is successfully cancelled.
         *
         * @param orderHash The hash of the cancelled order.
         * @param offerer   The offerer of the cancelled order.
         * @param zone      The zone of the cancelled order.
         */
        event OrderCancelled(
            bytes32 orderHash,
            address indexed offerer,
            address indexed zone
        );
        /**
         * @dev Emit an event whenever an order is explicitly validated. Note that
         *      this event will not be emitted on partial fills even though they do
         *      validate the order as part of partial fulfillment.
         *
         * @param orderHash The hash of the validated order.
         * @param offerer   The offerer of the validated order.
         * @param zone      The zone of the validated order.
         */
        event OrderValidated(
            bytes32 orderHash,
            address indexed offerer,
            address indexed zone
        );
        /**
         * @dev Emit an event whenever a counter for a given offerer is incremented.
         *
         * @param newCounter The new counter for the offerer.
         * @param offerer  The offerer in question.
         */
        event CounterIncremented(uint256 newCounter, address indexed offerer);
        /**
         * @dev Revert with an error when attempting to fill an order that has
         *      already been fully filled.
         *
         * @param orderHash The order hash on which a fill was attempted.
         */
        error OrderAlreadyFilled(bytes32 orderHash);
        /**
         * @dev Revert with an error when attempting to fill an order outside the
         *      specified start time and end time.
         */
        error InvalidTime();
        /**
         * @dev Revert with an error when attempting to fill an order referencing an
         *      invalid conduit (i.e. one that has not been deployed).
         */
        error InvalidConduit(bytes32 conduitKey, address conduit);
        /**
         * @dev Revert with an error when an order is supplied for fulfillment with
         *      a consideration array that is shorter than the original array.
         */
        error MissingOriginalConsiderationItems();
        /**
         * @dev Revert with an error when a call to a conduit fails with revert data
         *      that is too expensive to return.
         */
        error InvalidCallToConduit(address conduit);
        /**
         * @dev Revert with an error if a consideration amount has not been fully
         *      zeroed out after applying all fulfillments.
         *
         * @param orderIndex         The index of the order with the consideration
         *                           item with a shortfall.
         * @param considerationIndex The index of the consideration item on the
         *                           order.
         * @param shortfallAmount    The unfulfilled consideration amount.
         */
        error ConsiderationNotMet(
            uint256 orderIndex,
            uint256 considerationIndex,
            uint256 shortfallAmount
        );
        /**
         * @dev Revert with an error when insufficient ether is supplied as part of
         *      msg.value when fulfilling orders.
         */
        error InsufficientEtherSupplied();
        /**
         * @dev Revert with an error when an ether transfer reverts.
         */
        error EtherTransferGenericFailure(address account, uint256 amount);
        /**
         * @dev Revert with an error when a partial fill is attempted on an order
         *      that does not specify partial fill support in its order type.
         */
        error PartialFillsNotEnabledForOrder();
        /**
         * @dev Revert with an error when attempting to fill an order that has been
         *      cancelled.
         *
         * @param orderHash The hash of the cancelled order.
         */
        error OrderIsCancelled(bytes32 orderHash);
        /**
         * @dev Revert with an error when attempting to fill a basic order that has
         *      been partially filled.
         *
         * @param orderHash The hash of the partially used order.
         */
        error OrderPartiallyFilled(bytes32 orderHash);
        /**
         * @dev Revert with an error when attempting to cancel an order as a caller
         *      other than the indicated offerer or zone.
         */
        error InvalidCanceller();
        /**
         * @dev Revert with an error when supplying a fraction with a value of zero
         *      for the numerator or denominator, or one where the numerator exceeds
         *      the denominator.
         */
        error BadFraction();
        /**
         * @dev Revert with an error when a caller attempts to supply callvalue to a
         *      non-payable basic order route or does not supply any callvalue to a
         *      payable basic order route.
         */
        error InvalidMsgValue(uint256 value);
        /**
         * @dev Revert with an error when attempting to fill a basic order using
         *      calldata not produced by default ABI encoding.
         */
        error InvalidBasicOrderParameterEncoding();
        /**
         * @dev Revert with an error when attempting to fulfill any number of
         *      available orders when none are fulfillable.
         */
        error NoSpecifiedOrdersAvailable();
        /**
         * @dev Revert with an error when attempting to fulfill an order with an
         *      offer for ETH outside of matching orders.
         */
        error InvalidNativeOfferItem();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ReentrancyErrors } from "../interfaces/ReentrancyErrors.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title ReentrancyGuard
     * @author 0age
     * @notice ReentrancyGuard contains a storage variable and related functionality
     *         for protecting against reentrancy.
     */
    contract ReentrancyGuard is ReentrancyErrors {
        // Prevent reentrant calls on protected functions.
        uint256 private _reentrancyGuard;
        /**
         * @dev Initialize the reentrancy guard during deployment.
         */
        constructor() {
            // Initialize the reentrancy guard in a cleared state.
            _reentrancyGuard = _NOT_ENTERED;
        }
        /**
         * @dev Internal function to ensure that the sentinel value for the
         *      reentrancy guard is not currently set and, if not, to set the
         *      sentinel value for the reentrancy guard.
         */
        function _setReentrancyGuard() internal {
            // Ensure that the reentrancy guard is not already set.
            _assertNonReentrant();
            // Set the reentrancy guard.
            _reentrancyGuard = _ENTERED;
        }
        /**
         * @dev Internal function to unset the reentrancy guard sentinel value.
         */
        function _clearReentrancyGuard() internal {
            // Clear the reentrancy guard.
            _reentrancyGuard = _NOT_ENTERED;
        }
        /**
         * @dev Internal view function to ensure that the sentinel value for the
                reentrancy guard is not currently set.
         */
        function _assertNonReentrant() internal view {
            // Ensure that the reentrancy guard is not currently set.
            if (_reentrancyGuard != _NOT_ENTERED) {
                revert NoReentrantCalls();
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title ReentrancyErrors
     * @author 0age
     * @notice ReentrancyErrors contains errors related to reentrancy.
     */
    interface ReentrancyErrors {
        /**
         * @dev Revert with an error when a caller attempts to reenter a protected
         *      function.
         */
        error NoReentrantCalls();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    interface EIP1271Interface {
        function isValidSignature(bytes32 digest, bytes calldata signature)
            external
            view
            returns (bytes4);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title SignatureVerificationErrors
     * @author 0age
     * @notice SignatureVerificationErrors contains all errors related to signature
     *         verification.
     */
    interface SignatureVerificationErrors {
        /**
         * @dev Revert with an error when a signature that does not contain a v
         *      value of 27 or 28 has been supplied.
         *
         * @param v The invalid v value.
         */
        error BadSignatureV(uint8 v);
        /**
         * @dev Revert with an error when the signer recovered by the supplied
         *      signature does not match the offerer or an allowed EIP-1271 signer
         *      as specified by the offerer in the event they are a contract.
         */
        error InvalidSigner();
        /**
         * @dev Revert with an error when a signer cannot be recovered from the
         *      supplied signature.
         */
        error InvalidSignature();
        /**
         * @dev Revert with an error when an EIP-1271 call to an account fails.
         */
        error BadContractSignature();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import "./ConsiderationConstants.sol";
    /**
     * @title LowLevelHelpers
     * @author 0age
     * @notice LowLevelHelpers contains logic for performing various low-level
     *         operations.
     */
    contract LowLevelHelpers {
        /**
         * @dev Internal view function to staticcall an arbitrary target with given
         *      calldata. Note that no data is written to memory and no contract
         *      size check is performed.
         *
         * @param target   The account to staticcall.
         * @param callData The calldata to supply when staticcalling the target.
         *
         * @return success The status of the staticcall to the target.
         */
        function _staticcall(address target, bytes memory callData)
            internal
            view
            returns (bool success)
        {
            assembly {
                // Perform the staticcall.
                success := staticcall(
                    gas(),
                    target,
                    add(callData, OneWord),
                    mload(callData),
                    0,
                    0
                )
            }
        }
        /**
         * @dev Internal view function to revert and pass along the revert reason if
         *      data was returned by the last call and that the size of that data
         *      does not exceed the currently allocated memory size.
         */
        function _revertWithReasonIfOneIsReturned() internal view {
            assembly {
                // If it returned a message, bubble it up as long as sufficient gas
                // remains to do so:
                if returndatasize() {
                    // Ensure that sufficient gas is available to copy returndata
                    // while expanding memory where necessary. Start by computing
                    // the word size of returndata and allocated memory.
                    let returnDataWords := div(
                        add(returndatasize(), AlmostOneWord),
                        OneWord
                    )
                    // Note: use the free memory pointer in place of msize() to work
                    // around a Yul warning that prevents accessing msize directly
                    // when the IR pipeline is activated.
                    let msizeWords := div(mload(FreeMemoryPointerSlot), OneWord)
                    // Next, compute the cost of the returndatacopy.
                    let cost := mul(CostPerWord, returnDataWords)
                    // Then, compute cost of new memory allocation.
                    if gt(returnDataWords, msizeWords) {
                        cost := add(
                            cost,
                            add(
                                mul(sub(returnDataWords, msizeWords), CostPerWord),
                                div(
                                    sub(
                                        mul(returnDataWords, returnDataWords),
                                        mul(msizeWords, msizeWords)
                                    ),
                                    MemoryExpansionCoefficient
                                )
                            )
                        )
                    }
                    // Finally, add a small constant and compare to gas remaining;
                    // bubble up the revert data if enough gas is still available.
                    if lt(add(cost, ExtraGasBuffer), gas()) {
                        // Copy returndata to memory; overwrite existing memory.
                        returndatacopy(0, 0, returndatasize())
                        // Revert, specifying memory region with copied returndata.
                        revert(0, returndatasize())
                    }
                }
            }
        }
        /**
         * @dev Internal pure function to determine if the first word of returndata
         *      matches an expected magic value.
         *
         * @param expected The expected magic value.
         *
         * @return A boolean indicating whether the expected value matches the one
         *         located in the first word of returndata.
         */
        function _doesNotMatchMagic(bytes4 expected) internal pure returns (bool) {
            // Declare a variable for the value held by the return data buffer.
            bytes4 result;
            // Utilize assembly in order to read directly from returndata buffer.
            assembly {
                // Only put result on stack if return data is exactly one word.
                if eq(returndatasize(), OneWord) {
                    // Copy the word directly from return data into scratch space.
                    returndatacopy(0, 0, OneWord)
                    // Take value from scratch space and place it on the stack.
                    result := mload(0)
                }
            }
            // Return a boolean indicating whether expected and located value match.
            return result != expected;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ItemType, Side } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        OfferItem,
        ConsiderationItem,
        ReceivedItem,
        OrderParameters,
        AdvancedOrder,
        Execution,
        FulfillmentComponent
    } from "./ConsiderationStructs.sol";
    import "./ConsiderationConstants.sol";
    // prettier-ignore
    import {
        FulfillmentApplicationErrors
    } from "../interfaces/FulfillmentApplicationErrors.sol";
    /**
     * @title FulfillmentApplier
     * @author 0age
     * @notice FulfillmentApplier contains logic related to applying fulfillments,
     *         both as part of order matching (where offer items are matched to
     *         consideration items) as well as fulfilling available orders (where
     *         order items and consideration items are independently aggregated).
     */
    contract FulfillmentApplier is FulfillmentApplicationErrors {
        /**
         * @dev Internal pure function to match offer items to consideration items
         *      on a group of orders via a supplied fulfillment.
         *
         * @param advancedOrders          The orders to match.
         * @param offerComponents         An array designating offer components to
         *                                match to consideration components.
         * @param considerationComponents An array designating consideration
         *                                components to match to offer components.
         *                                Note that each consideration amount must
         *                                be zero in order for the match operation
         *                                to be valid.
         *
         * @return execution The transfer performed as a result of the fulfillment.
         */
        function _applyFulfillment(
            AdvancedOrder[] memory advancedOrders,
            FulfillmentComponent[] calldata offerComponents,
            FulfillmentComponent[] calldata considerationComponents
        ) internal pure returns (Execution memory execution) {
            // Ensure 1+ of both offer and consideration components are supplied.
            if (
                offerComponents.length == 0 || considerationComponents.length == 0
            ) {
                revert OfferAndConsiderationRequiredOnFulfillment();
            }
            // Declare a new Execution struct.
            Execution memory considerationExecution;
            // Validate & aggregate consideration items to new Execution object.
            _aggregateValidFulfillmentConsiderationItems(
                advancedOrders,
                considerationComponents,
                considerationExecution
            );
            // Retrieve the consideration item from the execution struct.
            ReceivedItem memory considerationItem = considerationExecution.item;
            // Recipient does not need to be specified because it will always be set
            // to that of the consideration.
            // Validate & aggregate offer items to Execution object.
            _aggregateValidFulfillmentOfferItems(
                advancedOrders,
                offerComponents,
                execution
            );
            // Ensure offer and consideration share types, tokens and identifiers.
            if (
                execution.item.itemType != considerationItem.itemType ||
                execution.item.token != considerationItem.token ||
                execution.item.identifier != considerationItem.identifier
            ) {
                revert MismatchedFulfillmentOfferAndConsiderationComponents();
            }
            // If total consideration amount exceeds the offer amount...
            if (considerationItem.amount > execution.item.amount) {
                // Retrieve the first consideration component from the fulfillment.
                FulfillmentComponent memory targetComponent = (
                    considerationComponents[0]
                );
                // Skip underflow check as the conditional being true implies that
                // considerationItem.amount > execution.item.amount.
                unchecked {
                    // Add excess consideration item amount to original order array.
                    advancedOrders[targetComponent.orderIndex]
                        .parameters
                        .consideration[targetComponent.itemIndex]
                        .startAmount = (considerationItem.amount -
                        execution.item.amount);
                }
                // Reduce total consideration amount to equal the offer amount.
                considerationItem.amount = execution.item.amount;
            } else {
                // Retrieve the first offer component from the fulfillment.
                FulfillmentComponent memory targetComponent = offerComponents[0];
                // Skip underflow check as the conditional being false implies that
                // execution.item.amount >= considerationItem.amount.
                unchecked {
                    // Add excess offer item amount to the original array of orders.
                    advancedOrders[targetComponent.orderIndex]
                        .parameters
                        .offer[targetComponent.itemIndex]
                        .startAmount = (execution.item.amount -
                        considerationItem.amount);
                }
                // Reduce total offer amount to equal the consideration amount.
                execution.item.amount = considerationItem.amount;
            }
            // Reuse consideration recipient.
            execution.item.recipient = considerationItem.recipient;
            // Return the final execution that will be triggered for relevant items.
            return execution; // Execution(considerationItem, offerer, conduitKey);
        }
        /**
         * @dev Internal view function to aggregate offer or consideration items
         *      from a group of orders into a single execution via a supplied array
         *      of fulfillment components. Items that are not available to aggregate
         *      will not be included in the aggregated execution.
         *
         * @param advancedOrders        The orders to aggregate.
         * @param side                  The side (i.e. offer or consideration).
         * @param fulfillmentComponents An array designating item components to
         *                              aggregate if part of an available order.
         * @param fulfillerConduitKey   A bytes32 value indicating what conduit, if
         *                              any, to source the fulfiller's token
         *                              approvals from. The zero hash signifies that
         *                              no conduit should be used, with approvals
         *                              set directly on this contract.
         * @param recipient             The intended recipient for all received
         *                              items.
         *
         * @return execution The transfer performed as a result of the fulfillment.
         */
        function _aggregateAvailable(
            AdvancedOrder[] memory advancedOrders,
            Side side,
            FulfillmentComponent[] memory fulfillmentComponents,
            bytes32 fulfillerConduitKey,
            address recipient
        ) internal view returns (Execution memory execution) {
            // Skip overflow / underflow checks; conditions checked or unreachable.
            unchecked {
                // Retrieve fulfillment components array length and place on stack.
                // Ensure at least one fulfillment component has been supplied.
                if (fulfillmentComponents.length == 0) {
                    revert MissingFulfillmentComponentOnAggregation(side);
                }
                // If the fulfillment components are offer components...
                if (side == Side.OFFER) {
                    // Set the supplied recipient on the execution item.
                    execution.item.recipient = payable(recipient);
                    // Return execution for aggregated items provided by offerer.
                    _aggregateValidFulfillmentOfferItems(
                        advancedOrders,
                        fulfillmentComponents,
                        execution
                    );
                } else {
                    // Otherwise, fulfillment components are consideration
                    // components. Return execution for aggregated items provided by
                    // the fulfiller.
                    _aggregateValidFulfillmentConsiderationItems(
                        advancedOrders,
                        fulfillmentComponents,
                        execution
                    );
                    // Set the caller as the offerer on the execution.
                    execution.offerer = msg.sender;
                    // Set fulfiller conduit key as the conduit key on execution.
                    execution.conduitKey = fulfillerConduitKey;
                }
                // Set the offerer and recipient to null address if execution
                // amount is zero. This will cause the execution item to be skipped.
                if (execution.item.amount == 0) {
                    execution.offerer = address(0);
                    execution.item.recipient = payable(0);
                }
            }
        }
        /**
         * @dev Internal pure function to aggregate a group of offer items using
         *      supplied directives on which component items are candidates for
         *      aggregation, skipping items on orders that are not available.
         *
         * @param advancedOrders  The orders to aggregate offer items from.
         * @param offerComponents An array of FulfillmentComponent structs
         *                        indicating the order index and item index of each
         *                        candidate offer item for aggregation.
         * @param execution       The execution to apply the aggregation to.
         */
        function _aggregateValidFulfillmentOfferItems(
            AdvancedOrder[] memory advancedOrders,
            FulfillmentComponent[] memory offerComponents,
            Execution memory execution
        ) internal pure {
            assembly {
                // Declare function for reverts on invalid fulfillment data.
                function throwInvalidFulfillmentComponentData() {
                    // Store the InvalidFulfillmentComponentData error signature.
                    mstore(0, InvalidFulfillmentComponentData_error_signature)
                    // Return, supplying InvalidFulfillmentComponentData signature.
                    revert(0, InvalidFulfillmentComponentData_error_len)
                }
                // Declare function for reverts due to arithmetic overflows.
                function throwOverflow() {
                    // Store the Panic error signature.
                    mstore(0, Panic_error_signature)
                    // Store the arithmetic (0x11) panic code as initial argument.
                    mstore(Panic_error_offset, Panic_arithmetic)
                    // Return, supplying Panic signature and arithmetic code.
                    revert(0, Panic_error_length)
                }
                // Get position in offerComponents head.
                let fulfillmentHeadPtr := add(offerComponents, OneWord)
                // Retrieve the order index using the fulfillment pointer.
                let orderIndex := mload(mload(fulfillmentHeadPtr))
                // Ensure that the order index is not out of range.
                if iszero(lt(orderIndex, mload(advancedOrders))) {
                    throwInvalidFulfillmentComponentData()
                }
                // Read advancedOrders[orderIndex] pointer from its array head.
                let orderPtr := mload(
                    // Calculate head position of advancedOrders[orderIndex].
                    add(add(advancedOrders, OneWord), mul(orderIndex, OneWord))
                )
                // Read the pointer to OrderParameters from the AdvancedOrder.
                let paramsPtr := mload(orderPtr)
                // Load the offer array pointer.
                let offerArrPtr := mload(
                    add(paramsPtr, OrderParameters_offer_head_offset)
                )
                // Retrieve item index using an offset of the fulfillment pointer.
                let itemIndex := mload(
                    add(mload(fulfillmentHeadPtr), Fulfillment_itemIndex_offset)
                )
                // Only continue if the fulfillment is not invalid.
                if iszero(lt(itemIndex, mload(offerArrPtr))) {
                    throwInvalidFulfillmentComponentData()
                }
                // Retrieve consideration item pointer using the item index.
                let offerItemPtr := mload(
                    add(
                        // Get pointer to beginning of receivedItem.
                        add(offerArrPtr, OneWord),
                        // Calculate offset to pointer for desired order.
                        mul(itemIndex, OneWord)
                    )
                )
                // Declare a variable for the final aggregated item amount.
                let amount := 0
                // Create variable to track errors encountered with amount.
                let errorBuffer := 0
                // Only add offer amount to execution amount on a nonzero numerator.
                if mload(add(orderPtr, AdvancedOrder_numerator_offset)) {
                    // Retrieve amount pointer using consideration item pointer.
                    let amountPtr := add(offerItemPtr, Common_amount_offset)
                    // Set the amount.
                    amount := mload(amountPtr)
                    // Zero out amount on item to indicate it is credited.
                    mstore(amountPtr, 0)
                    // Buffer indicating whether issues were found.
                    errorBuffer := iszero(amount)
                }
                // Retrieve the received item pointer.
                let receivedItemPtr := mload(execution)
                // Set the item type on the received item.
                mstore(receivedItemPtr, mload(offerItemPtr))
                // Set the token on the received item.
                mstore(
                    add(receivedItemPtr, Common_token_offset),
                    mload(add(offerItemPtr, Common_token_offset))
                )
                // Set the identifier on the received item.
                mstore(
                    add(receivedItemPtr, Common_identifier_offset),
                    mload(add(offerItemPtr, Common_identifier_offset))
                )
                // Set the offerer on returned execution using order pointer.
                mstore(add(execution, Execution_offerer_offset), mload(paramsPtr))
                // Set conduitKey on returned execution via offset of order pointer.
                mstore(
                    add(execution, Execution_conduit_offset),
                    mload(add(paramsPtr, OrderParameters_conduit_offset))
                )
                // Calculate the hash of (itemType, token, identifier).
                let dataHash := keccak256(
                    receivedItemPtr,
                    ReceivedItem_CommonParams_size
                )
                // Get position one word past last element in head of array.
                let endPtr := add(
                    offerComponents,
                    mul(mload(offerComponents), OneWord)
                )
                // Iterate over remaining offer components.
                // prettier-ignore
                for {} lt(fulfillmentHeadPtr,  endPtr) {} {
                    // Increment the pointer to the fulfillment head by one word.
                    fulfillmentHeadPtr := add(fulfillmentHeadPtr, OneWord)
                    // Get the order index using the fulfillment pointer.
                    orderIndex := mload(mload(fulfillmentHeadPtr))
                    // Ensure the order index is in range.
                    if iszero(lt(orderIndex, mload(advancedOrders))) {
                      throwInvalidFulfillmentComponentData()
                    }
                    // Get pointer to AdvancedOrder element.
                    orderPtr := mload(
                        add(
                            add(advancedOrders, OneWord),
                            mul(orderIndex, OneWord)
                        )
                    )
                    // Only continue if numerator is not zero.
                    if iszero(mload(
                        add(orderPtr, AdvancedOrder_numerator_offset)
                    )) {
                      continue
                    }
                    // Read the pointer to OrderParameters from the AdvancedOrder.
                    paramsPtr := mload(orderPtr)
                    // Load offer array pointer.
                    offerArrPtr := mload(
                        add(
                            paramsPtr,
                            OrderParameters_offer_head_offset
                        )
                    )
                    // Get the item index using the fulfillment pointer.
                    itemIndex := mload(add(mload(fulfillmentHeadPtr), OneWord))
                    // Throw if itemIndex is out of the range of array.
                    if iszero(
                        lt(itemIndex, mload(offerArrPtr))
                    ) {
                        throwInvalidFulfillmentComponentData()
                    }
                    // Retrieve offer item pointer using index.
                    offerItemPtr := mload(
                        add(
                            // Get pointer to beginning of receivedItem.
                            add(offerArrPtr, OneWord),
                            // Use offset to pointer for desired order.
                            mul(itemIndex, OneWord)
                        )
                    )
                    // Retrieve amount pointer using offer item pointer.
                    let amountPtr := add(
                          offerItemPtr,
                          Common_amount_offset
                    )
                    // Add offer amount to execution amount.
                    let newAmount := add(amount, mload(amountPtr))
                    // Update error buffer: 1 = zero amount, 2 = overflow, 3 = both.
                    errorBuffer := or(
                      errorBuffer,
                      or(
                        shl(1, lt(newAmount, amount)),
                        iszero(mload(amountPtr))
                      )
                    )
                    // Update the amount to the new, summed amount.
                    amount := newAmount
                    // Zero out amount on original item to indicate it is credited.
                    mstore(amountPtr, 0)
                    // Ensure the indicated item matches original item.
                    if iszero(
                        and(
                            and(
                              // The offerer must match on both items.
                              eq(
                                  mload(paramsPtr),
                                  mload(
                                      add(execution, Execution_offerer_offset)
                                  )
                              ),
                              // The conduit key must match on both items.
                              eq(
                                  mload(
                                      add(
                                          paramsPtr,
                                          OrderParameters_conduit_offset
                                      )
                                  ),
                                  mload(
                                      add(
                                          execution,
                                          Execution_conduit_offset
                                      )
                                  )
                              )
                            ),
                            // The itemType, token, and identifier must match.
                            eq(
                                dataHash,
                                keccak256(
                                    offerItemPtr,
                                    ReceivedItem_CommonParams_size
                                )
                            )
                        )
                    ) {
                        // Throw if any of the requirements are not met.
                        throwInvalidFulfillmentComponentData()
                    }
                }
                // Write final amount to execution.
                mstore(add(mload(execution), Common_amount_offset), amount)
                // Determine whether the error buffer contains a nonzero error code.
                if errorBuffer {
                    // If errorBuffer is 1, an item had an amount of zero.
                    if eq(errorBuffer, 1) {
                        // Store the MissingItemAmount error signature.
                        mstore(0, MissingItemAmount_error_signature)
                        // Return, supplying MissingItemAmount signature.
                        revert(0, MissingItemAmount_error_len)
                    }
                    // If errorBuffer is not 1 or 0, the sum overflowed.
                    // Panic!
                    throwOverflow()
                }
            }
        }
        /**
         * @dev Internal pure function to aggregate a group of consideration items
         *      using supplied directives on which component items are candidates
         *      for aggregation, skipping items on orders that are not available.
         *
         * @param advancedOrders          The orders to aggregate consideration
         *                                items from.
         * @param considerationComponents An array of FulfillmentComponent structs
         *                                indicating the order index and item index
         *                                of each candidate consideration item for
         *                                aggregation.
         * @param execution       The execution to apply the aggregation to.
         */
        function _aggregateValidFulfillmentConsiderationItems(
            AdvancedOrder[] memory advancedOrders,
            FulfillmentComponent[] memory considerationComponents,
            Execution memory execution
        ) internal pure {
            // Utilize assembly in order to efficiently aggregate the items.
            assembly {
                // Declare function for reverts on invalid fulfillment data.
                function throwInvalidFulfillmentComponentData() {
                    // Store the InvalidFulfillmentComponentData error signature.
                    mstore(0, InvalidFulfillmentComponentData_error_signature)
                    // Return, supplying InvalidFulfillmentComponentData signature.
                    revert(0, InvalidFulfillmentComponentData_error_len)
                }
                // Declare function for reverts due to arithmetic overflows.
                function throwOverflow() {
                    // Store the Panic error signature.
                    mstore(0, Panic_error_signature)
                    // Store the arithmetic (0x11) panic code as initial argument.
                    mstore(Panic_error_offset, Panic_arithmetic)
                    // Return, supplying Panic signature and arithmetic code.
                    revert(0, Panic_error_length)
                }
                // Get position in considerationComponents head.
                let fulfillmentHeadPtr := add(considerationComponents, OneWord)
                // Retrieve the order index using the fulfillment pointer.
                let orderIndex := mload(mload(fulfillmentHeadPtr))
                // Ensure that the order index is not out of range.
                if iszero(lt(orderIndex, mload(advancedOrders))) {
                    throwInvalidFulfillmentComponentData()
                }
                // Read advancedOrders[orderIndex] pointer from its array head.
                let orderPtr := mload(
                    // Calculate head position of advancedOrders[orderIndex].
                    add(add(advancedOrders, OneWord), mul(orderIndex, OneWord))
                )
                // Load consideration array pointer.
                let considerationArrPtr := mload(
                    add(
                        // Read pointer to OrderParameters from the AdvancedOrder.
                        mload(orderPtr),
                        OrderParameters_consideration_head_offset
                    )
                )
                // Retrieve item index using an offset of the fulfillment pointer.
                let itemIndex := mload(
                    add(mload(fulfillmentHeadPtr), Fulfillment_itemIndex_offset)
                )
                // Ensure that the order index is not out of range.
                if iszero(lt(itemIndex, mload(considerationArrPtr))) {
                    throwInvalidFulfillmentComponentData()
                }
                // Retrieve consideration item pointer using the item index.
                let considerationItemPtr := mload(
                    add(
                        // Get pointer to beginning of receivedItem.
                        add(considerationArrPtr, OneWord),
                        // Calculate offset to pointer for desired order.
                        mul(itemIndex, OneWord)
                    )
                )
                // Declare a variable for the final aggregated item amount.
                let amount := 0
                // Create variable to track errors encountered with amount.
                let errorBuffer := 0
                // Only add consideration amount to execution amount if numerator is
                // greater than zero.
                if mload(add(orderPtr, AdvancedOrder_numerator_offset)) {
                    // Retrieve amount pointer using consideration item pointer.
                    let amountPtr := add(considerationItemPtr, Common_amount_offset)
                    // Set the amount.
                    amount := mload(amountPtr)
                    // Set error bit if amount is zero.
                    errorBuffer := iszero(amount)
                    // Zero out amount on item to indicate it is credited.
                    mstore(amountPtr, 0)
                }
                // Retrieve ReceivedItem pointer from Execution.
                let receivedItem := mload(execution)
                // Set the item type on the received item.
                mstore(receivedItem, mload(considerationItemPtr))
                // Set the token on the received item.
                mstore(
                    add(receivedItem, Common_token_offset),
                    mload(add(considerationItemPtr, Common_token_offset))
                )
                // Set the identifier on the received item.
                mstore(
                    add(receivedItem, Common_identifier_offset),
                    mload(add(considerationItemPtr, Common_identifier_offset))
                )
                // Set the recipient on the received item.
                mstore(
                    add(receivedItem, ReceivedItem_recipient_offset),
                    mload(
                        add(
                            considerationItemPtr,
                            ConsiderationItem_recipient_offset
                        )
                    )
                )
                // Calculate the hash of (itemType, token, identifier).
                let dataHash := keccak256(
                    receivedItem,
                    ReceivedItem_CommonParams_size
                )
                // Get position one word past last element in head of array.
                let endPtr := add(
                    considerationComponents,
                    mul(mload(considerationComponents), OneWord)
                )
                // Iterate over remaining offer components.
                // prettier-ignore
                for {} lt(fulfillmentHeadPtr,  endPtr) {} {
                    // Increment position in considerationComponents head.
                    fulfillmentHeadPtr := add(fulfillmentHeadPtr, OneWord)
                    // Get the order index using the fulfillment pointer.
                    orderIndex := mload(mload(fulfillmentHeadPtr))
                    // Ensure the order index is in range.
                    if iszero(lt(orderIndex, mload(advancedOrders))) {
                      throwInvalidFulfillmentComponentData()
                    }
                    // Get pointer to AdvancedOrder element.
                    orderPtr := mload(
                        add(
                            add(advancedOrders, OneWord),
                            mul(orderIndex, OneWord)
                        )
                    )
                    // Only continue if numerator is not zero.
                    if iszero(
                        mload(add(orderPtr, AdvancedOrder_numerator_offset))
                    ) {
                      continue
                    }
                    // Load consideration array pointer from OrderParameters.
                    considerationArrPtr := mload(
                        add(
                            // Get pointer to OrderParameters from AdvancedOrder.
                            mload(orderPtr),
                            OrderParameters_consideration_head_offset
                        )
                    )
                    // Get the item index using the fulfillment pointer.
                    itemIndex := mload(add(mload(fulfillmentHeadPtr), OneWord))
                    // Check if itemIndex is within the range of array.
                    if iszero(lt(itemIndex, mload(considerationArrPtr))) {
                        throwInvalidFulfillmentComponentData()
                    }
                    // Retrieve consideration item pointer using index.
                    considerationItemPtr := mload(
                        add(
                            // Get pointer to beginning of receivedItem.
                            add(considerationArrPtr, OneWord),
                            // Use offset to pointer for desired order.
                            mul(itemIndex, OneWord)
                        )
                    )
                    // Retrieve amount pointer using consideration item pointer.
                    let amountPtr := add(
                          considerationItemPtr,
                          Common_amount_offset
                    )
                    // Add offer amount to execution amount.
                    let newAmount := add(amount, mload(amountPtr))
                    // Update error buffer: 1 = zero amount, 2 = overflow, 3 = both.
                    errorBuffer := or(
                      errorBuffer,
                      or(
                        shl(1, lt(newAmount, amount)),
                        iszero(mload(amountPtr))
                      )
                    )
                    // Update the amount to the new, summed amount.
                    amount := newAmount
                    // Zero out amount on original item to indicate it is credited.
                    mstore(amountPtr, 0)
                    // Ensure the indicated item matches original item.
                    if iszero(
                        and(
                            // Item recipients must match.
                            eq(
                                mload(
                                    add(
                                        considerationItemPtr,
                                        ConsiderItem_recipient_offset
                                    )
                                ),
                                mload(
                                    add(
                                        receivedItem,
                                        ReceivedItem_recipient_offset
                                    )
                                )
                            ),
                            // The itemType, token, identifier must match.
                            eq(
                              dataHash,
                              keccak256(
                                considerationItemPtr,
                                ReceivedItem_CommonParams_size
                              )
                            )
                        )
                    ) {
                        // Throw if any of the requirements are not met.
                        throwInvalidFulfillmentComponentData()
                    }
                }
                // Write final amount to execution.
                mstore(add(receivedItem, Common_amount_offset), amount)
                // Determine whether the error buffer contains a nonzero error code.
                if errorBuffer {
                    // If errorBuffer is 1, an item had an amount of zero.
                    if eq(errorBuffer, 1) {
                        // Store the MissingItemAmount error signature.
                        mstore(0, MissingItemAmount_error_signature)
                        // Return, supplying MissingItemAmount signature.
                        revert(0, MissingItemAmount_error_len)
                    }
                    // If errorBuffer is not 1 or 0, the sum overflowed.
                    // Panic!
                    throwOverflow()
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { Side } from "../lib/ConsiderationEnums.sol";
    /**
     * @title FulfillmentApplicationErrors
     * @author 0age
     * @notice FulfillmentApplicationErrors contains errors related to fulfillment
     *         application and aggregation.
     */
    interface FulfillmentApplicationErrors {
        /**
         * @dev Revert with an error when a fulfillment is provided that does not
         *      declare at least one component as part of a call to fulfill
         *      available orders.
         */
        error MissingFulfillmentComponentOnAggregation(Side side);
        /**
         * @dev Revert with an error when a fulfillment is provided that does not
         *      declare at least one offer component and at least one consideration
         *      component.
         */
        error OfferAndConsiderationRequiredOnFulfillment();
        /**
         * @dev Revert with an error when the initial offer item named by a
         *      fulfillment component does not match the type, token, identifier,
         *      or conduit preference of the initial consideration item.
         */
        error MismatchedFulfillmentOfferAndConsiderationComponents();
        /**
         * @dev Revert with an error when an order or item index are out of range
         *      or a fulfillment component does not match the type, token,
         *      identifier, or conduit preference of the initial consideration item.
         */
        error InvalidFulfillmentComponentData();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ItemType, Side } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        OfferItem,
        ConsiderationItem,
        OrderParameters,
        AdvancedOrder,
        CriteriaResolver
    } from "./ConsiderationStructs.sol";
    import "./ConsiderationConstants.sol";
    // prettier-ignore
    import {
        CriteriaResolutionErrors
    } from "../interfaces/CriteriaResolutionErrors.sol";
    /**
     * @title CriteriaResolution
     * @author 0age
     * @notice CriteriaResolution contains a collection of pure functions related to
     *         resolving criteria-based items.
     */
    contract CriteriaResolution is CriteriaResolutionErrors {
        /**
         * @dev Internal pure function to apply criteria resolvers containing
         *      specific token identifiers and associated proofs to order items.
         *
         * @param advancedOrders     The orders to apply criteria resolvers to.
         * @param criteriaResolvers  An array where each element contains a
         *                           reference to a specific order as well as that
         *                           order's offer or consideration, a token
         *                           identifier, and a proof that the supplied token
         *                           identifier is contained in the order's merkle
         *                           root. Note that a root of zero indicates that
         *                           any transferable token identifier is valid and
         *                           that no proof needs to be supplied.
         */
        function _applyCriteriaResolvers(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] memory criteriaResolvers
        ) internal pure {
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Retrieve length of criteria resolvers array and place on stack.
                uint256 totalCriteriaResolvers = criteriaResolvers.length;
                // Retrieve length of orders array and place on stack.
                uint256 totalAdvancedOrders = advancedOrders.length;
                // Iterate over each criteria resolver.
                for (uint256 i = 0; i < totalCriteriaResolvers; ++i) {
                    // Retrieve the criteria resolver.
                    CriteriaResolver memory criteriaResolver = (
                        criteriaResolvers[i]
                    );
                    // Read the order index from memory and place it on the stack.
                    uint256 orderIndex = criteriaResolver.orderIndex;
                    // Ensure that the order index is in range.
                    if (orderIndex >= totalAdvancedOrders) {
                        revert OrderCriteriaResolverOutOfRange();
                    }
                    // Skip criteria resolution for order if not fulfilled.
                    if (advancedOrders[orderIndex].numerator == 0) {
                        continue;
                    }
                    // Retrieve the parameters for the order.
                    OrderParameters memory orderParameters = (
                        advancedOrders[orderIndex].parameters
                    );
                    // Read component index from memory and place it on the stack.
                    uint256 componentIndex = criteriaResolver.index;
                    // Declare values for item's type and criteria.
                    ItemType itemType;
                    uint256 identifierOrCriteria;
                    // If the criteria resolver refers to an offer item...
                    if (criteriaResolver.side == Side.OFFER) {
                        // Retrieve the offer.
                        OfferItem[] memory offer = orderParameters.offer;
                        // Ensure that the component index is in range.
                        if (componentIndex >= offer.length) {
                            revert OfferCriteriaResolverOutOfRange();
                        }
                        // Retrieve relevant item using the component index.
                        OfferItem memory offerItem = offer[componentIndex];
                        // Read item type and criteria from memory & place on stack.
                        itemType = offerItem.itemType;
                        identifierOrCriteria = offerItem.identifierOrCriteria;
                        // Optimistically update item type to remove criteria usage.
                        // Use assembly to operate on ItemType enum as a number.
                        ItemType newItemType;
                        assembly {
                            // Item type 4 becomes 2 and item type 5 becomes 3.
                            newItemType := sub(3, eq(itemType, 4))
                        }
                        offerItem.itemType = newItemType;
                        // Optimistically update identifier w/ supplied identifier.
                        offerItem.identifierOrCriteria = criteriaResolver
                            .identifier;
                    } else {
                        // Otherwise, the resolver refers to a consideration item.
                        ConsiderationItem[] memory consideration = (
                            orderParameters.consideration
                        );
                        // Ensure that the component index is in range.
                        if (componentIndex >= consideration.length) {
                            revert ConsiderationCriteriaResolverOutOfRange();
                        }
                        // Retrieve relevant item using order and component index.
                        ConsiderationItem memory considerationItem = (
                            consideration[componentIndex]
                        );
                        // Read item type and criteria from memory & place on stack.
                        itemType = considerationItem.itemType;
                        identifierOrCriteria = (
                            considerationItem.identifierOrCriteria
                        );
                        // Optimistically update item type to remove criteria usage.
                        // Use assembly to operate on ItemType enum as a number.
                        ItemType newItemType;
                        assembly {
                            // Item type 4 becomes 2 and item type 5 becomes 3.
                            newItemType := sub(3, eq(itemType, 4))
                        }
                        considerationItem.itemType = newItemType;
                        // Optimistically update identifier w/ supplied identifier.
                        considerationItem.identifierOrCriteria = (
                            criteriaResolver.identifier
                        );
                    }
                    // Ensure the specified item type indicates criteria usage.
                    if (!_isItemWithCriteria(itemType)) {
                        revert CriteriaNotEnabledForItem();
                    }
                    // If criteria is not 0 (i.e. a collection-wide offer)...
                    if (identifierOrCriteria != uint256(0)) {
                        // Verify identifier inclusion in criteria root using proof.
                        _verifyProof(
                            criteriaResolver.identifier,
                            identifierOrCriteria,
                            criteriaResolver.criteriaProof
                        );
                    }
                }
                // Iterate over each advanced order.
                for (uint256 i = 0; i < totalAdvancedOrders; ++i) {
                    // Retrieve the advanced order.
                    AdvancedOrder memory advancedOrder = advancedOrders[i];
                    // Skip criteria resolution for order if not fulfilled.
                    if (advancedOrder.numerator == 0) {
                        continue;
                    }
                    // Retrieve the parameters for the order.
                    OrderParameters memory orderParameters = (
                        advancedOrder.parameters
                    );
                    // Read consideration length from memory and place on stack.
                    uint256 totalItems = orderParameters.consideration.length;
                    // Iterate over each consideration item on the order.
                    for (uint256 j = 0; j < totalItems; ++j) {
                        // Ensure item type no longer indicates criteria usage.
                        if (
                            _isItemWithCriteria(
                                orderParameters.consideration[j].itemType
                            )
                        ) {
                            revert UnresolvedConsiderationCriteria();
                        }
                    }
                    // Read offer length from memory and place on stack.
                    totalItems = orderParameters.offer.length;
                    // Iterate over each offer item on the order.
                    for (uint256 j = 0; j < totalItems; ++j) {
                        // Ensure item type no longer indicates criteria usage.
                        if (
                            _isItemWithCriteria(orderParameters.offer[j].itemType)
                        ) {
                            revert UnresolvedOfferCriteria();
                        }
                    }
                }
            }
        }
        /**
         * @dev Internal pure function to check whether a given item type represents
         *      a criteria-based ERC721 or ERC1155 item (e.g. an item that can be
         *      resolved to one of a number of different identifiers at the time of
         *      order fulfillment).
         *
         * @param itemType The item type in question.
         *
         * @return withCriteria A boolean indicating that the item type in question
         *                      represents a criteria-based item.
         */
        function _isItemWithCriteria(ItemType itemType)
            internal
            pure
            returns (bool withCriteria)
        {
            // ERC721WithCriteria is ItemType 4. ERC1155WithCriteria is ItemType 5.
            assembly {
                withCriteria := gt(itemType, 3)
            }
        }
        /**
         * @dev Internal pure function to ensure that a given element is contained
         *      in a merkle root via a supplied proof.
         *
         * @param leaf  The element for which to prove inclusion.
         * @param root  The merkle root that inclusion will be proved against.
         * @param proof The merkle proof.
         */
        function _verifyProof(
            uint256 leaf,
            uint256 root,
            bytes32[] memory proof
        ) internal pure {
            // Declare a variable that will be used to determine proof validity.
            bool isValid;
            // Utilize assembly to efficiently verify the proof against the root.
            assembly {
                // Store the leaf at the beginning of scratch space.
                mstore(0, leaf)
                // Derive the hash of the leaf to use as the initial proof element.
                let computedHash := keccak256(0, OneWord)
                // Based on: https://github.com/Rari-Capital/solmate/blob/v7/src/utils/MerkleProof.sol
                // Get memory start location of the first element in proof array.
                let data := add(proof, OneWord)
                // Iterate over each proof element to compute the root hash.
                for {
                    // Left shift by 5 is equivalent to multiplying by 0x20.
                    let end := add(data, shl(5, mload(proof)))
                } lt(data, end) {
                    // Increment by one word at a time.
                    data := add(data, OneWord)
                } {
                    // Get the proof element.
                    let loadedData := mload(data)
                    // Sort proof elements and place them in scratch space.
                    // Slot of `computedHash` in scratch space.
                    // If the condition is true: 0x20, otherwise: 0x00.
                    let scratch := shl(5, gt(computedHash, loadedData))
                    // Store elements to hash contiguously in scratch space. Scratch
                    // space is 64 bytes (0x00 - 0x3f) & both elements are 32 bytes.
                    mstore(scratch, computedHash)
                    mstore(xor(scratch, OneWord), loadedData)
                    // Derive the updated hash.
                    computedHash := keccak256(0, TwoWords)
                }
                // Compare the final hash to the supplied root.
                isValid := eq(computedHash, root)
            }
            // Revert if computed hash does not equal supplied root.
            if (!isValid) {
                revert InvalidProof();
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title CriteriaResolutionErrors
     * @author 0age
     * @notice CriteriaResolutionErrors contains all errors related to criteria
     *         resolution.
     */
    interface CriteriaResolutionErrors {
        /**
         * @dev Revert with an error when providing a criteria resolver that refers
         *      to an order that has not been supplied.
         */
        error OrderCriteriaResolverOutOfRange();
        /**
         * @dev Revert with an error if an offer item still has unresolved criteria
         *      after applying all criteria resolvers.
         */
        error UnresolvedOfferCriteria();
        /**
         * @dev Revert with an error if a consideration item still has unresolved
         *      criteria after applying all criteria resolvers.
         */
        error UnresolvedConsiderationCriteria();
        /**
         * @dev Revert with an error when providing a criteria resolver that refers
         *      to an order with an offer item that has not been supplied.
         */
        error OfferCriteriaResolverOutOfRange();
        /**
         * @dev Revert with an error when providing a criteria resolver that refers
         *      to an order with a consideration item that has not been supplied.
         */
        error ConsiderationCriteriaResolverOutOfRange();
        /**
         * @dev Revert with an error when providing a criteria resolver that refers
         *      to an order with an item that does not expect a criteria to be
         *      resolved.
         */
        error CriteriaNotEnabledForItem();
        /**
         * @dev Revert with an error when providing a criteria resolver that
         *      contains an invalid proof with respect to the given item and
         *      chosen identifier.
         */
        error InvalidProof();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { ZoneInterface } from "../interfaces/ZoneInterface.sol";
    // prettier-ignore
    import {
        AdvancedOrder,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    contract TestZone is ZoneInterface {
        function isValidOrder(
            bytes32 orderHash,
            address caller,
            address offerer,
            bytes32 zoneHash
        ) external pure override returns (bytes4 validOrderMagicValue) {
            orderHash;
            caller;
            offerer;
            if (zoneHash == bytes32(uint256(1))) {
                revert("Revert on zone hash 1");
            } else if (zoneHash == bytes32(uint256(2))) {
                assembly {
                    revert(0, 0)
                }
            }
            validOrderMagicValue = zoneHash != bytes32(uint256(3))
                ? ZoneInterface.isValidOrder.selector
                : bytes4(0xffffffff);
        }
        function isValidOrderIncludingExtraData(
            bytes32 orderHash,
            address caller,
            AdvancedOrder calldata order,
            bytes32[] calldata priorOrderHashes,
            CriteriaResolver[] calldata criteriaResolvers
        ) external pure override returns (bytes4 validOrderMagicValue) {
            orderHash;
            caller;
            order;
            priorOrderHashes;
            criteriaResolvers;
            if (order.extraData.length == 4) {
                revert("Revert on extraData length 4");
            } else if (order.extraData.length == 5) {
                assembly {
                    revert(0, 0)
                }
            }
            validOrderMagicValue = order.parameters.zoneHash != bytes32(uint256(3))
                ? ZoneInterface.isValidOrder.selector
                : bytes4(0xffffffff);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        AdvancedOrder,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    interface ZoneInterface {
        // Called by Consideration whenever extraData is not provided by the caller.
        function isValidOrder(
            bytes32 orderHash,
            address caller,
            address offerer,
            bytes32 zoneHash
        ) external view returns (bytes4 validOrderMagicValue);
        // Called by Consideration whenever any extraData is provided by the caller.
        function isValidOrderIncludingExtraData(
            bytes32 orderHash,
            address caller,
            AdvancedOrder calldata order,
            bytes32[] calldata priorOrderHashes,
            CriteriaResolver[] calldata criteriaResolvers
        ) external view returns (bytes4 validOrderMagicValue);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ZoneInterface } from "../interfaces/ZoneInterface.sol";
    import { OrderType } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import { AdvancedOrder, CriteriaResolver } from "./ConsiderationStructs.sol";
    import "./ConsiderationConstants.sol";
    // prettier-ignore
    import {
        ZoneInteractionErrors
    } from "../interfaces/ZoneInteractionErrors.sol";
    import { LowLevelHelpers } from "./LowLevelHelpers.sol";
    /**
     * @title ZoneInteraction
     * @author 0age
     * @notice ZoneInteraction contains logic related to interacting with zones.
     */
    contract ZoneInteraction is ZoneInteractionErrors, LowLevelHelpers {
        /**
         * @dev Internal view function to determine if an order has a restricted
         *      order type and, if so, to ensure that either the offerer or the zone
         *      are the fulfiller or that a staticcall to `isValidOrder` on the zone
         *      returns a magic value indicating that the order is currently valid.
         *
         * @param orderHash The hash of the order.
         * @param zoneHash  The hash to provide upon calling the zone.
         * @param orderType The type of the order.
         * @param offerer   The offerer in question.
         * @param zone      The zone in question.
         */
        function _assertRestrictedBasicOrderValidity(
            bytes32 orderHash,
            bytes32 zoneHash,
            OrderType orderType,
            address offerer,
            address zone
        ) internal view {
            // Order type 2-3 require zone or offerer be caller or zone to approve.
            if (
                uint256(orderType) > 1 &&
                msg.sender != zone &&
                msg.sender != offerer
            ) {
                // Perform minimal staticcall to the zone.
                _callIsValidOrder(zone, orderHash, offerer, zoneHash);
            }
        }
        function _callIsValidOrder(
            address zone,
            bytes32 orderHash,
            address offerer,
            bytes32 zoneHash
        ) internal view {
            // Perform minimal staticcall to the zone.
            bool success = _staticcall(
                zone,
                abi.encodeWithSelector(
                    ZoneInterface.isValidOrder.selector,
                    orderHash,
                    msg.sender,
                    offerer,
                    zoneHash
                )
            );
            // Ensure call was successful and returned the correct magic value.
            _assertIsValidOrderStaticcallSuccess(success, orderHash);
        }
        /**
         * @dev Internal view function to determine whether an order is a restricted
         *      order and, if so, to ensure that it was either submitted by the
         *      offerer or the zone for the order, or that the zone returns the
         *      expected magic value upon performing a staticcall to `isValidOrder`
         *      or `isValidOrderIncludingExtraData` depending on whether the order
         *      fulfillment specifies extra data or criteria resolvers.
         *
         * @param advancedOrder     The advanced order in question.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific offer or consideration, a token
         *                          identifier, and a proof that the supplied token
         *                          identifier is contained in the order's merkle
         *                          root. Note that a criteria of zero indicates
         *                          that any (transferable) token identifier is
         *                          valid and that no proof needs to be supplied.
         * @param priorOrderHashes  The order hashes of each order supplied prior to
         *                          the current order as part of a "match" variety
         *                          of order fulfillment (e.g. this array will be
         *                          empty for single or "fulfill available").
         * @param orderHash         The hash of the order.
         * @param zoneHash          The hash to provide upon calling the zone.
         * @param orderType         The type of the order.
         * @param offerer           The offerer in question.
         * @param zone              The zone in question.
         */
        function _assertRestrictedAdvancedOrderValidity(
            AdvancedOrder memory advancedOrder,
            CriteriaResolver[] memory criteriaResolvers,
            bytes32[] memory priorOrderHashes,
            bytes32 orderHash,
            bytes32 zoneHash,
            OrderType orderType,
            address offerer,
            address zone
        ) internal view {
            // Order type 2-3 require zone or offerer be caller or zone to approve.
            if (
                uint256(orderType) > 1 &&
                msg.sender != zone &&
                msg.sender != offerer
            ) {
                // If no extraData or criteria resolvers are supplied...
                if (
                    advancedOrder.extraData.length == 0 &&
                    criteriaResolvers.length == 0
                ) {
                    // Perform minimal staticcall to the zone.
                    _callIsValidOrder(zone, orderHash, offerer, zoneHash);
                } else {
                    // Otherwise, extra data or criteria resolvers were supplied; in
                    // that event, perform a more verbose staticcall to the zone.
                    bool success = _staticcall(
                        zone,
                        abi.encodeWithSelector(
                            ZoneInterface.isValidOrderIncludingExtraData.selector,
                            orderHash,
                            msg.sender,
                            advancedOrder,
                            priorOrderHashes,
                            criteriaResolvers
                        )
                    );
                    // Ensure call was successful and returned correct magic value.
                    _assertIsValidOrderStaticcallSuccess(success, orderHash);
                }
            }
        }
        /**
         * @dev Internal view function to ensure that a staticcall to `isValidOrder`
         *      or `isValidOrderIncludingExtraData` as part of validating a
         *      restricted order that was not submitted by the named offerer or zone
         *      was successful and returned the required magic value.
         *
         * @param success   A boolean indicating the status of the staticcall.
         * @param orderHash The order hash of the order in question.
         */
        function _assertIsValidOrderStaticcallSuccess(
            bool success,
            bytes32 orderHash
        ) internal view {
            // If the call failed...
            if (!success) {
                // Revert and pass reason along if one was returned.
                _revertWithReasonIfOneIsReturned();
                // Otherwise, revert with a generic error message.
                revert InvalidRestrictedOrder(orderHash);
            }
            // Ensure result was extracted and matches isValidOrder magic value.
            if (_doesNotMatchMagic(ZoneInterface.isValidOrder.selector)) {
                revert InvalidRestrictedOrder(orderHash);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title ZoneInteractionErrors
     * @author 0age
     * @notice ZoneInteractionErrors contains errors related to zone interaction.
     */
    interface ZoneInteractionErrors {
        /**
         * @dev Revert with an error when attempting to fill an order that specifies
         *      a restricted submitter as its order type when not submitted by
         *      either the offerer or the order's zone or approved as valid by the
         *      zone in question via a staticcall to `isValidOrder`.
         *
         * @param orderHash The order hash for the invalid restricted order.
         */
        error InvalidRestrictedOrder(bytes32 orderHash);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ConduitInterface } from "../interfaces/ConduitInterface.sol";
    // prettier-ignore
    import {
        OrderType,
        ItemType,
        BasicOrderRouteType
    } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        AdditionalRecipient,
        BasicOrderParameters,
        OfferItem,
        ConsiderationItem,
        SpentItem,
        ReceivedItem
    } from "./ConsiderationStructs.sol";
    import { OrderValidator } from "./OrderValidator.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title BasicOrderFulfiller
     * @author 0age
     * @notice BasicOrderFulfiller contains functionality for fulfilling "basic"
     *         orders with minimal overhead. See documentation for details on what
     *         qualifies as a basic order.
     */
    contract BasicOrderFulfiller is OrderValidator {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) OrderValidator(conduitController) {}
        /**
         * @dev Internal function to fulfill an order offering an ERC20, ERC721, or
         *      ERC1155 item by supplying Ether (or other native tokens), ERC20
         *      tokens, an ERC721 item, or an ERC1155 item as consideration. Six
         *      permutations are supported: Native token to ERC721, Native token to
         *      ERC1155, ERC20 to ERC721, ERC20 to ERC1155, ERC721 to ERC20, and
         *      ERC1155 to ERC20 (with native tokens supplied as msg.value). For an
         *      order to be eligible for fulfillment via this method, it must
         *      contain a single offer item (though that item may have a greater
         *      amount if the item is not an ERC721). An arbitrary number of
         *      "additional recipients" may also be supplied which will each receive
         *      native tokens or ERC20 items from the fulfiller as consideration.
         *      Refer to the documentation for a more comprehensive summary of how
         *      to utilize this method and what orders are compatible with it.
         *
         * @param parameters Additional information on the fulfilled order. Note
         *                   that the offerer and the fulfiller must first approve
         *                   this contract (or their chosen conduit if indicated)
         *                   before any tokens can be transferred. Also note that
         *                   contract recipients of ERC1155 consideration items must
         *                   implement `onERC1155Received` in order to receive those
         *                   items.
         *
         * @return A boolean indicating whether the order has been fulfilled.
         */
        function _validateAndFulfillBasicOrder(
            BasicOrderParameters calldata parameters
        ) internal returns (bool) {
            // Declare enums for order type & route to extract from basicOrderType.
            BasicOrderRouteType route;
            OrderType orderType;
            // Declare additional recipient item type to derive from the route type.
            ItemType additionalRecipientsItemType;
            // Utilize assembly to extract the order type and the basic order route.
            assembly {
                // Read basicOrderType from calldata.
                let basicOrderType := calldataload(BasicOrder_basicOrderType_cdPtr)
                // Mask all but 2 least-significant bits to derive the order type.
                orderType := and(basicOrderType, 3)
                // Divide basicOrderType by four to derive the route.
                route := shr(2, basicOrderType)
                // If route > 1 additionalRecipient items are ERC20 (1) else Eth (0)
                additionalRecipientsItemType := gt(route, 1)
            }
            {
                // Declare temporary variable for enforcing payable status.
                bool correctPayableStatus;
                // Utilize assembly to compare the route to the callvalue.
                assembly {
                    // route 0 and 1 are payable, otherwise route is not payable.
                    correctPayableStatus := eq(
                        additionalRecipientsItemType,
                        iszero(callvalue())
                    )
                }
                // Revert if msg.value has not been supplied as part of payable
                // routes or has been supplied as part of non-payable routes.
                if (!correctPayableStatus) {
                    revert InvalidMsgValue(msg.value);
                }
            }
            // Declare more arguments that will be derived from route and calldata.
            address additionalRecipientsToken;
            ItemType offeredItemType;
            bool offerTypeIsAdditionalRecipientsType;
            // Declare scope for received item type to manage stack pressure.
            {
                ItemType receivedItemType;
                // Utilize assembly to retrieve function arguments and cast types.
                assembly {
                    // Check if offered item type == additional recipient item type.
                    offerTypeIsAdditionalRecipientsType := gt(route, 3)
                    // If route > 3 additionalRecipientsToken is at 0xc4 else 0x24.
                    additionalRecipientsToken := calldataload(
                        add(
                            BasicOrder_considerationToken_cdPtr,
                            mul(
                                offerTypeIsAdditionalRecipientsType,
                                BasicOrder_common_params_size
                            )
                        )
                    )
                    // If route > 2, receivedItemType is route - 2. If route is 2,
                    // the receivedItemType is ERC20 (1). Otherwise, it is Eth (0).
                    receivedItemType := add(
                        mul(sub(route, 2), gt(route, 2)),
                        eq(route, 2)
                    )
                    // If route > 3, offeredItemType is ERC20 (1). Route is 2 or 3,
                    // offeredItemType = route. Route is 0 or 1, it is route + 2.
                    offeredItemType := sub(
                        add(route, mul(iszero(additionalRecipientsItemType), 2)),
                        mul(
                            offerTypeIsAdditionalRecipientsType,
                            add(receivedItemType, 1)
                        )
                    )
                }
                // Derive & validate order using parameters and update order status.
                _prepareBasicFulfillmentFromCalldata(
                    parameters,
                    orderType,
                    receivedItemType,
                    additionalRecipientsItemType,
                    additionalRecipientsToken,
                    offeredItemType
                );
            }
            // Declare conduitKey argument used by transfer functions.
            bytes32 conduitKey;
            // Utilize assembly to derive conduit (if relevant) based on route.
            assembly {
                // use offerer conduit for routes 0-3, fulfiller conduit otherwise.
                conduitKey := calldataload(
                    add(
                        BasicOrder_offererConduit_cdPtr,
                        mul(offerTypeIsAdditionalRecipientsType, OneWord)
                    )
                )
            }
            // Transfer tokens based on the route.
            if (additionalRecipientsItemType == ItemType.NATIVE) {
                // Ensure neither the token nor the identifier parameters are set.
                if (
                    (uint160(parameters.considerationToken) |
                        parameters.considerationIdentifier) != 0
                ) {
                    revert UnusedItemParameters();
                }
                // Transfer the ERC721 or ERC1155 item, bypassing the accumulator.
                _transferIndividual721Or1155Item(
                    offeredItemType,
                    parameters.offerToken,
                    parameters.offerer,
                    msg.sender,
                    parameters.offerIdentifier,
                    parameters.offerAmount,
                    conduitKey
                );
                // Transfer native to recipients, return excess to caller & wrap up.
                _transferEthAndFinalize(
                    parameters.considerationAmount,
                    parameters.offerer,
                    parameters.additionalRecipients
                );
            } else {
                // Initialize an accumulator array. From this point forward, no new
                // memory regions can be safely allocated until the accumulator is
                // no longer being utilized, as the accumulator operates in an
                // open-ended fashion from this memory pointer; existing memory may
                // still be accessed and modified, however.
                bytes memory accumulator = new bytes(AccumulatorDisarmed);
                // Choose transfer method for ERC721 or ERC1155 item based on route.
                if (route == BasicOrderRouteType.ERC20_TO_ERC721) {
                    // Transfer ERC721 to caller using offerer's conduit preference.
                    _transferERC721(
                        parameters.offerToken,
                        parameters.offerer,
                        msg.sender,
                        parameters.offerIdentifier,
                        parameters.offerAmount,
                        conduitKey,
                        accumulator
                    );
                } else if (route == BasicOrderRouteType.ERC20_TO_ERC1155) {
                    // Transfer ERC1155 to caller with offerer's conduit preference.
                    _transferERC1155(
                        parameters.offerToken,
                        parameters.offerer,
                        msg.sender,
                        parameters.offerIdentifier,
                        parameters.offerAmount,
                        conduitKey,
                        accumulator
                    );
                } else if (route == BasicOrderRouteType.ERC721_TO_ERC20) {
                    // Transfer ERC721 to offerer using caller's conduit preference.
                    _transferERC721(
                        parameters.considerationToken,
                        msg.sender,
                        parameters.offerer,
                        parameters.considerationIdentifier,
                        parameters.considerationAmount,
                        conduitKey,
                        accumulator
                    );
                } else {
                    // route == BasicOrderRouteType.ERC1155_TO_ERC20
                    // Transfer ERC1155 to offerer with caller's conduit preference.
                    _transferERC1155(
                        parameters.considerationToken,
                        msg.sender,
                        parameters.offerer,
                        parameters.considerationIdentifier,
                        parameters.considerationAmount,
                        conduitKey,
                        accumulator
                    );
                }
                // Transfer ERC20 tokens to all recipients and wrap up.
                _transferERC20AndFinalize(
                    parameters.offerer,
                    parameters,
                    offerTypeIsAdditionalRecipientsType,
                    accumulator
                );
                // Trigger any remaining accumulated transfers via call to conduit.
                _triggerIfArmed(accumulator);
            }
            // Clear the reentrancy guard.
            _clearReentrancyGuard();
            return true;
        }
        /**
         * @dev Internal function to prepare fulfillment of a basic order with
         *      manual calldata and memory access. This calculates the order hash,
         *      emits an OrderFulfilled event, and asserts basic order validity.
         *      Note that calldata offsets must be validated as this function
         *      accesses constant calldata pointers for dynamic types that match
         *      default ABI encoding, but valid ABI encoding can use arbitrary
         *      offsets. Checking that the offsets were produced by default encoding
         *      will ensure that other functions using Solidity's calldata accessors
         *      (which calculate pointers from the stored offsets) are reading the
         *      same data as the order hash is derived from. Also note that This
         *      function accesses memory directly. It does not clear the expanded
         *      memory regions used, nor does it update the free memory pointer, so
         *      other direct memory access must not assume that unused memory is
         *      empty.
         *
         * @param parameters                   The parameters of the basic order.
         * @param orderType                    The order type.
         * @param receivedItemType             The item type of the initial
         *                                     consideration item on the order.
         * @param additionalRecipientsItemType The item type of any additional
         *                                     consideration item on the order.
         * @param additionalRecipientsToken    The ERC20 token contract address (if
         *                                     applicable) for any additional
         *                                     consideration item on the order.
         * @param offeredItemType              The item type of the offered item on
         *                                     the order.
         */
        function _prepareBasicFulfillmentFromCalldata(
            BasicOrderParameters calldata parameters,
            OrderType orderType,
            ItemType receivedItemType,
            ItemType additionalRecipientsItemType,
            address additionalRecipientsToken,
            ItemType offeredItemType
        ) internal {
            // Ensure this function cannot be triggered during a reentrant call.
            _setReentrancyGuard();
            // Ensure current timestamp falls between order start time and end time.
            _verifyTime(parameters.startTime, parameters.endTime, true);
            // Verify that calldata offsets for all dynamic types were produced by
            // default encoding. This ensures that the constants we use for calldata
            // pointers to dynamic types are the same as those calculated by
            // Solidity using their offsets. Also verify that the basic order type
            // is within range.
            _assertValidBasicOrderParameters();
            // Ensure supplied consideration array length is not less than original.
            _assertConsiderationLengthIsNotLessThanOriginalConsiderationLength(
                parameters.additionalRecipients.length,
                parameters.totalOriginalAdditionalRecipients
            );
            // Declare stack element for the order hash.
            bytes32 orderHash;
            {
                /**
                 * First, handle consideration items. Memory Layout:
                 *  0x60: final hash of the array of consideration item hashes
                 *  0x80-0x160: reused space for EIP712 hashing of each item
                 *   - 0x80: ConsiderationItem EIP-712 typehash (constant)
                 *   - 0xa0: itemType
                 *   - 0xc0: token
                 *   - 0xe0: identifier
                 *   - 0x100: startAmount
                 *   - 0x120: endAmount
                 *   - 0x140: recipient
                 *  0x160-END_ARR: array of consideration item hashes
                 *   - 0x160: primary consideration item EIP712 hash
                 *   - 0x180-END_ARR: additional recipient item EIP712 hashes
                 *  END_ARR: beginning of data for OrderFulfilled event
                 *   - END_ARR + 0x120: length of ReceivedItem array
                 *   - END_ARR + 0x140: beginning of data for first ReceivedItem
                 * (Note: END_ARR = 0x180 + RECIPIENTS_LENGTH * 0x20)
                 */
                // Load consideration item typehash from runtime and place on stack.
                bytes32 typeHash = _CONSIDERATION_ITEM_TYPEHASH;
                // Utilize assembly to enable reuse of memory regions and use
                // constant pointers when possible.
                assembly {
                    /*
                     * 1. Calculate the EIP712 ConsiderationItem hash for the
                     * primary consideration item of the basic order.
                     */
                    // Write ConsiderationItem type hash and item type to memory.
                    mstore(BasicOrder_considerationItem_typeHash_ptr, typeHash)
                    mstore(
                        BasicOrder_considerationItem_itemType_ptr,
                        receivedItemType
                    )
                    // Copy calldata region with (token, identifier, amount) from
                    // BasicOrderParameters to ConsiderationItem. The
                    // considerationAmount is written to startAmount and endAmount
                    // as basic orders do not have dynamic amounts.
                    calldatacopy(
                        BasicOrder_considerationItem_token_ptr,
                        BasicOrder_considerationToken_cdPtr,
                        ThreeWords
                    )
                    // Copy calldata region with considerationAmount and offerer
                    // from BasicOrderParameters to endAmount and recipient in
                    // ConsiderationItem.
                    calldatacopy(
                        BasicOrder_considerationItem_endAmount_ptr,
                        BasicOrder_considerationAmount_cdPtr,
                        TwoWords
                    )
                    // Calculate EIP712 ConsiderationItem hash and store it in the
                    // array of EIP712 consideration hashes.
                    mstore(
                        BasicOrder_considerationHashesArray_ptr,
                        keccak256(
                            BasicOrder_considerationItem_typeHash_ptr,
                            EIP712_ConsiderationItem_size
                        )
                    )
                    /*
                     * 2. Write a ReceivedItem struct for the primary consideration
                     * item to the consideration array in OrderFulfilled.
                     */
                    // Get the length of the additional recipients array.
                    let totalAdditionalRecipients := calldataload(
                        BasicOrder_additionalRecipients_length_cdPtr
                    )
                    // Calculate pointer to length of OrderFulfilled consideration
                    // array.
                    let eventConsiderationArrPtr := add(
                        OrderFulfilled_consideration_length_baseOffset,
                        mul(totalAdditionalRecipients, OneWord)
                    )
                    // Set the length of the consideration array to the number of
                    // additional recipients, plus one for the primary consideration
                    // item.
                    mstore(
                        eventConsiderationArrPtr,
                        add(
                            calldataload(
                                BasicOrder_additionalRecipients_length_cdPtr
                            ),
                            1
                        )
                    )
                    // Overwrite the consideration array pointer so it points to the
                    // body of the first element
                    eventConsiderationArrPtr := add(
                        eventConsiderationArrPtr,
                        OneWord
                    )
                    // Set itemType at start of the ReceivedItem memory region.
                    mstore(eventConsiderationArrPtr, receivedItemType)
                    // Copy calldata region (token, identifier, amount & recipient)
                    // from BasicOrderParameters to ReceivedItem memory.
                    calldatacopy(
                        add(eventConsiderationArrPtr, Common_token_offset),
                        BasicOrder_considerationToken_cdPtr,
                        FourWords
                    )
                    /*
                     * 3. Calculate EIP712 ConsiderationItem hashes for original
                     * additional recipients and add a ReceivedItem for each to the
                     * consideration array in the OrderFulfilled event. The original
                     * additional recipients are all the considerations signed by
                     * the offerer aside from the primary consideration of the
                     * order. Uses memory region from 0x80-0x160 as a buffer for
                     * calculating EIP712 ConsiderationItem hashes.
                     */
                    // Put pointer to consideration hashes array on the stack.
                    // This will be updated as each additional recipient is hashed
                    let
                        considerationHashesPtr
                    := BasicOrder_considerationHashesArray_ptr
                    // Write item type, token, & identifier for additional recipient
                    // to memory region for hashing EIP712 ConsiderationItem; these
                    // values will be reused for each recipient.
                    mstore(
                        BasicOrder_considerationItem_itemType_ptr,
                        additionalRecipientsItemType
                    )
                    mstore(
                        BasicOrder_considerationItem_token_ptr,
                        additionalRecipientsToken
                    )
                    mstore(BasicOrder_considerationItem_identifier_ptr, 0)
                    // Read length of the additionalRecipients array from calldata
                    // and iterate.
                    totalAdditionalRecipients := calldataload(
                        BasicOrder_totalOriginalAdditionalRecipients_cdPtr
                    )
                    let i := 0
                    // prettier-ignore
                    for {} lt(i, totalAdditionalRecipients) {
                        i := add(i, 1)
                    } {
                        /*
                         * Calculate EIP712 ConsiderationItem hash for recipient.
                         */
                        // Retrieve calldata pointer for additional recipient.
                        let additionalRecipientCdPtr := add(
                            BasicOrder_additionalRecipients_data_cdPtr,
                            mul(AdditionalRecipients_size, i)
                        )
                        // Copy startAmount from calldata to the ConsiderationItem
                        // struct.
                        calldatacopy(
                            BasicOrder_considerationItem_startAmount_ptr,
                            additionalRecipientCdPtr,
                            OneWord
                        )
                        // Copy endAmount and recipient from calldata to the
                        // ConsiderationItem struct.
                        calldatacopy(
                            BasicOrder_considerationItem_endAmount_ptr,
                            additionalRecipientCdPtr,
                            AdditionalRecipients_size
                        )
                        // Add 1 word to the pointer as part of each loop to reduce
                        // operations needed to get local offset into the array.
                        considerationHashesPtr := add(
                            considerationHashesPtr,
                            OneWord
                        )
                        // Calculate EIP712 ConsiderationItem hash and store it in
                        // the array of consideration hashes.
                        mstore(
                            considerationHashesPtr,
                            keccak256(
                                BasicOrder_considerationItem_typeHash_ptr,
                                EIP712_ConsiderationItem_size
                            )
                        )
                        /*
                         * Write ReceivedItem to OrderFulfilled data.
                         */
                        // At this point, eventConsiderationArrPtr points to the
                        // beginning of the ReceivedItem struct of the previous
                        // element in the array. Increase it by the size of the
                        // struct to arrive at the pointer for the current element.
                        eventConsiderationArrPtr := add(
                            eventConsiderationArrPtr,
                            ReceivedItem_size
                        )
                        // Write itemType to the ReceivedItem struct.
                        mstore(
                            eventConsiderationArrPtr,
                            additionalRecipientsItemType
                        )
                        // Write token to the next word of the ReceivedItem struct.
                        mstore(
                            add(eventConsiderationArrPtr, OneWord),
                            additionalRecipientsToken
                        )
                        // Copy endAmount & recipient words to ReceivedItem struct.
                        calldatacopy(
                            add(
                                eventConsiderationArrPtr,
                                ReceivedItem_amount_offset
                            ),
                            additionalRecipientCdPtr,
                            TwoWords
                        )
                    }
                    /*
                     * 4. Hash packed array of ConsiderationItem EIP712 hashes:
                     *   `keccak256(abi.encodePacked(receivedItemHashes))`
                     * Note that it is set at 0x60 — all other memory begins at
                     * 0x80. 0x60 is the "zero slot" and will be restored at the end
                     * of the assembly section and before required by the compiler.
                     */
                    mstore(
                        receivedItemsHash_ptr,
                        keccak256(
                            BasicOrder_considerationHashesArray_ptr,
                            mul(add(totalAdditionalRecipients, 1), OneWord)
                        )
                    )
                    /*
                     * 5. Add a ReceivedItem for each tip to the consideration array
                     * in the OrderFulfilled event. The tips are all the
                     * consideration items that were not signed by the offerer and
                     * were provided by the fulfiller.
                     */
                    // Overwrite length to length of the additionalRecipients array.
                    totalAdditionalRecipients := calldataload(
                        BasicOrder_additionalRecipients_length_cdPtr
                    )
                    // prettier-ignore
                    for {} lt(i, totalAdditionalRecipients) {
                        i := add(i, 1)
                    } {
                        // Retrieve calldata pointer for additional recipient.
                        let additionalRecipientCdPtr := add(
                            BasicOrder_additionalRecipients_data_cdPtr,
                            mul(AdditionalRecipients_size, i)
                        )
                        // At this point, eventConsiderationArrPtr points to the
                        // beginning of the ReceivedItem struct of the previous
                        // element in the array. Increase it by the size of the
                        // struct to arrive at the pointer for the current element.
                        eventConsiderationArrPtr := add(
                            eventConsiderationArrPtr,
                            ReceivedItem_size
                        )
                        // Write itemType to the ReceivedItem struct.
                        mstore(
                            eventConsiderationArrPtr,
                            additionalRecipientsItemType
                        )
                        // Write token to the next word of the ReceivedItem struct.
                        mstore(
                            add(eventConsiderationArrPtr, OneWord),
                            additionalRecipientsToken
                        )
                        // Copy endAmount & recipient words to ReceivedItem struct.
                        calldatacopy(
                            add(
                                eventConsiderationArrPtr,
                                ReceivedItem_amount_offset
                            ),
                            additionalRecipientCdPtr,
                            TwoWords
                        )
                    }
                }
            }
            {
                /**
                 * Next, handle offered items. Memory Layout:
                 *  EIP712 data for OfferItem
                 *   - 0x80:  OfferItem EIP-712 typehash (constant)
                 *   - 0xa0:  itemType
                 *   - 0xc0:  token
                 *   - 0xe0:  identifier (reused for offeredItemsHash)
                 *   - 0x100: startAmount
                 *   - 0x120: endAmount
                 */
                // Place offer item typehash on the stack.
                bytes32 typeHash = _OFFER_ITEM_TYPEHASH;
                // Utilize assembly to enable reuse of memory regions when possible.
                assembly {
                    /*
                     * 1. Calculate OfferItem EIP712 hash
                     */
                    // Write the OfferItem typeHash to memory.
                    mstore(BasicOrder_offerItem_typeHash_ptr, typeHash)
                    // Write the OfferItem item type to memory.
                    mstore(BasicOrder_offerItem_itemType_ptr, offeredItemType)
                    // Copy calldata region with (offerToken, offerIdentifier,
                    // offerAmount) from OrderParameters to (token, identifier,
                    // startAmount) in OfferItem struct. The offerAmount is written
                    // to startAmount and endAmount as basic orders do not have
                    // dynamic amounts.
                    calldatacopy(
                        BasicOrder_offerItem_token_ptr,
                        BasicOrder_offerToken_cdPtr,
                        ThreeWords
                    )
                    // Copy offerAmount from calldata to endAmount in OfferItem
                    // struct.
                    calldatacopy(
                        BasicOrder_offerItem_endAmount_ptr,
                        BasicOrder_offerAmount_cdPtr,
                        OneWord
                    )
                    // Compute EIP712 OfferItem hash, write result to scratch space:
                    //   `keccak256(abi.encode(offeredItem))`
                    mstore(
                        0,
                        keccak256(
                            BasicOrder_offerItem_typeHash_ptr,
                            EIP712_OfferItem_size
                        )
                    )
                    /*
                     * 2. Calculate hash of array of EIP712 hashes and write the
                     * result to the corresponding OfferItem struct:
                     *   `keccak256(abi.encodePacked(offerItemHashes))`
                     */
                    mstore(BasicOrder_order_offerHashes_ptr, keccak256(0, OneWord))
                    /*
                     * 3. Write SpentItem to offer array in OrderFulfilled event.
                     */
                    let eventConsiderationArrPtr := add(
                        OrderFulfilled_offer_length_baseOffset,
                        mul(
                            calldataload(
                                BasicOrder_additionalRecipients_length_cdPtr
                            ),
                            OneWord
                        )
                    )
                    // Set a length of 1 for the offer array.
                    mstore(eventConsiderationArrPtr, 1)
                    // Write itemType to the SpentItem struct.
                    mstore(add(eventConsiderationArrPtr, OneWord), offeredItemType)
                    // Copy calldata region with (offerToken, offerIdentifier,
                    // offerAmount) from OrderParameters to (token, identifier,
                    // amount) in SpentItem struct.
                    calldatacopy(
                        add(eventConsiderationArrPtr, AdditionalRecipients_size),
                        BasicOrder_offerToken_cdPtr,
                        ThreeWords
                    )
                }
            }
            {
                /**
                 * Once consideration items and offer items have been handled,
                 * derive the final order hash. Memory Layout:
                 *  0x80-0x1c0: EIP712 data for order
                 *   - 0x80:   Order EIP-712 typehash (constant)
                 *   - 0xa0:   orderParameters.offerer
                 *   - 0xc0:   orderParameters.zone
                 *   - 0xe0:   keccak256(abi.encodePacked(offerHashes))
                 *   - 0x100:  keccak256(abi.encodePacked(considerationHashes))
                 *   - 0x120:  orderParameters.basicOrderType (% 4 = orderType)
                 *   - 0x140:  orderParameters.startTime
                 *   - 0x160:  orderParameters.endTime
                 *   - 0x180:  orderParameters.zoneHash
                 *   - 0x1a0:  orderParameters.salt
                 *   - 0x1c0:  orderParameters.conduitKey
                 *   - 0x1e0:  _counters[orderParameters.offerer] (from storage)
                 */
                // Read the offerer from calldata and place on the stack.
                address offerer;
                assembly {
                    offerer := calldataload(BasicOrder_offerer_cdPtr)
                }
                // Read offerer's current counter from storage and place on stack.
                uint256 counter = _getCounter(offerer);
                // Load order typehash from runtime code and place on stack.
                bytes32 typeHash = _ORDER_TYPEHASH;
                assembly {
                    // Set the OrderItem typeHash in memory.
                    mstore(BasicOrder_order_typeHash_ptr, typeHash)
                    // Copy offerer and zone from OrderParameters in calldata to the
                    // Order struct.
                    calldatacopy(
                        BasicOrder_order_offerer_ptr,
                        BasicOrder_offerer_cdPtr,
                        TwoWords
                    )
                    // Copy receivedItemsHash from zero slot to the Order struct.
                    mstore(
                        BasicOrder_order_considerationHashes_ptr,
                        mload(receivedItemsHash_ptr)
                    )
                    // Write the supplied orderType to the Order struct.
                    mstore(BasicOrder_order_orderType_ptr, orderType)
                    // Copy startTime, endTime, zoneHash, salt & conduit from
                    // calldata to the Order struct.
                    calldatacopy(
                        BasicOrder_order_startTime_ptr,
                        BasicOrder_startTime_cdPtr,
                        FiveWords
                    )
                    // Write offerer's counter, retrieved from storage, to struct.
                    mstore(BasicOrder_order_counter_ptr, counter)
                    // Compute the EIP712 Order hash.
                    orderHash := keccak256(
                        BasicOrder_order_typeHash_ptr,
                        EIP712_Order_size
                    )
                }
            }
            assembly {
                /**
                 * After the order hash has been derived, emit OrderFulfilled event:
                 *   event OrderFulfilled(
                 *     bytes32 orderHash,
                 *     address indexed offerer,
                 *     address indexed zone,
                 *     address fulfiller,
                 *     SpentItem[] offer,
                 *       > (itemType, token, id, amount)
                 *     ReceivedItem[] consideration
                 *       > (itemType, token, id, amount, recipient)
                 *   )
                 * topic0 - OrderFulfilled event signature
                 * topic1 - offerer
                 * topic2 - zone
                 * data:
                 *  - 0x00: orderHash
                 *  - 0x20: fulfiller
                 *  - 0x40: offer arr ptr (0x80)
                 *  - 0x60: consideration arr ptr (0x120)
                 *  - 0x80: offer arr len (1)
                 *  - 0xa0: offer.itemType
                 *  - 0xc0: offer.token
                 *  - 0xe0: offer.identifier
                 *  - 0x100: offer.amount
                 *  - 0x120: 1 + recipients.length
                 *  - 0x140: recipient 0
                 */
                // Derive pointer to start of OrderFulfilled event data
                let eventDataPtr := add(
                    OrderFulfilled_baseOffset,
                    mul(
                        calldataload(BasicOrder_additionalRecipients_length_cdPtr),
                        OneWord
                    )
                )
                // Write the order hash to the head of the event's data region.
                mstore(eventDataPtr, orderHash)
                // Write the fulfiller (i.e. the caller) next for receiver argument.
                mstore(add(eventDataPtr, OrderFulfilled_fulfiller_offset), caller())
                // Write the SpentItem and ReceivedItem array offsets (constants).
                mstore(
                    // SpentItem array offset
                    add(eventDataPtr, OrderFulfilled_offer_head_offset),
                    OrderFulfilled_offer_body_offset
                )
                mstore(
                    // ReceivedItem array offset
                    add(eventDataPtr, OrderFulfilled_consideration_head_offset),
                    OrderFulfilled_consideration_body_offset
                )
                // Derive total data size including SpentItem and ReceivedItem data.
                // SpentItem portion is already included in the baseSize constant,
                // as there can only be one element in the array.
                let dataSize := add(
                    OrderFulfilled_baseSize,
                    mul(
                        calldataload(BasicOrder_additionalRecipients_length_cdPtr),
                        ReceivedItem_size
                    )
                )
                // Emit OrderFulfilled log with three topics (the event signature
                // as well as the two indexed arguments, the offerer and the zone).
                log3(
                    // Supply the pointer for event data in memory.
                    eventDataPtr,
                    // Supply the size of event data in memory.
                    dataSize,
                    // Supply the OrderFulfilled event signature.
                    OrderFulfilled_selector,
                    // Supply the first topic (the offerer).
                    calldataload(BasicOrder_offerer_cdPtr),
                    // Supply the second topic (the zone).
                    calldataload(BasicOrder_zone_cdPtr)
                )
                // Restore the zero slot.
                mstore(ZeroSlot, 0)
            }
            // Determine whether order is restricted and, if so, that it is valid.
            _assertRestrictedBasicOrderValidity(
                orderHash,
                parameters.zoneHash,
                orderType,
                parameters.offerer,
                parameters.zone
            );
            // Verify and update the status of the derived order.
            _validateBasicOrderAndUpdateStatus(
                orderHash,
                parameters.offerer,
                parameters.signature
            );
        }
        /**
         * @dev Internal function to transfer Ether (or other native tokens) to a
         *      given recipient as part of basic order fulfillment. Note that
         *      conduits are not utilized for native tokens as the transferred
         *      amount must be provided as msg.value.
         *
         * @param amount               The amount to transfer.
         * @param to                   The recipient of the native token transfer.
         * @param additionalRecipients The additional recipients of the order.
         */
        function _transferEthAndFinalize(
            uint256 amount,
            address payable to,
            AdditionalRecipient[] calldata additionalRecipients
        ) internal {
            // Put ether value supplied by the caller on the stack.
            uint256 etherRemaining = msg.value;
            // Retrieve total number of additional recipients and place on stack.
            uint256 totalAdditionalRecipients = additionalRecipients.length;
            // Skip overflow check as for loop is indexed starting at zero.
            unchecked {
                // Iterate over each additional recipient.
                for (uint256 i = 0; i < totalAdditionalRecipients; ++i) {
                    // Retrieve the additional recipient.
                    AdditionalRecipient calldata additionalRecipient = (
                        additionalRecipients[i]
                    );
                    // Read ether amount to transfer to recipient & place on stack.
                    uint256 additionalRecipientAmount = additionalRecipient.amount;
                    // Ensure that sufficient Ether is available.
                    if (additionalRecipientAmount > etherRemaining) {
                        revert InsufficientEtherSupplied();
                    }
                    // Transfer Ether to the additional recipient.
                    _transferEth(
                        additionalRecipient.recipient,
                        additionalRecipientAmount
                    );
                    // Reduce ether value available. Skip underflow check as
                    // subtracted value is confirmed above as less than remaining.
                    etherRemaining -= additionalRecipientAmount;
                }
            }
            // Ensure that sufficient Ether is still available.
            if (amount > etherRemaining) {
                revert InsufficientEtherSupplied();
            }
            // Transfer Ether to the offerer.
            _transferEth(to, amount);
            // If any Ether remains after transfers, return it to the caller.
            if (etherRemaining > amount) {
                // Skip underflow check as etherRemaining > amount.
                unchecked {
                    // Transfer remaining Ether to the caller.
                    _transferEth(payable(msg.sender), etherRemaining - amount);
                }
            }
        }
        /**
         * @dev Internal function to transfer ERC20 tokens to a given recipient as
         *      part of basic order fulfillment.
         *
         * @param offerer     The offerer of the fulfiller order.
         * @param parameters  The basic order parameters.
         * @param fromOfferer A boolean indicating whether to decrement amount from
         *                    the offered amount.
         * @param accumulator An open-ended array that collects transfers to execute
         *                    against a given conduit in a single call.
         */
        function _transferERC20AndFinalize(
            address offerer,
            BasicOrderParameters calldata parameters,
            bool fromOfferer,
            bytes memory accumulator
        ) internal {
            // Declare from and to variables determined by fromOfferer value.
            address from;
            address to;
            // Declare token and amount variables determined by fromOfferer value.
            address token;
            uint256 amount;
            // Declare and check identifier variable within an isolated scope.
            {
                // Declare identifier variable determined by fromOfferer value.
                uint256 identifier;
                // Set ERC20 token transfer variables based on fromOfferer boolean.
                if (fromOfferer) {
                    // Use offerer as from value and msg.sender as to value.
                    from = offerer;
                    to = msg.sender;
                    // Use offer token and related values if token is from offerer.
                    token = parameters.offerToken;
                    identifier = parameters.offerIdentifier;
                    amount = parameters.offerAmount;
                } else {
                    // Use msg.sender as from value and offerer as to value.
                    from = msg.sender;
                    to = offerer;
                    // Otherwise, use consideration token and related values.
                    token = parameters.considerationToken;
                    identifier = parameters.considerationIdentifier;
                    amount = parameters.considerationAmount;
                }
                // Ensure that no identifier is supplied.
                if (identifier != 0) {
                    revert UnusedItemParameters();
                }
            }
            // Determine the appropriate conduit to utilize.
            bytes32 conduitKey;
            // Utilize assembly to derive conduit (if relevant) based on route.
            assembly {
                // Use offerer conduit if fromOfferer, fulfiller conduit otherwise.
                conduitKey := calldataload(
                    sub(
                        BasicOrder_fulfillerConduit_cdPtr,
                        mul(fromOfferer, OneWord)
                    )
                )
            }
            // Retrieve total number of additional recipients and place on stack.
            uint256 totalAdditionalRecipients = (
                parameters.additionalRecipients.length
            );
            // Iterate over each additional recipient.
            for (uint256 i = 0; i < totalAdditionalRecipients; ) {
                // Retrieve the additional recipient.
                AdditionalRecipient calldata additionalRecipient = (
                    parameters.additionalRecipients[i]
                );
                uint256 additionalRecipientAmount = additionalRecipient.amount;
                // Decrement the amount to transfer to fulfiller if indicated.
                if (fromOfferer) {
                    amount -= additionalRecipientAmount;
                }
                // Transfer ERC20 tokens to additional recipient given approval.
                _transferERC20(
                    token,
                    from,
                    additionalRecipient.recipient,
                    additionalRecipientAmount,
                    conduitKey,
                    accumulator
                );
                // Skip overflow check as for loop is indexed starting at zero.
                unchecked {
                    ++i;
                }
            }
            // Transfer ERC20 token amount (from account must have proper approval).
            _transferERC20(token, from, to, amount, conduitKey, accumulator);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { OrderType } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        OrderParameters,
        Order,
        AdvancedOrder,
        OrderComponents,
        OrderStatus,
        CriteriaResolver
    } from "./ConsiderationStructs.sol";
    import "./ConsiderationConstants.sol";
    import { Executor } from "./Executor.sol";
    import { ZoneInteraction } from "./ZoneInteraction.sol";
    /**
     * @title OrderValidator
     * @author 0age
     * @notice OrderValidator contains functionality related to validating orders
     *         and updating their status.
     */
    contract OrderValidator is Executor, ZoneInteraction {
        // Track status of each order (validated, cancelled, and fraction filled).
        mapping(bytes32 => OrderStatus) private _orderStatus;
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) Executor(conduitController) {}
        /**
         * @dev Internal function to verify and update the status of a basic order.
         *
         * @param orderHash The hash of the order.
         * @param offerer   The offerer of the order.
         * @param signature A signature from the offerer indicating that the order
         *                  has been approved.
         */
        function _validateBasicOrderAndUpdateStatus(
            bytes32 orderHash,
            address offerer,
            bytes memory signature
        ) internal {
            // Retrieve the order status for the given order hash.
            OrderStatus storage orderStatus = _orderStatus[orderHash];
            // Ensure order is fillable and is not cancelled.
            _verifyOrderStatus(
                orderHash,
                orderStatus,
                true, // Only allow unused orders when fulfilling basic orders.
                true // Signifies to revert if the order is invalid.
            );
            // If the order is not already validated, verify the supplied signature.
            if (!orderStatus.isValidated) {
                _verifySignature(offerer, orderHash, signature);
            }
            // Update order status as fully filled, packing struct values.
            orderStatus.isValidated = true;
            orderStatus.isCancelled = false;
            orderStatus.numerator = 1;
            orderStatus.denominator = 1;
        }
        /**
         * @dev Internal function to validate an order, determine what portion to
         *      fill, and update its status. The desired fill amount is supplied as
         *      a fraction, as is the returned amount to fill.
         *
         * @param advancedOrder     The order to fulfill as well as the fraction to
         *                          fill. Note that all offer and consideration
         *                          amounts must divide with no remainder in order
         *                          for a partial fill to be valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific offer or consideration, a token
         *                          identifier, and a proof that the supplied token
         *                          identifier is contained in the order's merkle
         *                          root. Note that a criteria of zero indicates
         *                          that any (transferable) token identifier is
         *                          valid and that no proof needs to be supplied.
         * @param revertOnInvalid   A boolean indicating whether to revert if the
         *                          order is invalid due to the time or status.
         * @param priorOrderHashes  The order hashes of each order supplied prior to
         *                          the current order as part of a "match" variety
         *                          of order fulfillment (e.g. this array will be
         *                          empty for single or "fulfill available").
         *
         * @return orderHash      The order hash.
         * @return newNumerator   A value indicating the portion of the order that
         *                        will be filled.
         * @return newDenominator A value indicating the total size of the order.
         */
        function _validateOrderAndUpdateStatus(
            AdvancedOrder memory advancedOrder,
            CriteriaResolver[] memory criteriaResolvers,
            bool revertOnInvalid,
            bytes32[] memory priorOrderHashes
        )
            internal
            returns (
                bytes32 orderHash,
                uint256 newNumerator,
                uint256 newDenominator
            )
        {
            // Retrieve the parameters for the order.
            OrderParameters memory orderParameters = advancedOrder.parameters;
            // Ensure current timestamp falls between order start time and end time.
            if (
                !_verifyTime(
                    orderParameters.startTime,
                    orderParameters.endTime,
                    revertOnInvalid
                )
            ) {
                // Assuming an invalid time and no revert, return zeroed out values.
                return (bytes32(0), 0, 0);
            }
            // Read numerator and denominator from memory and place on the stack.
            uint256 numerator = uint256(advancedOrder.numerator);
            uint256 denominator = uint256(advancedOrder.denominator);
            // Ensure that the supplied numerator and denominator are valid.
            if (numerator > denominator || numerator == 0) {
                revert BadFraction();
            }
            // If attempting partial fill (n < d) check order type & ensure support.
            if (
                numerator < denominator &&
                _doesNotSupportPartialFills(orderParameters.orderType)
            ) {
                // Revert if partial fill was attempted on an unsupported order.
                revert PartialFillsNotEnabledForOrder();
            }
            // Retrieve current counter & use it w/ parameters to derive order hash.
            orderHash = _assertConsiderationLengthAndGetOrderHash(orderParameters);
            // Ensure restricted orders have a valid submitter or pass a zone check.
            _assertRestrictedAdvancedOrderValidity(
                advancedOrder,
                criteriaResolvers,
                priorOrderHashes,
                orderHash,
                orderParameters.zoneHash,
                orderParameters.orderType,
                orderParameters.offerer,
                orderParameters.zone
            );
            // Retrieve the order status using the derived order hash.
            OrderStatus storage orderStatus = _orderStatus[orderHash];
            // Ensure order is fillable and is not cancelled.
            if (
                !_verifyOrderStatus(
                    orderHash,
                    orderStatus,
                    false, // Allow partially used orders to be filled.
                    revertOnInvalid
                )
            ) {
                // Assuming an invalid order status and no revert, return zero fill.
                return (orderHash, 0, 0);
            }
            // If the order is not already validated, verify the supplied signature.
            if (!orderStatus.isValidated) {
                _verifySignature(
                    orderParameters.offerer,
                    orderHash,
                    advancedOrder.signature
                );
            }
            // Read filled amount as numerator and denominator and put on the stack.
            uint256 filledNumerator = orderStatus.numerator;
            uint256 filledDenominator = orderStatus.denominator;
            // If order (orderStatus) currently has a non-zero denominator it is
            // partially filled.
            if (filledDenominator != 0) {
                // If denominator of 1 supplied, fill all remaining amount on order.
                if (denominator == 1) {
                    // Scale numerator & denominator to match current denominator.
                    numerator = filledDenominator;
                    denominator = filledDenominator;
                }
                // Otherwise, if supplied denominator differs from current one...
                else if (filledDenominator != denominator) {
                    // scale current numerator by the supplied denominator, then...
                    filledNumerator *= denominator;
                    // the supplied numerator & denominator by current denominator.
                    numerator *= filledDenominator;
                    denominator *= filledDenominator;
                }
                // Once adjusted, if current+supplied numerator exceeds denominator:
                if (filledNumerator + numerator > denominator) {
                    // Skip underflow check: denominator >= orderStatus.numerator
                    unchecked {
                        // Reduce current numerator so it + supplied = denominator.
                        numerator = denominator - filledNumerator;
                    }
                }
                // Increment the filled numerator by the new numerator.
                filledNumerator += numerator;
                // Use assembly to ensure fractional amounts are below max uint120.
                assembly {
                    // Check filledNumerator and denominator for uint120 overflow.
                    if or(
                        gt(filledNumerator, MaxUint120),
                        gt(denominator, MaxUint120)
                    ) {
                        // Derive greatest common divisor using euclidean algorithm.
                        function gcd(_a, _b) -> out {
                            for {
                            } _b {
                            } {
                                let _c := _b
                                _b := mod(_a, _c)
                                _a := _c
                            }
                            out := _a
                        }
                        let scaleDown := gcd(
                            numerator,
                            gcd(filledNumerator, denominator)
                        )
                        // Ensure that the divisor is at least one.
                        let safeScaleDown := add(scaleDown, iszero(scaleDown))
                        // Scale all fractional values down by gcd.
                        numerator := div(numerator, safeScaleDown)
                        filledNumerator := div(filledNumerator, safeScaleDown)
                        denominator := div(denominator, safeScaleDown)
                        // Perform the overflow check a second time.
                        if or(
                            gt(filledNumerator, MaxUint120),
                            gt(denominator, MaxUint120)
                        ) {
                            // Store the Panic error signature.
                            mstore(0, Panic_error_signature)
                            // Set arithmetic (0x11) panic code as initial argument.
                            mstore(Panic_error_offset, Panic_arithmetic)
                            // Return, supplying Panic signature & arithmetic code.
                            revert(0, Panic_error_length)
                        }
                    }
                }
                // Skip overflow check: checked above unless numerator is reduced.
                unchecked {
                    // Update order status and fill amount, packing struct values.
                    orderStatus.isValidated = true;
                    orderStatus.isCancelled = false;
                    orderStatus.numerator = uint120(filledNumerator);
                    orderStatus.denominator = uint120(denominator);
                }
            } else {
                // Update order status and fill amount, packing struct values.
                orderStatus.isValidated = true;
                orderStatus.isCancelled = false;
                orderStatus.numerator = uint120(numerator);
                orderStatus.denominator = uint120(denominator);
            }
            // Return order hash, a modified numerator, and a modified denominator.
            return (orderHash, numerator, denominator);
        }
        /**
         * @dev Internal function to cancel an arbitrary number of orders. Note that
         *      only the offerer or the zone of a given order may cancel it. Callers
         *      should ensure that the intended order was cancelled by calling
         *      `getOrderStatus` and confirming that `isCancelled` returns `true`.
         *
         * @param orders The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders were
         *                   successfully cancelled.
         */
        function _cancel(OrderComponents[] calldata orders)
            internal
            returns (bool cancelled)
        {
            // Ensure that the reentrancy guard is not currently set.
            _assertNonReentrant();
            // Declare variables outside of the loop.
            OrderStatus storage orderStatus;
            address offerer;
            address zone;
            // Skip overflow check as for loop is indexed starting at zero.
            unchecked {
                // Read length of the orders array from memory and place on stack.
                uint256 totalOrders = orders.length;
                // Iterate over each order.
                for (uint256 i = 0; i < totalOrders; ) {
                    // Retrieve the order.
                    OrderComponents calldata order = orders[i];
                    offerer = order.offerer;
                    zone = order.zone;
                    // Ensure caller is either offerer or zone of the order.
                    if (msg.sender != offerer && msg.sender != zone) {
                        revert InvalidCanceller();
                    }
                    // Derive order hash using the order parameters and the counter.
                    bytes32 orderHash = _deriveOrderHash(
                        OrderParameters(
                            offerer,
                            zone,
                            order.offer,
                            order.consideration,
                            order.orderType,
                            order.startTime,
                            order.endTime,
                            order.zoneHash,
                            order.salt,
                            order.conduitKey,
                            order.consideration.length
                        ),
                        order.counter
                    );
                    // Retrieve the order status using the derived order hash.
                    orderStatus = _orderStatus[orderHash];
                    // Update the order status as not valid and cancelled.
                    orderStatus.isValidated = false;
                    orderStatus.isCancelled = true;
                    // Emit an event signifying that the order has been cancelled.
                    emit OrderCancelled(orderHash, offerer, zone);
                    // Increment counter inside body of loop for gas efficiency.
                    ++i;
                }
            }
            // Return a boolean indicating that orders were successfully cancelled.
            cancelled = true;
        }
        /**
         * @dev Internal function to validate an arbitrary number of orders, thereby
         *      registering their signatures as valid and allowing the fulfiller to
         *      skip signature verification on fulfillment. Note that validated
         *      orders may still be unfulfillable due to invalid item amounts or
         *      other factors; callers should determine whether validated orders are
         *      fulfillable by simulating the fulfillment call prior to execution.
         *      Also note that anyone can validate a signed order, but only the
         *      offerer can validate an order without supplying a signature.
         *
         * @param orders The orders to validate.
         *
         * @return validated A boolean indicating whether the supplied orders were
         *                   successfully validated.
         */
        function _validate(Order[] calldata orders)
            internal
            returns (bool validated)
        {
            // Ensure that the reentrancy guard is not currently set.
            _assertNonReentrant();
            // Declare variables outside of the loop.
            OrderStatus storage orderStatus;
            bytes32 orderHash;
            address offerer;
            // Skip overflow check as for loop is indexed starting at zero.
            unchecked {
                // Read length of the orders array from memory and place on stack.
                uint256 totalOrders = orders.length;
                // Iterate over each order.
                for (uint256 i = 0; i < totalOrders; ) {
                    // Retrieve the order.
                    Order calldata order = orders[i];
                    // Retrieve the order parameters.
                    OrderParameters calldata orderParameters = order.parameters;
                    // Move offerer from memory to the stack.
                    offerer = orderParameters.offerer;
                    // Get current counter & use it w/ params to derive order hash.
                    orderHash = _assertConsiderationLengthAndGetOrderHash(
                        orderParameters
                    );
                    // Retrieve the order status using the derived order hash.
                    orderStatus = _orderStatus[orderHash];
                    // Ensure order is fillable and retrieve the filled amount.
                    _verifyOrderStatus(
                        orderHash,
                        orderStatus,
                        false, // Signifies that partially filled orders are valid.
                        true // Signifies to revert if the order is invalid.
                    );
                    // If the order has not already been validated...
                    if (!orderStatus.isValidated) {
                        // Verify the supplied signature.
                        _verifySignature(offerer, orderHash, order.signature);
                        // Update order status to mark the order as valid.
                        orderStatus.isValidated = true;
                        // Emit an event signifying the order has been validated.
                        emit OrderValidated(
                            orderHash,
                            offerer,
                            orderParameters.zone
                        );
                    }
                    // Increment counter inside body of the loop for gas efficiency.
                    ++i;
                }
            }
            // Return a boolean indicating that orders were successfully validated.
            validated = true;
        }
        /**
         * @dev Internal view function to retrieve the status of a given order by
         *      hash, including whether the order has been cancelled or validated
         *      and the fraction of the order that has been filled.
         *
         * @param orderHash The order hash in question.
         *
         * @return isValidated A boolean indicating whether the order in question
         *                     has been validated (i.e. previously approved or
         *                     partially filled).
         * @return isCancelled A boolean indicating whether the order in question
         *                     has been cancelled.
         * @return totalFilled The total portion of the order that has been filled
         *                     (i.e. the "numerator").
         * @return totalSize   The total size of the order that is either filled or
         *                     unfilled (i.e. the "denominator").
         */
        function _getOrderStatus(bytes32 orderHash)
            internal
            view
            returns (
                bool isValidated,
                bool isCancelled,
                uint256 totalFilled,
                uint256 totalSize
            )
        {
            // Retrieve the order status using the order hash.
            OrderStatus storage orderStatus = _orderStatus[orderHash];
            // Return the fields on the order status.
            return (
                orderStatus.isValidated,
                orderStatus.isCancelled,
                orderStatus.numerator,
                orderStatus.denominator
            );
        }
        /**
         * @dev Internal pure function to check whether a given order type indicates
         *      that partial fills are not supported (e.g. only "full fills" are
         *      allowed for the order in question).
         *
         * @param orderType The order type in question.
         *
         * @return isFullOrder A boolean indicating whether the order type only
         *                     supports full fills.
         */
        function _doesNotSupportPartialFills(OrderType orderType)
            internal
            pure
            returns (bool isFullOrder)
        {
            // The "full" order types are even, while "partial" order types are odd.
            // Bitwise and by 1 is equivalent to modulo by 2, but 2 gas cheaper.
            assembly {
                // Equivalent to `uint256(orderType) & 1 == 0`.
                isFullOrder := iszero(and(orderType, 1))
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { ItemType } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        OfferItem,
        ConsiderationItem,
        SpentItem,
        ReceivedItem,
        OrderParameters,
        Order,
        AdvancedOrder,
        CriteriaResolver
    } from "./ConsiderationStructs.sol";
    import { BasicOrderFulfiller } from "./BasicOrderFulfiller.sol";
    import { CriteriaResolution } from "./CriteriaResolution.sol";
    import { AmountDeriver } from "./AmountDeriver.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title OrderFulfiller
     * @author 0age
     * @notice OrderFulfiller contains logic related to order fulfillment where a
     *         single order is being fulfilled and where basic order fulfillment is
     *         not available as an option.
     */
    contract OrderFulfiller is
        BasicOrderFulfiller,
        CriteriaResolution,
        AmountDeriver
    {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController)
            BasicOrderFulfiller(conduitController)
        {}
        /**
         * @dev Internal function to validate an order and update its status, adjust
         *      prices based on current time, apply criteria resolvers, determine
         *      what portion to fill, and transfer relevant tokens.
         *
         * @param advancedOrder       The order to fulfill as well as the fraction
         *                            to fill. Note that all offer and consideration
         *                            components must divide with no remainder for
         *                            the partial fill to be valid.
         * @param criteriaResolvers   An array where each element contains a
         *                            reference to a specific offer or
         *                            consideration, a token identifier, and a proof
         *                            that the supplied token identifier is
         *                            contained in the order's merkle root. Note
         *                            that a criteria of zero indicates that any
         *                            (transferable) token identifier is valid and
         *                            that no proof needs to be supplied.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Consideration.
         * @param recipient           The intended recipient for all received items.
         *
         * @return A boolean indicating whether the order has been fulfilled.
         */
        function _validateAndFulfillAdvancedOrder(
            AdvancedOrder memory advancedOrder,
            CriteriaResolver[] memory criteriaResolvers,
            bytes32 fulfillerConduitKey,
            address recipient
        ) internal returns (bool) {
            // Ensure this function cannot be triggered during a reentrant call.
            _setReentrancyGuard();
            // Declare empty bytes32 array (unused, will remain empty).
            bytes32[] memory priorOrderHashes;
            // Validate order, update status, and determine fraction to fill.
            (
                bytes32 orderHash,
                uint256 fillNumerator,
                uint256 fillDenominator
            ) = _validateOrderAndUpdateStatus(
                    advancedOrder,
                    criteriaResolvers,
                    true,
                    priorOrderHashes
                );
            // Create an array with length 1 containing the order.
            AdvancedOrder[] memory advancedOrders = new AdvancedOrder[](1);
            // Populate the order as the first and only element of the new array.
            advancedOrders[0] = advancedOrder;
            // Apply criteria resolvers using generated orders and details arrays.
            _applyCriteriaResolvers(advancedOrders, criteriaResolvers);
            // Retrieve the order parameters after applying criteria resolvers.
            OrderParameters memory orderParameters = advancedOrders[0].parameters;
            // Perform each item transfer with the appropriate fractional amount.
            _applyFractionsAndTransferEach(
                orderParameters,
                fillNumerator,
                fillDenominator,
                fulfillerConduitKey,
                recipient
            );
            // Emit an event signifying that the order has been fulfilled.
            _emitOrderFulfilledEvent(
                orderHash,
                orderParameters.offerer,
                orderParameters.zone,
                recipient,
                orderParameters.offer,
                orderParameters.consideration
            );
            // Clear the reentrancy guard.
            _clearReentrancyGuard();
            return true;
        }
        /**
         * @dev Internal function to transfer each item contained in a given single
         *      order fulfillment after applying a respective fraction to the amount
         *      being transferred.
         *
         * @param orderParameters     The parameters for the fulfilled order.
         * @param numerator           A value indicating the portion of the order
         *                            that should be filled.
         * @param denominator         A value indicating the total order size.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Consideration.
         * @param recipient           The intended recipient for all received items.
         */
        function _applyFractionsAndTransferEach(
            OrderParameters memory orderParameters,
            uint256 numerator,
            uint256 denominator,
            bytes32 fulfillerConduitKey,
            address recipient
        ) internal {
            // Read start time & end time from order parameters and place on stack.
            uint256 startTime = orderParameters.startTime;
            uint256 endTime = orderParameters.endTime;
            // Initialize an accumulator array. From this point forward, no new
            // memory regions can be safely allocated until the accumulator is no
            // longer being utilized, as the accumulator operates in an open-ended
            // fashion from this memory pointer; existing memory may still be
            // accessed and modified, however.
            bytes memory accumulator = new bytes(AccumulatorDisarmed);
            // As of solidity 0.6.0, inline assembly cannot directly access function
            // definitions, but can still access locally scoped function variables.
            // This means that in order to recast the type of a function, we need to
            // create a local variable to reference the internal function definition
            // (using the same type) and a local variable with the desired type,
            // and then cast the original function pointer to the desired type.
            /**
             * Repurpose existing OfferItem memory regions on the offer array for
             * the order by overriding the _transfer function pointer to accept a
             * modified OfferItem argument in place of the usual ReceivedItem:
             *
             *   ========= OfferItem ==========   ====== ReceivedItem ======
             *   ItemType itemType; ------------> ItemType itemType;
             *   address token; ----------------> address token;
             *   uint256 identifierOrCriteria; -> uint256 identifier;
             *   uint256 startAmount; ----------> uint256 amount;
             *   uint256 endAmount; ------------> address recipient;
             */
            // Declare a nested scope to minimize stack depth.
            unchecked {
                // Declare a virtual function pointer taking an OfferItem argument.
                function(OfferItem memory, address, bytes32, bytes memory)
                    internal _transferOfferItem;
                {
                    // Assign _transfer function to a new function pointer (it takes
                    // a ReceivedItem as its initial argument)
                    function(ReceivedItem memory, address, bytes32, bytes memory)
                        internal _transferReceivedItem = _transfer;
                    // Utilize assembly to override the virtual function pointer.
                    assembly {
                        // Cast initial ReceivedItem type to an OfferItem type.
                        _transferOfferItem := _transferReceivedItem
                    }
                }
                // Read offer array length from memory and place on stack.
                uint256 totalOfferItems = orderParameters.offer.length;
                // Iterate over each offer on the order.
                // Skip overflow check as for loop is indexed starting at zero.
                for (uint256 i = 0; i < totalOfferItems; ++i) {
                    // Retrieve the offer item.
                    OfferItem memory offerItem = orderParameters.offer[i];
                    // Offer items for the native token can not be received
                    // outside of a match order function.
                    if (offerItem.itemType == ItemType.NATIVE) {
                        revert InvalidNativeOfferItem();
                    }
                    // Declare an additional nested scope to minimize stack depth.
                    {
                        // Apply fill fraction to get offer item amount to transfer.
                        uint256 amount = _applyFraction(
                            offerItem.startAmount,
                            offerItem.endAmount,
                            numerator,
                            denominator,
                            startTime,
                            endTime,
                            false
                        );
                        // Utilize assembly to set overloaded offerItem arguments.
                        assembly {
                            // Write new fractional amount to startAmount as amount.
                            mstore(
                                add(offerItem, ReceivedItem_amount_offset),
                                amount
                            )
                            // Write recipient to endAmount.
                            mstore(
                                add(offerItem, ReceivedItem_recipient_offset),
                                recipient
                            )
                        }
                    }
                    // Transfer the item from the offerer to the recipient.
                    _transferOfferItem(
                        offerItem,
                        orderParameters.offerer,
                        orderParameters.conduitKey,
                        accumulator
                    );
                }
            }
            // Put ether value supplied by the caller on the stack.
            uint256 etherRemaining = msg.value;
            /**
             * Repurpose existing ConsiderationItem memory regions on the
             * consideration array for the order by overriding the _transfer
             * function pointer to accept a modified ConsiderationItem argument in
             * place of the usual ReceivedItem:
             *
             *   ====== ConsiderationItem =====   ====== ReceivedItem ======
             *   ItemType itemType; ------------> ItemType itemType;
             *   address token; ----------------> address token;
             *   uint256 identifierOrCriteria;--> uint256 identifier;
             *   uint256 startAmount; ----------> uint256 amount;
             *   uint256 endAmount;        /----> address recipient;
             *   address recipient; ------/
             */
            // Declare a nested scope to minimize stack depth.
            unchecked {
                // Declare virtual function pointer with ConsiderationItem argument.
                function(ConsiderationItem memory, address, bytes32, bytes memory)
                    internal _transferConsiderationItem;
                {
                    // Reassign _transfer function to a new function pointer (it
                    // takes a ReceivedItem as its initial argument).
                    function(ReceivedItem memory, address, bytes32, bytes memory)
                        internal _transferReceivedItem = _transfer;
                    // Utilize assembly to override the virtual function pointer.
                    assembly {
                        // Cast ReceivedItem type to ConsiderationItem type.
                        _transferConsiderationItem := _transferReceivedItem
                    }
                }
                // Read consideration array length from memory and place on stack.
                uint256 totalConsiderationItems = orderParameters
                    .consideration
                    .length;
                // Iterate over each consideration item on the order.
                // Skip overflow check as for loop is indexed starting at zero.
                for (uint256 i = 0; i < totalConsiderationItems; ++i) {
                    // Retrieve the consideration item.
                    ConsiderationItem memory considerationItem = (
                        orderParameters.consideration[i]
                    );
                    // Apply fraction & derive considerationItem amount to transfer.
                    uint256 amount = _applyFraction(
                        considerationItem.startAmount,
                        considerationItem.endAmount,
                        numerator,
                        denominator,
                        startTime,
                        endTime,
                        true
                    );
                    // Use assembly to set overloaded considerationItem arguments.
                    assembly {
                        // Write derived fractional amount to startAmount as amount.
                        mstore(
                            add(considerationItem, ReceivedItem_amount_offset),
                            amount
                        )
                        // Write original recipient to endAmount as recipient.
                        mstore(
                            add(considerationItem, ReceivedItem_recipient_offset),
                            mload(
                                add(
                                    considerationItem,
                                    ConsiderationItem_recipient_offset
                                )
                            )
                        )
                    }
                    // Reduce available value if offer spent ETH or a native token.
                    if (considerationItem.itemType == ItemType.NATIVE) {
                        // Ensure that sufficient native tokens are still available.
                        if (amount > etherRemaining) {
                            revert InsufficientEtherSupplied();
                        }
                        // Skip underflow check as a comparison has just been made.
                        etherRemaining -= amount;
                    }
                    // Transfer item from caller to recipient specified by the item.
                    _transferConsiderationItem(
                        considerationItem,
                        msg.sender,
                        fulfillerConduitKey,
                        accumulator
                    );
                }
            }
            // Trigger any remaining accumulated transfers via call to the conduit.
            _triggerIfArmed(accumulator);
            // If any ether remains after fulfillments...
            if (etherRemaining != 0) {
                // return it to the caller.
                _transferEth(payable(msg.sender), etherRemaining);
            }
        }
        /**
         * @dev Internal function to emit an OrderFulfilled event. OfferItems are
         *      translated into SpentItems and ConsiderationItems are translated
         *      into ReceivedItems.
         *
         * @param orderHash     The order hash.
         * @param offerer       The offerer for the order.
         * @param zone          The zone for the order.
         * @param fulfiller     The fulfiller of the order, or the null address if
         *                      the order was fulfilled via order matching.
         * @param offer         The offer items for the order.
         * @param consideration The consideration items for the order.
         */
        function _emitOrderFulfilledEvent(
            bytes32 orderHash,
            address offerer,
            address zone,
            address fulfiller,
            OfferItem[] memory offer,
            ConsiderationItem[] memory consideration
        ) internal {
            // Cast already-modified offer memory region as spent items.
            SpentItem[] memory spentItems;
            assembly {
                spentItems := offer
            }
            // Cast already-modified consideration memory region as received items.
            ReceivedItem[] memory receivedItems;
            assembly {
                receivedItems := consideration
            }
            // Emit an event signifying that the order has been fulfilled.
            emit OrderFulfilled(
                orderHash,
                offerer,
                zone,
                fulfiller,
                spentItems,
                receivedItems
            );
        }
        /**
         * @dev Internal pure function to convert an order to an advanced order with
         *      numerator and denominator of 1 and empty extraData.
         *
         * @param order The order to convert.
         *
         * @return advancedOrder The new advanced order.
         */
        function _convertOrderToAdvanced(Order calldata order)
            internal
            pure
            returns (AdvancedOrder memory advancedOrder)
        {
            // Convert to partial order (1/1 or full fill) and return new value.
            advancedOrder = AdvancedOrder(
                order.parameters,
                1,
                1,
                order.signature,
                ""
            );
        }
        /**
         * @dev Internal pure function to convert an array of orders to an array of
         *      advanced orders with numerator and denominator of 1.
         *
         * @param orders The orders to convert.
         *
         * @return advancedOrders The new array of partial orders.
         */
        function _convertOrdersToAdvanced(Order[] calldata orders)
            internal
            pure
            returns (AdvancedOrder[] memory advancedOrders)
        {
            // Read the number of orders from calldata and place on the stack.
            uint256 totalOrders = orders.length;
            // Allocate new empty array for each partial order in memory.
            advancedOrders = new AdvancedOrder[](totalOrders);
            // Skip overflow check as the index for the loop starts at zero.
            unchecked {
                // Iterate over the given orders.
                for (uint256 i = 0; i < totalOrders; ++i) {
                    // Convert to partial order (1/1 or full fill) and update array.
                    advancedOrders[i] = _convertOrderToAdvanced(orders[i]);
                }
            }
            // Return the array of advanced orders.
            return advancedOrders;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    // prettier-ignore
    import {
        AmountDerivationErrors
    } from "../interfaces/AmountDerivationErrors.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title AmountDeriver
     * @author 0age
     * @notice AmountDeriver contains view and pure functions related to deriving
     *         item amounts based on partial fill quantity and on linear
     *         interpolation based on current time when the start amount and end
     *         amount differ.
     */
    contract AmountDeriver is AmountDerivationErrors {
        /**
         * @dev Internal view function to derive the current amount of a given item
         *      based on the current price, the starting price, and the ending
         *      price. If the start and end prices differ, the current price will be
         *      interpolated on a linear basis. Note that this function expects that
         *      the startTime parameter of orderParameters is not greater than the
         *      current block timestamp and that the endTime parameter is greater
         *      than the current block timestamp. If this condition is not upheld,
         *      duration / elapsed / remaining variables will underflow.
         *
         * @param startAmount The starting amount of the item.
         * @param endAmount   The ending amount of the item.
         * @param startTime   The starting time of the order.
         * @param endTime     The end time of the order.
         * @param roundUp     A boolean indicating whether the resultant amount
         *                    should be rounded up or down.
         *
         * @return amount The current amount.
         */
        function _locateCurrentAmount(
            uint256 startAmount,
            uint256 endAmount,
            uint256 startTime,
            uint256 endTime,
            bool roundUp
        ) internal view returns (uint256 amount) {
            // Only modify end amount if it doesn't already equal start amount.
            if (startAmount != endAmount) {
                // Declare variables to derive in the subsequent unchecked scope.
                uint256 duration;
                uint256 elapsed;
                uint256 remaining;
                // Skip underflow checks as startTime <= block.timestamp < endTime.
                unchecked {
                    // Derive the duration for the order and place it on the stack.
                    duration = endTime - startTime;
                    // Derive time elapsed since the order started & place on stack.
                    elapsed = block.timestamp - startTime;
                    // Derive time remaining until order expires and place on stack.
                    remaining = duration - elapsed;
                }
                // Aggregate new amounts weighted by time with rounding factor.
                uint256 totalBeforeDivision = ((startAmount * remaining) +
                    (endAmount * elapsed));
                // Use assembly to combine operations and skip divide-by-zero check.
                assembly {
                    // Multiply by iszero(iszero(totalBeforeDivision)) to ensure
                    // amount is set to zero if totalBeforeDivision is zero,
                    // as intermediate overflow can occur if it is zero.
                    amount := mul(
                        iszero(iszero(totalBeforeDivision)),
                        // Subtract 1 from the numerator and add 1 to the result if
                        // roundUp is true to get the proper rounding direction.
                        // Division is performed with no zero check as duration
                        // cannot be zero as long as startTime < endTime.
                        add(
                            div(sub(totalBeforeDivision, roundUp), duration),
                            roundUp
                        )
                    )
                }
                // Return the current amount.
                return amount;
            }
            // Return the original amount as startAmount == endAmount.
            return endAmount;
        }
        /**
         * @dev Internal pure function to return a fraction of a given value and to
         *      ensure the resultant value does not have any fractional component.
         *      Note that this function assumes that zero will never be supplied as
         *      the denominator parameter; invalid / undefined behavior will result
         *      should a denominator of zero be provided.
         *
         * @param numerator   A value indicating the portion of the order that
         *                    should be filled.
         * @param denominator A value indicating the total size of the order. Note
         *                    that this value cannot be equal to zero.
         * @param value       The value for which to compute the fraction.
         *
         * @return newValue The value after applying the fraction.
         */
        function _getFraction(
            uint256 numerator,
            uint256 denominator,
            uint256 value
        ) internal pure returns (uint256 newValue) {
            // Return value early in cases where the fraction resolves to 1.
            if (numerator == denominator) {
                return value;
            }
            // Ensure fraction can be applied to the value with no remainder. Note
            // that the denominator cannot be zero.
            assembly {
                // Ensure new value contains no remainder via mulmod operator.
                // Credit to @hrkrshnn + @axic for proposing this optimal solution.
                if mulmod(value, numerator, denominator) {
                    mstore(0, InexactFraction_error_signature)
                    revert(0, InexactFraction_error_len)
                }
            }
            // Multiply the numerator by the value and ensure no overflow occurs.
            uint256 valueTimesNumerator = value * numerator;
            // Divide and check for remainder. Note that denominator cannot be zero.
            assembly {
                // Perform division without zero check.
                newValue := div(valueTimesNumerator, denominator)
            }
        }
        /**
         * @dev Internal view function to apply a fraction to a consideration
         * or offer item.
         *
         * @param startAmount     The starting amount of the item.
         * @param endAmount       The ending amount of the item.
         * @param numerator       A value indicating the portion of the order that
         *                        should be filled.
         * @param denominator     A value indicating the total size of the order.
         * @param startTime       The starting time of the order.
         * @param endTime         The end time of the order.
         * @param roundUp         A boolean indicating whether the resultant
         *                        amount should be rounded up or down.
         *
         * @return amount The received item to transfer with the final amount.
         */
        function _applyFraction(
            uint256 startAmount,
            uint256 endAmount,
            uint256 numerator,
            uint256 denominator,
            uint256 startTime,
            uint256 endTime,
            bool roundUp
        ) internal view returns (uint256 amount) {
            // If start amount equals end amount, apply fraction to end amount.
            if (startAmount == endAmount) {
                // Apply fraction to end amount.
                amount = _getFraction(numerator, denominator, endAmount);
            } else {
                // Otherwise, apply fraction to both and interpolated final amount.
                amount = _locateCurrentAmount(
                    _getFraction(numerator, denominator, startAmount),
                    _getFraction(numerator, denominator, endAmount),
                    startTime,
                    endTime,
                    roundUp
                );
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title AmountDerivationErrors
     * @author 0age
     * @notice AmountDerivationErrors contains errors related to amount derivation.
     */
    interface AmountDerivationErrors {
        /**
         * @dev Revert with an error when attempting to apply a fraction as part of
         *      a partial fill that does not divide the target amount cleanly.
         */
        error InexactFraction();
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    import { Side, ItemType } from "./ConsiderationEnums.sol";
    // prettier-ignore
    import {
        OfferItem,
        ConsiderationItem,
        ReceivedItem,
        OrderParameters,
        Fulfillment,
        FulfillmentComponent,
        Execution,
        Order,
        AdvancedOrder,
        CriteriaResolver
    } from "./ConsiderationStructs.sol";
    import { OrderFulfiller } from "./OrderFulfiller.sol";
    import { FulfillmentApplier } from "./FulfillmentApplier.sol";
    import "./ConsiderationConstants.sol";
    /**
     * @title OrderCombiner
     * @author 0age
     * @notice OrderCombiner contains logic for fulfilling combinations of orders,
     *         either by matching offer items to consideration items or by
     *         fulfilling orders where available.
     */
    contract OrderCombiner is OrderFulfiller, FulfillmentApplier {
        /**
         * @dev Derive and set hashes, reference chainId, and associated domain
         *      separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) OrderFulfiller(conduitController) {}
        /**
         * @notice Internal function to attempt to fill a group of orders, fully or
         *         partially, with an arbitrary number of items for offer and
         *         consideration per order alongside criteria resolvers containing
         *         specific token identifiers and associated proofs. Any order that
         *         is not currently active, has already been fully filled, or has
         *         been cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or a conduit if indicated by
         *                                  the order) to transfer any relevant
         *                                  tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` in order to receive
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param criteriaResolvers         An array where each element contains a
         *                                  reference to a specific offer or
         *                                  consideration, a token identifier, and a
         *                                  proof that the supplied token identifier
         *                                  is contained in the merkle root held by
         *                                  the item in question's criteria element.
         *                                  Note that an empty criteria indicates
         *                                  that any (transferable) token
         *                                  identifier on the token in question is
         *                                  valid and that no associated proof needs
         *                                  to be supplied.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used (and
         *                                  direct approvals set on Consideration).
         * @param recipient                 The intended recipient for all received
         *                                  items.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function _fulfillAvailableAdvancedOrders(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] memory criteriaResolvers,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            address recipient,
            uint256 maximumFulfilled
        )
            internal
            returns (bool[] memory availableOrders, Execution[] memory executions)
        {
            // Validate orders, apply amounts, & determine if they utilize conduits.
            _validateOrdersAndPrepareToFulfill(
                advancedOrders,
                criteriaResolvers,
                false, // Signifies that invalid orders should NOT revert.
                maximumFulfilled,
                recipient
            );
            // Aggregate used offer and consideration items and execute transfers.
            (availableOrders, executions) = _executeAvailableFulfillments(
                advancedOrders,
                offerFulfillments,
                considerationFulfillments,
                fulfillerConduitKey,
                recipient
            );
            // Return order fulfillment details and executions.
            return (availableOrders, executions);
        }
        /**
         * @dev Internal function to validate a group of orders, update their
         *      statuses, reduce amounts by their previously filled fractions, apply
         *      criteria resolvers, and emit OrderFulfilled events.
         *
         * @param advancedOrders    The advanced orders to validate and reduce by
         *                          their previously filled amounts.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          a root of zero indicates that any transferable
         *                          token identifier is valid and that no proof
         *                          needs to be supplied.
         * @param revertOnInvalid   A boolean indicating whether to revert on any
         *                          order being invalid; setting this to false will
         *                          instead cause the invalid order to be skipped.
         * @param maximumFulfilled  The maximum number of orders to fulfill.
         * @param recipient         The intended recipient for all received items.
         */
        function _validateOrdersAndPrepareToFulfill(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] memory criteriaResolvers,
            bool revertOnInvalid,
            uint256 maximumFulfilled,
            address recipient
        ) internal {
            // Ensure this function cannot be triggered during a reentrant call.
            _setReentrancyGuard();
            // Read length of orders array and place on the stack.
            uint256 totalOrders = advancedOrders.length;
            // Track the order hash for each order being fulfilled.
            bytes32[] memory orderHashes = new bytes32[](totalOrders);
            // Override orderHashes length to zero after memory has been allocated.
            assembly {
                mstore(orderHashes, 0)
            }
            // Declare an error buffer indicating status of any native offer items.
            // {00} == 0 => In a match function, no native offer items: allow.
            // {01} == 1 => In a match function, some native offer items: allow.
            // {10} == 2 => Not in a match function, no native offer items: allow.
            // {11} == 3 => Not in a match function, some native offer items: THROW.
            uint256 invalidNativeOfferItemErrorBuffer;
            // Use assembly to set the value for the second bit of the error buffer.
            assembly {
                // Use the second bit of the error buffer to indicate whether the
                // current function is not matchAdvancedOrders or matchOrders.
                invalidNativeOfferItemErrorBuffer := shl(
                    1,
                    gt(
                        // Take the remainder of the selector modulo a magic value.
                        mod(
                            shr(NumBitsAfterSelector, calldataload(0)),
                            NonMatchSelector_MagicModulus
                        ),
                        // Check if remainder is higher than the greatest remainder
                        // of the two match selectors modulo the magic value.
                        NonMatchSelector_MagicRemainder
                    )
                )
            }
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Iterate over each order.
                for (uint256 i = 0; i < totalOrders; ++i) {
                    // Retrieve the current order.
                    AdvancedOrder memory advancedOrder = advancedOrders[i];
                    // Determine if max number orders have already been fulfilled.
                    if (maximumFulfilled == 0) {
                        // Mark fill fraction as zero as the order will not be used.
                        advancedOrder.numerator = 0;
                        // Update the length of the orderHashes array.
                        assembly {
                            mstore(orderHashes, add(i, 1))
                        }
                        // Continue iterating through the remaining orders.
                        continue;
                    }
                    // Validate it, update status, and determine fraction to fill.
                    (
                        bytes32 orderHash,
                        uint256 numerator,
                        uint256 denominator
                    ) = _validateOrderAndUpdateStatus(
                            advancedOrder,
                            criteriaResolvers,
                            revertOnInvalid,
                            orderHashes
                        );
                    // Update the length of the orderHashes array.
                    assembly {
                        mstore(orderHashes, add(i, 1))
                    }
                    // Do not track hash or adjust prices if order is not fulfilled.
                    if (numerator == 0) {
                        // Mark fill fraction as zero if the order is not fulfilled.
                        advancedOrder.numerator = 0;
                        // Continue iterating through the remaining orders.
                        continue;
                    }
                    // Otherwise, track the order hash in question.
                    orderHashes[i] = orderHash;
                    // Decrement the number of fulfilled orders.
                    // Skip underflow check as the condition before
                    // implies that maximumFulfilled > 0.
                    maximumFulfilled--;
                    // Place the start time for the order on the stack.
                    uint256 startTime = advancedOrder.parameters.startTime;
                    // Place the end time for the order on the stack.
                    uint256 endTime = advancedOrder.parameters.endTime;
                    // Retrieve array of offer items for the order in question.
                    OfferItem[] memory offer = advancedOrder.parameters.offer;
                    // Read length of offer array and place on the stack.
                    uint256 totalOfferItems = offer.length;
                    // Iterate over each offer item on the order.
                    for (uint256 j = 0; j < totalOfferItems; ++j) {
                        // Retrieve the offer item.
                        OfferItem memory offerItem = offer[j];
                        assembly {
                            // If the offer item is for the native token, set the
                            // first bit of the error buffer to true.
                            invalidNativeOfferItemErrorBuffer := or(
                                invalidNativeOfferItemErrorBuffer,
                                iszero(mload(offerItem))
                            )
                        }
                        // Apply order fill fraction to offer item end amount.
                        uint256 endAmount = _getFraction(
                            numerator,
                            denominator,
                            offerItem.endAmount
                        );
                        // Reuse same fraction if start and end amounts are equal.
                        if (offerItem.startAmount == offerItem.endAmount) {
                            // Apply derived amount to both start and end amount.
                            offerItem.startAmount = endAmount;
                        } else {
                            // Apply order fill fraction to offer item start amount.
                            offerItem.startAmount = _getFraction(
                                numerator,
                                denominator,
                                offerItem.startAmount
                            );
                        }
                        // Update end amount in memory to match the derived amount.
                        offerItem.endAmount = endAmount;
                        // Adjust offer amount using current time; round down.
                        offerItem.startAmount = _locateCurrentAmount(
                            offerItem.startAmount,
                            offerItem.endAmount,
                            startTime,
                            endTime,
                            false // round down
                        );
                    }
                    // Retrieve array of consideration items for order in question.
                    ConsiderationItem[] memory consideration = (
                        advancedOrder.parameters.consideration
                    );
                    // Read length of consideration array and place on the stack.
                    uint256 totalConsiderationItems = consideration.length;
                    // Iterate over each consideration item on the order.
                    for (uint256 j = 0; j < totalConsiderationItems; ++j) {
                        // Retrieve the consideration item.
                        ConsiderationItem memory considerationItem = (
                            consideration[j]
                        );
                        // Apply fraction to consideration item end amount.
                        uint256 endAmount = _getFraction(
                            numerator,
                            denominator,
                            considerationItem.endAmount
                        );
                        // Reuse same fraction if start and end amounts are equal.
                        if (
                            considerationItem.startAmount ==
                            considerationItem.endAmount
                        ) {
                            // Apply derived amount to both start and end amount.
                            considerationItem.startAmount = endAmount;
                        } else {
                            // Apply fraction to consideration item start amount.
                            considerationItem.startAmount = _getFraction(
                                numerator,
                                denominator,
                                considerationItem.startAmount
                            );
                        }
                        // Update end amount in memory to match the derived amount.
                        considerationItem.endAmount = endAmount;
                        // Adjust consideration amount using current time; round up.
                        considerationItem.startAmount = (
                            _locateCurrentAmount(
                                considerationItem.startAmount,
                                considerationItem.endAmount,
                                startTime,
                                endTime,
                                true // round up
                            )
                        );
                        // Utilize assembly to manually "shift" the recipient value.
                        assembly {
                            // Write recipient to endAmount, as endAmount is not
                            // used from this point on and can be repurposed to fit
                            // the layout of a ReceivedItem.
                            mstore(
                                add(
                                    considerationItem,
                                    ReceivedItem_recipient_offset // old endAmount
                                ),
                                mload(
                                    add(
                                        considerationItem,
                                        ConsiderationItem_recipient_offset
                                    )
                                )
                            )
                        }
                    }
                }
            }
            // If the first bit is set, a native offer item was encountered. If the
            // second bit is set in the error buffer, the current function is not
            // matchOrders or matchAdvancedOrders. If the value is three, both the
            // first and second bits were set; in that case, revert with an error.
            if (invalidNativeOfferItemErrorBuffer == 3) {
                revert InvalidNativeOfferItem();
            }
            // Apply criteria resolvers to each order as applicable.
            _applyCriteriaResolvers(advancedOrders, criteriaResolvers);
            // Emit an event for each order signifying that it has been fulfilled.
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Iterate over each order.
                for (uint256 i = 0; i < totalOrders; ++i) {
                    // Do not emit an event if no order hash is present.
                    if (orderHashes[i] == bytes32(0)) {
                        continue;
                    }
                    // Retrieve parameters for the order in question.
                    OrderParameters memory orderParameters = (
                        advancedOrders[i].parameters
                    );
                    // Emit an OrderFulfilled event.
                    _emitOrderFulfilledEvent(
                        orderHashes[i],
                        orderParameters.offerer,
                        orderParameters.zone,
                        recipient,
                        orderParameters.offer,
                        orderParameters.consideration
                    );
                }
            }
        }
        /**
         * @dev Internal function to fulfill a group of validated orders, fully or
         *      partially, with an arbitrary number of items for offer and
         *      consideration per order and to execute transfers. Any order that is
         *      not currently active, has already been fully filled, or has been
         *      cancelled will be omitted. Remaining offer and consideration items
         *      will then be aggregated where possible as indicated by the supplied
         *      offer and consideration component arrays and aggregated items will
         *      be transferred to the fulfiller or to each intended recipient,
         *      respectively. Note that a failing item transfer or an issue with
         *      order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or the conduit if indicated by
         *                                  the order) to transfer any relevant
         *                                  tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` in order to receive
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on Consideration.
         * @param recipient                 The intended recipient for all received
         *                                  items.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function _executeAvailableFulfillments(
            AdvancedOrder[] memory advancedOrders,
            FulfillmentComponent[][] memory offerFulfillments,
            FulfillmentComponent[][] memory considerationFulfillments,
            bytes32 fulfillerConduitKey,
            address recipient
        )
            internal
            returns (bool[] memory availableOrders, Execution[] memory executions)
        {
            // Retrieve length of offer fulfillments array and place on the stack.
            uint256 totalOfferFulfillments = offerFulfillments.length;
            // Retrieve length of consideration fulfillments array & place on stack.
            uint256 totalConsiderationFulfillments = (
                considerationFulfillments.length
            );
            // Allocate an execution for each offer and consideration fulfillment.
            executions = new Execution[](
                totalOfferFulfillments + totalConsiderationFulfillments
            );
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Track number of filtered executions.
                uint256 totalFilteredExecutions = 0;
                // Iterate over each offer fulfillment.
                for (uint256 i = 0; i < totalOfferFulfillments; ++i) {
                    /// Retrieve the offer fulfillment components in question.
                    FulfillmentComponent[] memory components = (
                        offerFulfillments[i]
                    );
                    // Derive aggregated execution corresponding with fulfillment.
                    Execution memory execution = _aggregateAvailable(
                        advancedOrders,
                        Side.OFFER,
                        components,
                        fulfillerConduitKey,
                        recipient
                    );
                    // If offerer and recipient on the execution are the same...
                    if (execution.item.recipient == execution.offerer) {
                        // Increment total filtered executions.
                        ++totalFilteredExecutions;
                    } else {
                        // Otherwise, assign the execution to the executions array.
                        executions[i - totalFilteredExecutions] = execution;
                    }
                }
                // Iterate over each consideration fulfillment.
                for (uint256 i = 0; i < totalConsiderationFulfillments; ++i) {
                    /// Retrieve consideration fulfillment components in question.
                    FulfillmentComponent[] memory components = (
                        considerationFulfillments[i]
                    );
                    // Derive aggregated execution corresponding with fulfillment.
                    Execution memory execution = _aggregateAvailable(
                        advancedOrders,
                        Side.CONSIDERATION,
                        components,
                        fulfillerConduitKey,
                        address(0) // unused
                    );
                    // If offerer and recipient on the execution are the same...
                    if (execution.item.recipient == execution.offerer) {
                        // Increment total filtered executions.
                        ++totalFilteredExecutions;
                    } else {
                        // Otherwise, assign the execution to the executions array.
                        executions[
                            i + totalOfferFulfillments - totalFilteredExecutions
                        ] = execution;
                    }
                }
                // If some number of executions have been filtered...
                if (totalFilteredExecutions != 0) {
                    // reduce the total length of the executions array.
                    assembly {
                        mstore(
                            executions,
                            sub(mload(executions), totalFilteredExecutions)
                        )
                    }
                }
            }
            // Revert if no orders are available.
            if (executions.length == 0) {
                revert NoSpecifiedOrdersAvailable();
            }
            // Perform final checks and return.
            availableOrders = _performFinalChecksAndExecuteOrders(
                advancedOrders,
                executions
            );
            return (availableOrders, executions);
        }
        /**
         * @dev Internal function to perform a final check that each consideration
         *      item for an arbitrary number of fulfilled orders has been met and to
         *      trigger associated executions, transferring the respective items.
         *
         * @param advancedOrders     The orders to check and perform executions for.
         * @param executions         An array of elements indicating the sequence of
         *                           transfers to perform when fulfilling the given
         *                           orders.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         */
        function _performFinalChecksAndExecuteOrders(
            AdvancedOrder[] memory advancedOrders,
            Execution[] memory executions
        ) internal returns (bool[] memory availableOrders) {
            // Retrieve the length of the advanced orders array and place on stack.
            uint256 totalOrders = advancedOrders.length;
            // Initialize array for tracking available orders.
            availableOrders = new bool[](totalOrders);
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Iterate over orders to ensure all considerations are met.
                for (uint256 i = 0; i < totalOrders; ++i) {
                    // Retrieve the order in question.
                    AdvancedOrder memory advancedOrder = advancedOrders[i];
                    // Skip consideration item checks for order if not fulfilled.
                    if (advancedOrder.numerator == 0) {
                        // Note: orders do not need to be marked as unavailable as a
                        // new memory region has been allocated. Review carefully if
                        // altering compiler version or managing memory manually.
                        continue;
                    }
                    // Mark the order as available.
                    availableOrders[i] = true;
                    // Retrieve consideration items to ensure they are fulfilled.
                    ConsiderationItem[] memory consideration = (
                        advancedOrder.parameters.consideration
                    );
                    // Read length of consideration array and place on the stack.
                    uint256 totalConsiderationItems = consideration.length;
                    // Iterate over each consideration item to ensure it is met.
                    for (uint256 j = 0; j < totalConsiderationItems; ++j) {
                        // Retrieve remaining amount on the consideration item.
                        uint256 unmetAmount = consideration[j].startAmount;
                        // Revert if the remaining amount is not zero.
                        if (unmetAmount != 0) {
                            revert ConsiderationNotMet(i, j, unmetAmount);
                        }
                    }
                }
            }
            // Put ether value supplied by the caller on the stack.
            uint256 etherRemaining = msg.value;
            // Initialize an accumulator array. From this point forward, no new
            // memory regions can be safely allocated until the accumulator is no
            // longer being utilized, as the accumulator operates in an open-ended
            // fashion from this memory pointer; existing memory may still be
            // accessed and modified, however.
            bytes memory accumulator = new bytes(AccumulatorDisarmed);
            // Retrieve the length of the executions array and place on stack.
            uint256 totalExecutions = executions.length;
            // Iterate over each execution.
            for (uint256 i = 0; i < totalExecutions; ) {
                // Retrieve the execution and the associated received item.
                Execution memory execution = executions[i];
                ReceivedItem memory item = execution.item;
                // If execution transfers native tokens, reduce value available.
                if (item.itemType == ItemType.NATIVE) {
                    // Ensure that sufficient native tokens are still available.
                    if (item.amount > etherRemaining) {
                        revert InsufficientEtherSupplied();
                    }
                    // Skip underflow check as amount is less than ether remaining.
                    unchecked {
                        etherRemaining -= item.amount;
                    }
                }
                // Transfer the item specified by the execution.
                _transfer(
                    item,
                    execution.offerer,
                    execution.conduitKey,
                    accumulator
                );
                // Skip overflow check as for loop is indexed starting at zero.
                unchecked {
                    ++i;
                }
            }
            // Trigger any remaining accumulated transfers via call to the conduit.
            _triggerIfArmed(accumulator);
            // If any ether remains after fulfillments, return it to the caller.
            if (etherRemaining != 0) {
                _transferEth(payable(msg.sender), etherRemaining);
            }
            // Clear the reentrancy guard.
            _clearReentrancyGuard();
            // Return the array containing available orders.
            return (availableOrders);
        }
        /**
         * @dev Internal function to match an arbitrary number of full or partial
         *      orders, each with an arbitrary number of items for offer and
         *      consideration, supplying criteria resolvers containing specific
         *      token identifiers and associated proofs as well as fulfillments
         *      allocating offer components to consideration components.
         *
         * @param advancedOrders    The advanced orders to match. Note that both the
         *                          offerer and fulfiller on each order must first
         *                          approve this contract (or their conduit if
         *                          indicated by the order) to transfer any relevant
         *                          tokens on their behalf and each consideration
         *                          recipient must implement `onERC1155Received` in
         *                          order to receive ERC1155 tokens. Also note that
         *                          the offer and consideration components for each
         *                          order must have no remainder after multiplying
         *                          the respective amount with the supplied fraction
         *                          in order for the group of partial fills to be
         *                          considered valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          an empty root indicates that any (transferable)
         *                          token identifier is valid and that no associated
         *                          proof needs to be supplied.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function _matchAdvancedOrders(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] memory criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) internal returns (Execution[] memory executions) {
            // Validate orders, update order status, and determine item amounts.
            _validateOrdersAndPrepareToFulfill(
                advancedOrders,
                criteriaResolvers,
                true, // Signifies that invalid orders should revert.
                advancedOrders.length,
                address(0) // OrderFulfilled event has no recipient when matching.
            );
            // Fulfill the orders using the supplied fulfillments.
            return _fulfillAdvancedOrders(advancedOrders, fulfillments);
        }
        /**
         * @dev Internal function to fulfill an arbitrary number of orders, either
         *      full or partial, after validating, adjusting amounts, and applying
         *      criteria resolvers.
         *
         * @param advancedOrders     The orders to match, including a fraction to
         *                           attempt to fill for each order.
         * @param fulfillments       An array of elements allocating offer
         *                           components to consideration components. Note
         *                           that the final amount of each consideration
         *                           component must be zero for a match operation to
         *                           be considered valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function _fulfillAdvancedOrders(
            AdvancedOrder[] memory advancedOrders,
            Fulfillment[] calldata fulfillments
        ) internal returns (Execution[] memory executions) {
            // Retrieve fulfillments array length and place on the stack.
            uint256 totalFulfillments = fulfillments.length;
            // Allocate executions by fulfillment and apply them to each execution.
            executions = new Execution[](totalFulfillments);
            // Skip overflow checks as all for loops are indexed starting at zero.
            unchecked {
                // Track number of filtered executions.
                uint256 totalFilteredExecutions = 0;
                // Iterate over each fulfillment.
                for (uint256 i = 0; i < totalFulfillments; ++i) {
                    /// Retrieve the fulfillment in question.
                    Fulfillment calldata fulfillment = fulfillments[i];
                    // Derive the execution corresponding with the fulfillment.
                    Execution memory execution = _applyFulfillment(
                        advancedOrders,
                        fulfillment.offerComponents,
                        fulfillment.considerationComponents
                    );
                    // If offerer and recipient on the execution are the same...
                    if (execution.item.recipient == execution.offerer) {
                        // Increment total filtered executions.
                        ++totalFilteredExecutions;
                    } else {
                        // Otherwise, assign the execution to the executions array.
                        executions[i - totalFilteredExecutions] = execution;
                    }
                }
                // If some number of executions have been filtered...
                if (totalFilteredExecutions != 0) {
                    // reduce the total length of the executions array.
                    assembly {
                        mstore(
                            executions,
                            sub(mload(executions), totalFilteredExecutions)
                        )
                    }
                }
            }
            // Perform final checks and execute orders.
            _performFinalChecksAndExecuteOrders(advancedOrders, executions);
            // Return the executions array.
            return (executions);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.13;
    // prettier-ignore
    import {
        ConsiderationInterface
    } from "../interfaces/ConsiderationInterface.sol";
    // prettier-ignore
    import {
        OrderComponents,
        BasicOrderParameters,
        OrderParameters,
        Order,
        AdvancedOrder,
        OrderStatus,
        CriteriaResolver,
        Fulfillment,
        FulfillmentComponent,
        Execution
    } from "./ConsiderationStructs.sol";
    import { OrderCombiner } from "./OrderCombiner.sol";
    /**
     * @title Consideration
     * @author 0age
     * @custom:coauthor d1ll0n
     * @custom:coauthor transmissions11
     * @custom:version 1.1
     * @notice Consideration is a generalized ETH/ERC20/ERC721/ERC1155 marketplace.
     *         It minimizes external calls to the greatest extent possible and
     *         provides lightweight methods for common routes as well as more
     *         flexible methods for composing advanced orders or groups of orders.
     *         Each order contains an arbitrary number of items that may be spent
     *         (the "offer") along with an arbitrary number of items that must be
     *         received back by the indicated recipients (the "consideration").
     */
    contract Consideration is ConsiderationInterface, OrderCombiner {
        /**
         * @notice Derive and set hashes, reference chainId, and associated domain
         *         separator during deployment.
         *
         * @param conduitController A contract that deploys conduits, or proxies
         *                          that may optionally be used to transfer approved
         *                          ERC20/721/1155 tokens.
         */
        constructor(address conduitController) OrderCombiner(conduitController) {}
        /**
         * @notice Fulfill an order offering an ERC20, ERC721, or ERC1155 item by
         *         supplying Ether (or other native tokens), ERC20 tokens, an ERC721
         *         item, or an ERC1155 item as consideration. Six permutations are
         *         supported: Native token to ERC721, Native token to ERC1155, ERC20
         *         to ERC721, ERC20 to ERC1155, ERC721 to ERC20, and ERC1155 to
         *         ERC20 (with native tokens supplied as msg.value). For an order to
         *         be eligible for fulfillment via this method, it must contain a
         *         single offer item (though that item may have a greater amount if
         *         the item is not an ERC721). An arbitrary number of "additional
         *         recipients" may also be supplied which will each receive native
         *         tokens or ERC20 items from the fulfiller as consideration. Refer
         *         to the documentation for a more comprehensive summary of how to
         *         utilize this method and what orders are compatible with it.
         *
         * @param parameters Additional information on the fulfilled order. Note
         *                   that the offerer and the fulfiller must first approve
         *                   this contract (or their chosen conduit if indicated)
         *                   before any tokens can be transferred. Also note that
         *                   contract recipients of ERC1155 consideration items must
         *                   implement `onERC1155Received` in order to receive those
         *                   items.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillBasicOrder(BasicOrderParameters calldata parameters)
            external
            payable
            override
            returns (bool fulfilled)
        {
            // Validate and fulfill the basic order.
            fulfilled = _validateAndFulfillBasicOrder(parameters);
        }
        /**
         * @notice Fulfill an order with an arbitrary number of items for offer and
         *         consideration. Note that this function does not support
         *         criteria-based orders or partial filling of orders (though
         *         filling the remainder of a partially-filled order is supported).
         *
         * @param order               The order to fulfill. Note that both the
         *                            offerer and the fulfiller must first approve
         *                            this contract (or the corresponding conduit if
         *                            indicated) to transfer any relevant tokens on
         *                            their behalf and that contracts must implement
         *                            `onERC1155Received` to receive ERC1155 tokens
         *                            as consideration.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used (and direct approvals set on
         *                            Consideration).
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillOrder(Order calldata order, bytes32 fulfillerConduitKey)
            external
            payable
            override
            returns (bool fulfilled)
        {
            // Convert order to "advanced" order, then validate and fulfill it.
            fulfilled = _validateAndFulfillAdvancedOrder(
                _convertOrderToAdvanced(order),
                new CriteriaResolver[](0), // No criteria resolvers supplied.
                fulfillerConduitKey,
                msg.sender
            );
        }
        /**
         * @notice Fill an order, fully or partially, with an arbitrary number of
         *         items for offer and consideration alongside criteria resolvers
         *         containing specific token identifiers and associated proofs.
         *
         * @param advancedOrder       The order to fulfill along with the fraction
         *                            of the order to attempt to fill. Note that
         *                            both the offerer and the fulfiller must first
         *                            approve this contract (or their conduit if
         *                            indicated by the order) to transfer any
         *                            relevant tokens on their behalf and that
         *                            contracts must implement `onERC1155Received`
         *                            to receive ERC1155 tokens as consideration.
         *                            Also note that all offer and consideration
         *                            components must have no remainder after
         *                            multiplication of the respective amount with
         *                            the supplied fraction for the partial fill to
         *                            be considered valid.
         * @param criteriaResolvers   An array where each element contains a
         *                            reference to a specific offer or
         *                            consideration, a token identifier, and a proof
         *                            that the supplied token identifier is
         *                            contained in the merkle root held by the item
         *                            in question's criteria element. Note that an
         *                            empty criteria indicates that any
         *                            (transferable) token identifier on the token
         *                            in question is valid and that no associated
         *                            proof needs to be supplied.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used (and direct approvals set on
         *                            Consideration).
         * @param recipient           The intended recipient for all received items,
         *                            with `address(0)` indicating that the caller
         *                            should receive the items.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillAdvancedOrder(
            AdvancedOrder calldata advancedOrder,
            CriteriaResolver[] calldata criteriaResolvers,
            bytes32 fulfillerConduitKey,
            address recipient
        ) external payable override returns (bool fulfilled) {
            // Validate and fulfill the order.
            fulfilled = _validateAndFulfillAdvancedOrder(
                advancedOrder,
                criteriaResolvers,
                fulfillerConduitKey,
                recipient == address(0) ? msg.sender : recipient
            );
        }
        /**
         * @notice Attempt to fill a group of orders, each with an arbitrary number
         *         of items for offer and consideration. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *         Note that this function does not support criteria-based orders or
         *         partial filling of orders (though filling the remainder of a
         *         partially-filled order is supported).
         *
         * @param orders                    The orders to fulfill. Note that both
         *                                  the offerer and the fulfiller must first
         *                                  approve this contract (or the
         *                                  corresponding conduit if indicated) to
         *                                  transfer any relevant tokens on their
         *                                  behalf and that contracts must implement
         *                                  `onERC1155Received` to receive ERC1155
         *                                  tokens as consideration.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used (and
         *                                  direct approvals set on Consideration).
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableOrders(
            Order[] calldata orders,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            uint256 maximumFulfilled
        )
            external
            payable
            override
            returns (bool[] memory availableOrders, Execution[] memory executions)
        {
            // Convert orders to "advanced" orders and fulfill all available orders.
            return
                _fulfillAvailableAdvancedOrders(
                    _convertOrdersToAdvanced(orders), // Convert to advanced orders.
                    new CriteriaResolver[](0), // No criteria resolvers supplied.
                    offerFulfillments,
                    considerationFulfillments,
                    fulfillerConduitKey,
                    msg.sender,
                    maximumFulfilled
                );
        }
        /**
         * @notice Attempt to fill a group of orders, fully or partially, with an
         *         arbitrary number of items for offer and consideration per order
         *         alongside criteria resolvers containing specific token
         *         identifiers and associated proofs. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or their conduit if indicated
         *                                  by the order) to transfer any relevant
         *                                  tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` in order to receive
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param criteriaResolvers         An array where each element contains a
         *                                  reference to a specific offer or
         *                                  consideration, a token identifier, and a
         *                                  proof that the supplied token identifier
         *                                  is contained in the merkle root held by
         *                                  the item in question's criteria element.
         *                                  Note that an empty criteria indicates
         *                                  that any (transferable) token
         *                                  identifier on the token in question is
         *                                  valid and that no associated proof needs
         *                                  to be supplied.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used (and
         *                                  direct approvals set on Consideration).
         * @param recipient                 The intended recipient for all received
         *                                  items, with `address(0)` indicating that
         *                                  the caller should receive the items.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableAdvancedOrders(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] calldata criteriaResolvers,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            address recipient,
            uint256 maximumFulfilled
        )
            external
            payable
            override
            returns (bool[] memory availableOrders, Execution[] memory executions)
        {
            // Fulfill all available orders.
            return
                _fulfillAvailableAdvancedOrders(
                    advancedOrders,
                    criteriaResolvers,
                    offerFulfillments,
                    considerationFulfillments,
                    fulfillerConduitKey,
                    recipient == address(0) ? msg.sender : recipient,
                    maximumFulfilled
                );
        }
        /**
         * @notice Match an arbitrary number of orders, each with an arbitrary
         *         number of items for offer and consideration along with a set of
         *         fulfillments allocating offer components to consideration
         *         components. Note that this function does not support
         *         criteria-based or partial filling of orders (though filling the
         *         remainder of a partially-filled order is supported).
         *
         * @param orders            The orders to match. Note that both the offerer
         *                          and fulfiller on each order must first approve
         *                          this contract (or their conduit if indicated by
         *                          the order) to transfer any relevant tokens on
         *                          their behalf and each consideration recipient
         *                          must implement `onERC1155Received` in order to
         *                          receive ERC1155 tokens.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchOrders(
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        ) external payable override returns (Execution[] memory executions) {
            // Convert to advanced, validate, and match orders using fulfillments.
            return
                _matchAdvancedOrders(
                    _convertOrdersToAdvanced(orders),
                    new CriteriaResolver[](0), // No criteria resolvers supplied.
                    fulfillments
                );
        }
        /**
         * @notice Match an arbitrary number of full or partial orders, each with an
         *         arbitrary number of items for offer and consideration, supplying
         *         criteria resolvers containing specific token identifiers and
         *         associated proofs as well as fulfillments allocating offer
         *         components to consideration components.
         *
         * @param advancedOrders    The advanced orders to match. Note that both the
         *                          offerer and fulfiller on each order must first
         *                          approve this contract (or their conduit if
         *                          indicated by the order) to transfer any relevant
         *                          tokens on their behalf and each consideration
         *                          recipient must implement `onERC1155Received` in
         *                          order to receive ERC1155 tokens. Also note that
         *                          the offer and consideration components for each
         *                          order must have no remainder after multiplying
         *                          the respective amount with the supplied fraction
         *                          in order for the group of partial fills to be
         *                          considered valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          an empty root indicates that any (transferable)
         *                          token identifier is valid and that no associated
         *                          proof needs to be supplied.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchAdvancedOrders(
            AdvancedOrder[] memory advancedOrders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) external payable override returns (Execution[] memory executions) {
            // Validate and match the advanced orders using supplied fulfillments.
            return
                _matchAdvancedOrders(
                    advancedOrders,
                    criteriaResolvers,
                    fulfillments
                );
        }
        /**
         * @notice Cancel an arbitrary number of orders. Note that only the offerer
         *         or the zone of a given order may cancel it. Callers should ensure
         *         that the intended order was cancelled by calling `getOrderStatus`
         *         and confirming that `isCancelled` returns `true`.
         *
         * @param orders The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancel(OrderComponents[] calldata orders)
            external
            override
            returns (bool cancelled)
        {
            // Cancel the orders.
            cancelled = _cancel(orders);
        }
        /**
         * @notice Validate an arbitrary number of orders, thereby registering their
         *         signatures as valid and allowing the fulfiller to skip signature
         *         verification on fulfillment. Note that validated orders may still
         *         be unfulfillable due to invalid item amounts or other factors;
         *         callers should determine whether validated orders are fulfillable
         *         by simulating the fulfillment call prior to execution. Also note
         *         that anyone can validate a signed order, but only the offerer can
         *         validate an order without supplying a signature.
         *
         * @param orders The orders to validate.
         *
         * @return validated A boolean indicating whether the supplied orders have
         *                   been successfully validated.
         */
        function validate(Order[] calldata orders)
            external
            override
            returns (bool validated)
        {
            // Validate the orders.
            validated = _validate(orders);
        }
        /**
         * @notice Cancel all orders from a given offerer with a given zone in bulk
         *         by incrementing a counter. Note that only the offerer may
         *         increment the counter.
         *
         * @return newCounter The new counter.
         */
        function incrementCounter() external override returns (uint256 newCounter) {
            // Increment current counter for the supplied offerer.
            newCounter = _incrementCounter();
        }
        /**
         * @notice Retrieve the order hash for a given order.
         *
         * @param order The components of the order.
         *
         * @return orderHash The order hash.
         */
        function getOrderHash(OrderComponents calldata order)
            external
            view
            override
            returns (bytes32 orderHash)
        {
            // Derive order hash by supplying order parameters along with counter.
            orderHash = _deriveOrderHash(
                OrderParameters(
                    order.offerer,
                    order.zone,
                    order.offer,
                    order.consideration,
                    order.orderType,
                    order.startTime,
                    order.endTime,
                    order.zoneHash,
                    order.salt,
                    order.conduitKey,
                    order.consideration.length
                ),
                order.counter
            );
        }
        /**
         * @notice Retrieve the status of a given order by hash, including whether
         *         the order has been cancelled or validated and the fraction of the
         *         order that has been filled.
         *
         * @param orderHash The order hash in question.
         *
         * @return isValidated A boolean indicating whether the order in question
         *                     has been validated (i.e. previously approved or
         *                     partially filled).
         * @return isCancelled A boolean indicating whether the order in question
         *                     has been cancelled.
         * @return totalFilled The total portion of the order that has been filled
         *                     (i.e. the "numerator").
         * @return totalSize   The total size of the order that is either filled or
         *                     unfilled (i.e. the "denominator").
         */
        function getOrderStatus(bytes32 orderHash)
            external
            view
            override
            returns (
                bool isValidated,
                bool isCancelled,
                uint256 totalFilled,
                uint256 totalSize
            )
        {
            // Retrieve the order status using the order hash.
            return _getOrderStatus(orderHash);
        }
        /**
         * @notice Retrieve the current counter for a given offerer.
         *
         * @param offerer The offerer in question.
         *
         * @return counter The current counter.
         */
        function getCounter(address offerer)
            external
            view
            override
            returns (uint256 counter)
        {
            // Return the counter for the supplied offerer.
            counter = _getCounter(offerer);
        }
        /**
         * @notice Retrieve configuration information for this contract.
         *
         * @return version           The contract version.
         * @return domainSeparator   The domain separator for this contract.
         * @return conduitController The conduit Controller set for this contract.
         */
        function information()
            external
            view
            override
            returns (
                string memory version,
                bytes32 domainSeparator,
                address conduitController
            )
        {
            // Return the information for this contract.
            return _information();
        }
        /**
         * @notice Retrieve the name of this contract.
         *
         * @return contractName The name of this contract.
         */
        function name()
            external
            pure
            override
            returns (string memory contractName)
        {
            // Return the name of the contract.
            contractName = _name();
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        BasicOrderParameters,
        OrderComponents,
        Fulfillment,
        FulfillmentComponent,
        Execution,
        Order,
        AdvancedOrder,
        OrderStatus,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    /**
     * @title ConsiderationInterface
     * @author 0age
     * @custom:version 1.1
     * @notice Consideration is a generalized ETH/ERC20/ERC721/ERC1155 marketplace.
     *         It minimizes external calls to the greatest extent possible and
     *         provides lightweight methods for common routes as well as more
     *         flexible methods for composing advanced orders.
     *
     * @dev ConsiderationInterface contains all external function interfaces for
     *      Consideration.
     */
    interface ConsiderationInterface {
        /**
         * @notice Fulfill an order offering an ERC721 token by supplying Ether (or
         *         the native token for the given chain) as consideration for the
         *         order. An arbitrary number of "additional recipients" may also be
         *         supplied which will each receive native tokens from the fulfiller
         *         as consideration.
         *
         * @param parameters Additional information on the fulfilled order. Note
         *                   that the offerer must first approve this contract (or
         *                   their preferred conduit if indicated by the order) for
         *                   their offered ERC721 token to be transferred.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillBasicOrder(BasicOrderParameters calldata parameters)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fulfill an order with an arbitrary number of items for offer and
         *         consideration. Note that this function does not support
         *         criteria-based orders or partial filling of orders (though
         *         filling the remainder of a partially-filled order is supported).
         *
         * @param order               The order to fulfill. Note that both the
         *                            offerer and the fulfiller must first approve
         *                            this contract (or the corresponding conduit if
         *                            indicated) to transfer any relevant tokens on
         *                            their behalf and that contracts must implement
         *                            `onERC1155Received` to receive ERC1155 tokens
         *                            as consideration.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Consideration.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillOrder(Order calldata order, bytes32 fulfillerConduitKey)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fill an order, fully or partially, with an arbitrary number of
         *         items for offer and consideration alongside criteria resolvers
         *         containing specific token identifiers and associated proofs.
         *
         * @param advancedOrder       The order to fulfill along with the fraction
         *                            of the order to attempt to fill. Note that
         *                            both the offerer and the fulfiller must first
         *                            approve this contract (or their preferred
         *                            conduit if indicated by the order) to transfer
         *                            any relevant tokens on their behalf and that
         *                            contracts must implement `onERC1155Received`
         *                            to receive ERC1155 tokens as consideration.
         *                            Also note that all offer and consideration
         *                            components must have no remainder after
         *                            multiplication of the respective amount with
         *                            the supplied fraction for the partial fill to
         *                            be considered valid.
         * @param criteriaResolvers   An array where each element contains a
         *                            reference to a specific offer or
         *                            consideration, a token identifier, and a proof
         *                            that the supplied token identifier is
         *                            contained in the merkle root held by the item
         *                            in question's criteria element. Note that an
         *                            empty criteria indicates that any
         *                            (transferable) token identifier on the token
         *                            in question is valid and that no associated
         *                            proof needs to be supplied.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Consideration.
         * @param recipient           The intended recipient for all received items,
         *                            with `address(0)` indicating that the caller
         *                            should receive the items.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillAdvancedOrder(
            AdvancedOrder calldata advancedOrder,
            CriteriaResolver[] calldata criteriaResolvers,
            bytes32 fulfillerConduitKey,
            address recipient
        ) external payable returns (bool fulfilled);
        /**
         * @notice Attempt to fill a group of orders, each with an arbitrary number
         *         of items for offer and consideration. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *         Note that this function does not support criteria-based orders or
         *         partial filling of orders (though filling the remainder of a
         *         partially-filled order is supported).
         *
         * @param orders                    The orders to fulfill. Note that both
         *                                  the offerer and the fulfiller must first
         *                                  approve this contract (or the
         *                                  corresponding conduit if indicated) to
         *                                  transfer any relevant tokens on their
         *                                  behalf and that contracts must implement
         *                                  `onERC1155Received` to receive ERC1155
         *                                  tokens as consideration.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableOrders(
            Order[] calldata orders,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            uint256 maximumFulfilled
        )
            external
            payable
            returns (bool[] memory availableOrders, Execution[] memory executions);
        /**
         * @notice Attempt to fill a group of orders, fully or partially, with an
         *         arbitrary number of items for offer and consideration per order
         *         alongside criteria resolvers containing specific token
         *         identifiers and associated proofs. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or their preferred conduit if
         *                                  indicated by the order) to transfer any
         *                                  relevant tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` to enable receipt of
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param criteriaResolvers         An array where each element contains a
         *                                  reference to a specific offer or
         *                                  consideration, a token identifier, and a
         *                                  proof that the supplied token identifier
         *                                  is contained in the merkle root held by
         *                                  the item in question's criteria element.
         *                                  Note that an empty criteria indicates
         *                                  that any (transferable) token
         *                                  identifier on the token in question is
         *                                  valid and that no associated proof needs
         *                                  to be supplied.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param recipient                 The intended recipient for all received
         *                                  items, with `address(0)` indicating that
         *                                  the caller should receive the items.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableAdvancedOrders(
            AdvancedOrder[] calldata 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);
        /**
         * @notice Match an arbitrary number of orders, each with an arbitrary
         *         number of items for offer and consideration along with as set of
         *         fulfillments allocating offer components to consideration
         *         components. Note that this function does not support
         *         criteria-based or partial filling of orders (though filling the
         *         remainder of a partially-filled order is supported).
         *
         * @param orders       The orders to match. Note that both the offerer and
         *                     fulfiller on each order must first approve this
         *                     contract (or their conduit if indicated by the order)
         *                     to transfer any relevant tokens on their behalf and
         *                     each consideration recipient must implement
         *                     `onERC1155Received` to enable ERC1155 token receipt.
         * @param fulfillments An array of elements allocating offer components to
         *                     consideration components. Note that each
         *                     consideration component must be fully met for the
         *                     match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchOrders(
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Match an arbitrary number of full or partial orders, each with an
         *         arbitrary number of items for offer and consideration, supplying
         *         criteria resolvers containing specific token identifiers and
         *         associated proofs as well as fulfillments allocating offer
         *         components to consideration components.
         *
         * @param orders            The advanced orders to match. Note that both the
         *                          offerer and fulfiller on each order must first
         *                          approve this contract (or a preferred conduit if
         *                          indicated by the order) to transfer any relevant
         *                          tokens on their behalf and each consideration
         *                          recipient must implement `onERC1155Received` in
         *                          order to receive ERC1155 tokens. Also note that
         *                          the offer and consideration components for each
         *                          order must have no remainder after multiplying
         *                          the respective amount with the supplied fraction
         *                          in order for the group of partial fills to be
         *                          considered valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          an empty root indicates that any (transferable)
         *                          token identifier is valid and that no associated
         *                          proof needs to be supplied.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchAdvancedOrders(
            AdvancedOrder[] calldata orders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Cancel an arbitrary number of orders. Note that only the offerer
         *         or the zone of a given order may cancel it. Callers should ensure
         *         that the intended order was cancelled by calling `getOrderStatus`
         *         and confirming that `isCancelled` returns `true`.
         *
         * @param orders The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancel(OrderComponents[] calldata orders)
            external
            returns (bool cancelled);
        /**
         * @notice Validate an arbitrary number of orders, thereby registering their
         *         signatures as valid and allowing the fulfiller to skip signature
         *         verification on fulfillment. Note that validated orders may still
         *         be unfulfillable due to invalid item amounts or other factors;
         *         callers should determine whether validated orders are fulfillable
         *         by simulating the fulfillment call prior to execution. Also note
         *         that anyone can validate a signed order, but only the offerer can
         *         validate an order without supplying a signature.
         *
         * @param orders The orders to validate.
         *
         * @return validated A boolean indicating whether the supplied orders have
         *                   been successfully validated.
         */
        function validate(Order[] calldata orders)
            external
            returns (bool validated);
        /**
         * @notice Cancel all orders from a given offerer with a given zone in bulk
         *         by incrementing a counter. Note that only the offerer may
         *         increment the counter.
         *
         * @return newCounter The new counter.
         */
        function incrementCounter() external returns (uint256 newCounter);
        /**
         * @notice Retrieve the order hash for a given order.
         *
         * @param order The components of the order.
         *
         * @return orderHash The order hash.
         */
        function getOrderHash(OrderComponents calldata order)
            external
            view
            returns (bytes32 orderHash);
        /**
         * @notice Retrieve the status of a given order by hash, including whether
         *         the order has been cancelled or validated and the fraction of the
         *         order that has been filled.
         *
         * @param orderHash The order hash in question.
         *
         * @return isValidated A boolean indicating whether the order in question
         *                     has been validated (i.e. previously approved or
         *                     partially filled).
         * @return isCancelled A boolean indicating whether the order in question
         *                     has been cancelled.
         * @return totalFilled The total portion of the order that has been filled
         *                     (i.e. the "numerator").
         * @return totalSize   The total size of the order that is either filled or
         *                     unfilled (i.e. the "denominator").
         */
        function getOrderStatus(bytes32 orderHash)
            external
            view
            returns (
                bool isValidated,
                bool isCancelled,
                uint256 totalFilled,
                uint256 totalSize
            );
        /**
         * @notice Retrieve the current counter for a given offerer.
         *
         * @param offerer The offerer in question.
         *
         * @return counter The current counter.
         */
        function getCounter(address offerer)
            external
            view
            returns (uint256 counter);
        /**
         * @notice Retrieve configuration information for this contract.
         *
         * @return version           The contract version.
         * @return domainSeparator   The domain separator for this contract.
         * @return conduitController The conduit Controller set for this contract.
         */
        function information()
            external
            view
            returns (
                string memory version,
                bytes32 domainSeparator,
                address conduitController
            );
        /**
         * @notice Retrieve the name of this contract.
         *
         * @return contractName The name of this contract.
         */
        function name() external view returns (string memory contractName);
    }
    

    File 2 of 2: PausableZone
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { ZoneInterface } from "../interfaces/ZoneInterface.sol";
    import { ZoneInteractionErrors } from "../interfaces/ZoneInteractionErrors.sol";
    // prettier-ignore
    import {
        PausableZoneEventsAndErrors
    } from "./interfaces/PausableZoneEventsAndErrors.sol";
    import { SeaportInterface } from "../interfaces/SeaportInterface.sol";
    // prettier-ignore
    import {
        AdvancedOrder,
        CriteriaResolver,
        Order,
        OrderComponents,
        Fulfillment,
        Execution
    } from "../lib/ConsiderationStructs.sol";
    import { PausableZoneInterface } from "./interfaces/PausableZoneInterface.sol";
    /**
     * @title  PausableZone
     * @author cupOJoseph, BCLeFevre, ryanio
     * @notice PausableZone is a simple zone implementation that approves every
     *         order. It can be self-destructed by its controller to pause
     *         restricted orders that have it set as their zone.
     */
    contract PausableZone is
        PausableZoneEventsAndErrors,
        ZoneInterface,
        PausableZoneInterface
    {
        // Set an immutable controller that can pause the zone & update an operator.
        address internal immutable _controller;
        // Set an operator that can instruct the zone to cancel or execute orders.
        address public operator;
        /**
         * @dev Ensure that the caller is either the operator or controller.
         */
        modifier isOperator() {
            // Ensure that the caller is either the operator or the controller.
            if (msg.sender != operator && msg.sender != _controller) {
                revert InvalidOperator();
            }
            // Continue with function execution.
            _;
        }
        /**
         * @dev Ensure that the caller is the controller.
         */
        modifier isController() {
            // Ensure that the caller is the controller.
            if (msg.sender != _controller) {
                revert InvalidController();
            }
            // Continue with function execution.
            _;
        }
        /**
         * @notice Set the deployer as the controller of the zone.
         */
        constructor() {
            // Set the controller to the deployer.
            _controller = msg.sender;
            // Emit an event signifying that the zone is unpaused.
            emit Unpaused();
        }
        /**
         * @notice Check if a given order is currently valid.
         *
         * @dev This function is called by Seaport whenever extraData is not
         *      provided by the caller.
         *
         * @param orderHash The hash of the order.
         * @param caller    The caller in question.
         * @param offerer   The offerer in question.
         * @param zoneHash  The hash to provide upon calling the zone.
         *
         * @return validOrderMagicValue A magic value indicating if the order is
         *                              currently valid.
         */
        function isValidOrder(
            bytes32 orderHash,
            address caller,
            address offerer,
            bytes32 zoneHash
        ) external pure override returns (bytes4 validOrderMagicValue) {
            orderHash;
            caller;
            offerer;
            zoneHash;
            // Return the selector of isValidOrder as the magic value.
            validOrderMagicValue = ZoneInterface.isValidOrder.selector;
        }
        /**
         * @notice Check if a given order including extraData is currently valid.
         *
         * @dev This function is called by Seaport whenever any extraData is
         *      provided by the caller.
         *
         * @param orderHash         The hash of the order.
         * @param caller            The caller in question.
         * @param order             The order in question.
         * @param priorOrderHashes  The order hashes of each order supplied prior to
         *                          the current order as part of a "match" variety
         *                          of order fulfillment.
         * @param criteriaResolvers The criteria resolvers corresponding to
         *                          the order.
         *
         * @return validOrderMagicValue A magic value indicating if the order is
         *                              currently valid.
         */
        function isValidOrderIncludingExtraData(
            bytes32 orderHash,
            address caller,
            AdvancedOrder calldata order,
            bytes32[] calldata priorOrderHashes,
            CriteriaResolver[] calldata criteriaResolvers
        ) external pure override returns (bytes4 validOrderMagicValue) {
            orderHash;
            caller;
            order;
            priorOrderHashes;
            criteriaResolvers;
            // Return the selector of isValidOrder as the magic value.
            validOrderMagicValue = ZoneInterface.isValidOrder.selector;
        }
        /**
         * @notice Cancel an arbitrary number of orders that have agreed to use the
         *         contract as their zone.
         *
         * @param seaport  The Seaport address.
         * @param orders   The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancelOrders(
            SeaportInterface seaport,
            OrderComponents[] calldata orders
        ) external override isOperator returns (bool cancelled) {
            // Call cancel on Seaport and return its boolean value.
            cancelled = seaport.cancel(orders);
        }
        /**
         * @notice Execute an arbitrary number of matched orders, each with
         *         an arbitrary number of items for offer and consideration
         *         along with a set of fulfillments allocating offer components
         *         to consideration components.
         *
         * @param seaport      The Seaport address.
         * @param orders       The orders to match.
         * @param fulfillments An array of elements allocating offer components
         *                     to consideration components.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function executeMatchOrders(
            SeaportInterface seaport,
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        )
            external
            payable
            override
            isOperator
            returns (Execution[] memory executions)
        {
            // Call matchOrders on Seaport and return the sequence of transfers
            // performed as part of matching the given orders.
            executions = seaport.matchOrders{ value: msg.value }(
                orders,
                fulfillments
            );
        }
        /**
         * @notice Execute an arbitrary number of matched advanced orders,
         *         each with an arbitrary number of items for offer and
         *         consideration along with a set of fulfillments allocating
         *         offer components to consideration components.
         *
         * @param seaport           The Seaport address.
         * @param orders            The orders to match.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function executeMatchAdvancedOrders(
            SeaportInterface seaport,
            AdvancedOrder[] calldata orders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        )
            external
            payable
            override
            isOperator
            returns (Execution[] memory executions)
        {
            // Call matchAdvancedOrders on Seaport and return the sequence of
            // transfers performed as part of matching the given orders.
            executions = seaport.matchAdvancedOrders{ value: msg.value }(
                orders,
                criteriaResolvers,
                fulfillments
            );
        }
        /**
         * @notice Pause this contract, safely stopping orders from using
         *         the contract as a zone. Restricted orders with this address as a
         *         zone will not be fulfillable unless the zone is redeployed to the
         *         same address.
         */
        function pause() external override isController {
            // Emit an event signifying that the zone is paused.
            emit Paused();
            // Destroy the zone, sending any ether to the transaction submitter.
            selfdestruct(payable(tx.origin));
        }
        /**
         * @notice Assign the given address with the ability to operate the zone.
         *
         * @param operatorToAssign The address to assign as the operator.
         */
        function assignOperator(address operatorToAssign)
            external
            override
            isController
        {
            // Ensure the operator being assigned is not the null address.
            require(
                operatorToAssign != address(0),
                "Operator can not be set to the null address"
            );
            // Set the given address as the new operator.
            operator = operatorToAssign;
            // Emit an event indicating the operator has been updated.
            emit OperatorUpdated(operator);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        AdvancedOrder,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    interface ZoneInterface {
        /**
         * @dev Emit an event whenever a zone is successfully paused.
         */
        event Paused();
        /**
         * @dev Emit an event whenever a zone is successfully unpaused (created).
         */
        event Unpaused();
        // Called by Consideration whenever extraData is not provided by the caller.
        function isValidOrder(
            bytes32 orderHash,
            address caller,
            address offerer,
            bytes32 zoneHash
        ) external view returns (bytes4 validOrderMagicValue);
        // Called by Consideration whenever any extraData is provided by the caller.
        function isValidOrderIncludingExtraData(
            bytes32 orderHash,
            address caller,
            AdvancedOrder calldata order,
            bytes32[] calldata priorOrderHashes,
            CriteriaResolver[] calldata criteriaResolvers
        ) external view returns (bytes4 validOrderMagicValue);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @title ZoneInteractionErrors
     * @author 0age
     * @notice ZoneInteractionErrors contains errors related to zone interaction.
     */
    interface ZoneInteractionErrors {
        /**
         * @dev Revert with an error when attempting to fill an order that specifies
         *      a restricted submitter as its order type when not submitted by
         *      either the offerer or the order's zone or approved as valid by the
         *      zone in question via a staticcall to `isValidOrder`.
         *
         * @param orderHash The order hash for the invalid restricted order.
         */
        error InvalidRestrictedOrder(bytes32 orderHash);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    /**
     * @notice PausableZoneEventsAndErrors contains errors and events
     *         related to zone interaction.
     */
    interface PausableZoneEventsAndErrors {
        /**
         * @dev Emit an event whenever a zone owner registers a new potential
         *      owner for that zone.
         *
         * @param newPotentialOwner The new potential owner of the zone.
         */
        event PotentialOwnerUpdated(address newPotentialOwner);
        /**
         * @dev Emit an event whenever zone ownership is transferred.
         *
         * @param previousOwner The previous owner of the zone.
         * @param newOwner      The new owner of the zone.
         */
        event OwnershipTransferred(address previousOwner, address newOwner);
        /**
         * @dev Emit an event whenever a new zone is created.
         *
         * @param zone The address of the zone.
         * @param salt The salt used to deploy the zone.
         */
        event ZoneCreated(address zone, bytes32 salt);
        /**
         * @dev Emit an event whenever a zone owner assigns a new pauser
         *
         * @param newPauser The new pausear of the zone.
         */
        event PauserUpdated(address newPauser);
        /**
         * @dev Emit an event whenever a zone owner assigns a new operator
         *
         * @param newOperator The new operator of the zone.
         */
        event OperatorUpdated(address newOperator);
        /**
         * @dev Revert with an error when attempting to pause the zone
         *      while the caller is not the owner or pauser of the zone.
         */
        error InvalidPauser();
        /**
         * @dev Revert with an error when attempting to call an operation
         *      while the caller is not the controller or operator of the zone.
         */
        error InvalidOperator();
        /**
         * @dev Revert with an error when attempting to pause the zone or update the
         *      operator while the caller is not the controller of the zone.
         */
        error InvalidController();
        /**
         * @dev Revert with an error when attempting to deploy a zone that is
         *      currently deployed.
         */
        error ZoneAlreadyExists(address zone);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        BasicOrderParameters,
        OrderComponents,
        Fulfillment,
        FulfillmentComponent,
        Execution,
        Order,
        AdvancedOrder,
        OrderStatus,
        CriteriaResolver
    } from "../lib/ConsiderationStructs.sol";
    /**
     * @title SeaportInterface
     * @author 0age
     * @custom:version 1.1
     * @notice Seaport is a generalized ETH/ERC20/ERC721/ERC1155 marketplace. It
     *         minimizes external calls to the greatest extent possible and provides
     *         lightweight methods for common routes as well as more flexible
     *         methods for composing advanced orders.
     *
     * @dev SeaportInterface contains all external function interfaces for Seaport.
     */
    interface SeaportInterface {
        /**
         * @notice Fulfill an order offering an ERC721 token by supplying Ether (or
         *         the native token for the given chain) as consideration for the
         *         order. An arbitrary number of "additional recipients" may also be
         *         supplied which will each receive native tokens from the fulfiller
         *         as consideration.
         *
         * @param parameters Additional information on the fulfilled order. Note
         *                   that the offerer must first approve this contract (or
         *                   their preferred conduit if indicated by the order) for
         *                   their offered ERC721 token to be transferred.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillBasicOrder(BasicOrderParameters calldata parameters)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fulfill an order with an arbitrary number of items for offer and
         *         consideration. Note that this function does not support
         *         criteria-based orders or partial filling of orders (though
         *         filling the remainder of a partially-filled order is supported).
         *
         * @param order               The order to fulfill. Note that both the
         *                            offerer and the fulfiller must first approve
         *                            this contract (or the corresponding conduit if
         *                            indicated) to transfer any relevant tokens on
         *                            their behalf and that contracts must implement
         *                            `onERC1155Received` to receive ERC1155 tokens
         *                            as consideration.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Seaport.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillOrder(Order calldata order, bytes32 fulfillerConduitKey)
            external
            payable
            returns (bool fulfilled);
        /**
         * @notice Fill an order, fully or partially, with an arbitrary number of
         *         items for offer and consideration alongside criteria resolvers
         *         containing specific token identifiers and associated proofs.
         *
         * @param advancedOrder       The order to fulfill along with the fraction
         *                            of the order to attempt to fill. Note that
         *                            both the offerer and the fulfiller must first
         *                            approve this contract (or their preferred
         *                            conduit if indicated by the order) to transfer
         *                            any relevant tokens on their behalf and that
         *                            contracts must implement `onERC1155Received`
         *                            to receive ERC1155 tokens as consideration.
         *                            Also note that all offer and consideration
         *                            components must have no remainder after
         *                            multiplication of the respective amount with
         *                            the supplied fraction for the partial fill to
         *                            be considered valid.
         * @param criteriaResolvers   An array where each element contains a
         *                            reference to a specific offer or
         *                            consideration, a token identifier, and a proof
         *                            that the supplied token identifier is
         *                            contained in the merkle root held by the item
         *                            in question's criteria element. Note that an
         *                            empty criteria indicates that any
         *                            (transferable) token identifier on the token
         *                            in question is valid and that no associated
         *                            proof needs to be supplied.
         * @param fulfillerConduitKey A bytes32 value indicating what conduit, if
         *                            any, to source the fulfiller's token approvals
         *                            from. The zero hash signifies that no conduit
         *                            should be used, with direct approvals set on
         *                            Seaport.
         * @param recipient           The intended recipient for all received items,
         *                            with `address(0)` indicating that the caller
         *                            should receive the items.
         *
         * @return fulfilled A boolean indicating whether the order has been
         *                   successfully fulfilled.
         */
        function fulfillAdvancedOrder(
            AdvancedOrder calldata advancedOrder,
            CriteriaResolver[] calldata criteriaResolvers,
            bytes32 fulfillerConduitKey,
            address recipient
        ) external payable returns (bool fulfilled);
        /**
         * @notice Attempt to fill a group of orders, each with an arbitrary number
         *         of items for offer and consideration. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *         Note that this function does not support criteria-based orders or
         *         partial filling of orders (though filling the remainder of a
         *         partially-filled order is supported).
         *
         * @param orders                    The orders to fulfill. Note that both
         *                                  the offerer and the fulfiller must first
         *                                  approve this contract (or the
         *                                  corresponding conduit if indicated) to
         *                                  transfer any relevant tokens on their
         *                                  behalf and that contracts must implement
         *                                  `onERC1155Received` to receive ERC1155
         *                                  tokens as consideration.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableOrders(
            Order[] calldata orders,
            FulfillmentComponent[][] calldata offerFulfillments,
            FulfillmentComponent[][] calldata considerationFulfillments,
            bytes32 fulfillerConduitKey,
            uint256 maximumFulfilled
        )
            external
            payable
            returns (bool[] memory availableOrders, Execution[] memory executions);
        /**
         * @notice Attempt to fill a group of orders, fully or partially, with an
         *         arbitrary number of items for offer and consideration per order
         *         alongside criteria resolvers containing specific token
         *         identifiers and associated proofs. Any order that is not
         *         currently active, has already been fully filled, or has been
         *         cancelled will be omitted. Remaining offer and consideration
         *         items will then be aggregated where possible as indicated by the
         *         supplied offer and consideration component arrays and aggregated
         *         items will be transferred to the fulfiller or to each intended
         *         recipient, respectively. Note that a failing item transfer or an
         *         issue with order formatting will cause the entire batch to fail.
         *
         * @param advancedOrders            The orders to fulfill along with the
         *                                  fraction of those orders to attempt to
         *                                  fill. Note that both the offerer and the
         *                                  fulfiller must first approve this
         *                                  contract (or their preferred conduit if
         *                                  indicated by the order) to transfer any
         *                                  relevant tokens on their behalf and that
         *                                  contracts must implement
         *                                  `onERC1155Received` to enable receipt of
         *                                  ERC1155 tokens as consideration. Also
         *                                  note that all offer and consideration
         *                                  components must have no remainder after
         *                                  multiplication of the respective amount
         *                                  with the supplied fraction for an
         *                                  order's partial fill amount to be
         *                                  considered valid.
         * @param criteriaResolvers         An array where each element contains a
         *                                  reference to a specific offer or
         *                                  consideration, a token identifier, and a
         *                                  proof that the supplied token identifier
         *                                  is contained in the merkle root held by
         *                                  the item in question's criteria element.
         *                                  Note that an empty criteria indicates
         *                                  that any (transferable) token
         *                                  identifier on the token in question is
         *                                  valid and that no associated proof needs
         *                                  to be supplied.
         * @param offerFulfillments         An array of FulfillmentComponent arrays
         *                                  indicating which offer items to attempt
         *                                  to aggregate when preparing executions.
         * @param considerationFulfillments An array of FulfillmentComponent arrays
         *                                  indicating which consideration items to
         *                                  attempt to aggregate when preparing
         *                                  executions.
         * @param fulfillerConduitKey       A bytes32 value indicating what conduit,
         *                                  if any, to source the fulfiller's token
         *                                  approvals from. The zero hash signifies
         *                                  that no conduit should be used, with
         *                                  direct approvals set on this contract.
         * @param recipient                 The intended recipient for all received
         *                                  items, with `address(0)` indicating that
         *                                  the caller should receive the items.
         * @param maximumFulfilled          The maximum number of orders to fulfill.
         *
         * @return availableOrders An array of booleans indicating if each order
         *                         with an index corresponding to the index of the
         *                         returned boolean was fulfillable or not.
         * @return executions      An array of elements indicating the sequence of
         *                         transfers performed as part of matching the given
         *                         orders.
         */
        function fulfillAvailableAdvancedOrders(
            AdvancedOrder[] calldata 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);
        /**
         * @notice Match an arbitrary number of orders, each with an arbitrary
         *         number of items for offer and consideration along with as set of
         *         fulfillments allocating offer components to consideration
         *         components. Note that this function does not support
         *         criteria-based or partial filling of orders (though filling the
         *         remainder of a partially-filled order is supported).
         *
         * @param orders       The orders to match. Note that both the offerer and
         *                     fulfiller on each order must first approve this
         *                     contract (or their conduit if indicated by the order)
         *                     to transfer any relevant tokens on their behalf and
         *                     each consideration recipient must implement
         *                     `onERC1155Received` to enable ERC1155 token receipt.
         * @param fulfillments An array of elements allocating offer components to
         *                     consideration components. Note that each
         *                     consideration component must be fully met for the
         *                     match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchOrders(
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Match an arbitrary number of full or partial orders, each with an
         *         arbitrary number of items for offer and consideration, supplying
         *         criteria resolvers containing specific token identifiers and
         *         associated proofs as well as fulfillments allocating offer
         *         components to consideration components.
         *
         * @param orders            The advanced orders to match. Note that both the
         *                          offerer and fulfiller on each order must first
         *                          approve this contract (or a preferred conduit if
         *                          indicated by the order) to transfer any relevant
         *                          tokens on their behalf and each consideration
         *                          recipient must implement `onERC1155Received` in
         *                          order to receive ERC1155 tokens. Also note that
         *                          the offer and consideration components for each
         *                          order must have no remainder after multiplying
         *                          the respective amount with the supplied fraction
         *                          in order for the group of partial fills to be
         *                          considered valid.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root. Note that
         *                          an empty root indicates that any (transferable)
         *                          token identifier is valid and that no associated
         *                          proof needs to be supplied.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components. Note that each
         *                          consideration component must be fully met in
         *                          order for the match operation to be valid.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function matchAdvancedOrders(
            AdvancedOrder[] calldata orders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Cancel an arbitrary number of orders. Note that only the offerer
         *         or the zone of a given order may cancel it. Callers should ensure
         *         that the intended order was cancelled by calling `getOrderStatus`
         *         and confirming that `isCancelled` returns `true`.
         *
         * @param orders The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancel(OrderComponents[] calldata orders)
            external
            returns (bool cancelled);
        /**
         * @notice Validate an arbitrary number of orders, thereby registering their
         *         signatures as valid and allowing the fulfiller to skip signature
         *         verification on fulfillment. Note that validated orders may still
         *         be unfulfillable due to invalid item amounts or other factors;
         *         callers should determine whether validated orders are fulfillable
         *         by simulating the fulfillment call prior to execution. Also note
         *         that anyone can validate a signed order, but only the offerer can
         *         validate an order without supplying a signature.
         *
         * @param orders The orders to validate.
         *
         * @return validated A boolean indicating whether the supplied orders have
         *                   been successfully validated.
         */
        function validate(Order[] calldata orders)
            external
            returns (bool validated);
        /**
         * @notice Cancel all orders from a given offerer with a given zone in bulk
         *         by incrementing a counter. Note that only the offerer may
         *         increment the counter.
         *
         * @return newCounter The new counter.
         */
        function incrementCounter() external returns (uint256 newCounter);
        /**
         * @notice Retrieve the order hash for a given order.
         *
         * @param order The components of the order.
         *
         * @return orderHash The order hash.
         */
        function getOrderHash(OrderComponents calldata order)
            external
            view
            returns (bytes32 orderHash);
        /**
         * @notice Retrieve the status of a given order by hash, including whether
         *         the order has been cancelled or validated and the fraction of the
         *         order that has been filled.
         *
         * @param orderHash The order hash in question.
         *
         * @return isValidated A boolean indicating whether the order in question
         *                     has been validated (i.e. previously approved or
         *                     partially filled).
         * @return isCancelled A boolean indicating whether the order in question
         *                     has been cancelled.
         * @return totalFilled The total portion of the order that has been filled
         *                     (i.e. the "numerator").
         * @return totalSize   The total size of the order that is either filled or
         *                     unfilled (i.e. the "denominator").
         */
        function getOrderStatus(bytes32 orderHash)
            external
            view
            returns (
                bool isValidated,
                bool isCancelled,
                uint256 totalFilled,
                uint256 totalSize
            );
        /**
         * @notice Retrieve the current counter for a given offerer.
         *
         * @param offerer The offerer in question.
         *
         * @return counter The current counter.
         */
        function getCounter(address offerer)
            external
            view
            returns (uint256 counter);
        /**
         * @notice Retrieve configuration information for this contract.
         *
         * @return version           The contract version.
         * @return domainSeparator   The domain separator for this contract.
         * @return conduitController The conduit Controller set for this contract.
         */
        function information()
            external
            view
            returns (
                string memory version,
                bytes32 domainSeparator,
                address conduitController
            );
        /**
         * @notice Retrieve the name of this contract.
         *
         * @return contractName The name of this contract.
         */
        function name() external view returns (string memory contractName);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    import {
        OrderType,
        BasicOrderType,
        ItemType,
        Side
    } from "./ConsiderationEnums.sol";
    /**
     * @dev An order contains eleven components: an offerer, a zone (or account that
     *      can cancel the order or restrict who can fulfill the order depending on
     *      the type), the order type (specifying partial fill support as well as
     *      restricted order status), the start and end time, a hash that will be
     *      provided to the zone when validating restricted orders, a salt, a key
     *      corresponding to a given conduit, a counter, and an arbitrary number of
     *      offer items that can be spent along with consideration items that must
     *      be received by their respective 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;
    }
    /**
     * @dev An offer item has five components: an item type (ETH or other native
     *      tokens, ERC20, ERC721, and ERC1155, as well as criteria-based ERC721 and
     *      ERC1155), a token address, a dual-purpose "identifierOrCriteria"
     *      component that will either represent a tokenId or a merkle root
     *      depending on the item type, and a start and end amount that support
     *      increasing or decreasing amounts over the duration of the respective
     *      order.
     */
    struct OfferItem {
        ItemType itemType;
        address token;
        uint256 identifierOrCriteria;
        uint256 startAmount;
        uint256 endAmount;
    }
    /**
     * @dev A consideration item has the same five components as an offer item and
     *      an additional sixth component designating the required recipient of the
     *      item.
     */
    struct ConsiderationItem {
        ItemType itemType;
        address token;
        uint256 identifierOrCriteria;
        uint256 startAmount;
        uint256 endAmount;
        address payable recipient;
    }
    /**
     * @dev A spent item is translated from a utilized offer item and has four
     *      components: an item type (ETH or other native tokens, ERC20, ERC721, and
     *      ERC1155), a token address, a tokenId, and an amount.
     */
    struct SpentItem {
        ItemType itemType;
        address token;
        uint256 identifier;
        uint256 amount;
    }
    /**
     * @dev A received item is translated from a utilized consideration item and has
     *      the same four components as a spent item, as well as an additional fifth
     *      component designating the required recipient of the item.
     */
    struct ReceivedItem {
        ItemType itemType;
        address token;
        uint256 identifier;
        uint256 amount;
        address payable recipient;
    }
    /**
     * @dev For basic orders involving ETH / native / ERC20 <=> ERC721 / ERC1155
     *      matching, a group of six functions may be called that only requires a
     *      subset of the usual order arguments. Note the use of a "basicOrderType"
     *      enum; this represents both the usual order type as well as the "route"
     *      of the basic order (a simple derivation function for the basic order
     *      type is `basicOrderType = orderType + (4 * basicOrderRoute)`.)
     */
    struct BasicOrderParameters {
        // calldata offset
        address considerationToken; // 0x24
        uint256 considerationIdentifier; // 0x44
        uint256 considerationAmount; // 0x64
        address payable offerer; // 0x84
        address zone; // 0xa4
        address offerToken; // 0xc4
        uint256 offerIdentifier; // 0xe4
        uint256 offerAmount; // 0x104
        BasicOrderType basicOrderType; // 0x124
        uint256 startTime; // 0x144
        uint256 endTime; // 0x164
        bytes32 zoneHash; // 0x184
        uint256 salt; // 0x1a4
        bytes32 offererConduitKey; // 0x1c4
        bytes32 fulfillerConduitKey; // 0x1e4
        uint256 totalOriginalAdditionalRecipients; // 0x204
        AdditionalRecipient[] additionalRecipients; // 0x224
        bytes signature; // 0x244
        // Total length, excluding dynamic array data: 0x264 (580)
    }
    /**
     * @dev Basic orders can supply any number of additional recipients, with the
     *      implied assumption that they are supplied from the offered ETH (or other
     *      native token) or ERC20 token for the order.
     */
    struct AdditionalRecipient {
        uint256 amount;
        address payable recipient;
    }
    /**
     * @dev The full set of order components, with the exception of the counter,
     *      must be supplied when fulfilling more sophisticated orders or groups of
     *      orders. The total number of original consideration items must also be
     *      supplied, as the caller may specify additional consideration items.
     */
    struct OrderParameters {
        address offerer; // 0x00
        address zone; // 0x20
        OfferItem[] offer; // 0x40
        ConsiderationItem[] consideration; // 0x60
        OrderType orderType; // 0x80
        uint256 startTime; // 0xa0
        uint256 endTime; // 0xc0
        bytes32 zoneHash; // 0xe0
        uint256 salt; // 0x100
        bytes32 conduitKey; // 0x120
        uint256 totalOriginalConsiderationItems; // 0x140
        // offer.length                          // 0x160
    }
    /**
     * @dev Orders require a signature in addition to the other order parameters.
     */
    struct Order {
        OrderParameters parameters;
        bytes signature;
    }
    /**
     * @dev Advanced orders include a numerator (i.e. a fraction to attempt to fill)
     *      and a denominator (the total size of the order) in addition to the
     *      signature and other order parameters. It also supports an optional field
     *      for supplying extra data; this data will be included in a staticcall to
     *      `isValidOrderIncludingExtraData` on the zone for the order if the order
     *      type is restricted and the offerer or zone are not the caller.
     */
    struct AdvancedOrder {
        OrderParameters parameters;
        uint120 numerator;
        uint120 denominator;
        bytes signature;
        bytes extraData;
    }
    /**
     * @dev Orders can be validated (either explicitly via `validate`, or as a
     *      consequence of a full or partial fill), specifically cancelled (they can
     *      also be cancelled in bulk via incrementing a per-zone counter), and
     *      partially or fully filled (with the fraction filled represented by a
     *      numerator and denominator).
     */
    struct OrderStatus {
        bool isValidated;
        bool isCancelled;
        uint120 numerator;
        uint120 denominator;
    }
    /**
     * @dev A criteria resolver specifies an order, side (offer vs. consideration),
     *      and item index. It then provides a chosen identifier (i.e. tokenId)
     *      alongside a merkle proof demonstrating the identifier meets the required
     *      criteria.
     */
    struct CriteriaResolver {
        uint256 orderIndex;
        Side side;
        uint256 index;
        uint256 identifier;
        bytes32[] criteriaProof;
    }
    /**
     * @dev A fulfillment is applied to a group of orders. It decrements a series of
     *      offer and consideration items, then generates a single execution
     *      element. A given fulfillment can be applied to as many offer and
     *      consideration items as desired, but must contain at least one offer and
     *      at least one consideration that match. The fulfillment must also remain
     *      consistent on all key parameters across all offer items (same offerer,
     *      token, type, tokenId, and conduit preference) as well as across all
     *      consideration items (token, type, tokenId, and recipient).
     */
    struct Fulfillment {
        FulfillmentComponent[] offerComponents;
        FulfillmentComponent[] considerationComponents;
    }
    /**
     * @dev Each fulfillment component contains one index referencing a specific
     *      order and another referencing a specific offer or consideration item.
     */
    struct FulfillmentComponent {
        uint256 orderIndex;
        uint256 itemIndex;
    }
    /**
     * @dev An execution is triggered once all consideration items have been zeroed
     *      out. It sends the item in question from the offerer to the item's
     *      recipient, optionally sourcing approvals from either this contract
     *      directly or from the offerer's chosen conduit if one is specified. An
     *      execution is not provided as an argument, but rather is derived via
     *      orders, criteria resolvers, and fulfillments (where the total number of
     *      executions will be less than or equal to the total number of indicated
     *      fulfillments) and returned as part of `matchOrders`.
     */
    struct Execution {
        ReceivedItem item;
        address offerer;
        bytes32 conduitKey;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    import { SeaportInterface } from "../../interfaces/SeaportInterface.sol";
    // prettier-ignore
    import {
        AdvancedOrder,
        CriteriaResolver,
        Order,
        OrderComponents,
        Fulfillment,
        Execution
    } from "../../lib/ConsiderationStructs.sol";
    /**
     * @title  PausableZone
     * @author cupOJoseph, BCLeFevre, ryanio
     * @notice PausableZone is a simple zone implementation that approves every
     *         order. It can be self-destructed by its controller to pause
     *         restricted orders that have it set as their zone.
     */
    interface PausableZoneInterface {
        /**
         * @notice Cancel an arbitrary number of orders that have agreed to use the
         *         contract as their zone.
         *
         * @param seaport  The Seaport address.
         * @param orders   The orders to cancel.
         *
         * @return cancelled A boolean indicating whether the supplied orders have
         *                   been successfully cancelled.
         */
        function cancelOrders(
            SeaportInterface seaport,
            OrderComponents[] calldata orders
        ) external returns (bool cancelled);
        /**
         * @notice Execute an arbitrary number of matched orders, each with
         *         an arbitrary number of items for offer and consideration
         *         along with a set of fulfillments allocating offer components
         *         to consideration components.
         *
         * @param seaport      The Seaport address.
         * @param orders       The orders to match.
         * @param fulfillments An array of elements allocating offer components
         *                     to consideration components.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function executeMatchOrders(
            SeaportInterface seaport,
            Order[] calldata orders,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Execute an arbitrary number of matched advanced orders,
         *         each with an arbitrary number of items for offer and
         *         consideration along with a set of fulfillments allocating
         *         offer components to consideration components.
         *
         * @param seaport           The Seaport address.
         * @param orders            The orders to match.
         * @param criteriaResolvers An array where each element contains a reference
         *                          to a specific order as well as that order's
         *                          offer or consideration, a token identifier, and
         *                          a proof that the supplied token identifier is
         *                          contained in the order's merkle root.
         * @param fulfillments      An array of elements allocating offer components
         *                          to consideration components.
         *
         * @return executions An array of elements indicating the sequence of
         *                    transfers performed as part of matching the given
         *                    orders.
         */
        function executeMatchAdvancedOrders(
            SeaportInterface seaport,
            AdvancedOrder[] calldata orders,
            CriteriaResolver[] calldata criteriaResolvers,
            Fulfillment[] calldata fulfillments
        ) external payable returns (Execution[] memory executions);
        /**
         * @notice Pause this contract, safely stopping orders from using
         *         the contract as a zone. Restricted orders with this address as a
         *         zone will not be fulfillable unless the zone is redeployed to the
         *         same address.
         */
        function pause() external;
        /**
         * @notice Assign the given address with the ability to operate the zone.
         *
         * @param operatorToAssign The address to assign as the operator.
         */
        function assignOperator(address operatorToAssign) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity >=0.8.7;
    // prettier-ignore
    enum OrderType {
        // 0: no partial fills, anyone can execute
        FULL_OPEN,
        // 1: partial fills supported, anyone can execute
        PARTIAL_OPEN,
        // 2: no partial fills, only offerer or zone can execute
        FULL_RESTRICTED,
        // 3: partial fills supported, only offerer or zone can execute
        PARTIAL_RESTRICTED
    }
    // prettier-ignore
    enum BasicOrderType {
        // 0: no partial fills, anyone can execute
        ETH_TO_ERC721_FULL_OPEN,
        // 1: partial fills supported, anyone can execute
        ETH_TO_ERC721_PARTIAL_OPEN,
        // 2: no partial fills, only offerer or zone can execute
        ETH_TO_ERC721_FULL_RESTRICTED,
        // 3: partial fills supported, only offerer or zone can execute
        ETH_TO_ERC721_PARTIAL_RESTRICTED,
        // 4: no partial fills, anyone can execute
        ETH_TO_ERC1155_FULL_OPEN,
        // 5: partial fills supported, anyone can execute
        ETH_TO_ERC1155_PARTIAL_OPEN,
        // 6: no partial fills, only offerer or zone can execute
        ETH_TO_ERC1155_FULL_RESTRICTED,
        // 7: partial fills supported, only offerer or zone can execute
        ETH_TO_ERC1155_PARTIAL_RESTRICTED,
        // 8: no partial fills, anyone can execute
        ERC20_TO_ERC721_FULL_OPEN,
        // 9: partial fills supported, anyone can execute
        ERC20_TO_ERC721_PARTIAL_OPEN,
        // 10: no partial fills, only offerer or zone can execute
        ERC20_TO_ERC721_FULL_RESTRICTED,
        // 11: partial fills supported, only offerer or zone can execute
        ERC20_TO_ERC721_PARTIAL_RESTRICTED,
        // 12: no partial fills, anyone can execute
        ERC20_TO_ERC1155_FULL_OPEN,
        // 13: partial fills supported, anyone can execute
        ERC20_TO_ERC1155_PARTIAL_OPEN,
        // 14: no partial fills, only offerer or zone can execute
        ERC20_TO_ERC1155_FULL_RESTRICTED,
        // 15: partial fills supported, only offerer or zone can execute
        ERC20_TO_ERC1155_PARTIAL_RESTRICTED,
        // 16: no partial fills, anyone can execute
        ERC721_TO_ERC20_FULL_OPEN,
        // 17: partial fills supported, anyone can execute
        ERC721_TO_ERC20_PARTIAL_OPEN,
        // 18: no partial fills, only offerer or zone can execute
        ERC721_TO_ERC20_FULL_RESTRICTED,
        // 19: partial fills supported, only offerer or zone can execute
        ERC721_TO_ERC20_PARTIAL_RESTRICTED,
        // 20: no partial fills, anyone can execute
        ERC1155_TO_ERC20_FULL_OPEN,
        // 21: partial fills supported, anyone can execute
        ERC1155_TO_ERC20_PARTIAL_OPEN,
        // 22: no partial fills, only offerer or zone can execute
        ERC1155_TO_ERC20_FULL_RESTRICTED,
        // 23: partial fills supported, only offerer or zone can execute
        ERC1155_TO_ERC20_PARTIAL_RESTRICTED
    }
    // prettier-ignore
    enum BasicOrderRouteType {
        // 0: provide Ether (or other native token) to receive offered ERC721 item.
        ETH_TO_ERC721,
        // 1: provide Ether (or other native token) to receive offered ERC1155 item.
        ETH_TO_ERC1155,
        // 2: provide ERC20 item to receive offered ERC721 item.
        ERC20_TO_ERC721,
        // 3: provide ERC20 item to receive offered ERC1155 item.
        ERC20_TO_ERC1155,
        // 4: provide ERC721 item to receive offered ERC20 item.
        ERC721_TO_ERC20,
        // 5: provide ERC1155 item to receive offered ERC20 item.
        ERC1155_TO_ERC20
    }
    // prettier-ignore
    enum ItemType {
        // 0: ETH on mainnet, MATIC on polygon, etc.
        NATIVE,
        // 1: ERC20 items (ERC777 and ERC20 analogues could also technically work)
        ERC20,
        // 2: ERC721 items
        ERC721,
        // 3: ERC1155 items
        ERC1155,
        // 4: ERC721 items where a number of tokenIds are supported
        ERC721_WITH_CRITERIA,
        // 5: ERC1155 items where a number of ids are supported
        ERC1155_WITH_CRITERIA
    }
    // prettier-ignore
    enum Side {
        // 0: Items that can be spent
        OFFER,
        // 1: Items that must be received
        CONSIDERATION
    }