// File: contracts/minter-suite/MinterFilterV0.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

import "../interfaces/0.8.x/IMinterFilterV0.sol";
import "../interfaces/0.8.x/IFilteredMinterV0.sol";
import "../interfaces/0.8.x/IGenArt721CoreContractV1.sol";

import "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";

pragma solidity 0.8.9;

/**
 * @title Minter filter contract that allows filtered minters to be set
 * on a per-project basis.
 * @author Art Blocks Inc.
 */
contract MinterFilterV0 is IMinterFilterV0 {
    /**
     * @notice This minter is to be considered `_coreContractAddress`'s
     * canonical minter.
     * @dev may be vestigial after migrating to V3 core contracts
     */
    event IsCanonicalMinterFilter(address indexed _coreContractAddress);

    // add Enumerable Map methods
    using EnumerableMap for EnumerableMap.UintToAddressMap;

    /// Core contract address this minter interacts with
    address public immutable genArt721CoreAddress;

    /// This contract only uses the portion of V3 interface also on V1 core
    IGenArt721CoreContractV1 private immutable genArtCoreContract;

    /// projectId => minter address
    EnumerableMap.UintToAddressMap private minterForProject;

    /// minter address => qty projects currently using minter
    mapping(address => uint256) public numProjectsUsingMinter;

    /// minter address => is an approved minter?
    mapping(address => bool) public isApprovedMinter;

    modifier onlyCoreWhitelisted() {
        require(
            genArtCoreContract.isWhitelisted(msg.sender),
            "Only Core whitelisted"
        );
        _;
    }

    modifier onlyCoreWhitelistedOrArtist(uint256 _projectId) {
        require(
            (genArtCoreContract.isWhitelisted(msg.sender) ||
                msg.sender ==
                genArtCoreContract.projectIdToArtistAddress(_projectId)),
            "Only Core whitelisted or Artist"
        );
        _;
    }

    modifier projectExists(uint256 _projectId) {
        require(
            _projectId < genArtCoreContract.nextProjectId(),
            "Only existing projects"
        );
        _;
    }

    modifier usingApprovedMinter(address _minterAddress) {
        require(
            isApprovedMinter[_minterAddress],
            "Only approved minters are allowed"
        );
        _;
    }

    modifier onlyMintWhitelisted() {
        require(
            genArtCoreContract.isMintWhitelisted(address(this)),
            "Only mint allowlisted"
        );
        _;
    }

    /**
     * @notice Initializes contract to be a Minter for `_genArt721Address`.
     * @param _genArt721Address Art Blocks core contract address
     * this contract will be a minter for. Can never be updated.
     */
    constructor(address _genArt721Address) {
        genArt721CoreAddress = _genArt721Address;
        genArtCoreContract = IGenArt721CoreContractV1(_genArt721Address);
    }

    /**
     * @notice Emits event notifying indexers that this is core contract's
     * canonical minter filter.
     * @dev may be vestigial after migrating to V3 core contracts
     */
    function alertAsCanonicalMinterFilter()
        external
        onlyCoreWhitelisted
        onlyMintWhitelisted
    {
        emit IsCanonicalMinterFilter(genArt721CoreAddress);
    }

    /**
     * @notice Approves minter `_minterAddress`.
     * @param _minterAddress Minter to be added as an approved minter.
     */
    function addApprovedMinter(address _minterAddress)
        external
        onlyCoreWhitelisted
    {
        isApprovedMinter[_minterAddress] = true;
        emit MinterApproved(
            _minterAddress,
            IFilteredMinterV0(_minterAddress).minterType()
        );
    }

    /**
     * @notice Removes previously approved minter `_minterAddress`.
     * @param _minterAddress Minter to remove.
     */
    function removeApprovedMinter(address _minterAddress)
        external
        onlyCoreWhitelisted
    {
        require(
            numProjectsUsingMinter[_minterAddress] == 0,
            "Only unused minters"
        );
        isApprovedMinter[_minterAddress] = false;
        emit MinterRevoked(_minterAddress);
    }

    /**
     * @notice Sets minter for project `_projectId` to minter
     * `_minterAddress`.
     * @param _projectId Project ID to set minter for.
     * @param _minterAddress Minter to be the project's minter.
     */
    function setMinterForProject(uint256 _projectId, address _minterAddress)
        external
        onlyCoreWhitelistedOrArtist(_projectId)
        usingApprovedMinter(_minterAddress)
        projectExists(_projectId)
    {
        // decrement number of projects using a previous minter
        (bool hasPreviousMinter, address previousMinter) = minterForProject
            .tryGet(_projectId);
        if (hasPreviousMinter) {
            numProjectsUsingMinter[previousMinter]--;
        }
        // add new minter
        numProjectsUsingMinter[_minterAddress]++;
        minterForProject.set(_projectId, _minterAddress);
        emit ProjectMinterRegistered(
            _projectId,
            _minterAddress,
            IFilteredMinterV0(_minterAddress).minterType()
        );
    }

    /**
     * @notice Updates project `_projectId` to have no configured minter.
     * @param _projectId Project ID to remove minter.
     * @dev requires project to have an assigned minter
     */
    function removeMinterForProject(uint256 _projectId)
        external
        onlyCoreWhitelistedOrArtist(_projectId)
    {
        _removeMinterForProject(_projectId);
    }

    /**
     * @notice Updates an array of project IDs to have no configured minter.
     * @param _projectIds Array of project IDs to remove minters for.
     * @dev requires all project IDs to have an assigned minter
     * @dev caution with respect to single tx gas limits
     */
    function removeMintersForProjects(uint256[] calldata _projectIds)
        external
        onlyCoreWhitelisted
    {
        uint256 numProjects = _projectIds.length;
        for (uint256 i; i < numProjects; i++) {
            _removeMinterForProject(_projectIds[i]);
        }
    }

    /**
     * @notice Updates project `_projectId` to have no configured minter
     * (reverts tx if project does not have an assigned minter).
     * @param _projectId Project ID to remove minter.
     */
    function _removeMinterForProject(uint256 _projectId) private {
        // remove minter for project and emit
        // `minterForProject.get()` reverts tx if no minter set for project
        numProjectsUsingMinter[minterForProject.get(_projectId)]--;
        minterForProject.remove(_projectId);
        emit ProjectMinterRemoved(_projectId);
    }

    /**
     * @notice Mint a token from project `_projectId` to `_to`, originally
     * purchased by `sender`.
     * @param _to The new token's owner.
     * @param _projectId Project ID to mint a new token on.
     * @param sender Address purchasing a new token.
     * @return _tokenId Token ID of minted token
     * @dev reverts w/nonexistent key error when project has no assigned minter
     */
    function mint(
        address _to,
        uint256 _projectId,
        address sender
    ) external returns (uint256 _tokenId) {
        // CHECKS
        // minter is the project's minter
        require(
            msg.sender == minterForProject.get(_projectId),
            "Only assigned minter"
        );
        // EFFECTS
        uint256 tokenId = genArtCoreContract.mint(_to, _projectId, sender);
        return tokenId;
    }

    /**
     * @notice Gets the assigned minter for project `_projectId`.
     * @param _projectId Project ID to query.
     * @return address Minter address assigned to project `_projectId`
     * @dev requires project to have an assigned minter
     */
    function getMinterForProject(uint256 _projectId)
        external
        view
        returns (address)
    {
        (bool _hasMinter, address _currentMinter) = minterForProject.tryGet(
            _projectId
        );
        require(_hasMinter, "No minter assigned");
        return _currentMinter;
    }

    /**
     * @notice Queries if project `_projectId` has an assigned minter.
     * @param _projectId Project ID to query.
     * @return bool true if project has an assigned minter, else false
     * @dev requires project to have an assigned minter
     */
    function projectHasMinter(uint256 _projectId) external view returns (bool) {
        (bool _hasMinter, ) = minterForProject.tryGet(_projectId);
        return _hasMinter;
    }

    /**
     * @notice Gets quantity of projects that have assigned minters.
     * @return uint256 quantity of projects that have assigned minters
     */
    function getNumProjectsWithMinters() external view returns (uint256) {
        return minterForProject.length();
    }

    /**
     * @notice Get project ID and minter address at index `_index` of
     * enumerable map.
     * @param _index enumerable map index to query.
     * @return projectId project ID at index `_index`
     * @return minterAddress minter address for project at index `_index`
     * @return minterType minter type of minter at minterAddress
     * @dev index must be < quantity of projects that have assigned minters
     */
    function getProjectAndMinterInfoAt(uint256 _index)
        external
        view
        returns (
            uint256 projectId,
            address minterAddress,
            string memory minterType
        )
    {
        (projectId, minterAddress) = minterForProject.at(_index);
        minterType = IFilteredMinterV0(minterAddress).minterType();
        return (projectId, minterAddress, minterType);
    }
}

// File: contracts/interfaces/0.8.x/IMinterFilterV0.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

pragma solidity ^0.8.0;

interface IMinterFilterV0 {
    /**
     * @notice Approved minter `_minterAddress`.
     */
    event MinterApproved(address indexed _minterAddress, string _minterType);

    /**
     * @notice Revoked approval for minter `_minterAddress`
     */
    event MinterRevoked(address indexed _minterAddress);

    /**
     * @notice Minter `_minterAddress` of type `_minterType`
     * registered for project `_projectId`.
     */
    event ProjectMinterRegistered(
        uint256 indexed _projectId,
        address indexed _minterAddress,
        string _minterType
    );

    /**
     * @notice Any active minter removed for project `_projectId`.
     */
    event ProjectMinterRemoved(uint256 indexed _projectId);

    function genArt721CoreAddress() external returns (address);

    function setMinterForProject(uint256, address) external;

    function removeMinterForProject(uint256) external;

    function mint(
        address _to,
        uint256 _projectId,
        address sender
    ) external returns (uint256);

    function getMinterForProject(uint256) external view returns (address);

    function projectHasMinter(uint256) external view returns (bool);
}

// File: contracts/interfaces/0.8.x/IFilteredMinterV0.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

pragma solidity ^0.8.0;

interface IFilteredMinterV0 {
    /**
     * @notice Price per token in wei updated for project `_projectId` to
     * `_pricePerTokenInWei`.
     */
    event PricePerTokenInWeiUpdated(
        uint256 indexed _projectId,
        uint256 indexed _pricePerTokenInWei
    );

    /**
     * @notice Currency updated for project `_projectId` to symbol
     * `_currencySymbol` and address `_currencyAddress`.
     */
    event ProjectCurrencyInfoUpdated(
        uint256 indexed _projectId,
        address indexed _currencyAddress,
        string _currencySymbol
    );

    /// togglePurchaseToDisabled updated
    event PurchaseToDisabledUpdated(
        uint256 indexed _projectId,
        bool _purchaseToDisabled
    );

    // getter function of public variable
    function minterType() external view returns (string memory);

    function genArt721CoreAddress() external returns (address);

    function minterFilterAddress() external returns (address);

    // Triggers a purchase of a token from the desired project, to the
    // TX-sending address.
    function purchase(uint256 _projectId)
        external
        payable
        returns (uint256 tokenId);

    // Triggers a purchase of a token from the desired project, to the specified
    // receiving address.
    function purchaseTo(address _to, uint256 _projectId)
        external
        payable
        returns (uint256 tokenId);

    // Toggles the ability for `purchaseTo` to be called directly with a
    // specified receiving address that differs from the TX-sending address.
    function togglePurchaseToDisabled(uint256 _projectId) external;

    // Called to make the minter contract aware of the max invocations for a
    // given project.
    function setProjectMaxInvocations(uint256 _projectId) external;

    // Gets if token price is configured, token price in wei, currency symbol,
    // and currency address, assuming this is project's minter.
    // Supersedes any defined core price.
    function getPriceInfo(uint256 _projectId)
        external
        view
        returns (
            bool isConfigured,
            uint256 tokenPriceInWei,
            string memory currencySymbol,
            address currencyAddress
        );
}

// File: contracts/interfaces/0.8.x/IGenArt721CoreContractV1.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

pragma solidity ^0.8.0;

interface IGenArt721CoreContractV1 {
    // getter function of public variable
    function admin() external view returns (address);

    // getter function of public variable
    function nextProjectId() external view returns (uint256);

    // getter function of public mapping
    function tokenIdToProjectId(uint256 tokenId)
        external
        view
        returns (uint256 projectId);

    function isWhitelisted(address sender) external view returns (bool);

    // @dev this is not available in V0
    function isMintWhitelisted(address minter) external view returns (bool);

    function projectIdToArtistAddress(uint256 _projectId)
        external
        view
        returns (address payable);

    function projectIdToAdditionalPayee(uint256 _projectId)
        external
        view
        returns (address payable);

    function projectIdToAdditionalPayeePercentage(uint256 _projectId)
        external
        view
        returns (uint256);

    function projectTokenInfo(uint256 _projectId)
        external
        view
        returns (
            address,
            uint256,
            uint256,
            uint256,
            bool,
            address,
            uint256,
            string memory,
            address
        );

    function artblocksAddress() external view returns (address payable);

    function artblocksPercentage() external view returns (uint256);

    function mint(
        address _to,
        uint256 _projectId,
        address _by
    ) external returns (uint256 tokenId);

    function getRoyaltyData(uint256 _tokenId)
        external
        view
        returns (
            address artistAddress,
            address additionalPayee,
            uint256 additionalPayeePercentage,
            uint256 royaltyFeeByID
        );
}

// File: @openzeppelin/contracts/utils/structs/EnumerableMap.sol



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

pragma solidity ^0.8.0;

import "./EnumerableSet.sol";

/**
 * @dev Library for managing an enumerable variant of Solidity's
 * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
 * type.
 *
 * Maps have the following properties:
 *
 * - Entries are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Entries are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableMap for EnumerableMap.UintToAddressMap;
 *
 *     // Declare a set state variable
 *     EnumerableMap.UintToAddressMap private myMap;
 * }
 * ```
 *
 * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
 * supported.
 */
library EnumerableMap {
    using EnumerableSet for EnumerableSet.Bytes32Set;

    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Map type with
    // bytes32 keys and values.
    // The Map implementation uses private functions, and user-facing
    // implementations (such as Uint256ToAddressMap) are just wrappers around
    // the underlying Map.
    // This means that we can only create new EnumerableMaps for types that fit
    // in bytes32.

    struct Map {
        // Storage of keys
        EnumerableSet.Bytes32Set _keys;
        mapping(bytes32 => bytes32) _values;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function _set(
        Map storage map,
        bytes32 key,
        bytes32 value
    ) private returns (bool) {
        map._values[key] = value;
        return map._keys.add(key);
    }

    /**
     * @dev Removes a key-value pair from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function _remove(Map storage map, bytes32 key) private returns (bool) {
        delete map._values[key];
        return map._keys.remove(key);
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function _contains(Map storage map, bytes32 key) private view returns (bool) {
        return map._keys.contains(key);
    }

    /**
     * @dev Returns the number of key-value pairs in the map. O(1).
     */
    function _length(Map storage map) private view returns (uint256) {
        return map._keys.length();
    }

    /**
     * @dev Returns the key-value pair stored at position `index` in the map. O(1).
     *
     * Note that there are no guarantees on the ordering of entries inside the
     * array, and it may change when more entries are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {
        bytes32 key = map._keys.at(index);
        return (key, map._values[key]);
    }

    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     */
    function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {
        bytes32 value = map._values[key];
        if (value == bytes32(0)) {
            return (_contains(map, key), bytes32(0));
        } else {
            return (true, value);
        }
    }

    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function _get(Map storage map, bytes32 key) private view returns (bytes32) {
        bytes32 value = map._values[key];
        require(value != 0 || _contains(map, key), "EnumerableMap: nonexistent key");
        return value;
    }

    /**
     * @dev Same as {_get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {_tryGet}.
     */
    function _get(
        Map storage map,
        bytes32 key,
        string memory errorMessage
    ) private view returns (bytes32) {
        bytes32 value = map._values[key];
        require(value != 0 || _contains(map, key), errorMessage);
        return value;
    }

    // UintToAddressMap

    struct UintToAddressMap {
        Map _inner;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(
        UintToAddressMap storage map,
        uint256 key,
        address value
    ) internal returns (bool) {
        return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
        return _remove(map._inner, bytes32(key));
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
        return _contains(map._inner, bytes32(key));
    }

    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToAddressMap storage map) internal view returns (uint256) {
        return _length(map._inner);
    }

    /**
     * @dev Returns the element stored at position `index` in the set. O(1).
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
        (bytes32 key, bytes32 value) = _at(map._inner, index);
        return (uint256(key), address(uint160(uint256(value))));
    }

    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     *
     * _Available since v3.4._
     */
    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));
        return (success, address(uint160(uint256(value))));
    }

    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key)))));
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(
        UintToAddressMap storage map,
        uint256 key,
        string memory errorMessage
    ) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
    }
}

// File: @openzeppelin/contracts/utils/structs/EnumerableSet.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];

                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        assembly {
            result := store
        }

        return result;
    }
}