// File: Context.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: DefaultOperatorFilterer.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

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

abstract contract DefaultOperatorFilterer is OperatorFilterer {
    address constant DEFAULT_SUBSCRIPTION =
        address(0x3cc6CddA760b79bAfa08dF41ECFA224f810dCeB6);

    constructor() OperatorFilterer(DEFAULT_SUBSCRIPTION, true) {}
}

// File: EnumerableSet.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

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.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
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)
    {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // 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;

        /// @solidity memory-safe-assembly
        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 in 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;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// File: IOperatorFilterRegistry.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

interface IOperatorFilterRegistry {
    function isOperatorAllowed(address registrant, address operator) external view returns (bool);
    function register(address registrant) external;
    function registerAndSubscribe(address registrant, address subscription) external;
    function registerAndCopyEntries(address registrant, address registrantToCopy) external;
    function updateOperator(address registrant, address operator, bool filtered) external;
    function updateOperators(address registrant, address[] calldata operators, bool filtered) external;
    function updateCodeHash(address registrant, bytes32 codehash, bool filtered) external;
    function updateCodeHashes(address registrant, bytes32[] calldata codeHashes, bool filtered) external;
    function subscribe(address registrant, address registrantToSubscribe) external;
    function unsubscribe(address registrant, bool copyExistingEntries) external;
    function subscriptionOf(address addr) external returns (address registrant);
    function subscribers(address registrant) external returns (address[] memory);
    function subscriberAt(address registrant, uint256 index) external returns (address);
    function copyEntriesOf(address registrant, address registrantToCopy) external;
    function isOperatorFiltered(address registrant, address operator) external returns (bool);
    function isCodeHashOfFiltered(address registrant, address operatorWithCode) external returns (bool);
    function isCodeHashFiltered(address registrant, bytes32 codeHash) external returns (bool);
    function filteredOperators(address addr) external returns (address[] memory);
    function filteredCodeHashes(address addr) external returns (bytes32[] memory);
    function filteredOperatorAt(address registrant, uint256 index) external returns (address);
    function filteredCodeHashAt(address registrant, uint256 index) external returns (bytes32);
    function isRegistered(address addr) external returns (bool);
    function codeHashOf(address addr) external returns (bytes32);
}

// File: MetaInvaders.sol



// SPDX-License-Identifier: MIT

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

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

pragma solidity ^0.8.0; 

abstract contract ReentrancyGuard { 
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }
    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
   _status = _ENTERED;

        _;
        _status = _NOT_ENTERED;
    }
}

library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
 
    function toString(uint256 value) internal pure returns (string memory) { 
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }
 
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }
 
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}
 
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
 
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
 
    constructor() {
        _transferOwnership(_msgSender());
    }
 
    function owner() public view virtual returns (address) {
        return _owner;
    } 
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
 
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
 
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
 
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
 
library Address { 
    function isContract(address account) internal view returns (bool) { 
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    } 
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
 
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    } 
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
 
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
 
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    } 
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
 
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
 
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
 
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
 
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else { 
            if (returndata.length > 0) { 

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
 
interface IERC721Receiver { 
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}
 
interface IERC165 { 
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
 
abstract contract ERC165 is IERC165 { 
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
} 
interface IERC721 is IERC165 { 
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); 
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); 
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved); 
    function balanceOf(address owner) external view returns (uint256 balance); 
    function ownerOf(uint256 tokenId) external view returns (address owner); 
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external; 
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external; 
    function approve(address to, uint256 tokenId) external;
 
    function getApproved(uint256 tokenId) external view returns (address operator); 
    function setApprovalForAll(address operator, bool _approved) external; 
    function isApprovedForAll(address owner, address operator) external view returns (bool); 
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
} 
interface IERC721Enumerable is IERC721 { 
    function totalSupply() external view returns (uint256); 
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId); 
    function tokenByIndex(uint256 index) external view returns (uint256);
}  
interface IERC721Metadata is IERC721 { 
    function name() external view returns (string memory); 
    function symbol() external view returns (string memory); 
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

error ApprovalCallerNotOwnerNorApproved();
error ApprovalQueryForNonexistentToken();
error ApproveToCaller();
error ApprovalToCurrentOwner();
error BalanceQueryForZeroAddress();
error MintToZeroAddress();
error MintZeroQuantity();
error OwnerQueryForNonexistentToken();
error TransferCallerNotOwnerNorApproved();
error TransferFromIncorrectOwner();
error TransferToNonERC721ReceiverImplementer();
error TransferToZeroAddress();
error URIQueryForNonexistentToken();

contract ERC721A is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Compiler will pack this into a single 256bit word.
    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Keeps track of the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
    }

    // Compiler will pack this into a single 256bit word.
    struct AddressData {
        // Realistically, 2**64-1 is more than enough.
        uint64 balance;
        // Keeps track of mint count with minimal overhead for tokenomics.
        uint64 numberMinted;
        // Keeps track of burn count with minimal overhead for tokenomics.
        uint64 numberBurned;
        // For miscellaneous variable(s) pertaining to the address
        // (e.g. number of whitelist mint slots used).
        // If there are multiple variables, please pack them into a uint64.
        uint64 aux;
    }

    // The tokenId of the next token to be minted.
    uint256 internal _currentIndex;

    // The number of tokens burned.
    uint256 internal _burnCounter;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to ownership details
    // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.
    mapping(uint256 => TokenOwnership) internal _ownerships;

    // Mapping owner address to address data
    mapping(address => AddressData) private _addressData;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    /**
     * To change the starting tokenId, please override this function.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 1;
    }

    /**
     * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
     */
    function totalSupply() public view returns (uint256) {
        // Counter underflow is impossible as _burnCounter cannot be incremented
        // more than _currentIndex - _startTokenId() times
        unchecked {
            return _currentIndex - _burnCounter - _startTokenId();
        }
    }

    /**
     * Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view returns (uint256) {
        // Counter underflow is impossible as _currentIndex does not decrement,
        // and it is initialized to _startTokenId()
        unchecked {
            return _currentIndex - _startTokenId();
        }
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return uint256(_addressData[owner].balance);
    }

    /**
     * Returns the number of tokens minted by `owner`.
     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return uint256(_addressData[owner].numberMinted);
    }

    /**
     * Returns the number of tokens burned by or on behalf of `owner`.
     */
    function _numberBurned(address owner) internal view returns (uint256) {
        return uint256(_addressData[owner].numberBurned);
    }

    /**
     * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     */
    function _getAux(address owner) internal view returns (uint64) {
        return _addressData[owner].aux;
    }

    /**
     * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
     * If there are multiple variables, please pack them into a uint64.
     */
    function _setAux(address owner, uint64 aux) internal {
        _addressData[owner].aux = aux;
    }

    /**
     * Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around in the collection over time.
     */
    function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr && curr < _currentIndex) {
                TokenOwnership memory ownership = _ownerships[curr];
                if (!ownership.burned) {
                    if (ownership.addr != address(0)) {
                        return ownership;
                    }
                    // Invariant:
                    // There will always be an ownership that has an address and is not burned
                    // before an ownership that does not have an address and is not burned.
                    // Hence, curr will not underflow.
                    while (true) {
                        curr--;
                        ownership = _ownerships[curr];
                        if (ownership.addr != address(0)) {
                            return ownership;
                        }
                    }
                }
            }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view override returns (address) {
        return _ownershipOf(tokenId).addr;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

        string memory baseURI = _baseURI();
        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overriden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public override {
        address owner = ERC721A.ownerOf(tokenId);
        if (to == owner) revert ApprovalToCurrentOwner();

        if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {
            revert ApprovalCallerNotOwnerNorApproved();
        }

        _approve(to, tokenId, owner);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        if (operator == _msgSender()) revert ApproveToCaller();

        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        _transfer(from, to, tokenId);
        if (to.isContract() && !_checkContractOnERC721Received(from, to, tokenId, _data)) {
            revert TransferToNonERC721ReceiverImplementer();
        }
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     */
    function _exists(uint256 tokenId) internal view returns (bool) {
        return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;
    }

    function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, '');
    }

    /**
     * @dev Safely mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal {
        _mint(to, quantity, _data, true);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _mint(
        address to,
        uint256 quantity,
        bytes memory _data,
        bool safe
    ) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
        // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
        unchecked {
            _addressData[to].balance += uint64(quantity);
            _addressData[to].numberMinted += uint64(quantity);

            _ownerships[startTokenId].addr = to;
            _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

            uint256 updatedIndex = startTokenId;
            uint256 end = updatedIndex + quantity;

            if (safe && to.isContract()) {
                do {
                    emit Transfer(address(0), to, updatedIndex);
                    if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (updatedIndex != end);
                // Reentrancy protection
                if (_currentIndex != startTokenId) revert();
            } else {
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex != end);
            }
            _currentIndex = updatedIndex;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) private {
        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

        if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();

        bool isApprovedOrOwner = (_msgSender() == from ||
            isApprovedForAll(from, _msgSender()) ||
            getApproved(tokenId) == _msgSender());

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, from);

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            _addressData[from].balance -= 1;
            _addressData[to].balance += 1;

            TokenOwnership storage currSlot = _ownerships[tokenId];
            currSlot.addr = to;
            currSlot.startTimestamp = uint64(block.timestamp);

            // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            TokenOwnership storage nextSlot = _ownerships[nextTokenId];
            if (nextSlot.addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId != _currentIndex) {
                    nextSlot.addr = from;
                    nextSlot.startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**
     * @dev This is equivalent to _burn(tokenId, false)
     */
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

        address from = prevOwnership.addr;

        if (approvalCheck) {
            bool isApprovedOrOwner = (_msgSender() == from ||
                isApprovedForAll(from, _msgSender()) ||
                getApproved(tokenId) == _msgSender());

            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, from);

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
        unchecked {
            AddressData storage addressData = _addressData[from];
            addressData.balance -= 1;
            addressData.numberBurned += 1;

            // Keep track of who burned the token, and the timestamp of burning.
            TokenOwnership storage currSlot = _ownerships[tokenId];
            currSlot.addr = from;
            currSlot.startTimestamp = uint64(block.timestamp);
            currSlot.burned = true;

            // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            TokenOwnership storage nextSlot = _ownerships[nextTokenId];
            if (nextSlot.addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId != _currentIndex) {
                    nextSlot.addr = from;
                    nextSlot.startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
        unchecked {
            _burnCounter++;
        }
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(
        address to,
        uint256 tokenId,
        address owner
    ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
            return retval == IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    /**
     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
     * And also called before burning one token.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, `tokenId` will be burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
     * minting.
     * And also called after one token has been burned.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
     * transferred to `to`.
     * - When `from` is zero, `tokenId` has been minted for `to`.
     * - When `to` is zero, `tokenId` has been burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
}

contract MetaInvaders is Ownable, ERC721A, ReentrancyGuard, DefaultOperatorFilterer {
  using Strings for uint256;

  uint256 public MAX_PER_Transaction = 8; // maximam amount that user can mint/Transaction
  uint256 public MAX_PER_WALLET = 8; // maximam amount that user can mint/Wallet

  uint256 public PRICE = 0.1 ether; 

  uint256 private constant TotalCollectionSize_ = 9999; // total number of nfts
  uint256 private constant MaxMintPerBatch_ = 20; //max mint per transaction
  uint256 public TotalPhaseSize_ = 100;

  string private _baseTokenURI;

  uint public reserve = 0;
  uint public status = 0; //0-pause 1-whitelist 2-public
  mapping(address => bool) private whitelistedAddresses;
  mapping(address => uint256) public publicClaimedBy;

  uint256 public whiteListPerWallet = 1; //maximum amount that user can mint/Wallet in WL
  uint256 public MAX_PER_WL_TRANSACTION = 1; // maximum amount that user can mint/Transaction in WL
  mapping(address => uint256) public whiteListClaimedBy;
  uint256 private TotalWLavailable = 100; // total number of nfts in WL
  uint256 public WL_PRICE = 0 ether;

  constructor() ERC721A("Meta Invaders","MNV") {
  }

  modifier callerIsUser() {
    require(tx.origin == msg.sender, "The caller is another contract");
    _;
  }
 
  function mint(uint256 quantity) external payable callerIsUser {
    require(status == 1 && whitelistedAddresses[msg.sender] || status == 2 , "Sale is not Active");
    require(totalSupply() + quantity <= TotalCollectionSize_-reserve, "reached max supply");

    if(status == 1){

     require(totalSupply()+quantity<=TotalWLavailable,"Quantity must be lesser then MaxSupply");
     require(msg.value >= quantity * WL_PRICE, "Try to send more ETH");
     require(quantity <= MAX_PER_WL_TRANSACTION , "can not mint this many");

     whiteListClaimedBy[msg.sender] += quantity;
     require(whiteListClaimedBy[msg.sender] <= whiteListPerWallet, "Purchase exceeds max allowed");

    } else if(status == 2) {

    require(totalSupply() + quantity <= TotalPhaseSize_, "reached max phase supply");
     require(quantity <= MAX_PER_Transaction,"can not mint this many");
     require(msg.value >= PRICE * quantity, "Need to send more ETH.");

     publicClaimedBy[msg.sender] += quantity;
     require(publicClaimedBy[msg.sender] <= MAX_PER_WALLET, "Purchase exceeds max allowed");

    }

    _safeMint(msg.sender, quantity);
  }

   function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
    require(_exists(tokenId),"ERC721Metadata: URI query for nonexistent token");
    string memory baseURI = _baseURI();
    return
      bytes(baseURI).length > 0
        ? string(abi.encodePacked(baseURI, "/", tokenId.toString(), ".json")) : "";
  }
  
    function isWhitelisted(address _user) public view returns (bool) {
    return whitelistedAddresses[_user];
  }

  
  function addNewWhitelistUsers(address[] calldata _users) public onlyOwner {
    // ["","",""]
    for(uint i=0;i<_users.length;i++)
        whitelistedAddresses[_users[i]] = true;
  }

  function setBaseURI(string memory baseURI) external onlyOwner {
    _baseTokenURI = baseURI;
  }
  function _baseURI() internal view virtual override returns (string memory) {
    return _baseTokenURI;
  }

  function numberMinted(address owner) public view returns (uint256) {
    return _numberMinted(owner);
  }
  function getOwnershipData(uint256 tokenId)
    external
    view
    returns (TokenOwnership memory)
  {
    return _ownershipOf(tokenId);
  }

  function withdrawMoney() external onlyOwner nonReentrant {
    (bool success, ) = msg.sender.call{value: address(this).balance}("");
    require(success, "Transfer failed.");
  }

  function changeMintPrice(uint256 _newPrice) external onlyOwner
  {
      PRICE = _newPrice;
  }

  function changeMAX_PER_Transaction(uint256 q) external onlyOwner
  {
      MAX_PER_Transaction = q;
  }

     function changeMAX_PER_WALLET(uint256 q) external onlyOwner
  {
      MAX_PER_WALLET = q;
  }

  function setTotalPhaseSize(uint256 _collection) external onlyOwner
    {
        TotalPhaseSize_ = _collection;
    }


  function setStatus(uint256 s)external onlyOwner{
      status = s;
  }

  function setWL_Price(uint256 _newPrice) public onlyOwner() {
        WL_PRICE = _newPrice;
    }

   function getStatus()public view returns(uint){
      return status;
  }

 function setReserveTokens(uint256 _quantity) public onlyOwner {
        reserve=_quantity;
    }
    
  function getPrice(uint256 _quantity) public view returns (uint256) {
       
        return _quantity*PRICE;
    }

     function getWhitelistPrice(uint256 _quantity) public view returns (uint256) {
       
        return _quantity*WL_PRICE;
    }

 function mintReserveTokens(uint quantity) public onlyOwner {
        require(quantity <= reserve, "The quantity exceeds the reserve.");
        reserve -= quantity;
        _safeMint(msg.sender, quantity);

}

  function airdrop(address sendTo, uint quantity)public onlyOwner{
    require(totalSupply() + quantity <= TotalCollectionSize_, "reached max supply");
    _safeMint(sendTo, quantity);
  }

     function setWhiteListPerWallet(uint256 _whiteListPerWallet) external onlyOwner {
        whiteListPerWallet = _whiteListPerWallet;
    }

     function setWLavailable(uint256 _whiteListCollection) external onlyOwner {
        TotalWLavailable = _whiteListCollection;
    }

    function changeMAX_PER_WL_TRANSACTION(uint256 q) external onlyOwner
  {
      MAX_PER_WL_TRANSACTION = q;
  }

    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public override onlyAllowedOperator(from) {
        super.transferFrom(from, to, tokenId);
    }

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public override onlyAllowedOperator(from) {
        super.safeTransferFrom(from, to, tokenId);
    }

    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public override onlyAllowedOperator(from) {
        super.safeTransferFrom(from, to, tokenId, data);
    }
}

// File: OperatorFilterer.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

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

abstract contract OperatorFilterer {
    error OperatorNotAllowed(address operator);

    IOperatorFilterRegistry constant operatorFilterRegistry =
        IOperatorFilterRegistry(0x000000000000AAeB6D7670E522A718067333cd4E);

    constructor(address subscriptionOrRegistrantToCopy, bool subscribe) {
        // If an inheriting token contract is deployed to a network without the registry deployed, the modifier
        // will not revert, but the contract will need to be registered with the registry once it is deployed in
        // order for the modifier to filter addresses.
        if (address(operatorFilterRegistry).code.length > 0) {
            if (subscribe) {
                operatorFilterRegistry.registerAndSubscribe(
                    address(this),
                    subscriptionOrRegistrantToCopy
                );
            } else {
                if (subscriptionOrRegistrantToCopy != address(0)) {
                    operatorFilterRegistry.registerAndCopyEntries(
                        address(this),
                        subscriptionOrRegistrantToCopy
                    );
                } else {
                    operatorFilterRegistry.register(address(this));
                }
            }
        }
    }

    modifier onlyAllowedOperator(address from) virtual {
        // Check registry code length to facilitate testing in environments without a deployed registry.
        if (address(operatorFilterRegistry).code.length > 0) {
            // Allow spending tokens from addresses with balance
            // Note that this still allows listings and marketplaces with escrow to transfer tokens if transferred
            // from an EOA.
            if (from == msg.sender) {
                _;
                return;
            }
            if (
                !(operatorFilterRegistry.isOperatorAllowed(
                    address(this),
                    msg.sender
                ) &&
                    operatorFilterRegistry.isOperatorAllowed(
                        address(this),
                        from
                    ))
            ) {
                revert OperatorNotAllowed(msg.sender);
            }
        }
        _;
    }
}

// File: OperatorFilterRegistry.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

import {IOperatorFilterRegistry} from "./IOperatorFilterRegistry.sol";
import {Ownable} from "./Ownable.sol";
import {EnumerableSet} from "./EnumerableSet.sol";
import {OperatorFilterRegistryErrorsAndEvents} from "./OperatorFilterRegistryErrorsAndEvents.sol";

/**
 * @title  OperatorFilterRegistry
 * @notice Borrows heavily from the QQL BlacklistOperatorFilter contract:
 *         https://github.com/qql-art/contracts/blob/main/contracts/BlacklistOperatorFilter.sol
 * @notice This contracts allows tokens or token owners to register specific addresses or codeHashes that may be
 * *       restricted according to the isOperatorAllowed function.
 */
contract OperatorFilterRegistry is
    IOperatorFilterRegistry,
    OperatorFilterRegistryErrorsAndEvents
{
    using EnumerableSet for EnumerableSet.AddressSet;
    using EnumerableSet for EnumerableSet.Bytes32Set;

    /// @dev initialized accounts have a nonzero codehash (see https://eips.ethereum.org/EIPS/eip-1052)
    /// Note that this will also be a smart contract's codehash when making calls from its constructor.
    bytes32 constant EOA_CODEHASH = keccak256("");

    mapping(address => EnumerableSet.AddressSet) private _filteredOperators;
    mapping(address => EnumerableSet.Bytes32Set) private _filteredCodeHashes;
    mapping(address => address) private _registrations;
    mapping(address => EnumerableSet.AddressSet) private _subscribers;

    /**
     * @notice restricts method caller to the address or EIP-173 "owner()"
     */
    modifier onlyAddressOrOwner(address addr) {
        if (msg.sender != addr) {
            try Ownable(addr).owner() returns (address owner) {
                if (msg.sender != owner) {
                    revert OnlyAddressOrOwner();
                }
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert NotOwnable();
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }
        _;
    }

    /**
     * @notice Returns true if operator is not filtered for a given token, either by address or codeHash. Also returns
     *         true if supplied registrant address is not registered.
     */
    function isOperatorAllowed(address registrant, address operator)
        external
        view
        returns (bool)
    {
        address registration = _registrations[registrant];
        if (registration != address(0)) {
            EnumerableSet.AddressSet storage filteredOperatorsRef;
            EnumerableSet.Bytes32Set storage filteredCodeHashesRef;

            filteredOperatorsRef = _filteredOperators[registration];
            filteredCodeHashesRef = _filteredCodeHashes[registration];

            if (filteredOperatorsRef.contains(operator)) {
                revert AddressFiltered(operator);
            }
            if (operator.code.length > 0) {
                bytes32 codeHash = operator.codehash;
                if (filteredCodeHashesRef.contains(codeHash)) {
                    revert CodeHashFiltered(operator, codeHash);
                }
            }
        }
        return true;
    }

    //////////////////
    // AUTH METHODS //
    //////////////////

    /**
     * @notice Registers an address with the registry. May be called by address itself or by EIP-173 owner.
     */
    function register(address registrant)
        external
        onlyAddressOrOwner(registrant)
    {
        if (_registrations[registrant] != address(0)) {
            revert AlreadyRegistered();
        }
        _registrations[registrant] = registrant;
        emit RegistrationUpdated(registrant, true);
    }

    /**
     * @notice Unregisters an address with the registry and removes its subscription. May be called by address itself or by EIP-173 owner.
     *         Note that this does not remove any filtered addresses or codeHashes.
     *         Also note that any subscriptions to this registrant will still be active and follow the existing filtered addresses and codehashes.
     */
    function unregister(address registrant)
        external
        onlyAddressOrOwner(registrant)
    {
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            _subscribers[registration].remove(registrant);
            emit SubscriptionUpdated(registrant, registration, false);
        }
        _registrations[registrant] = address(0);
        emit RegistrationUpdated(registrant, false);
    }

    /**
     * @notice Registers an address with the registry and "subscribes" to another address's filtered operators and codeHashes.
     */
    function registerAndSubscribe(address registrant, address subscription)
        external
        onlyAddressOrOwner(registrant)
    {
        address registration = _registrations[registrant];
        if (registration != address(0)) {
            revert AlreadyRegistered();
        }
        if (registrant == subscription) {
            revert CannotSubscribeToSelf();
        }
        address subscriptionRegistration = _registrations[subscription];
        if (subscriptionRegistration == address(0)) {
            revert NotRegistered(subscription);
        }
        if (subscriptionRegistration != subscription) {
            revert CannotSubscribeToRegistrantWithSubscription(subscription);
        }

        _registrations[registrant] = subscription;
        _subscribers[subscription].add(registrant);
        emit RegistrationUpdated(registrant, true);
        emit SubscriptionUpdated(registrant, subscription, true);
    }

    /**
     * @notice Registers an address with the registry and copies the filtered operators and codeHashes from another
     *         address without subscribing.
     */
    function registerAndCopyEntries(
        address registrant,
        address registrantToCopy
    ) external onlyAddressOrOwner(registrant) {
        if (registrantToCopy == registrant) {
            revert CannotCopyFromSelf();
        }
        address registration = _registrations[registrant];
        if (registration != address(0)) {
            revert AlreadyRegistered();
        }
        address registrantRegistration = _registrations[registrantToCopy];
        if (registrantRegistration == address(0)) {
            revert NotRegistered(registrantToCopy);
        }
        _registrations[registrant] = registrant;
        emit RegistrationUpdated(registrant, true);
        _copyEntries(registrant, registrantToCopy);
    }

    /**
     * @notice Update an operator address for a registered address - when filtered is true, the operator is filtered.
     */
    function updateOperator(
        address registrant,
        address operator,
        bool filtered
    ) external onlyAddressOrOwner(registrant) {
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            revert CannotUpdateWhileSubscribed(registration);
        }
        EnumerableSet.AddressSet
            storage filteredOperatorsRef = _filteredOperators[registrant];

        if (!filtered) {
            bool removed = filteredOperatorsRef.remove(operator);
            if (!removed) {
                revert AddressNotFiltered(operator);
            }
        } else {
            bool added = filteredOperatorsRef.add(operator);
            if (!added) {
                revert AddressAlreadyFiltered(operator);
            }
        }
        emit OperatorUpdated(registrant, operator, filtered);
    }

    /**
     * @notice Update a codeHash for a registered address - when filtered is true, the codeHash is filtered.
     */
    function updateCodeHash(
        address registrant,
        bytes32 codeHash,
        bool filtered
    ) external onlyAddressOrOwner(registrant) {
        if (codeHash == EOA_CODEHASH) {
            revert CannotFilterEOAs();
        }
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            revert CannotUpdateWhileSubscribed(registration);
        }
        EnumerableSet.Bytes32Set
            storage filteredCodeHashesRef = _filteredCodeHashes[registrant];

        if (!filtered) {
            bool removed = filteredCodeHashesRef.remove(codeHash);
            if (!removed) {
                revert CodeHashNotFiltered(codeHash);
            }
        } else {
            bool added = filteredCodeHashesRef.add(codeHash);
            if (!added) {
                revert CodeHashAlreadyFiltered(codeHash);
            }
        }
        emit CodeHashUpdated(registrant, codeHash, filtered);
    }

    /**
     * @notice Update multiple operators for a registered address - when filtered is true, the operators will be filtered. Reverts on duplicates.
     */
    function updateOperators(
        address registrant,
        address[] calldata operators,
        bool filtered
    ) external onlyAddressOrOwner(registrant) {
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            revert CannotUpdateWhileSubscribed(registration);
        }
        EnumerableSet.AddressSet
            storage filteredOperatorsRef = _filteredOperators[registrant];
        uint256 operatorsLength = operators.length;
        unchecked {
            if (!filtered) {
                for (uint256 i = 0; i < operatorsLength; ++i) {
                    address operator = operators[i];
                    bool removed = filteredOperatorsRef.remove(operator);
                    if (!removed) {
                        revert AddressNotFiltered(operator);
                    }
                }
            } else {
                for (uint256 i = 0; i < operatorsLength; ++i) {
                    address operator = operators[i];
                    bool added = filteredOperatorsRef.add(operator);
                    if (!added) {
                        revert AddressAlreadyFiltered(operator);
                    }
                }
            }
        }
        emit OperatorsUpdated(registrant, operators, filtered);
    }

    /**
     * @notice Update multiple codeHashes for a registered address - when filtered is true, the codeHashes will be filtered. Reverts on duplicates.
     */
    function updateCodeHashes(
        address registrant,
        bytes32[] calldata codeHashes,
        bool filtered
    ) external onlyAddressOrOwner(registrant) {
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            revert CannotUpdateWhileSubscribed(registration);
        }
        EnumerableSet.Bytes32Set
            storage filteredCodeHashesRef = _filteredCodeHashes[registrant];
        uint256 codeHashesLength = codeHashes.length;
        unchecked {
            if (!filtered) {
                for (uint256 i = 0; i < codeHashesLength; ++i) {
                    bytes32 codeHash = codeHashes[i];
                    bool removed = filteredCodeHashesRef.remove(codeHash);
                    if (!removed) {
                        revert CodeHashNotFiltered(codeHash);
                    }
                }
            } else {
                for (uint256 i = 0; i < codeHashesLength; ++i) {
                    bytes32 codeHash = codeHashes[i];
                    if (codeHash == EOA_CODEHASH) {
                        revert CannotFilterEOAs();
                    }
                    bool added = filteredCodeHashesRef.add(codeHash);
                    if (!added) {
                        revert CodeHashAlreadyFiltered(codeHash);
                    }
                }
            }
        }
        emit CodeHashesUpdated(registrant, codeHashes, filtered);
    }

    /**
     * @notice Subscribe an address to another registrant's filtered operators and codeHashes. Will remove previous
     *         subscription if present.
     *         Note that accounts with subscriptions may go on to subscribe to other accounts - in this case,
     *         subscriptions will not be forwarded. Instead the former subscription's existing entries will still be
     *         used.
     */
    function subscribe(address registrant, address newSubscription)
        external
        onlyAddressOrOwner(registrant)
    {
        if (registrant == newSubscription) {
            revert CannotSubscribeToSelf();
        }
        if (newSubscription == address(0)) {
            revert CannotSubscribeToZeroAddress();
        }
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration == newSubscription) {
            revert AlreadySubscribed(newSubscription);
        }
        address newSubscriptionRegistration = _registrations[newSubscription];
        if (newSubscriptionRegistration == address(0)) {
            revert NotRegistered(newSubscription);
        }
        if (newSubscriptionRegistration != newSubscription) {
            revert CannotSubscribeToRegistrantWithSubscription(newSubscription);
        }

        if (registration != registrant) {
            _subscribers[registration].remove(registrant);
            emit SubscriptionUpdated(registrant, registration, false);
        }
        _registrations[registrant] = newSubscription;
        _subscribers[newSubscription].add(registrant);
        emit SubscriptionUpdated(registrant, newSubscription, true);
    }

    /**
     * @notice Unsubscribe an address from its current subscribed registrant, and optionally copy its filtered operators and codeHashes.
     */
    function unsubscribe(address registrant, bool copyExistingEntries)
        external
        onlyAddressOrOwner(registrant)
    {
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration == registrant) {
            revert NotSubscribed();
        }
        _subscribers[registration].remove(registrant);
        _registrations[registrant] = registrant;
        emit SubscriptionUpdated(registrant, registration, false);
        if (copyExistingEntries) {
            _copyEntries(registrant, registration);
        }
    }

    /**
     * @notice Copy filtered operators and codeHashes from a different registrantToCopy to addr.
     */
    function copyEntriesOf(address registrant, address registrantToCopy)
        external
        onlyAddressOrOwner(registrant)
    {
        if (registrant == registrantToCopy) {
            revert CannotCopyFromSelf();
        }
        address registration = _registrations[registrant];
        if (registration == address(0)) {
            revert NotRegistered(registrant);
        }
        if (registration != registrant) {
            revert CannotUpdateWhileSubscribed(registration);
        }
        address registrantRegistration = _registrations[registrantToCopy];
        if (registrantRegistration == address(0)) {
            revert NotRegistered(registrantToCopy);
        }
        _copyEntries(registrant, registrantToCopy);
    }

    /// @dev helper to copy entries from registrantToCopy to registrant and emit events
    function _copyEntries(address registrant, address registrantToCopy)
        private
    {
        EnumerableSet.AddressSet
            storage filteredOperatorsRef = _filteredOperators[registrantToCopy];
        EnumerableSet.Bytes32Set
            storage filteredCodeHashesRef = _filteredCodeHashes[
                registrantToCopy
            ];
        uint256 filteredOperatorsLength = filteredOperatorsRef.length();
        uint256 filteredCodeHashesLength = filteredCodeHashesRef.length();
        unchecked {
            for (uint256 i = 0; i < filteredOperatorsLength; ++i) {
                address operator = filteredOperatorsRef.at(i);
                bool added = _filteredOperators[registrant].add(operator);
                if (added) {
                    emit OperatorUpdated(registrant, operator, true);
                }
            }
            for (uint256 i = 0; i < filteredCodeHashesLength; ++i) {
                bytes32 codehash = filteredCodeHashesRef.at(i);
                bool added = _filteredCodeHashes[registrant].add(codehash);
                if (added) {
                    emit CodeHashUpdated(registrant, codehash, true);
                }
            }
        }
    }

    //////////////////
    // VIEW METHODS //
    //////////////////

    /**
     * @notice Get the subscription address of a given registrant, if any.
     */
    function subscriptionOf(address registrant)
        external
        view
        returns (address subscription)
    {
        subscription = _registrations[registrant];
        if (subscription == address(0)) {
            revert NotRegistered(registrant);
        } else if (subscription == registrant) {
            subscription = address(0);
        }
    }

    /**
     * @notice Get the set of addresses subscribed to a given registrant.
     *         Note that order is not guaranteed as updates are made.
     */
    function subscribers(address registrant)
        external
        view
        returns (address[] memory)
    {
        return _subscribers[registrant].values();
    }

    /**
     * @notice Get the subscriber at a given index in the set of addresses subscribed to a given registrant.
     *         Note that order is not guaranteed as updates are made.
     */
    function subscriberAt(address registrant, uint256 index)
        external
        view
        returns (address)
    {
        return _subscribers[registrant].at(index);
    }

    /**
     * @notice Returns true if operator is filtered by a given address or its subscription.
     */
    function isOperatorFiltered(address registrant, address operator)
        external
        view
        returns (bool)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredOperators[registration].contains(operator);
        }
        return _filteredOperators[registrant].contains(operator);
    }

    /**
     * @notice Returns true if a codeHash is filtered by a given address or its subscription.
     */
    function isCodeHashFiltered(address registrant, bytes32 codeHash)
        external
        view
        returns (bool)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredCodeHashes[registration].contains(codeHash);
        }
        return _filteredCodeHashes[registrant].contains(codeHash);
    }

    /**
     * @notice Returns true if the hash of an address's code is filtered by a given address or its subscription.
     */
    function isCodeHashOfFiltered(address registrant, address operatorWithCode)
        external
        view
        returns (bool)
    {
        bytes32 codeHash = operatorWithCode.codehash;
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredCodeHashes[registration].contains(codeHash);
        }
        return _filteredCodeHashes[registrant].contains(codeHash);
    }

    /**
     * @notice Returns true if an address has registered
     */
    function isRegistered(address registrant) external view returns (bool) {
        return _registrations[registrant] != address(0);
    }

    /**
     * @notice Returns a list of filtered operators for a given address or its subscription.
     */
    function filteredOperators(address registrant)
        external
        view
        returns (address[] memory)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredOperators[registration].values();
        }
        return _filteredOperators[registrant].values();
    }

    /**
     * @notice Returns the set of filtered codeHashes for a given address or its subscription.
     *         Note that order is not guaranteed as updates are made.
     */
    function filteredCodeHashes(address registrant)
        external
        view
        returns (bytes32[] memory)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredCodeHashes[registration].values();
        }
        return _filteredCodeHashes[registrant].values();
    }

    /**
     * @notice Returns the filtered operator at the given index of the set of filtered operators for a given address or
     *         its subscription.
     *         Note that order is not guaranteed as updates are made.
     */
    function filteredOperatorAt(address registrant, uint256 index)
        external
        view
        returns (address)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredOperators[registration].at(index);
        }
        return _filteredOperators[registrant].at(index);
    }

    /**
     * @notice Returns the filtered codeHash at the given index of the list of filtered codeHashes for a given address or
     *         its subscription.
     *         Note that order is not guaranteed as updates are made.
     */
    function filteredCodeHashAt(address registrant, uint256 index)
        external
        view
        returns (bytes32)
    {
        address registration = _registrations[registrant];
        if (registration != registrant) {
            return _filteredCodeHashes[registration].at(index);
        }
        return _filteredCodeHashes[registrant].at(index);
    }

    /// @dev Convenience method to compute the code hash of an arbitrary contract
    function codeHashOf(address a) external view returns (bytes32) {
        return a.codehash;
    }
}

// File: OperatorFilterRegistryErrorsAndEvents.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

contract OperatorFilterRegistryErrorsAndEvents {
    error CannotFilterEOAs();
    error AddressAlreadyFiltered(address operator);
    error AddressNotFiltered(address operator);
    error CodeHashAlreadyFiltered(bytes32 codeHash);
    error CodeHashNotFiltered(bytes32 codeHash);
    error OnlyAddressOrOwner();
    error NotRegistered(address registrant);
    error AlreadyRegistered();
    error AlreadySubscribed(address subscription);
    error NotSubscribed();
    error CannotUpdateWhileSubscribed(address subscription);
    error CannotSubscribeToSelf();
    error CannotSubscribeToZeroAddress();
    error NotOwnable();
    error AddressFiltered(address filtered);
    error CodeHashFiltered(address account, bytes32 codeHash);
    error CannotSubscribeToRegistrantWithSubscription(address registrant);
    error CannotCopyFromSelf();

    event RegistrationUpdated(address indexed registrant, bool indexed registered);
    event OperatorUpdated(address indexed registrant, address indexed operator, bool indexed filtered);
    event OperatorsUpdated(address indexed registrant, address[] operators, bool indexed filtered);
    event CodeHashUpdated(address indexed registrant, bytes32 indexed codeHash, bool indexed filtered);
    event CodeHashesUpdated(address indexed registrant, bytes32[] codeHashes, bool indexed filtered);
    event SubscriptionUpdated(address indexed registrant, address indexed subscription, bool indexed subscribed);
}

// File: Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: Ownable2Step.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (access/Ownable2Step.sol)

pragma solidity ^0.8.0;

import "./Ownable.sol";

/**
 * @dev Contract module which provides access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2Step is Ownable {
    address private _pendingOwner;

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

    /**
     * @dev Returns the address of the pending owner.
     */
    function pendingOwner() public view virtual returns (address) {
        return _pendingOwner;
    }

    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner)
        public
        virtual
        override
        onlyOwner
    {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }

    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() external {
        address sender = _msgSender();
        require(
            pendingOwner() == sender,
            "Ownable2Step: caller is not the new owner"
        );
        _transferOwnership(sender);
    }
}

// File: OwnedRegistrant.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

import {IOperatorFilterRegistry} from "./IOperatorFilterRegistry.sol";
import {Ownable2Step} from "./Ownable2Step.sol";

/**
 * @title  OwnedRegistrant
 * @notice Ownable contract that registers itself with the OperatorFilterRegistry and administers its own entries,
 *         to facilitate a subscription whose ownership can be transferred.
 */
contract OwnedRegistrant is Ownable2Step {
    address constant registry = 0x000000000000AAeB6D7670E522A718067333cd4E;

    constructor(address _owner) {
        IOperatorFilterRegistry(registry).register(address(this));
        transferOwnership(_owner);
    }
}