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Contract Name:
Goobaloo

Contract Source Code:

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "./OwnablePermissions.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

abstract contract OwnableBasic is OwnablePermissions, Ownable {
    function _requireCallerIsContractOwner() internal view virtual override {
        _checkOwner();
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/utils/Context.sol";

abstract contract OwnablePermissions is Context {
    function _requireCallerIsContractOwner() internal view virtual;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../utils/CreatorTokenBase.sol";
import "erc721a/contracts/ERC721A.sol";

/**
 * @title ERC721AC
 * @author Limit Break, Inc.
 * @notice Extends Azuki's ERC721-A implementation with Creator Token functionality, which
 *         allows the contract owner to update the transfer validation logic by managing a security policy in
 *         an external transfer validation security policy registry.  See {CreatorTokenTransferValidator}.
 */
abstract contract ERC721AC is ERC721A, CreatorTokenBase {

    constructor(string memory name_, string memory symbol_) CreatorTokenBase() ERC721A(name_, symbol_) {}

    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(ICreatorToken).interfaceId || super.supportsInterface(interfaceId);
    }

    /// @dev Ties the erc721a _beforeTokenTransfers hook to more granular transfer validation logic
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual override {
        for (uint256 i = 0; i < quantity;) {
            _validateBeforeTransfer(from, to, startTokenId + i);
            unchecked {
                ++i;
            }
        }
    }

    /// @dev Ties the erc721a _afterTokenTransfer hook to more granular transfer validation logic
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual override {
        for (uint256 i = 0; i < quantity;) {
            _validateAfterTransfer(from, to, startTokenId + i);
            unchecked {
                ++i;
            }
        }
    }

    function _msgSenderERC721A() internal view virtual override returns (address) {
        return _msgSender();
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../interfaces/ICreatorTokenTransferValidator.sol";

interface ICreatorToken {
    event TransferValidatorUpdated(address oldValidator, address newValidator);

    function getTransferValidator() external view returns (ICreatorTokenTransferValidator);
    function getSecurityPolicy() external view returns (CollectionSecurityPolicy memory);
    function getWhitelistedOperators() external view returns (address[] memory);
    function getPermittedContractReceivers() external view returns (address[] memory);
    function isOperatorWhitelisted(address operator) external view returns (bool);
    function isContractReceiverPermitted(address receiver) external view returns (bool);
    function isTransferAllowed(address caller, address from, address to) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "./IEOARegistry.sol";
import "./ITransferSecurityRegistry.sol";
import "./ITransferValidator.sol";

interface ICreatorTokenTransferValidator is ITransferSecurityRegistry, ITransferValidator, IEOARegistry {}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface IEOARegistry is IERC165 {
    function isVerifiedEOA(address account) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../utils/TransferPolicy.sol";

interface ITransferSecurityRegistry {
    event AddedToAllowlist(AllowlistTypes indexed kind, uint256 indexed id, address indexed account);
    event CreatedAllowlist(AllowlistTypes indexed kind, uint256 indexed id, string indexed name);
    event ReassignedAllowlistOwnership(AllowlistTypes indexed kind, uint256 indexed id, address indexed newOwner);
    event RemovedFromAllowlist(AllowlistTypes indexed kind, uint256 indexed id, address indexed account);
    event SetAllowlist(AllowlistTypes indexed kind, address indexed collection, uint120 indexed id);
    event SetTransferSecurityLevel(address indexed collection, TransferSecurityLevels level);

    function createOperatorWhitelist(string calldata name) external returns (uint120);
    function createPermittedContractReceiverAllowlist(string calldata name) external returns (uint120);
    function reassignOwnershipOfOperatorWhitelist(uint120 id, address newOwner) external;
    function reassignOwnershipOfPermittedContractReceiverAllowlist(uint120 id, address newOwner) external;
    function renounceOwnershipOfOperatorWhitelist(uint120 id) external;
    function renounceOwnershipOfPermittedContractReceiverAllowlist(uint120 id) external;
    function setTransferSecurityLevelOfCollection(address collection, TransferSecurityLevels level) external;
    function setOperatorWhitelistOfCollection(address collection, uint120 id) external;
    function setPermittedContractReceiverAllowlistOfCollection(address collection, uint120 id) external;
    function addOperatorToWhitelist(uint120 id, address operator) external;
    function addPermittedContractReceiverToAllowlist(uint120 id, address receiver) external;
    function removeOperatorFromWhitelist(uint120 id, address operator) external;
    function removePermittedContractReceiverFromAllowlist(uint120 id, address receiver) external;
    function getCollectionSecurityPolicy(address collection) external view returns (CollectionSecurityPolicy memory);
    function getWhitelistedOperators(uint120 id) external view returns (address[] memory);
    function getPermittedContractReceivers(uint120 id) external view returns (address[] memory);
    function isOperatorWhitelisted(uint120 id, address operator) external view returns (bool);
    function isContractReceiverPermitted(uint120 id, address receiver) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../utils/TransferPolicy.sol";

interface ITransferValidator {
    function applyCollectionTransferPolicy(address caller, address from, address to) external view;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../access/OwnablePermissions.sol";
import "@openzeppelin/contracts/interfaces/IERC2981.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";

/**
 * @title ImmutableMinterRoyaltiesBase
 * @author Limit Break, Inc.
 * @dev Base functionality of an NFT mix-in contract implementing programmable royalties for minters
 */
abstract contract ImmutableMinterRoyaltiesBase is IERC2981, ERC165 {

    error ImmutableMinterRoyalties__MinterCannotBeZeroAddress();
    error ImmutableMinterRoyalties__MinterHasAlreadyBeenAssignedToTokenId();
    error ImmutableMinterRoyalties__RoyaltyFeeWillExceedSalePrice();

    uint256 public constant FEE_DENOMINATOR = 10_000;
    uint256 private _royaltyFeeNumerator;

    mapping (uint256 => address) private _minters;

    /**
     * @notice Indicates whether the contract implements the specified interface.
     * @dev Overrides supportsInterface in ERC165.
     * @param interfaceId The interface id
     * @return true if the contract implements the specified interface, false otherwise
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC2981).interfaceId || super.supportsInterface(interfaceId);
    }

    function royaltyFeeNumerator() public virtual view returns (uint256) {
        return _royaltyFeeNumerator;
    }

    /**
     * @notice Returns the royalty info for a given token ID and sale price.
     * @dev Implements the IERC2981 interface.
     * @param tokenId The token ID
     * @param salePrice The sale price
     * @return receiver The minter's address
     * @return royaltyAmount The royalty amount
     */
    function royaltyInfo(
        uint256 tokenId,
        uint256 salePrice
    ) external view override returns (address receiver, uint256 royaltyAmount) {
        return (_minters[tokenId], (salePrice * royaltyFeeNumerator()) / FEE_DENOMINATOR);
    }

    /**
     * @dev Internal function to be called when a new token is minted.
     *
     * @dev Throws when the minter is the zero address.
     * @dev Throws when a minter has already been assigned to the specified token ID.
     * @param minter The minter's address
     * @param tokenId The token ID
     */
    function _onMinted(address minter, uint256 tokenId) internal {
        if (minter == address(0)) {
            revert ImmutableMinterRoyalties__MinterCannotBeZeroAddress();
        }

        if (_minters[tokenId] != address(0)) {
            revert ImmutableMinterRoyalties__MinterHasAlreadyBeenAssignedToTokenId();
        }

        _minters[tokenId] = minter;
    }

    /**
     * @dev Internal function to be called when a token is burned.  Clears the minter's address.
     * @param tokenId The token ID
     */
    function _onBurned(uint256 tokenId) internal {
        delete _minters[tokenId];
    }

    function _setRoyaltyFeeNumerator(uint256 royaltyFeeNumerator_) internal {
        if(royaltyFeeNumerator_ > FEE_DENOMINATOR) {
            revert ImmutableMinterRoyalties__RoyaltyFeeWillExceedSalePrice();
        }

        _royaltyFeeNumerator = royaltyFeeNumerator_;
    }
}

/**
 * @title ImmutableMinterRoyalties
 * @author Limit Break, Inc.
 * @notice Constructable ImmutableMinterRoyalties Contract implementation.
 */
abstract contract ImmutableMinterRoyalties is ImmutableMinterRoyaltiesBase {

    uint256 private immutable _royaltyFeeNumeratorImmutable;

    constructor(uint256 royaltyFeeNumerator_) {
        _setRoyaltyFeeNumerator(royaltyFeeNumerator_);
        _royaltyFeeNumeratorImmutable = royaltyFeeNumerator_;
    }

    function royaltyFeeNumerator() public view override returns (uint256) {
        return _royaltyFeeNumeratorImmutable;
    }
}

/**
 * @title ImmutableMinterRoyaltiesInitializable
 * @author Limit Break, Inc.
 * @notice Initializable ImmutableMinterRoyalties Contract implementation to allow for EIP-1167 clones. 
 */
abstract contract ImmutableMinterRoyaltiesInitializable is OwnablePermissions, ImmutableMinterRoyaltiesBase {

    error ImmutableMinterRoyaltiesInitializable__MinterRoyaltyFeeAlreadyInitialized();

    bool private _minterRoyaltyFeeInitialized;

    function initializeMinterRoyaltyFee(uint256 royaltyFeeNumerator_) public {
        _requireCallerIsContractOwner();

        if(_minterRoyaltyFeeInitialized) {
            revert ImmutableMinterRoyaltiesInitializable__MinterRoyaltyFeeAlreadyInitialized();
        }

        _minterRoyaltyFeeInitialized = true;

        _setRoyaltyFeeNumerator(royaltyFeeNumerator_);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "../access/OwnablePermissions.sol";
import "../interfaces/ICreatorToken.sol";
import "../interfaces/ICreatorTokenTransferValidator.sol";
import "../utils/TransferValidation.sol";
import "@openzeppelin/contracts/interfaces/IERC165.sol";

/**
 * @title CreatorTokenBase
 * @author Limit Break, Inc.
 * @notice CreatorTokenBase is an abstract contract that provides basic functionality for managing token 
 * transfer policies through an implementation of ICreatorTokenTransferValidator. This contract is intended to be used
 * as a base for creator-specific token contracts, enabling customizable transfer restrictions and security policies.
 *
 * <h4>Features:</h4>
 * <ul>Ownable: This contract can have an owner who can set and update the transfer validator.</ul>
 * <ul>TransferValidation: Implements the basic token transfer validation interface.</ul>
 * <ul>ICreatorToken: Implements the interface for creator tokens, providing view functions for token security policies.</ul>
 *
 * <h4>Benefits:</h4>
 * <ul>Provides a flexible and modular way to implement custom token transfer restrictions and security policies.</ul>
 * <ul>Allows creators to enforce policies such as whitelisted operators and permitted contract receivers.</ul>
 * <ul>Can be easily integrated into other token contracts as a base contract.</ul>
 *
 * <h4>Intended Usage:</h4>
 * <ul>Use as a base contract for creator token implementations that require advanced transfer restrictions and 
 *   security policies.</ul>
 * <ul>Set and update the ICreatorTokenTransferValidator implementation contract to enforce desired policies for the 
 *   creator token.</ul>
 */
abstract contract CreatorTokenBase is OwnablePermissions, TransferValidation, ICreatorToken {
    
    error CreatorTokenBase__InvalidTransferValidatorContract();
    error CreatorTokenBase__SetTransferValidatorFirst();

    address public constant DEFAULT_TRANSFER_VALIDATOR = address(0x0000721C310194CcfC01E523fc93C9cCcFa2A0Ac);
    TransferSecurityLevels public constant DEFAULT_TRANSFER_SECURITY_LEVEL = TransferSecurityLevels.One;
    uint120 public constant DEFAULT_OPERATOR_WHITELIST_ID = uint120(1);

    ICreatorTokenTransferValidator private transferValidator;

    /**
     * @notice Allows the contract owner to set the transfer validator to the official validator contract
     *         and set the security policy to the recommended default settings.
     * @dev    May be overridden to change the default behavior of an individual collection.
     */
    function setToDefaultSecurityPolicy() public virtual {
        _requireCallerIsContractOwner();
        setTransferValidator(DEFAULT_TRANSFER_VALIDATOR);
        ICreatorTokenTransferValidator(DEFAULT_TRANSFER_VALIDATOR).setTransferSecurityLevelOfCollection(address(this), DEFAULT_TRANSFER_SECURITY_LEVEL);
        ICreatorTokenTransferValidator(DEFAULT_TRANSFER_VALIDATOR).setOperatorWhitelistOfCollection(address(this), DEFAULT_OPERATOR_WHITELIST_ID);
    }

    /**
     * @notice Allows the contract owner to set the transfer validator to a custom validator contract
     *         and set the security policy to their own custom settings.
     */
    function setToCustomValidatorAndSecurityPolicy(
        address validator, 
        TransferSecurityLevels level, 
        uint120 operatorWhitelistId, 
        uint120 permittedContractReceiversAllowlistId) public {
        _requireCallerIsContractOwner();

        setTransferValidator(validator);

        ICreatorTokenTransferValidator(validator).
            setTransferSecurityLevelOfCollection(address(this), level);

        ICreatorTokenTransferValidator(validator).
            setOperatorWhitelistOfCollection(address(this), operatorWhitelistId);

        ICreatorTokenTransferValidator(validator).
            setPermittedContractReceiverAllowlistOfCollection(address(this), permittedContractReceiversAllowlistId);
    }

    /**
     * @notice Allows the contract owner to set the security policy to their own custom settings.
     * @dev    Reverts if the transfer validator has not been set.
     */
    function setToCustomSecurityPolicy(
        TransferSecurityLevels level, 
        uint120 operatorWhitelistId, 
        uint120 permittedContractReceiversAllowlistId) public {
        _requireCallerIsContractOwner();

        ICreatorTokenTransferValidator validator = getTransferValidator();
        if (address(validator) == address(0)) {
            revert CreatorTokenBase__SetTransferValidatorFirst();
        }

        validator.setTransferSecurityLevelOfCollection(address(this), level);
        validator.setOperatorWhitelistOfCollection(address(this), operatorWhitelistId);
        validator.setPermittedContractReceiverAllowlistOfCollection(address(this), permittedContractReceiversAllowlistId);
    }

    /**
     * @notice Sets the transfer validator for the token contract.
     *
     * @dev    Throws when provided validator contract is not the zero address and doesn't support 
     *         the ICreatorTokenTransferValidator interface. 
     * @dev    Throws when the caller is not the contract owner.
     *
     * @dev    <h4>Postconditions:</h4>
     *         1. The transferValidator address is updated.
     *         2. The `TransferValidatorUpdated` event is emitted.
     *
     * @param transferValidator_ The address of the transfer validator contract.
     */
    function setTransferValidator(address transferValidator_) public {
        _requireCallerIsContractOwner();

        bool isValidTransferValidator = false;

        if(transferValidator_.code.length > 0) {
            try IERC165(transferValidator_).supportsInterface(type(ICreatorTokenTransferValidator).interfaceId) 
                returns (bool supportsInterface) {
                isValidTransferValidator = supportsInterface;
            } catch {}
        }

        if(transferValidator_ != address(0) && !isValidTransferValidator) {
            revert CreatorTokenBase__InvalidTransferValidatorContract();
        }

        emit TransferValidatorUpdated(address(transferValidator), transferValidator_);

        transferValidator = ICreatorTokenTransferValidator(transferValidator_);
    }

    /**
     * @notice Returns the transfer validator contract address for this token contract.
     */
    function getTransferValidator() public view override returns (ICreatorTokenTransferValidator) {
        return transferValidator;
    }

    /**
     * @notice Returns the security policy for this token contract, which includes:
     *         Transfer security level, operator whitelist id, permitted contract receiver allowlist id.
     */
    function getSecurityPolicy() public view override returns (CollectionSecurityPolicy memory) {
        if (address(transferValidator) != address(0)) {
            return transferValidator.getCollectionSecurityPolicy(address(this));
        }

        return CollectionSecurityPolicy({
            transferSecurityLevel: TransferSecurityLevels.Zero,
            operatorWhitelistId: 0,
            permittedContractReceiversId: 0
        });
    }

    /**
     * @notice Returns the list of all whitelisted operators for this token contract.
     * @dev    This can be an expensive call and should only be used in view-only functions.
     */
    function getWhitelistedOperators() public view override returns (address[] memory) {
        if (address(transferValidator) != address(0)) {
            return transferValidator.getWhitelistedOperators(
                transferValidator.getCollectionSecurityPolicy(address(this)).operatorWhitelistId);
        }

        return new address[](0);
    }

    /**
     * @notice Returns the list of permitted contract receivers for this token contract.
     * @dev    This can be an expensive call and should only be used in view-only functions.
     */
    function getPermittedContractReceivers() public view override returns (address[] memory) {
        if (address(transferValidator) != address(0)) {
            return transferValidator.getPermittedContractReceivers(
                transferValidator.getCollectionSecurityPolicy(address(this)).permittedContractReceiversId);
        }

        return new address[](0);
    }

    /**
     * @notice Checks if an operator is whitelisted for this token contract.
     * @param operator The address of the operator to check.
     */
    function isOperatorWhitelisted(address operator) public view override returns (bool) {
        if (address(transferValidator) != address(0)) {
            return transferValidator.isOperatorWhitelisted(
                transferValidator.getCollectionSecurityPolicy(address(this)).operatorWhitelistId, operator);
        }

        return false;
    }

    /**
     * @notice Checks if a contract receiver is permitted for this token contract.
     * @param receiver The address of the receiver to check.
     */
    function isContractReceiverPermitted(address receiver) public view override returns (bool) {
        if (address(transferValidator) != address(0)) {
            return transferValidator.isContractReceiverPermitted(
                transferValidator.getCollectionSecurityPolicy(address(this)).permittedContractReceiversId, receiver);
        }

        return false;
    }

    /**
     * @notice Determines if a transfer is allowed based on the token contract's security policy.  Use this function
     *         to simulate whether or not a transfer made by the specified `caller` from the `from` address to the `to`
     *         address would be allowed by this token's security policy.
     *
     * @notice This function only checks the security policy restrictions and does not check whether token ownership
     *         or approvals are in place. 
     *
     * @param caller The address of the simulated caller.
     * @param from   The address of the sender.
     * @param to     The address of the receiver.
     * @return       True if the transfer is allowed, false otherwise.
     */
    function isTransferAllowed(address caller, address from, address to) public view override returns (bool) {
        if (address(transferValidator) != address(0)) {
            try transferValidator.applyCollectionTransferPolicy(caller, from, to) {
                return true;
            } catch {
                return false;
            }
        }
        return true;
    }

    /**
     * @dev Pre-validates a token transfer, reverting if the transfer is not allowed by this token's security policy.
     *      Inheriting contracts are responsible for overriding the _beforeTokenTransfer function, or its equivalent
     *      and calling _validateBeforeTransfer so that checks can be properly applied during token transfers.
     *
     * @dev Throws when the transfer doesn't comply with the collection's transfer policy, if the transferValidator is
     *      set to a non-zero address.
     *
     * @param caller  The address of the caller.
     * @param from    The address of the sender.
     * @param to      The address of the receiver.
     */
    function _preValidateTransfer(
        address caller, 
        address from, 
        address to, 
        uint256 /*tokenId*/, 
        uint256 /*value*/) internal virtual override {
        if (address(transferValidator) != address(0)) {
            transferValidator.applyCollectionTransferPolicy(caller, from, to);
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

enum AllowlistTypes {
    Operators,
    PermittedContractReceivers
}

enum ReceiverConstraints {
    None,
    NoCode,
    EOA
}

enum CallerConstraints {
    None,
    OperatorWhitelistEnableOTC,
    OperatorWhitelistDisableOTC
}

enum StakerConstraints {
    None,
    CallerIsTxOrigin,
    EOA
}

enum TransferSecurityLevels {
    Zero,
    One,
    Two,
    Three,
    Four,
    Five,
    Six
}

struct TransferSecurityPolicy {
    CallerConstraints callerConstraints;
    ReceiverConstraints receiverConstraints;
}

struct CollectionSecurityPolicy {
    TransferSecurityLevels transferSecurityLevel;
    uint120 operatorWhitelistId;
    uint120 permittedContractReceiversId;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/utils/Context.sol";

/**
 * @title TransferValidation
 * @author Limit Break, Inc.
 * @notice A mix-in that can be combined with ERC-721 contracts to provide more granular hooks.
 * Openzeppelin's ERC721 contract only provides hooks for before and after transfer.  This allows
 * developers to validate or customize transfers within the context of a mint, a burn, or a transfer.
 */
abstract contract TransferValidation is Context {
    
    error ShouldNotMintToBurnAddress();

    /// @dev Inheriting contracts should call this function in the _beforeTokenTransfer function to get more granular hooks.
    function _validateBeforeTransfer(address from, address to, uint256 tokenId) internal virtual {
        bool fromZeroAddress = from == address(0);
        bool toZeroAddress = to == address(0);

        if(fromZeroAddress && toZeroAddress) {
            revert ShouldNotMintToBurnAddress();
        } else if(fromZeroAddress) {
            _preValidateMint(_msgSender(), to, tokenId, msg.value);
        } else if(toZeroAddress) {
            _preValidateBurn(_msgSender(), from, tokenId, msg.value);
        } else {
            _preValidateTransfer(_msgSender(), from, to, tokenId, msg.value);
        }
    }

    /// @dev Inheriting contracts should call this function in the _afterTokenTransfer function to get more granular hooks.
    function _validateAfterTransfer(address from, address to, uint256 tokenId) internal virtual {
        bool fromZeroAddress = from == address(0);
        bool toZeroAddress = to == address(0);

        if(fromZeroAddress && toZeroAddress) {
            revert ShouldNotMintToBurnAddress();
        } else if(fromZeroAddress) {
            _postValidateMint(_msgSender(), to, tokenId, msg.value);
        } else if(toZeroAddress) {
            _postValidateBurn(_msgSender(), from, tokenId, msg.value);
        } else {
            _postValidateTransfer(_msgSender(), from, to, tokenId, msg.value);
        }
    }

    /// @dev Optional validation hook that fires before a mint
    function _preValidateMint(address caller, address to, uint256 tokenId, uint256 value) internal virtual {}

    /// @dev Optional validation hook that fires after a mint
    function _postValidateMint(address caller, address to, uint256 tokenId, uint256 value) internal virtual {}

    /// @dev Optional validation hook that fires before a burn
    function _preValidateBurn(address caller, address from, uint256 tokenId, uint256 value) internal virtual {}

    /// @dev Optional validation hook that fires after a burn
    function _postValidateBurn(address caller, address from, uint256 tokenId, uint256 value) internal virtual {}

    /// @dev Optional validation hook that fires before a transfer
    function _preValidateTransfer(address caller, address from, address to, uint256 tokenId, uint256 value) internal virtual {}

    /// @dev Optional validation hook that fires after a transfer
    function _postValidateTransfer(address caller, address from, address to, uint256 tokenId, uint256 value) internal virtual {}
}

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

pragma solidity ^0.8.0;

import "../utils/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. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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);
    }
}

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

pragma solidity ^0.8.0;

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC2981.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Interface for the NFT Royalty Standard.
 *
 * A standardized way to retrieve royalty payment information for non-fungible tokens (NFTs) to enable universal
 * support for royalty payments across all NFT marketplaces and ecosystem participants.
 *
 * _Available since v4.5._
 */
interface IERC2981 is IERC165 {
    /**
     * @dev Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of
     * exchange. The royalty amount is denominated and should be paid in that same unit of exchange.
     */
    function royaltyInfo(
        uint256 tokenId,
        uint256 salePrice
    ) external view returns (address receiver, uint256 royaltyAmount);
}

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

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.6) (utils/Base64.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides a set of functions to operate with Base64 strings.
 *
 * _Available since v4.5._
 */
library Base64 {
    /**
     * @dev Base64 Encoding/Decoding Table
     */
    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    /**
     * @dev Converts a `bytes` to its Bytes64 `string` representation.
     */
    function encode(bytes memory data) internal pure returns (string memory) {
        /**
         * Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
         * https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
         */
        if (data.length == 0) return "";

        // Loads the table into memory
        string memory table = _TABLE;

        // Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
        // and split into 4 numbers of 6 bits.
        // The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
        // - `data.length + 2`  -> Round up
        // - `/ 3`              -> Number of 3-bytes chunks
        // - `4 *`              -> 4 characters for each chunk
        string memory result = new string(4 * ((data.length + 2) / 3));

        /// @solidity memory-safe-assembly
        assembly {
            // Prepare the lookup table (skip the first "length" byte)
            let tablePtr := add(table, 1)

            // Prepare result pointer, jump over length
            let resultPtr := add(result, 0x20)
            let dataPtr := data
            let endPtr := add(data, mload(data))

            // In some cases, the last iteration will read bytes after the end of the data. We cache the value, and
            // set it to zero to make sure no dirty bytes are read in that section.
            let afterPtr := add(endPtr, 0x20)
            let afterCache := mload(afterPtr)
            mstore(afterPtr, 0x00)

            // Run over the input, 3 bytes at a time
            for {

            } lt(dataPtr, endPtr) {

            } {
                // Advance 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // To write each character, shift the 3 byte (24 bits) chunk
                // 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
                // and apply logical AND with 0x3F to bitmask the least significant 6 bits.
                // Use this as an index into the lookup table, mload an entire word
                // so the desired character is in the least significant byte, and
                // mstore8 this least significant byte into the result and continue.

                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance
            }

            // Reset the value that was cached
            mstore(afterPtr, afterCache)

            // When data `bytes` is not exactly 3 bytes long
            // it is padded with `=` characters at the end
            switch mod(mload(data), 3)
            case 1 {
                mstore8(sub(resultPtr, 1), 0x3d)
                mstore8(sub(resultPtr, 2), 0x3d)
            }
            case 2 {
                mstore8(sub(resultPtr, 1), 0x3d)
            }
        }

        return result;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.4) (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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

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

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV // Deprecated in v4.8
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

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

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }

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

        return (signer, RecoverError.NoError);
    }

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

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, "\x19Ethereum Signed Message:\n32")
            mstore(0x1c, hash)
            message := keccak256(0x00, 0x3c)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
        /// @solidity memory-safe-assembly
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, "\x19\x01")
            mstore(add(ptr, 0x02), domainSeparator)
            mstore(add(ptr, 0x22), structHash)
            data := keccak256(ptr, 0x42)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Data with intended validator, created from a
     * `validator` and `data` according to the version 0 of EIP-191.
     *
     * See {recover}.
     */
    function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x00", validator, data));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

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

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

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

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

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

pragma solidity ^0.8.0;

import "./math/Math.sol";
import "./math/SignedMath.sol";

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `int256` to its ASCII `string` decimal representation.
     */
    function toString(int256 value) internal pure returns (string memory) {
        return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed 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] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }

    /**
     * @dev Returns true if the two strings are equal.
     */
    function equal(string memory a, string memory b) internal pure returns (bool) {
        return keccak256(bytes(a)) == keccak256(bytes(b));
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@limitbreak/creator-token-contracts/contracts/access/OwnableBasic.sol";
import "@limitbreak/creator-token-contracts/contracts/erc721c/ERC721AC.sol";
import "@limitbreak/creator-token-contracts/contracts/programmable-royalties/ImmutableMinterRoyalties.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/Base64.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";

interface IGoobalooData {
    function getGoobalooSVG(
        uint256 tokenId
    ) external view returns (string memory);

    function getTraits(uint256 tokenId) external view returns (string memory);
}

contract Goobaloo is
    OwnableBasic,
    ERC721AC,
    ImmutableMinterRoyalties,
    ReentrancyGuard
{
    using ECDSA for bytes32;
    using Strings for uint256;

    // Pack booleans together in a single slot
    struct TokenData {
        bool backgroundChanged;
        bool usesSecondaryColor;
        bool hasClaimedShare;
    }
    mapping(uint256 => TokenData) public tokenData;

    // Group immutable/constant variables
    uint256 public constant MAX_SUPPLY = 2222;
    uint256 public MINT_PRICE;
    uint256 public MAX_MINTS_PER_WALLET;
    uint256 public COLOR_CHANGE_PRICE;
    uint256 public immutable GAME_END_TIME;

    // Group addresses together
    address private signer;
    address private metadataContract;

    // Group counters together
    uint256 private defaultCount;
    uint256 private aquamarineCount;
    uint256 private orangeCount;
    uint256 private totalColorChangeFees;

    mapping(address => uint256) public mintedPerWallet;
    string private constant DEFAULT_BACKGROUND = "#0054fa";
    string private constant AQUAMARINE = "#16E6B6";
    string private constant ORANGE = "#EF9729";

    error SameColorAlreadySet();
    error InvalidColorChoice();
    error GameEnded();
    error GameNotEnded();
    error AlreadyClaimed();
    error NoWinningColor();
    error MaxSupplyExceeded();
    error GameNotEndedOrNotTied();

    // Add winning color state
    struct WinningColorState {
        uint8 color; // 0 = default, 1 = aquamarine, 2 = orange
        bool isTie;
    }
    WinningColorState public currentWinningColor;

    // Simplify event to only emit new state
    event WinningColorChanged(uint8 newWinningColor, bool isTie);

    // Add mapping to track who has used their free mint
    mapping(address => bool) public hasUsedFreeMint;

    // Add state variable for signature requirement
    bool public signatureRequired = true;

    // Add event at the top with other events
    event MetadataUpdate(uint256 _tokenId);

    bytes32 constant MINT_TYPEHASH = keccak256("Mint(address minter)");
    bytes32 constant FREEMINT_TYPEHASH = keccak256("FreeMint(address minter)");

    // Add domain separator for EIP-712
    bytes32 public immutable DOMAIN_SEPARATOR =
        keccak256(
            abi.encode(
                keccak256(
                    "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
                ),
                keccak256(bytes("Goobaloo")),
                keccak256(bytes("1")),
                block.chainid,
                address(this)
            )
        );

    // Add state variable to track if metadata contract is locked
    bool public isMetadataContractLocked;

    // Add error for locked metadata
    error MetadataContractLocked();

    constructor(
        uint256 royaltyFeeNumerator_,
        string memory name_,
        string memory symbol_,
        uint256 mintPrice_,
        uint256 maxMintsPerWallet_,
        uint256 colorChangePrice_,
        address transferValidator_
    ) ERC721AC(name_, symbol_) ImmutableMinterRoyalties(royaltyFeeNumerator_) {
        if (transferValidator_ != address(0)) {
            setTransferValidator(transferValidator_);
        }
        signer = address(msg.sender);
        GAME_END_TIME = block.timestamp + 1 weeks;
        defaultCount = MAX_SUPPLY;
        currentWinningColor = WinningColorState(0, false);
        MINT_PRICE = mintPrice_;
        MAX_MINTS_PER_WALLET = maxMintsPerWallet_;
        COLOR_CHANGE_PRICE = colorChangePrice_;
    }

    function supportsInterface(
        bytes4 interfaceId
    )
        public
        view
        virtual
        override(ERC721AC, ImmutableMinterRoyaltiesBase)
        returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }

    function mint(
        address to,
        uint256 quantity,
        bytes calldata signature
    ) external payable nonReentrant {
        uint256 nextTokenId = _nextTokenId();
        require(nextTokenId < MAX_SUPPLY, "Max supply reached");

        uint256 remainingSupply = MAX_SUPPLY - nextTokenId;
        uint256 remainingMints = MAX_MINTS_PER_WALLET -
            mintedPerWallet[msg.sender];
        require(remainingMints > 0, "No mints remaining");

        // Adjust quantity based on remaining supply and wallet limit
        uint256 actualMintQuantity = quantity;
        if (quantity > remainingMints) {
            actualMintQuantity = remainingMints;
        }
        if (actualMintQuantity > remainingSupply) {
            actualMintQuantity = remainingSupply;
        }

        // Skip signature check if not required
        if (signatureRequired) {
            bytes32 structHash = keccak256(
                abi.encode(MINT_TYPEHASH, msg.sender)
            );
            bytes32 hash = keccak256(
                abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR, structHash)
            );

            address recoveredSigner = ECDSA.recover(hash, signature);

            require(recoveredSigner == signer, "Invalid signature");
        }

        uint256 requiredPayment = MINT_PRICE * actualMintQuantity;
        require(msg.value >= requiredPayment, "Insufficient payment");

        // Refund excess payment including adjustment for reduced quantity
        uint256 refundAmount = msg.value - requiredPayment;
        if (refundAmount > 0) {
            (bool success, ) = payable(msg.sender).call{value: refundAmount}(
                ""
            );
            require(success, "Refund failed");
        }

        mintedPerWallet[msg.sender] += actualMintQuantity;
        _mint(to, actualMintQuantity);
    }

    function _mint(address to, uint256 quantity) internal virtual override {
        uint256 nextTokenId = _nextTokenId();

        for (uint256 i = 0; i < quantity; ) {
            _onMinted(to, nextTokenId + i);
            unchecked {
                ++i;
            }
        }

        super._mint(to, quantity);
    }

    function withdraw() external onlyOwner {
        // Calculate withdrawable amount (total balance minus game fees)
        uint256 withdrawableAmount = address(this).balance -
            totalColorChangeFees;
        require(withdrawableAmount > 0, "No funds to withdraw");

        // Transfer withdrawable amount to owner
        (bool success, ) = payable(msg.sender).call{value: withdrawableAmount}(
            ""
        );
        require(success, "Transfer failed");
    }

    function setMetadataContract(address _metadataContract) external onlyOwner {
        if (isMetadataContractLocked) revert MetadataContractLocked();
        require(_metadataContract != address(0), "Invalid metadata contract");
        metadataContract = _metadataContract;
    }

    function getBackgroundColor(
        uint256 tokenId
    ) public view returns (string memory) {
        if (!tokenData[tokenId].backgroundChanged) {
            return DEFAULT_BACKGROUND;
        }
        return tokenData[tokenId].usesSecondaryColor ? ORANGE : AQUAMARINE;
    }

    function setBackground(
        uint256 tokenId,
        uint8 colorChoice
    ) external payable {
        require(_exists(tokenId), "Token does not exist");
        require(ownerOf(tokenId) == msg.sender, "Not token owner");
        if (block.timestamp >= GAME_END_TIME) revert GameEnded();
        if (msg.value != COLOR_CHANGE_PRICE) revert("Incorrect payment amount");
        if (colorChoice != 1 && colorChoice != 2) revert InvalidColorChoice();

        TokenData storage data = tokenData[tokenId];
        bool isSecondaryColor = colorChoice == 2;

        if (
            data.backgroundChanged &&
            data.usesSecondaryColor == isSecondaryColor
        ) {
            revert SameColorAlreadySet();
        }

        unchecked {
            // Update color counts
            if (!data.backgroundChanged) {
                --defaultCount;
            } else {
                if (data.usesSecondaryColor) {
                    --orangeCount;
                } else {
                    --aquamarineCount;
                }
            }

            // Update to new color
            if (isSecondaryColor) {
                ++orangeCount;
            } else {
                ++aquamarineCount;
            }

            totalColorChangeFees += msg.value;
        }

        data.backgroundChanged = true;
        data.usesSecondaryColor = isSecondaryColor;

        // Update winning color state
        _updateWinningColor();

        // Emit metadata update event
        emit MetadataUpdate(tokenId);
    }

    function _updateWinningColor() private {
        unchecked {
            uint256 maxCount = defaultCount;
            uint8 winningColor = 0;
            bool isTie = false;

            if (aquamarineCount >= maxCount) {
                if (aquamarineCount > maxCount) {
                    maxCount = aquamarineCount;
                    winningColor = 1;
                    isTie = false;
                } else {
                    isTie = true;
                }
            }

            if (orangeCount >= maxCount) {
                if (orangeCount > maxCount) {
                    winningColor = 2;
                    isTie = false;
                } else {
                    isTie = true;
                }
            }

            // Only emit event if state changed
            if (
                currentWinningColor.color != winningColor ||
                currentWinningColor.isTie != isTie
            ) {
                currentWinningColor = WinningColorState(winningColor, isTie);
                emit WinningColorChanged(winningColor, isTie);
            }
        }
    }

    function claimShares(uint256[] calldata tokenIds) external nonReentrant {
        if (block.timestamp < GAME_END_TIME) revert GameNotEnded();
        if (currentWinningColor.isTie) revert NoWinningColor();

        uint256 totalShare;
        uint256 winningCount = currentWinningColor.color == 0
            ? defaultCount
            : (currentWinningColor.color == 1 ? aquamarineCount : orangeCount);
        uint256 sharePerToken = totalColorChangeFees / winningCount;

        for (uint256 i = 0; i < tokenIds.length; ) {
            uint256 tokenId = tokenIds[i];
            if (!_exists(tokenId)) revert("Token does not exist");
            if (ownerOf(tokenId) != msg.sender) revert("Not token owner");

            TokenData storage data = tokenData[tokenId];
            if (data.hasClaimedShare) revert AlreadyClaimed();

            bool hasWinningColor = currentWinningColor.color == 0
                ? !data.backgroundChanged
                : (data.backgroundChanged &&
                    data.usesSecondaryColor ==
                    (currentWinningColor.color == 2));

            if (!hasWinningColor) revert("Token does not have winning color");

            data.hasClaimedShare = true;
            totalShare += sharePerToken;

            unchecked {
                ++i;
            }
        }

        (bool success, ) = payable(msg.sender).call{value: totalShare}("");

        require(success, "Transfer failed");
    }

    function claimShare(uint256 tokenId) external nonReentrant {
        uint256[] memory tokenIds = new uint256[](1);
        tokenIds[0] = tokenId;
        this.claimShares(tokenIds);
    }

    // Add view function to get game state
    function getGameState()
        external
        view
        returns (
            uint256 endTime,
            uint256 defaultCount_,
            uint256 aquaCount,
            uint256 orangeCount_,
            uint256 totalFees
        )
    {
        return (
            GAME_END_TIME,
            defaultCount,
            aquamarineCount,
            orangeCount,
            totalColorChangeFees
        );
    }

    // Add helper function for random number generation
    function _random(uint256 seed) private view returns (uint256) {
        return
            uint256(
                keccak256(
                    abi.encodePacked(block.timestamp, block.prevrandao, seed)
                )
            );
    }

    function airdrop(
        address[] calldata recipients,
        uint256[] calldata quantities
    ) external onlyOwner {
        require(
            recipients.length == quantities.length,
            "Recipients and quantities length mismatch"
        );

        // Calculate total quantity and check max supply
        uint256 totalQuantity;
        for (uint256 i = 0; i < quantities.length; ) {
            require(quantities[i] > 0, "Quantity must be greater than 0");
            totalQuantity += quantities[i];
            unchecked {
                ++i;
            }
        }

        // Check max supply before proceeding
        _checkSupply(totalQuantity);

        // Create array of recipient addresses repeated by their quantities
        address[] memory expandedRecipients = new address[](totalQuantity);
        uint256 currentIndex;
        for (uint256 i = 0; i < recipients.length; ) {
            for (uint256 j = 0; j < quantities[i]; ) {
                expandedRecipients[currentIndex] = recipients[i];
                unchecked {
                    ++currentIndex;
                    ++j;
                }
            }
            unchecked {
                ++i;
            }
        }

        // Fisher-Yates shuffle
        for (uint256 i = expandedRecipients.length - 1; i > 0; ) {
            uint256 randomIndex = _random(i) % (i + 1);
            // Swap elements
            address temp = expandedRecipients[i];
            expandedRecipients[i] = expandedRecipients[randomIndex];
            expandedRecipients[randomIndex] = temp;
            unchecked {
                --i;
            }
        }

        // Mint tokens in shuffled order
        for (uint256 i = 0; i < expandedRecipients.length; ) {
            _mint(expandedRecipients[i], 1);
            unchecked {
                ++i;
            }
        }
    }

    // Add separate function for NPC holder free mint
    function freeMint(bytes calldata signature) external {
        // Check max supply before proceeding
        _checkSupply(1);
        require(!hasUsedFreeMint[msg.sender], "Free mint already used");

        // Verify signature
        bytes32 structHash = keccak256(
            abi.encode(FREEMINT_TYPEHASH, msg.sender)
        );
        bytes32 hash = keccak256(
            abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR, structHash)
        );
        address recoveredSigner = ECDSA.recover(hash, signature);
        require(recoveredSigner == signer, "Invalid signature");

        hasUsedFreeMint[msg.sender] = true;
        _mint(msg.sender, 1);
    }

    // Add function to toggle signature requirement (owner only)
    function setSignatureRequired(bool required) external onlyOwner {
        signatureRequired = required;
    }

    // Add helper function to check supply
    function _checkSupply(uint256 quantity) private view {
        if (_nextTokenId() + quantity > MAX_SUPPLY) {
            revert MaxSupplyExceeded();
        }
    }

    function tokenURI(
        uint256 tokenId
    ) public view override returns (string memory) {
        require(_exists(tokenId), "Token does not exist");

        // Get SVG data and traits from metadata contract
        string memory svgData = IGoobalooData(metadataContract).getGoobalooSVG(
            tokenId
        );
        string memory traits = IGoobalooData(metadataContract).getTraits(
            tokenId
        );

        // Get current background color for this token
        string memory background = getBackgroundColor(tokenId);

        // Construct full SVG with background and data
        string memory fullSVG = string(
            abi.encodePacked(
                '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 2048 2048">',
                '<rect width="100%" height="100%" fill="',
                background,
                '"/>',
                svgData,
                "</svg>"
            )
        );

        // Construct the JSON metadata
        string memory json = string(
            abi.encodePacked(
                '{"name": "Goobaloo #',
                tokenId.toString(),
                '", "image": "data:image/svg+xml;base64,',
                Base64.encode(bytes(fullSVG)),
                '", "attributes": ',
                traits,
                "}"
            )
        );

        // Return base64 encoded JSON
        return
            string(
                abi.encodePacked(
                    "data:application/json;base64,",
                    Base64.encode(bytes(json))
                )
            );
    }

    // Add function to lock metadata contract
    function lockMetadataContract() external onlyOwner {
        require(metadataContract != address(0), "Metadata contract not set");
        isMetadataContractLocked = true;
    }

    // Add function to withdraw color change fees in case of tie
    function withdrawColorChangeFees() external onlyOwner {
        if (block.timestamp < GAME_END_TIME || !currentWinningColor.isTie)
            revert GameNotEndedOrNotTied();

        uint256 fees = totalColorChangeFees;
        require(fees > 0, "No fees to withdraw");

        // Reset fees before transfer to prevent reentrancy
        totalColorChangeFees = 0;

        // Transfer fees to owner
        (bool success, ) = payable(msg.sender).call{value: fees}("");
        require(success, "Transfer failed");
    }

    // Add at the top with other functions
    function contractURI() public pure returns (string memory) {
        return "https://goobaloo.xyz/goobaloo.json";
    }
}

// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.3.0
// Creator: Chiru Labs

pragma solidity ^0.8.4;

import './IERC721A.sol';

/**
 * @dev Interface of ERC721 token receiver.
 */
interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

/**
 * @title ERC721A
 *
 * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
 * Non-Fungible Token Standard, including the Metadata extension.
 * Optimized for lower gas during batch mints.
 *
 * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
 * starting from `_startTokenId()`.
 *
 * The `_sequentialUpTo()` function can be overriden to enable spot mints
 * (i.e. non-consecutive mints) for `tokenId`s greater than `_sequentialUpTo()`.
 *
 * Assumptions:
 *
 * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
    // Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
    struct TokenApprovalRef {
        address value;
    }

    // =============================================================
    //                           CONSTANTS
    // =============================================================

    // Mask of an entry in packed address data.
    uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

    // The bit position of `numberMinted` in packed address data.
    uint256 private constant _BITPOS_NUMBER_MINTED = 64;

    // The bit position of `numberBurned` in packed address data.
    uint256 private constant _BITPOS_NUMBER_BURNED = 128;

    // The bit position of `aux` in packed address data.
    uint256 private constant _BITPOS_AUX = 192;

    // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
    uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

    // The bit position of `startTimestamp` in packed ownership.
    uint256 private constant _BITPOS_START_TIMESTAMP = 160;

    // The bit mask of the `burned` bit in packed ownership.
    uint256 private constant _BITMASK_BURNED = 1 << 224;

    // The bit position of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;

    // The bit mask of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;

    // The bit position of `extraData` in packed ownership.
    uint256 private constant _BITPOS_EXTRA_DATA = 232;

    // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;

    // The mask of the lower 160 bits for addresses.
    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;

    // The maximum `quantity` that can be minted with {_mintERC2309}.
    // This limit is to prevent overflows on the address data entries.
    // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
    // is required to cause an overflow, which is unrealistic.
    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;

    // The `Transfer` event signature is given by:
    // `keccak256(bytes("Transfer(address,address,uint256)"))`.
    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

    // =============================================================
    //                            STORAGE
    // =============================================================

    // The next token ID to be minted.
    uint256 private _currentIndex;

    // The number of tokens burned.
    uint256 private _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 {_packedOwnershipOf} implementation for details.
    //
    // Bits Layout:
    // - [0..159]   `addr`
    // - [160..223] `startTimestamp`
    // - [224]      `burned`
    // - [225]      `nextInitialized`
    // - [232..255] `extraData`
    mapping(uint256 => uint256) private _packedOwnerships;

    // Mapping owner address to address data.
    //
    // Bits Layout:
    // - [0..63]    `balance`
    // - [64..127]  `numberMinted`
    // - [128..191] `numberBurned`
    // - [192..255] `aux`
    mapping(address => uint256) private _packedAddressData;

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

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

    // The amount of tokens minted above `_sequentialUpTo()`.
    // We call these spot mints (i.e. non-sequential mints).
    uint256 private _spotMinted;

    // =============================================================
    //                          CONSTRUCTOR
    // =============================================================

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

        if (_sequentialUpTo() < _startTokenId()) _revert(SequentialUpToTooSmall.selector);
    }

    // =============================================================
    //                   TOKEN COUNTING OPERATIONS
    // =============================================================

    /**
     * @dev Returns the starting token ID for sequential mints.
     *
     * Override this function to change the starting token ID for sequential mints.
     *
     * Note: The value returned must never change after any tokens have been minted.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Returns the maximum token ID (inclusive) for sequential mints.
     *
     * Override this function to return a value less than 2**256 - 1,
     * but greater than `_startTokenId()`, to enable spot (non-sequential) mints.
     *
     * Note: The value returned must never change after any tokens have been minted.
     */
    function _sequentialUpTo() internal view virtual returns (uint256) {
        return type(uint256).max;
    }

    /**
     * @dev Returns the next token ID to be minted.
     */
    function _nextTokenId() internal view virtual returns (uint256) {
        return _currentIndex;
    }

    /**
     * @dev Returns the total number of tokens in existence.
     * Burned tokens will reduce the count.
     * To get the total number of tokens minted, please see {_totalMinted}.
     */
    function totalSupply() public view virtual override returns (uint256 result) {
        // Counter underflow is impossible as `_burnCounter` cannot be incremented
        // more than `_currentIndex + _spotMinted - _startTokenId()` times.
        unchecked {
            // With spot minting, the intermediate `result` can be temporarily negative,
            // and the computation must be unchecked.
            result = _currentIndex - _burnCounter - _startTokenId();
            if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
        }
    }

    /**
     * @dev Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view virtual returns (uint256 result) {
        // Counter underflow is impossible as `_currentIndex` does not decrement,
        // and it is initialized to `_startTokenId()`.
        unchecked {
            result = _currentIndex - _startTokenId();
            if (_sequentialUpTo() != type(uint256).max) result += _spotMinted;
        }
    }

    /**
     * @dev Returns the total number of tokens burned.
     */
    function _totalBurned() internal view virtual returns (uint256) {
        return _burnCounter;
    }

    /**
     * @dev Returns the total number of tokens that are spot-minted.
     */
    function _totalSpotMinted() internal view virtual returns (uint256) {
        return _spotMinted;
    }

    // =============================================================
    //                    ADDRESS DATA OPERATIONS
    // =============================================================

    /**
     * @dev Returns the number of tokens in `owner`'s account.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        if (owner == address(0)) _revert(BalanceQueryForZeroAddress.selector);
        return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the number of tokens minted by `owner`.
     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }

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

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

    /**
     * Sets the auxiliary 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 virtual {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        // Cast `aux` with assembly to avoid redundant masking.
        assembly {
            auxCasted := aux
        }
        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        // The interface IDs are constants representing the first 4 bytes
        // of the XOR of all function selectors in the interface.
        // See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
        // (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
        return
            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**
     * @dev Returns the token collection name.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        if (!_exists(tokenId)) _revert(URIQueryForNonexistentToken.selector);

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

    /**
     * @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, it can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    // =============================================================
    //                     OWNERSHIPS OPERATIONS
    // =============================================================

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    /**
     * @dev Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around over time.
     */
    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    /**
     * @dev Returns the unpacked `TokenOwnership` struct at `index`.
     */
    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }

    /**
     * @dev Returns whether the ownership slot at `index` is initialized.
     * An uninitialized slot does not necessarily mean that the slot has no owner.
     */
    function _ownershipIsInitialized(uint256 index) internal view virtual returns (bool) {
        return _packedOwnerships[index] != 0;
    }

    /**
     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
     */
    function _initializeOwnershipAt(uint256 index) internal virtual {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    /**
     * @dev Returns the packed ownership data of `tokenId`.
     */
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256 packed) {
        if (_startTokenId() <= tokenId) {
            packed = _packedOwnerships[tokenId];

            if (tokenId > _sequentialUpTo()) {
                if (_packedOwnershipExists(packed)) return packed;
                _revert(OwnerQueryForNonexistentToken.selector);
            }

            // If the data at the starting slot does not exist, start the scan.
            if (packed == 0) {
                if (tokenId >= _currentIndex) _revert(OwnerQueryForNonexistentToken.selector);
                // Invariant:
                // There will always be an initialized ownership slot
                // (i.e. `ownership.addr != address(0) && ownership.burned == false`)
                // before an unintialized ownership slot
                // (i.e. `ownership.addr == address(0) && ownership.burned == false`)
                // Hence, `tokenId` will not underflow.
                //
                // We can directly compare the packed value.
                // If the address is zero, packed will be zero.
                for (;;) {
                    unchecked {
                        packed = _packedOwnerships[--tokenId];
                    }
                    if (packed == 0) continue;
                    if (packed & _BITMASK_BURNED == 0) return packed;
                    // Otherwise, the token is burned, and we must revert.
                    // This handles the case of batch burned tokens, where only the burned bit
                    // of the starting slot is set, and remaining slots are left uninitialized.
                    _revert(OwnerQueryForNonexistentToken.selector);
                }
            }
            // Otherwise, the data exists and we can skip the scan.
            // This is possible because we have already achieved the target condition.
            // This saves 2143 gas on transfers of initialized tokens.
            // If the token is not burned, return `packed`. Otherwise, revert.
            if (packed & _BITMASK_BURNED == 0) return packed;
        }
        _revert(OwnerQueryForNonexistentToken.selector);
    }

    /**
     * @dev Returns the unpacked `TokenOwnership` struct from `packed`.
     */
    function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
        ownership.addr = address(uint160(packed));
        ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
        ownership.burned = packed & _BITMASK_BURNED != 0;
        ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
    }

    /**
     * @dev Packs ownership data into a single uint256.
     */
    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
        }
    }

    /**
     * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
     */
    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
        // For branchless setting of the `nextInitialized` flag.
        assembly {
            // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
        }
    }

    // =============================================================
    //                      APPROVAL OPERATIONS
    // =============================================================

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account. See {ERC721A-_approve}.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     */
    function approve(address to, uint256 tokenId) public payable virtual override {
        _approve(to, tokenId, true);
    }

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        if (!_exists(tokenId)) _revert(ApprovalQueryForNonexistentToken.selector);

        return _tokenApprovals[tokenId].value;
    }

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom}
     * for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }

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

    /**
     * @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. See {_mint}.
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool result) {
        if (_startTokenId() <= tokenId) {
            if (tokenId > _sequentialUpTo()) return _packedOwnershipExists(_packedOwnerships[tokenId]);

            if (tokenId < _currentIndex) {
                uint256 packed;
                while ((packed = _packedOwnerships[tokenId]) == 0) --tokenId;
                result = packed & _BITMASK_BURNED == 0;
            }
        }
    }

    /**
     * @dev Returns whether `packed` represents a token that exists.
     */
    function _packedOwnershipExists(uint256 packed) private pure returns (bool result) {
        assembly {
            // The following is equivalent to `owner != address(0) && burned == false`.
            // Symbolically tested.
            result := gt(and(packed, _BITMASK_ADDRESS), and(packed, _BITMASK_BURNED))
        }
    }

    /**
     * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
     */
    function _isSenderApprovedOrOwner(
        address approvedAddress,
        address owner,
        address msgSender
    ) private pure returns (bool result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
            msgSender := and(msgSender, _BITMASK_ADDRESS)
            // `msgSender == owner || msgSender == approvedAddress`.
            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
        }
    }

    /**
     * @dev Returns the storage slot and value for the approved address of `tokenId`.
     */
    function _getApprovedSlotAndAddress(uint256 tokenId)
        private
        view
        returns (uint256 approvedAddressSlot, address approvedAddress)
    {
        TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
        // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
        assembly {
            approvedAddressSlot := tokenApproval.slot
            approvedAddress := sload(approvedAddressSlot)
        }
    }

    // =============================================================
    //                      TRANSFER OPERATIONS
    // =============================================================

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token
     * by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public payable virtual override {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        // Mask `from` to the lower 160 bits, in case the upper bits somehow aren't clean.
        from = address(uint160(uint256(uint160(from)) & _BITMASK_ADDRESS));

        if (address(uint160(prevOwnershipPacked)) != from) _revert(TransferFromIncorrectOwner.selector);

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        // The nested ifs save around 20+ gas over a compound boolean condition.
        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
            if (!isApprovedForAll(from, _msgSenderERC721A())) _revert(TransferCallerNotOwnerNorApproved.selector);

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // 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 {
            // We can directly increment and decrement the balances.
            --_packedAddressData[from]; // Updates: `balance -= 1`.
            ++_packedAddressData[to]; // Updates: `balance += 1`.

            // Updates:
            // - `address` to the next owner.
            // - `startTimestamp` to the timestamp of transfering.
            // - `burned` to `false`.
            // - `nextInitialized` to `true`.
            _packedOwnerships[tokenId] = _packOwnershipData(
                to,
                _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
            );

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (_packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != _currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
        uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;
        assembly {
            // Emit the `Transfer` event.
            log4(
                0, // Start of data (0, since no data).
                0, // End of data (0, since no data).
                _TRANSFER_EVENT_SIGNATURE, // Signature.
                from, // `from`.
                toMasked, // `to`.
                tokenId // `tokenId`.
            )
        }
        if (toMasked == 0) _revert(TransferToZeroAddress.selector);

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

    /**
     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public payable virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token
     * by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement
     * {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public payable virtual override {
        transferFrom(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                _revert(TransferToNonERC721ReceiverImplementer.selector);
            }
    }

    /**
     * @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 {}

    /**
     * @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
     *
     * `from` - Previous owner of the given token ID.
     * `to` - Target address that will receive the token.
     * `tokenId` - Token ID to be transferred.
     * `_data` - Optional data to send along with the call.
     *
     * Returns whether the call correctly returned the expected magic value.
     */
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
            bytes4 retval
        ) {
            return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                _revert(TransferToNonERC721ReceiverImplementer.selector);
            }
            assembly {
                revert(add(32, reason), mload(reason))
            }
        }
    }

    // =============================================================
    //                        MINT OPERATIONS
    // =============================================================

    /**
     * @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 for each mint.
     */
    function _mint(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (quantity == 0) _revert(MintZeroQuantity.selector);

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

        // Overflows are incredibly unrealistic.
        // `balance` and `numberMinted` have a maximum limit of 2**64.
        // `tokenId` has a maximum limit of 2**256.
        unchecked {
            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            _packedOwnerships[startTokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

            // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
            uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;

            if (toMasked == 0) _revert(MintToZeroAddress.selector);

            uint256 end = startTokenId + quantity;
            uint256 tokenId = startTokenId;

            if (end - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);

            do {
                assembly {
                    // Emit the `Transfer` event.
                    log4(
                        0, // Start of data (0, since no data).
                        0, // End of data (0, since no data).
                        _TRANSFER_EVENT_SIGNATURE, // Signature.
                        0, // `address(0)`.
                        toMasked, // `to`.
                        tokenId // `tokenId`.
                    )
                }
                // The `!=` check ensures that large values of `quantity`
                // that overflows uint256 will make the loop run out of gas.
            } while (++tokenId != end);

            _currentIndex = end;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * This function is intended for efficient minting only during contract creation.
     *
     * It emits only one {ConsecutiveTransfer} as defined in
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
     * instead of a sequence of {Transfer} event(s).
     *
     * Calling this function outside of contract creation WILL make your contract
     * non-compliant with the ERC721 standard.
     * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
     * {ConsecutiveTransfer} event is only permissible during contract creation.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {ConsecutiveTransfer} event.
     */
    function _mintERC2309(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) _revert(MintToZeroAddress.selector);
        if (quantity == 0) _revert(MintZeroQuantity.selector);
        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) _revert(MintERC2309QuantityExceedsLimit.selector);

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

        // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `quantity == 1`.
            _packedOwnerships[startTokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            if (startTokenId + quantity - 1 > _sequentialUpTo()) _revert(SequentialMintExceedsLimit.selector);

            emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);

            _currentIndex = startTokenId + quantity;
        }
        _afterTokenTransfers(address(0), to, startTokenId, 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.
     *
     * See {_mint}.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal virtual {
        _mint(to, quantity);

        unchecked {
            if (to.code.length != 0) {
                uint256 end = _currentIndex;
                uint256 index = end - quantity;
                do {
                    if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
                        _revert(TransferToNonERC721ReceiverImplementer.selector);
                    }
                } while (index < end);
                // This prevents reentrancy to `_safeMint`.
                // It does not prevent reentrancy to `_safeMintSpot`.
                if (_currentIndex != end) revert();
            }
        }
    }

    /**
     * @dev Equivalent to `_safeMint(to, quantity, '')`.
     */
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, '');
    }

    /**
     * @dev Mints a single token at `tokenId`.
     *
     * Note: A spot-minted `tokenId` that has been burned can be re-minted again.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` must be greater than `_sequentialUpTo()`.
     * - `tokenId` must not exist.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _mintSpot(address to, uint256 tokenId) internal virtual {
        if (tokenId <= _sequentialUpTo()) _revert(SpotMintTokenIdTooSmall.selector);
        uint256 prevOwnershipPacked = _packedOwnerships[tokenId];
        if (_packedOwnershipExists(prevOwnershipPacked)) _revert(TokenAlreadyExists.selector);

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

        // Overflows are incredibly unrealistic.
        // The `numberMinted` for `to` is incremented by 1, and has a max limit of 2**64 - 1.
        // `_spotMinted` is incremented by 1, and has a max limit of 2**256 - 1.
        unchecked {
            // Updates:
            // - `address` to the owner.
            // - `startTimestamp` to the timestamp of minting.
            // - `burned` to `false`.
            // - `nextInitialized` to `true` (as `quantity == 1`).
            _packedOwnerships[tokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(1) | _nextExtraData(address(0), to, prevOwnershipPacked)
            );

            // Updates:
            // - `balance += 1`.
            // - `numberMinted += 1`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _packedAddressData[to] += (1 << _BITPOS_NUMBER_MINTED) | 1;

            // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
            uint256 toMasked = uint256(uint160(to)) & _BITMASK_ADDRESS;

            if (toMasked == 0) _revert(MintToZeroAddress.selector);

            assembly {
                // Emit the `Transfer` event.
                log4(
                    0, // Start of data (0, since no data).
                    0, // End of data (0, since no data).
                    _TRANSFER_EVENT_SIGNATURE, // Signature.
                    0, // `address(0)`.
                    toMasked, // `to`.
                    tokenId // `tokenId`.
                )
            }

            ++_spotMinted;
        }

        _afterTokenTransfers(address(0), to, tokenId, 1);
    }

    /**
     * @dev Safely mints a single token at `tokenId`.
     *
     * Note: A spot-minted `tokenId` that has been burned can be re-minted again.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}.
     * - `tokenId` must be greater than `_sequentialUpTo()`.
     * - `tokenId` must not exist.
     *
     * See {_mintSpot}.
     *
     * Emits a {Transfer} event.
     */
    function _safeMintSpot(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mintSpot(to, tokenId);

        unchecked {
            if (to.code.length != 0) {
                uint256 currentSpotMinted = _spotMinted;
                if (!_checkContractOnERC721Received(address(0), to, tokenId, _data)) {
                    _revert(TransferToNonERC721ReceiverImplementer.selector);
                }
                // This prevents reentrancy to `_safeMintSpot`.
                // It does not prevent reentrancy to `_safeMint`.
                if (_spotMinted != currentSpotMinted) revert();
            }
        }
    }

    /**
     * @dev Equivalent to `_safeMintSpot(to, tokenId, '')`.
     */
    function _safeMintSpot(address to, uint256 tokenId) internal virtual {
        _safeMintSpot(to, tokenId, '');
    }

    // =============================================================
    //                       APPROVAL OPERATIONS
    // =============================================================

    /**
     * @dev Equivalent to `_approve(to, tokenId, false)`.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _approve(to, tokenId, false);
    }

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the
     * zero address clears previous approvals.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function _approve(
        address to,
        uint256 tokenId,
        bool approvalCheck
    ) internal virtual {
        address owner = ownerOf(tokenId);

        if (approvalCheck && _msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                _revert(ApprovalCallerNotOwnerNorApproved.selector);
            }

        _tokenApprovals[tokenId].value = to;
        emit Approval(owner, to, tokenId);
    }

    // =============================================================
    //                        BURN OPERATIONS
    // =============================================================

    /**
     * @dev 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 {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        address from = address(uint160(prevOwnershipPacked));

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        if (approvalCheck) {
            // The nested ifs save around 20+ gas over a compound boolean condition.
            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
                if (!isApprovedForAll(from, _msgSenderERC721A())) _revert(TransferCallerNotOwnerNorApproved.selector);
        }

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

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // 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 {
            // Updates:
            // - `balance -= 1`.
            // - `numberBurned += 1`.
            //
            // We can directly decrement the balance, and increment the number burned.
            // This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
            _packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;

            // Updates:
            // - `address` to the last owner.
            // - `startTimestamp` to the timestamp of burning.
            // - `burned` to `true`.
            // - `nextInitialized` to `true`.
            _packedOwnerships[tokenId] = _packOwnershipData(
                from,
                (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
            );

            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                // If the next slot's address is zero and not burned (i.e. packed value is zero).
                if (_packedOwnerships[nextTokenId] == 0) {
                    // If the next slot is within bounds.
                    if (nextTokenId != _currentIndex) {
                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

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

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

    // =============================================================
    //                     EXTRA DATA OPERATIONS
    // =============================================================

    /**
     * @dev Directly sets the extra data for the ownership data `index`.
     */
    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
        uint256 packed = _packedOwnerships[index];
        if (packed == 0) _revert(OwnershipNotInitializedForExtraData.selector);
        uint256 extraDataCasted;
        // Cast `extraData` with assembly to avoid redundant masking.
        assembly {
            extraDataCasted := extraData
        }
        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
        _packedOwnerships[index] = packed;
    }

    /**
     * @dev Called during each token transfer to set the 24bit `extraData` field.
     * Intended to be overridden by the cosumer contract.
     *
     * `previousExtraData` - the value of `extraData` before transfer.
     *
     * 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 _extraData(
        address from,
        address to,
        uint24 previousExtraData
    ) internal view virtual returns (uint24) {}

    /**
     * @dev Returns the next extra data for the packed ownership data.
     * The returned result is shifted into position.
     */
    function _nextExtraData(
        address from,
        address to,
        uint256 prevOwnershipPacked
    ) private view returns (uint256) {
        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
        return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
    }

    // =============================================================
    //                       OTHER OPERATIONS
    // =============================================================

    /**
     * @dev Returns the message sender (defaults to `msg.sender`).
     *
     * If you are writing GSN compatible contracts, you need to override this function.
     */
    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }

    /**
     * @dev Converts a uint256 to its ASCII string decimal representation.
     */
    function _toString(uint256 value) internal pure virtual returns (string memory str) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
            // We will need 1 word for the trailing zeros padding, 1 word for the length,
            // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
            let m := add(mload(0x40), 0xa0)
            // Update the free memory pointer to allocate.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end of the memory to calculate the length later.
            let end := str

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }

    /**
     * @dev For more efficient reverts.
     */
    function _revert(bytes4 errorSelector) internal pure {
        assembly {
            mstore(0x00, errorSelector)
            revert(0x00, 0x04)
        }
    }
}

// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.3.0
// Creator: Chiru Labs

pragma solidity ^0.8.4;

/**
 * @dev Interface of ERC721A.
 */
interface IERC721A {
    /**
     * The caller must own the token or be an approved operator.
     */
    error ApprovalCallerNotOwnerNorApproved();

    /**
     * The token does not exist.
     */
    error ApprovalQueryForNonexistentToken();

    /**
     * Cannot query the balance for the zero address.
     */
    error BalanceQueryForZeroAddress();

    /**
     * Cannot mint to the zero address.
     */
    error MintToZeroAddress();

    /**
     * The quantity of tokens minted must be more than zero.
     */
    error MintZeroQuantity();

    /**
     * The token does not exist.
     */
    error OwnerQueryForNonexistentToken();

    /**
     * The caller must own the token or be an approved operator.
     */
    error TransferCallerNotOwnerNorApproved();

    /**
     * The token must be owned by `from`.
     */
    error TransferFromIncorrectOwner();

    /**
     * Cannot safely transfer to a contract that does not implement the
     * ERC721Receiver interface.
     */
    error TransferToNonERC721ReceiverImplementer();

    /**
     * Cannot transfer to the zero address.
     */
    error TransferToZeroAddress();

    /**
     * The token does not exist.
     */
    error URIQueryForNonexistentToken();

    /**
     * The `quantity` minted with ERC2309 exceeds the safety limit.
     */
    error MintERC2309QuantityExceedsLimit();

    /**
     * The `extraData` cannot be set on an unintialized ownership slot.
     */
    error OwnershipNotInitializedForExtraData();

    /**
     * `_sequentialUpTo()` must be greater than `_startTokenId()`.
     */
    error SequentialUpToTooSmall();

    /**
     * The `tokenId` of a sequential mint exceeds `_sequentialUpTo()`.
     */
    error SequentialMintExceedsLimit();

    /**
     * Spot minting requires a `tokenId` greater than `_sequentialUpTo()`.
     */
    error SpotMintTokenIdTooSmall();

    /**
     * Cannot mint over a token that already exists.
     */
    error TokenAlreadyExists();

    /**
     * The feature is not compatible with spot mints.
     */
    error NotCompatibleWithSpotMints();

    // =============================================================
    //                            STRUCTS
    // =============================================================

    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Stores the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
        // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
        uint24 extraData;
    }

    // =============================================================
    //                         TOKEN COUNTERS
    // =============================================================

    /**
     * @dev Returns the total number of tokens in existence.
     * Burned tokens will reduce the count.
     * To get the total number of tokens minted, please see {_totalMinted}.
     */
    function totalSupply() external view returns (uint256);

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);

    // =============================================================
    //                            IERC721
    // =============================================================

    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

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

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

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

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

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

    /**
     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external payable;

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom}
     * whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token
     * by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external payable;

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

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

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

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

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);

    // =============================================================
    //                           IERC2309
    // =============================================================

    /**
     * @dev Emitted when tokens in `fromTokenId` to `toTokenId`
     * (inclusive) is transferred from `from` to `to`, as defined in the
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
     *
     * See {_mintERC2309} for more details.
     */
    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}

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