// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

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

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

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: 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;

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

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

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

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

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @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);
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

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

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

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

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

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



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

pragma solidity ^0.8.0;

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

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

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_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) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @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] = _HEX_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);
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// 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;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// 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);
}

// File: contracts/LzApp.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

import "@openzeppelin/contracts/access/Ownable.sol";
import "./interfaces/ILayerZeroReceiver.sol";
import "./interfaces/ILayerZeroUserApplicationConfig.sol";
import "./interfaces/ILayerZeroEndpoint.sol";

/*
 * a generic LzReceiver implementation
 */
abstract contract LzApp is Ownable, ILayerZeroReceiver, ILayerZeroUserApplicationConfig {
    ILayerZeroEndpoint internal immutable lzEndpoint;

    mapping(uint16 => bytes) internal trustedRemoteLookup;

    event SetTrustedRemote(uint16 _srcChainId, bytes _srcAddress);

    constructor(address _endpoint) {
        lzEndpoint = ILayerZeroEndpoint(_endpoint);
    }

    function lzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) external override {
        // lzReceive must be called by the endpoint for security
        require(_msgSender() == address(lzEndpoint));
        // if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
        require(_srcAddress.length == trustedRemoteLookup[_srcChainId].length && keccak256(_srcAddress) == keccak256(trustedRemoteLookup[_srcChainId]), "LzReceiver: invalid source sending contract");

        _blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }

    // abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
    function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;

    function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParam) internal {
        require(trustedRemoteLookup[_dstChainId].length != 0, "LzSend: destination chain is not a trusted source.");
        lzEndpoint.send{value: msg.value}(_dstChainId, trustedRemoteLookup[_dstChainId], _payload, _refundAddress, _zroPaymentAddress, _adapterParam);
    }

    //---------------------------UserApplication config----------------------------------------
    function getConfig(uint16, uint16 _chainId, address, uint _configType) external view returns (bytes memory) {
        return lzEndpoint.getConfig(lzEndpoint.getSendVersion(address(this)), _chainId, address(this), _configType);
    }

    // generic config for LayerZero user Application
    function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override onlyOwner {
        lzEndpoint.setConfig(_version, _chainId, _configType, _config);
    }

    function setSendVersion(uint16 _version) external override onlyOwner {
        lzEndpoint.setSendVersion(_version);
    }

    function setReceiveVersion(uint16 _version) external override onlyOwner {
        lzEndpoint.setReceiveVersion(_version);
    }

    function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override onlyOwner {
        lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
    }

    // allow owner to set it multiple times.
    function setTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external onlyOwner {
        trustedRemoteLookup[_srcChainId] = _srcAddress;
        emit SetTrustedRemote(_srcChainId, _srcAddress);
    }

    function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool) {
        bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
        return keccak256(trustedSource) == keccak256(_srcAddress);
    }

    //--------------------------- VIEW FUNCTION ----------------------------------------
    // interacting with the LayerZero Endpoint and remote contracts

    function getTrustedRemote(uint16 _chainId) external view returns (bytes memory) {
        return trustedRemoteLookup[_chainId];
    }

    function getLzEndpoint() external view returns (address) {
        return address(lzEndpoint);
    }
}
// File: contracts/MojosToken.sol



// SPDX-License-Identifier: MIT

/// @title The Mojos ERC-721 token

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

pragma solidity ^0.8.6;

import { Ownable } from '@openzeppelin/contracts/access/Ownable.sol';
import { ERC721Checkpointable } from './base/ERC721Checkpointable.sol';
import { IMojosDescriptor } from './interfaces/IMojosDescriptor.sol';
import { IMojosSeeder } from './interfaces/IMojosSeeder.sol';
import { IMojosToken } from './interfaces/IMojosToken.sol';
import { ERC721 } from './base/ERC721.sol';
import { IERC721 } from '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import './NonBlockingLzApp.sol';

import './base/ERC721Enumerable.sol';

contract MojosToken is IMojosToken, NonblockingLzApp, ERC721Checkpointable {
    // used for Cross Chain and emergency minting
    // bytes32 public constant EXT_MINTER_ROLE = keccak256('EXT_MINTER_ROLE');

    // The mojos DAO address (creators org)
    address public mojosDAO;

    // An address who has permissions to mint Mojos
    address public minter;

    // The Mojos token URI descriptor
    IMojosDescriptor public descriptor;

    // The Mojos token seeder
    IMojosSeeder public seeder;

    // Whether the minter can be updated
    bool public isMinterLocked;

    // Whether the descriptor can be updated
    bool public isDescriptorLocked;

    // Whether the seeder can be updated
    bool public isSeederLocked;

    // The mojo seeds
    mapping(uint256 => IMojosSeeder.Seed) public seeds;

    // The internal mojo ID tracker
    uint256 public _currentMojoId;

    uint256 public _maxMintId;

    // IPFS content hash of contract-level metadata
    string private _contractURIHash = 'QmZi1n79FqWt2tTLwCqiy6nLM6xLGRsEPQ5JmReJQKNNzX';

    mapping(address => bool) externalMinters;

    /**
     * @notice Require that the minter has not been locked.
     */
    modifier whenMinterNotLocked() {
        require(!isMinterLocked, 'Minter is locked');
        _;
    }

    /**
     * @notice Require that the descriptor has not been locked.
     */
    modifier whenDescriptorNotLocked() {
        require(!isDescriptorLocked, 'Descriptor is locked');
        _;
    }

    /**
     * @notice Require that the seeder has not been locked.
     */
    modifier whenSeederNotLocked() {
        require(!isSeederLocked, 'Seeder is locked');
        _;
    }

    /**
     * @notice Require that the sender is the mojos DAO.
     */
    modifier onlyMojosDAO() {
        require(msg.sender == mojosDAO, 'Sender is not the mojos DAO');
        _;
    }

    /**
     * @notice Require that the sender is the minter.
     */
    modifier onlyMinter() {
        require(msg.sender == minter, 'Sender is not the minter');
        _;
    }

    constructor(
        address _mojosDAO,
        address _minter,
        IMojosDescriptor _descriptor,
        IMojosSeeder _seeder,
        address _lzEndpoint,
        uint256 _startMintId,
        uint256 _endMintId
    ) ERC721('Mojos', 'MOJO') NonblockingLzApp(_lzEndpoint) {
        mojosDAO = _mojosDAO;
        minter = _minter;
        descriptor = _descriptor;
        seeder = _seeder;
        _currentMojoId = _startMintId;
        _maxMintId = _endMintId;
        addExternalMinter(msg.sender);
        addExternalMinter(_lzEndpoint);
    }

    string public baseTokenURI;

    /**
     * @notice The IPFS URI of contract-level metadata.
     */
    function contractURI() public view returns (string memory) {
        return string(abi.encodePacked('ipfs://', _contractURIHash));
    }

    /**
     * @notice Set the _contractURIHash.
     * @dev Only callable by the owner.
     */
    function setContractURIHash(string memory newContractURIHash) external onlyOwner {
        _contractURIHash = newContractURIHash;
    }

    /**
     * @notice Mint a Mojo to the minter, along with a possible mojos reward
     * Mojo. Mojos reward Mojos are minted every 10 Mojos, starting at 0,
     * until 183 founder Mojos have been minted (5 years w/ 24 hour auctions).
     * @dev Call _mintTo with the to address(es).
     */
    function mint() public override onlyMinter returns (uint256) {
        if (_currentMojoId <= 3640 && _currentMojoId % 10 == 0) {
            _mintTo(mojosDAO, _currentMojoId++);
        }
        return _mintTo(minter, _currentMojoId++);
    }

    /**
     * @notice Mint a Mojo to a specific address, along with a possible mojos reward
     * Mojo. Mojos reward Mojos are minted every 10 Mojos, starting at 0,
     * this is only used for Cross-Chain functionality and emergency minting
     * @dev Call _mintTo with the to address(es).
     */
    function externalMint(
        address _to,
        uint48 _background,
        uint48 _body,
        uint48 _bodyAccessory,
        uint48 _face,
        uint48 _headAccessory
    ) public returns (uint256) {
        require(isExternalMinter(msg.sender),"Not External Minter");
        uint256 mojoId = _currentMojoId++;
        IMojosSeeder.Seed memory seed = seeds[mojoId] = IMojosSeeder.Seed({
            background: _background,
            body: _body,
            bodyAccessory: _bodyAccessory,
            face: _face,
            headAccessory: _headAccessory
        });

        _mint(owner(), _to, mojoId);
        emit MojoCreated(mojoId, seed);

        return mojoId;
    }

    /**
     * @notice Burn a mojo.
     */
    function burn(uint256 mojoId) public override onlyMinter {
        _burn(mojoId);
        emit MojoBurned(mojoId);
    }

    /**
     * @notice A distinct Uniform Resource Identifier (URI) for a given asset.
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        require(_exists(tokenId), 'MojosToken: URI query for nonexistent token');
        return descriptor.tokenURI(tokenId, seeds[tokenId]);
    }

    /**
     * @notice Similar to `tokenURI`, but always serves a base64 encoded data URI
     * with the JSON contents directly inlined.
     */
    function dataURI(uint256 tokenId) public view override returns (string memory) {
        require(_exists(tokenId), 'MojosToken: URI query for nonexistent token');
        return descriptor.dataURI(tokenId, seeds[tokenId]);
    }

    /**
     * @notice Set the mojos DAO.
     * @dev Only callable by the mojos DAO when not locked.
     */
    function setMojosDAO(address _mojosDAO) external override onlyMojosDAO {
        mojosDAO = _mojosDAO;

        emit MojosDAOUpdated(_mojosDAO);
    }

    /**
     * @notice Set the token minter.
     * @dev Only callable by the owner when not locked.
     */
    function setMinter(address _minter) external override onlyOwner whenMinterNotLocked {
        minter = _minter;

        emit MinterUpdated(_minter);
    }

    /**
     * @notice Lock the minter.
     * @dev This cannot be reversed and is only callable by the owner when not locked.
     */
    function lockMinter() external override onlyOwner whenMinterNotLocked {
        isMinterLocked = true;

        emit MinterLocked();
    }

    /**
     * @notice Set the token URI descriptor.
     * @dev Only callable by the owner when not locked.
     */
    function setDescriptor(IMojosDescriptor _descriptor) external override onlyOwner whenDescriptorNotLocked {
        descriptor = _descriptor;

        emit DescriptorUpdated(_descriptor);
    }

    /**
     * @notice Lock the descriptor.
     * @dev This cannot be reversed and is only callable by the owner when not locked.
     */
    function lockDescriptor() external override onlyOwner whenDescriptorNotLocked {
        isDescriptorLocked = true;

        emit DescriptorLocked();
    }

    /**
     * @notice Set the token seeder.
     * @dev Only callable by the owner when not locked.
     */
    function setSeeder(IMojosSeeder _seeder) external override onlyOwner whenSeederNotLocked {
        seeder = _seeder;

        emit SeederUpdated(_seeder);
    }

    /**
     * @notice Lock the seeder.
     * @dev This cannot be reversed and is only callable by the owner when not locked.
     */
    function lockSeeder() external override onlyOwner whenSeederNotLocked {
        isSeederLocked = true;

        emit SeederLocked();
    }

    /**
     * @notice Mint a Mojo with `mojoId` to the provided `to` address.
     */
    function _mintTo(address to, uint256 mojoId) internal returns (uint256) {
        IMojosSeeder.Seed memory seed = seeds[mojoId] = seeder.generateSeed(mojoId, descriptor);

        _mint(owner(), to, mojoId);
        emit MojoCreated(mojoId, seed);

        return mojoId;
    }

    /// LayerZero Implementation
    function estimateSendFee(
        uint16 _dstChainId,
        bytes calldata _toAddress,
        uint256 _tokenId,
        bool _useZro,
        bytes calldata _adapterParams
    ) external view virtual override returns (uint256 nativeFee, uint256 zroFee) {
        // mock the payload for send()
        bytes memory payload = abi.encode(_toAddress, _tokenId, seeds[_tokenId]);
        return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
    }

    function sendFrom(
        address _from,
        uint16 _dstChainId,
        bytes calldata _toAddress,
        uint256 _tokenId,
        address payable _refundAddress,
        address _zroPaymentAddress,
        bytes calldata _adapterParam
    ) external payable virtual override {
        _send(_from, _dstChainId, _toAddress, _tokenId, _refundAddress, _zroPaymentAddress, _adapterParam);
    }

    function send(
        uint16 _dstChainId,
        bytes calldata _toAddress,
        uint256 _tokenId,
        address payable _refundAddress,
        address _zroPaymentAddress,
        bytes calldata _adapterParam
    ) external payable virtual override {
        _send(_msgSender(), _dstChainId, _toAddress, _tokenId, _refundAddress, _zroPaymentAddress, _adapterParam);
    }

    function _send(
        address _from,
        uint16 _dstChainId,
        bytes memory _toAddress,
        uint256 _tokenId,
        address payable _refundAddress,
        address _zroPaymentAddress,
        bytes calldata _adapterParam
    ) internal virtual {
        require(_isApprovedOrOwner(_msgSender(), _tokenId), 'ONFT721: send caller is not owner nor approved');
        require(ERC721.ownerOf(_tokenId) == _from, 'ONFT721: send from incorrect owner');
        _beforeSend(_from, _dstChainId, _toAddress, _tokenId);

        bytes memory payload = abi.encode(_toAddress, _tokenId, seeds[_tokenId]);
        _lzSend(_dstChainId, payload, _refundAddress, _zroPaymentAddress, _adapterParam);

        uint64 nonce = lzEndpoint.getOutboundNonce(_dstChainId, address(this));
        emit SendToChain(_from, _dstChainId, _toAddress, _tokenId, nonce);
        _afterSend(_from, _dstChainId, _toAddress, _tokenId);
    }

    function _nonblockingLzReceive(
        uint16 _srcChainId,
        bytes memory _srcAddress,
        uint64 _nonce,
        bytes memory _payload
    ) internal virtual override {
        _beforeReceive(_srcChainId, _srcAddress, _payload);

        // decode and load the toAddress
        (bytes memory toAddress, uint256 tokenId, IMojosSeeder.Seed memory seed) = abi.decode(
            _payload,
            (bytes, uint256, IMojosSeeder.Seed)
        );
        address localToAddress;
        assembly {
            localToAddress := mload(add(toAddress, 20))
        }

        // if the toAddress is 0x0, convert to dead address, or it will get cached
        if (localToAddress == address(0x0)) localToAddress == address(0xdEaD);

        _afterReceive(_srcChainId, localToAddress, seed);

        emit ReceiveFromChain(_srcChainId, localToAddress, tokenId, _nonce);
    }

    function _beforeSend(
        address, /* _from */
        uint16, /* _dstChainId */
        bytes memory, /* _toAddress */
        uint256 _tokenId
    ) internal virtual {
        _burn(_tokenId);
    }

    function _afterSend(
        address, /* _from */
        uint16, /* _dstChainId */
        bytes memory, /* _toAddress */
        uint256 /* _tokenId */
    ) internal virtual {}

    function _beforeReceive(
        uint16, /* _srcChainId */
        bytes memory, /* _srcAddress */
        bytes memory /* _payload */
    ) internal virtual {}

    function _afterReceive(
        uint16, /* _srcChainId */
        address _toAddress,
IMojosSeeder.Seed memory _seed
    ) internal virtual {
        uint256 mojoId = _currentMojoId++;
        seeds[mojoId] = _seed;

        _mint(owner(), _toAddress, mojoId);
        emit MojoCreated(mojoId, _seed);
    }

    function setBaseURI(string memory _baseTokenURI) public onlyOwner {
        baseTokenURI = _baseTokenURI;
    }

    function _baseURI() internal view override returns (string memory) {
        return baseTokenURI;
    }

    function addExternalMinter(address _member) public onlyOwner {
        externalMinters[_member] = true;
    }

    function removeExternalMinter(address _member) public onlyOwner {
        externalMinters[_member] = false;
    }

    function isExternalMinter(address _account) public view virtual returns (bool) {
        return externalMinters[_account];
    }
}

// File: contracts/NonBlockingLzApp.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

import "./LzApp.sol";

/*
 * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
 * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
 * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
 */
abstract contract NonblockingLzApp is LzApp {
    constructor(address _endpoint) LzApp(_endpoint) {}

    mapping(uint16 => mapping(bytes => mapping(uint => bytes32))) public failedMessages;

    event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload);

    // overriding the virtual function in LzReceiver
    function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
        // try-catch all errors/exceptions
        try this.nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload) {
            // do nothing
        } catch {
            // error / exception
            failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload);
        }
    }

    function nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) public virtual {
        // only internal transaction
        require(_msgSender() == address(this), "LzReceiver: caller must be LzApp");
        _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }

    //@notice override this function
    function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;

    function retryMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes calldata _payload) external payable virtual {
        // assert there is message to retry
        bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
        require(payloadHash != bytes32(0), "LzReceiver: no stored message");
        require(keccak256(_payload) == payloadHash, "LzReceiver: invalid payload");
        // clear the stored message
        failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
        // execute the message. revert if it fails again
        this.nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }
}
// File: contracts/UniversalMojoToken.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.6;

import './MojosToken.sol';

/// @title Interface of the UniversalONFT standard
contract UniversalMojo is MojosToken {


    /// @notice Constructor for the UniversalNFT

    constructor(
        address _mojosDAO,
        address _minter,
        IMojosDescriptor _descriptor,
        IMojosSeeder _seeder,
        address _lzEndpoint,
        uint256 _startMintId,
        uint256 _endMintId
    ) MojosToken(_mojosDAO, _minter, _descriptor, _seeder, _lzEndpoint, _startMintId, _endMintId) {
      
    }
}

// File: contracts/base/ERC721.sol



// SPDX-License-Identifier: MIT

/// @title ERC721 Token Implementation

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/ERC721.sol
//
// ERC721.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Mojos DAO.
//
//
// MODIFICATIONS:
// `_safeMint` and `_mint` contain an additional `creator` argument and
// emit two `Transfer` logs, rather than one. The first log displays the
// transfer (mint) from `address(0)` to the `creator`. The second displays the
// transfer from the `creator` to the `to` address. This enables correct
// attribution on various NFT marketplaces.

pragma solidity ^0.8.6;

import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
import '@openzeppelin/contracts/utils/Address.sol';
import '@openzeppelin/contracts/utils/Context.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/utils/introspection/ERC165.sol';

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

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

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

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

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

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), 'ERC721: balance query for the zero address');
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), 'ERC721: owner query for nonexistent token');
        return owner;
    }

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

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

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), 'ERC721Metadata: URI query for nonexistent token');

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

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

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, 'ERC721: approval to current owner');

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            'ERC721: approve caller is not owner nor approved for all'
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), 'ERC721: approved query for nonexistent token');

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        require(operator != _msgSender(), 'ERC721: approve to caller');

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

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

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');

        _transfer(from, to, tokenId);
    }

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

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), 'ERC721: transfer caller is not owner nor approved');
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @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.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), 'ERC721: transfer to non ERC721Receiver implementer');
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), 'ERC721: operator query for nonexistent token');
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Safely mints `tokenId`, transfers it to `to`, and emits two log events -
     * 1. Credits the `minter` with the mint.
     * 2. Shows transfer from the `minter` to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(
        address creator,
        address to,
        uint256 tokenId
    ) internal virtual {
        _safeMint(creator, to, tokenId, '');
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address creator,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(creator, to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            'ERC721: transfer to non ERC721Receiver implementer'
        );
    }

    /**
     * @dev Mints `tokenId`, transfers it to `to`, and emits two log events -
     * 1. Credits the `creator` with the mint.
     * 2. Shows transfer from the `creator` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(
        address creator,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(to != address(0), 'ERC721: mint to the zero address');
        require(!_exists(tokenId), 'ERC721: token already minted');

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), creator, tokenId);
        emit Transfer(creator, to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, 'ERC721: transfer of token that is not own');
        require(to != address(0), 'ERC721: transfer to the zero address');

        _beforeTokenTransfer(from, to, tokenId);

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

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert('ERC721: transfer to non ERC721Receiver implementer');
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * 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, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: contracts/base/ERC721Checkpointable.sol



// SPDX-License-Identifier: BSD-3-Clause

/// @title Vote checkpointing for an ERC-721 token

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

// LICENSE
// ERC721Checkpointable.sol uses and modifies part of Compound Lab's Comp.sol:
// https://github.com/compound-finance/compound-protocol/blob/ae4388e780a8d596d97619d9704a931a2752c2bc/contracts/Governance/Comp.sol
//
// Comp.sol source code Copyright 2020 Compound Labs, Inc. licensed under the BSD-3-Clause license.
// With modifications by Mojos DAO.
//
// Additional conditions of BSD-3-Clause can be found here: https://opensource.org/licenses/BSD-3-Clause
//
// MODIFICATIONS
// Checkpointing logic from Comp.sol has been used with the following modifications:
// - `delegates` is renamed to `_delegates` and is set to private
// - `delegates` is a public function that uses the `_delegates` mapping look-up, but unlike
//   Comp.sol, returns the delegator's own address if there is no delegate.
//   This avoids the delegator needing to "delegate to self" with an additional transaction
// - `_transferTokens()` is renamed `_beforeTokenTransfer()` and adapted to hook into OpenZeppelin's ERC721 hooks.

pragma solidity ^0.8.6;

import './ERC721Enumerable.sol';

abstract contract ERC721Checkpointable is ERC721Enumerable {
    /// @notice Defines decimals as per ERC-20 convention to make integrations with 3rd party governance platforms easier
    uint8 public constant decimals = 0;

    /// @notice A record of each accounts delegate
    mapping(address => address) private _delegates;

    /// @notice A checkpoint for marking number of votes from a given block
    struct Checkpoint {
        uint32 fromBlock;
        uint96 votes;
    }

    /// @notice A record of votes checkpoints for each account, by index
    mapping(address => mapping(uint32 => Checkpoint)) public checkpoints;

    /// @notice The number of checkpoints for each account
    mapping(address => uint32) public numCheckpoints;

    /// @notice The EIP-712 typehash for the contract's domain
    bytes32 public constant DOMAIN_TYPEHASH =
        keccak256('EIP712Domain(string name,uint256 chainId,address verifyingContract)');

    /// @notice The EIP-712 typehash for the delegation struct used by the contract
    bytes32 public constant DELEGATION_TYPEHASH =
        keccak256('Delegation(address delegatee,uint256 nonce,uint256 expiry)');

    /// @notice A record of states for signing / validating signatures
    mapping(address => uint256) public nonces;

    /// @notice An event thats emitted when an account changes its delegate
    event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);

    /// @notice An event thats emitted when a delegate account's vote balance changes
    event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance);

    /**
     * @notice The votes a delegator can delegate, which is the current balance of the delegator.
     * @dev Used when calling `_delegate()`
     */
    function votesToDelegate(address delegator) public view returns (uint96) {
        return safe96(balanceOf(delegator), 'ERC721Checkpointable::votesToDelegate: amount exceeds 96 bits');
    }

    /**
     * @notice Overrides the standard `Comp.sol` delegates mapping to return
     * the delegator's own address if they haven't delegated.
     * This avoids having to delegate to oneself.
     */
    function delegates(address delegator) public view returns (address) {
        address current = _delegates[delegator];
        return current == address(0) ? delegator : current;
    }

    /**
     * @notice Adapted from `_transferTokens()` in `Comp.sol` to update delegate votes.
     * @dev hooks into OpenZeppelin's `ERC721._transfer`
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal override {
        super._beforeTokenTransfer(from, to, tokenId);

        /// @notice Differs from `_transferTokens()` to use `delegates` override method to simulate auto-delegation
        _moveDelegates(delegates(from), delegates(to), 1);
    }

    /**
     * @notice Delegate votes from `msg.sender` to `delegatee`
     * @param delegatee The address to delegate votes to
     */
    function delegate(address delegatee) public {
        if (delegatee == address(0)) delegatee = msg.sender;
        return _delegate(msg.sender, delegatee);
    }

    /**
     * @notice Delegates votes from signatory to `delegatee`
     * @param delegatee The address to delegate votes to
     * @param nonce The contract state required to match the signature
     * @param expiry The time at which to expire the signature
     * @param v The recovery byte of the signature
     * @param r Half of the ECDSA signature pair
     * @param s Half of the ECDSA signature pair
     */
    function delegateBySig(
        address delegatee,
        uint256 nonce,
        uint256 expiry,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public {
        bytes32 domainSeparator = keccak256(
            abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this))
        );
        bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
        bytes32 digest = keccak256(abi.encodePacked('\x19\x01', domainSeparator, structHash));
        address signatory = ecrecover(digest, v, r, s);
        require(signatory != address(0), 'ERC721Checkpointable::delegateBySig: invalid signature');
        require(nonce == nonces[signatory]++, 'ERC721Checkpointable::delegateBySig: invalid nonce');
        require(block.timestamp <= expiry, 'ERC721Checkpointable::delegateBySig: signature expired');
        return _delegate(signatory, delegatee);
    }

    /**
     * @notice Gets the current votes balance for `account`
     * @param account The address to get votes balance
     * @return The number of current votes for `account`
     */
    function getCurrentVotes(address account) external view returns (uint96) {
        uint32 nCheckpoints = numCheckpoints[account];
        return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
    }

    /**
     * @notice Determine the prior number of votes for an account as of a block number
     * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
     * @param account The address of the account to check
     * @param blockNumber The block number to get the vote balance at
     * @return The number of votes the account had as of the given block
     */
    function getPriorVotes(address account, uint256 blockNumber) public view returns (uint96) {
        require(blockNumber < block.number, 'ERC721Checkpointable::getPriorVotes: not yet determined');

        uint32 nCheckpoints = numCheckpoints[account];
        if (nCheckpoints == 0) {
            return 0;
        }

        // First check most recent balance
        if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
            return checkpoints[account][nCheckpoints - 1].votes;
        }

        // Next check implicit zero balance
        if (checkpoints[account][0].fromBlock > blockNumber) {
            return 0;
        }

        uint32 lower = 0;
        uint32 upper = nCheckpoints - 1;
        while (upper > lower) {
            uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
            Checkpoint memory cp = checkpoints[account][center];
            if (cp.fromBlock == blockNumber) {
                return cp.votes;
            } else if (cp.fromBlock < blockNumber) {
                lower = center;
            } else {
                upper = center - 1;
            }
        }
        return checkpoints[account][lower].votes;
    }

    function _delegate(address delegator, address delegatee) internal {
        /// @notice differs from `_delegate()` in `Comp.sol` to use `delegates` override method to simulate auto-delegation
        address currentDelegate = delegates(delegator);

        _delegates[delegator] = delegatee;

        emit DelegateChanged(delegator, currentDelegate, delegatee);

        uint96 amount = votesToDelegate(delegator);

        _moveDelegates(currentDelegate, delegatee, amount);
    }

    function _moveDelegates(
        address srcRep,
        address dstRep,
        uint96 amount
    ) internal {
        if (srcRep != dstRep && amount > 0) {
            if (srcRep != address(0)) {
                uint32 srcRepNum = numCheckpoints[srcRep];
                uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
                uint96 srcRepNew = sub96(srcRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount underflows');
                _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
            }

            if (dstRep != address(0)) {
                uint32 dstRepNum = numCheckpoints[dstRep];
                uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
                uint96 dstRepNew = add96(dstRepOld, amount, 'ERC721Checkpointable::_moveDelegates: amount overflows');
                _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
            }
        }
    }

    function _writeCheckpoint(
        address delegatee,
        uint32 nCheckpoints,
        uint96 oldVotes,
        uint96 newVotes
    ) internal {
        uint32 blockNumber = safe32(
            block.number,
            'ERC721Checkpointable::_writeCheckpoint: block number exceeds 32 bits'
        );

        if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
            checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
        } else {
            checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
            numCheckpoints[delegatee] = nCheckpoints + 1;
        }

        emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
    }

    function safe32(uint256 n, string memory errorMessage) internal pure returns (uint32) {
        require(n < 2**32, errorMessage);
        return uint32(n);
    }

    function safe96(uint256 n, string memory errorMessage) internal pure returns (uint96) {
        require(n < 2**96, errorMessage);
        return uint96(n);
    }

    function add96(
        uint96 a,
        uint96 b,
        string memory errorMessage
    ) internal pure returns (uint96) {
        uint96 c = a + b;
        require(c >= a, errorMessage);
        return c;
    }

    function sub96(
        uint96 a,
        uint96 b,
        string memory errorMessage
    ) internal pure returns (uint96) {
        require(b <= a, errorMessage);
        return a - b;
    }

    function getChainId() internal view returns (uint256) {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return chainId;
    }
}

// File: contracts/base/ERC721Enumerable.sol



// SPDX-License-Identifier: MIT

/// @title ERC721 Enumerable Extension

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

// LICENSE
// ERC721.sol modifies OpenZeppelin's ERC721Enumerable.sol:
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/6618f9f18424ade44116d0221719f4c93be6a078/contracts/token/ERC721/extensions/ERC721Enumerable.sol
//
// ERC721Enumerable.sol source code copyright OpenZeppelin licensed under the MIT License.
// With modifications by Mojos DAO.
//
// MODIFICATIONS:
// Consumes modified `ERC721` contract. See notes in `ERC721.sol`.

pragma solidity ^0.8.0;

import './ERC721.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol';

/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;

    // Array with all token ids, used for enumeration
    uint256[] private _allTokens;

    // Mapping from token id to position in the allTokens array
    mapping(uint256 => uint256) private _allTokensIndex;

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
        return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), 'ERC721Enumerable: owner index out of bounds');
        return _ownedTokens[owner][index];
    }

    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721Enumerable.totalSupply(), 'ERC721Enumerable: global index out of bounds');
        return _allTokens[index];
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * 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, ``from``'s `tokenId` will be burned.
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual override {
        super._beforeTokenTransfer(from, to, tokenId);

        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }

    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Private function to add a token to this extension's token tracking data structures.
     * @param tokenId uint256 ID of the token to be added to the tokens list
     */
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }

        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }

    /**
     * @dev Private function to remove a token from this extension's token tracking data structures.
     * This has O(1) time complexity, but alters the order of the _allTokens array.
     * @param tokenId uint256 ID of the token to be removed from the tokens list
     */
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
        uint256 lastTokenId = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index

        // This also deletes the contents at the last position of the array
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}

// File: contracts/interfaces/ILayerZeroEndpoint.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

import "./ILayerZeroUserApplicationConfig.sol";

interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
    // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
    // @param _dstChainId - the destination chain identifier
    // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
    // @param _payload - a custom bytes payload to send to the destination contract
    // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
    // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
    // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
    function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;

    // @notice used by the messaging library to publish verified payload
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source contract (as bytes) at the source chain
    // @param _dstAddress - the address on destination chain
    // @param _nonce - the unbound message ordering nonce
    // @param _gasLimit - the gas limit for external contract execution
    // @param _payload - verified payload to send to the destination contract
    function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;

    // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);

    // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
    // @param _srcAddress - the source chain contract address
    function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);

    // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
    // @param _dstChainId - the destination chain identifier
    // @param _userApplication - the user app address on this EVM chain
    // @param _payload - the custom message to send over LayerZero
    // @param _payInZRO - if false, user app pays the protocol fee in native token
    // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
    function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);

    // @notice get this Endpoint's immutable source identifier
    function getChainId() external view returns (uint16);

    // @notice the interface to retry failed message on this Endpoint destination
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    // @param _payload - the payload to be retried
    function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;

    // @notice query if any STORED payload (message blocking) at the endpoint.
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);

    // @notice query if the _libraryAddress is valid for sending msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getSendLibraryAddress(address _userApplication) external view returns (address);

    // @notice query if the _libraryAddress is valid for receiving msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getReceiveLibraryAddress(address _userApplication) external view returns (address);

    // @notice query if the non-reentrancy guard for send() is on
    // @return true if the guard is on. false otherwise
    function isSendingPayload() external view returns (bool);

    // @notice query if the non-reentrancy guard for receive() is on
    // @return true if the guard is on. false otherwise
    function isReceivingPayload() external view returns (bool);

    // @notice get the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _userApplication - the contract address of the user application
    // @param _configType - type of configuration. every messaging library has its own convention.
    function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);

    // @notice get the send() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getSendVersion(address _userApplication) external view returns (uint16);

    // @notice get the lzReceive() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getReceiveVersion(address _userApplication) external view returns (uint16);
}
// File: contracts/interfaces/ILayerZeroReceiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

interface ILayerZeroReceiver {
    // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
    // @param _srcChainId - the source endpoint identifier
    // @param _srcAddress - the source sending contract address from the source chain
    // @param _nonce - the ordered message nonce
    // @param _payload - the signed payload is the UA bytes has encoded to be sent
    function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
}
// File: contracts/interfaces/ILayerZeroUserApplicationConfig.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

interface ILayerZeroUserApplicationConfig {
    // @notice set the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _configType - type of configuration. every messaging library has its own convention.
    // @param _config - configuration in the bytes. can encode arbitrary content.
    function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;

    // @notice set the send() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setSendVersion(uint16 _version) external;

    // @notice set the lzReceive() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setReceiveVersion(uint16 _version) external;

    // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
    // @param _srcChainId - the chainId of the source chain
    // @param _srcAddress - the contract address of the source contract at the source chain
    function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
}
// File: contracts/interfaces/IMojosDescriptor.sol



// SPDX-License-Identifier: GPL-3.0

/// @title Interface for MojosDescriptor

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

pragma solidity ^0.8.6;

import { IMojosSeeder } from './IMojosSeeder.sol';

interface IMojosDescriptor {
    event PartsLocked();

    event DataURIToggled(bool enabled);

    event BaseURIUpdated(string baseURI);

    function arePartsLocked() external returns (bool);

    function isDataURIEnabled() external returns (bool);

    function baseURI() external returns (string memory);

    function palettes(uint8 paletteIndex, uint256 colorIndex) external view returns (string memory);

    function backgrounds(uint256 index) external view returns (string memory);

    function bodies(uint256 index) external view returns (bytes memory);

    function bodyAccessories(uint256 index) external view returns (bytes memory);

    function faces(uint256 index) external view returns (bytes memory);

    function headAccessories(uint256 index) external view returns (bytes memory);

    function backgroundCount() external view returns (uint256);

    function bodyCount() external view returns (uint256);

    function bodyAccessoryCount() external view returns (uint256);

    function faceCount() external view returns (uint256);

    function headAccessoryCount() external view returns (uint256);

    function addManyColorsToPalette(uint8 paletteIndex, string[] calldata newColors) external;

    function addManyBackgrounds(string[] calldata backgrounds) external;

    function addManyBodies(bytes[] calldata bodies) external;

    function addManyBodyAccessories(bytes[] calldata bodyAccessories) external;

    function addManyFaces(bytes[] calldata faces) external;

    function addManyHeadAccessories(bytes[] calldata headAccessories) external;

    function addColorToPalette(uint8 paletteIndex, string calldata color) external;

    function addBackground(string calldata background) external;

    function addBody(bytes calldata body) external;

    function addBodyAccessory(bytes calldata bodyAccessory) external;

    function addFace(bytes calldata face) external;

    function addHeadAccessory(bytes calldata headAccessory) external;

    function lockParts() external;

    function toggleDataURIEnabled() external;

    function setBaseURI(string calldata baseURI) external;

    function tokenURI(uint256 tokenId, IMojosSeeder.Seed memory seed) external view returns (string memory);

    function dataURI(uint256 tokenId, IMojosSeeder.Seed memory seed) external view returns (string memory);

    function genericDataURI(
        string calldata name,
        string calldata description,
        IMojosSeeder.Seed memory seed
    ) external view returns (string memory);

    function generateSVGImage(IMojosSeeder.Seed memory seed) external view returns (string memory);
}
// File: contracts/interfaces/IMojosSeeder.sol



// SPDX-License-Identifier: GPL-3.0

/// @title Interface for MojosSeeder

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

pragma solidity ^0.8.6;

import { IMojosDescriptor } from './IMojosDescriptor.sol';

interface IMojosSeeder {
    struct Seed {
        uint48 background;
        uint48 body;
        uint48 bodyAccessory;
        uint48 face;
        uint48 headAccessory;
    }

    function generateSeed(uint256 mojoId, IMojosDescriptor descriptor) external view returns (Seed memory);
}

// File: contracts/interfaces/IMojosToken.sol



// SPDX-License-Identifier: GPL-3.0

/// @title Interface for MojosToken

/*********************************
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ *
 * ░░░███████████████████████░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 * ░░░░░░█████████████████░░░░░░ *
 *********************************/

pragma solidity ^0.8.6;

import { IERC721 } from '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import { IMojosDescriptor } from './IMojosDescriptor.sol';
import { IMojosSeeder } from './IMojosSeeder.sol';

interface IMojosToken is IERC721 {
    event MojoCreated(uint256 indexed tokenId, IMojosSeeder.Seed seed);
    event LogThis(string  message, IMojosSeeder.Seed seed);

    event MojoBurned(uint256 indexed tokenId);

    event MojosDAOUpdated(address mojosDAO);

    event MinterUpdated(address minter);

    event MinterLocked();

    event DescriptorUpdated(IMojosDescriptor descriptor);

    event DescriptorLocked();

    event SeederUpdated(IMojosSeeder seeder);

    event SeederLocked();

    function mint() external returns (uint256);

    function burn(uint256 tokenId) external;

    function dataURI(uint256 tokenId) external returns (string memory);

    function setMojosDAO(address mojosDAO) external;

    function setMinter(address minter) external;

    function lockMinter() external;

    function setDescriptor(IMojosDescriptor descriptor) external;

    function lockDescriptor() external;

    function setSeeder(IMojosSeeder seeder) external;

    function lockSeeder() external;

     /**
     * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
     * _dstChainId - L0 defined chain id to send tokens too
     * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
     * _tokenId - token Id to transfer
     * _useZro - indicates to use zro to pay L0 fees
     * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
     */
    function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _tokenId, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);

    /**
     * @dev send token `_tokenId` to (`_dstChainId`, `_toAddress`)
     * `_toAddress` can be any size depending on the `dstChainId`.
     * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
     * `_adapterParam` is a flexible bytes array to indicate messaging adapter services
     */
    function send(uint16 _dstChainId, bytes calldata _toAddress, uint _tokenId, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParam) external payable;

    /**
     * @dev send token `_tokenId` to (`_dstChainId`, `_toAddress`) from `_from`
     * `_toAddress` can be any size depending on the `dstChainId`.
     * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
     * `_adapterParam` is a flexible bytes array to indicate messaging adapter services
     */
    function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _tokenId, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParam) external payable;

    /**
     * @dev Emitted when `_tokenId` are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
     * `_nonce` is the outbound nonce from
     */
    event SendToChain(address indexed _sender, uint16 indexed _dstChainId, bytes indexed _toAddress, uint _tokenId, uint64 _nonce);

    /**
     * @dev Emitted when `_tokenId` are sent from `_srcChainId` to the `_toAddress` at this chain. `_nonce` is the inbound nonce.
     */
    event ReceiveFromChain(uint16 _srcChainId, address _toAddress, uint _tokenId, uint64 _nonce);
}