// SPDX-License-Identifier: MIT
// File: @openzeppelin/contracts/utils/math/SafeMath.sol


// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: @openzeppelin/contracts/utils/Strings.sol


// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @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);
    }
}

// File: @openzeppelin/contracts/utils/Context.sol


// 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/access/Ownable.sol


// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @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 Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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/utils/Address.sol


// OpenZeppelin Contracts (last updated v4.5.0) (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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol


// 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/utils/introspection/IERC165.sol


// 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: @openzeppelin/contracts/utils/introspection/ERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;


/**
 * @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/token/ERC721/IERC721.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;


/**
 * @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 be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) 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/extensions/IERC721Enumerable.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;


/**
 * @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


// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;


/**
 * @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/token/ERC721/ERC721.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;








/**
 * @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 overridden 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 {
        _setApprovalForAll(_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 || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it 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 to, uint256 tokenId) internal virtual {
        _safeMint(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 to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it 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 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), to, tokenId);

        _afterTokenTransfer(address(0), 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);

        _afterTokenTransfer(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 from incorrect owner");
        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);

        _afterTokenTransfer(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 Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @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.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 {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)

pragma solidity ^0.8.0;



/**
 * @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/ILayerZeroUserApplicationConfig.sol



pragma solidity >=0.5.0;

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/ILayerZeroEndpoint.sol



pragma solidity >=0.5.0;


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 receiver 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



pragma solidity >=0.5.0;

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/NonblockingReceiver.sol


pragma solidity ^0.8.6;




abstract contract NonblockingReceiver is Ownable, ILayerZeroReceiver {

    ILayerZeroEndpoint internal endpoint;

    struct FailedMessages {
        uint payloadLength;
        bytes32 payloadHash;
    }

    mapping(uint16 => mapping(bytes => mapping(uint => FailedMessages))) public failedMessages;
    mapping(uint16 => bytes) public trustedRemoteLookup;

    event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload);

    function lzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) external override {
        require(msg.sender == address(endpoint)); // boilerplate! lzReceive must be called by the endpoint for security
        require(_srcAddress.length == trustedRemoteLookup[_srcChainId].length && keccak256(_srcAddress) == keccak256(trustedRemoteLookup[_srcChainId]), 
            "NonblockingReceiver: invalid source sending contract");

        // try-catch all errors/exceptions
        // having failed messages does not block messages passing
        try this.onLzReceive(_srcChainId, _srcAddress, _nonce, _payload) {
            // do nothing
        } catch {
            // error / exception
            failedMessages[_srcChainId][_srcAddress][_nonce] = FailedMessages(_payload.length, keccak256(_payload));
            emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload);
        }
    }

    function onLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) public {
        // only internal transaction
        require(msg.sender == address(this), "NonblockingReceiver: caller must be Bridge.");

        // handle incoming message
        _LzReceive( _srcChainId, _srcAddress, _nonce, _payload);
    }

    // abstract function
    function _LzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) virtual internal;

    function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _txParam) internal {
        endpoint.send{value: msg.value}(_dstChainId, trustedRemoteLookup[_dstChainId], _payload, _refundAddress, _zroPaymentAddress, _txParam);
    }

    function retryMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes calldata _payload) external payable {
        // assert there is message to retry
        FailedMessages storage failedMsg = failedMessages[_srcChainId][_srcAddress][_nonce];
        require(failedMsg.payloadHash != bytes32(0), "NonblockingReceiver: no stored message");
        require(_payload.length == failedMsg.payloadLength && keccak256(_payload) == failedMsg.payloadHash, "LayerZero: invalid payload");
        // clear the stored message
        failedMsg.payloadLength = 0;
        failedMsg.payloadHash = bytes32(0);
        // execute the message. revert if it fails again
        this.onLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    }

    function setTrustedRemote(uint16 _chainId, bytes calldata _trustedRemote) external onlyOwner {
        trustedRemoteLookup[_chainId] = _trustedRemote;
    }
}


// File: contracts/WeSeeGhosts.sol


pragma solidity ^0.8.0;


// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&              .,*&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&                  .*,*&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#,,,,*,     &&&&&&&&&&&
// &&&&&&&&&&&&&&##*                    /&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,,,,,,,               *%&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&##*       (########&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%,,               *###.    (&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&(       %&&&&&&&&&&&&&&&&&&&&,         .,/&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%,        (###&&&&&&.    %&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&(       &&&&&&&&&&&&&&&&&&&&&&%##          %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&&&&&&&&.  .#&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&(       (&&&&&&&&&&&&&&&&&&&&&&&.     #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&&&&&&&&  ,%&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&%       (&&&&&&&&&&&&&&&&&&&&&&&.     #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&%       #&&&&&&&&&&&&&&&&&&&&&&&.     #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(.,,,./&&&&&&&&&&&&&(.,,,,,,,,     /&&&&*        %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&&&&&&&&&&&&&.     #&&&&&#.,,,,,,,,,,,,.(&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,         .&&&&&&&&&#       ,%##&&&&&&&&&*         %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&&&&&&&&&&&&&.     #&&&%.      .%#######%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(    *&&&&&/    /&&&&&&&&*     *&&&&&&&&&&&&.         .,,,,     %&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&.      /&&&&&&&&&&&&&&&&&&&&&&.     #&&&&&/     ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,     %&&&&&&&&   ,&&&&&&&&/     *&&&&&&&&&&&&.              (%###&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&.       .&&&&&&&&&&&&*/&&&&&&&.     #&&&&&&(     ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%      #&&&&&&&%   ,&&&&&&&.       ..&&&&&&&&&&.         (%%&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&.        ,&&&&&&&&%.    ,&&&&&.     #&&&&&&#      ......#&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%.    %&&&&&&&&&&%%&&&&&&&.           ,&&&&&&&.         %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&%,        %&&&&&/          (&.      #&&&&&&#            #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/    /&&&&&&&&&&&&&&&&&.     (&&&&&&&&&&&&&.         %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&*        &&&%.                     #&&&&&&#      &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%.   .%&&&&&&&&&&&&&&.     (&&&&&&&&&&&&&.         %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&*         ..        #(             #&&&&&&#      &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/    /&&&&&&&&&&&&.     (&&&&&&&&&&&&&.       .%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&*                  %&&#            #&&&&&&#      &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%  (&&&&&&&%.   .%&&&&&&&%      %&&&&&&&&&&&&&&.       .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&/               .&&&&&&%,        #&&&&&&&&&      #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%   ,&&&&&&&&/    /&&&&&&%      %&&&&&&&&&&&&%         .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&(              *&&&&&&&&&/       &&&&&&&&&&      #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%   ,&&&&&&&&*    (&&&&&&&       #&&&&&&&&&&&%         .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&(             (&&&&&&&&&&&(      &&&&&&&&&&       (&&&&&&&&&&&&&&&&&&&&%.. (&&&&&&&&&&&%    ,&&&&&&*     /&&&&/                  %&&%         .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&(            %&&&&&&&&&&&&&%     &&&&&&&(                  #&&&&&&&&&*       ,&&&&&&&&&&%.     #%      %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&          ...        #%&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&#         .&&&&&&&&&&&&&&&&&,   &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&           %&&&&&&&&&&&(        *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/        #&%%%%%&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&&&&&&&&&&&%%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#             /&&&&&&&&&&&&&.   %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&%       (&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/               ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&%      %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*   %&*     .&&.  .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&%  *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&* .  %&&&&, ,&&&&#   /&&&&/  &&&&&. . .&&&&&&&&&&&&&&&&&&&&&&&&%. .... (&&&&&&&&&&&&&&&(.&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#              ,&&&&#   /&&&&/              (&&&&&&&&&&&&&&&&&&&&&&       (&&&&&&&&&&&&&&&( &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#              ,&&&&#   /&&&&/              /&&&&&&&&&&&&&&&&&&&&(       %&&&&&&&&&&&&&&&* .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&              .&&/     *&&,              #&&&&&&&&&&&#     .&&&#       %&&&&&&&&&&&&&&,  .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%    ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*               ,&&&*               ,&&&&&&&&&&&&&&&&&&&&%              .&&&&&&&&&%    .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.          #&&&&&&&&&&&&&&* ,&&&&&&&&&%  #&#             /&&&&&#             /&&&&&&&&,     (&&&&&&&&&&(       #&&%     &&&&%    .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(     .&&&/     ,&&&&&&&&&%    ,&&&&&&&*    #&&&            /&&&&&#            #&&&&&&#          .&&&&&&&&(       %&&&&&&&&&&&(     .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.     (&&&&&&&&.    &&&&&&*      ,&&&&#       #&&&&,          /&&&&&#           %&&&&&,    #&&&&&*    (&&&&&(       %&&&&&&&&&&*      .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(       %&&&&&&&&&.     #&&&&&/     ,&&&&&%      #&&&&,          /&&&&&#           &&&#     .&&&&&&&&#    ,&&&&(       %&&&&&&&%            (&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,        %&&&&&&&&&      #&&&&&/     ,&&&&&&      #&&&&&/         /&&&&&#         ,&&&&#     .&&&&&&&&(    ,&&&&(       %&&&&&*    (&&&&&&%    .&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&&&&&&&&&&/   #&&&&&/     ,&&&&&&      #&&&&&/                         ,&&&&&%    .&&&&&&&&&&&&*,&&&&(       %&&&&.    %&&&&&&&&&.    %&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&# %&&&&&&&&& (&&&&&/     ,&&&&&&      #&&&&&&#                       /&&&&&&&&&*    (&&&&&&&&&&&&&&*      .&&&&&&.    %&&&&&&&&&.    %&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*        %&&#  #&&&&&&&&&&&&&&&&#      &&&&&&,     /&&&&&#                       /&&&&&&&&&&&%    .&&&&&&&&&&&&*      .&&&&%      %&&&&&&&&&&*   %&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,        %&&#             /&&&&&#      &&&&&       /&&&&&#                       /&&&&&&&&&&&&&&*    (&&&&&&&&&*      .&&&&%      %&&&&&&&&&&&&% %&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        #&&&.            ,&&&&#      &&/         /&&&&&#                       /&&&&/ .&&&&&&&&&%    .&&&&&&&*      .&&&&&&.      *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        #&&&&&&&&&&/     ,&&&&#                  /&&&&&&&                     #&&&&&/    /&&&&&&&&&*    (&&&&*      .&&&&&&&&(       %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        #&&&&&&&&&&/     ,&&&&#         ,&&,     /&&&&&&&                     #&&&&&/    /&&&&&&&&&*    (&&&&*      .&&&&&&&&&&&.      *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        (&&&&&&&&&&/     ,&&&&#       #&&&&,     /&&&&&&&                     #&&&&&*    /&&&&&&&&.    %&&&&.      *&&&&&&&&&&&&&&(       %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        #&&&&&&&&&&/     ,&&&&&&      #&&&&&/     ,&&&&&&                     #&&&&&&#     .&&&(     .&&&&&&.      *&&&*,&&&&&&&&&&&&.      *&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(        #&&&&&&&&&&/     ,&&&&&&      #&&&&&/     ,&&&&&&                     #&&&&&&&&&,          (&&&&&&&&.      *&&&*   %&&&&&&&&&&*      .&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&#      &&&&&        ,&&&/     ,&&&&&&                     #&&&&&&&&&&&#     .&&&&&&&&&&&&&&&&&&&&&&*    (&&&&&&&&&&(     .&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&#      &&&&&        ,&&&/       &&&&&                     #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*    (&&&&&&&&&&(     .&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&#      &&&#    ,&&&&&&&&/       %&&&&&,                  &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*    (&&&&&&&&&&(     .&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%        *&&&&&&&&&&#      &&&&&&&&&&&&&&&&&&&&&&/    /&&&,                 .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*    (&&&&&&&&&*     *&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.      *&&&&&&&&&&#      &&&&&&&&&&&&&&&&&&&&&&&&&&&/ .&&/               ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*    (&&&&&&&&&*     *&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(       %&&&&&&/     ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#             /&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&*     ,&&&&&&&.      *&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.               #&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&           %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&      #&(       %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(          ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&,       .&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/          *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.       ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/     ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%      %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(     ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#    *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%    ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.  ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&/    (&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(    *&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.   &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&(  %&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&.     (&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&* ,&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
// &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&#   (&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&**&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
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contract WeSeeGhosts is ERC721Enumerable, Ownable, NonblockingReceiver  {
    using SafeMath for uint256;
    using SafeMath for uint128;
    using SafeMath for uint16;
    using Address for address;
    using Strings for uint256;

    event PresaleMint(address minter, uint256 numberOfGhosts, uint256 etherAmount, uint256 blockNumber);
    event SaleMint(address minter, uint256 numberOfGhosts, uint256 etherAmount, uint256 blockNumber);
    event DevMint(address recipient, uint256 numberOfGhosts);

    struct Coupon {
        bytes32 r;
        bytes32 s;
        uint8 v;
    }

    enum CouponType {
        FREE,
        REDUCED,
        WHITELIST,
        CLAIM,
        INVALID
    }

    uint128 public constant GHOST_PRICE = .08 ether;
    uint128 public constant DISCOUNT_GHOST_PRICE = .066 ether;
    uint16 public constant MAX_GHOSTS = 444;
    uint16 public constant MAX_DEV_GHOSTS = 45;
    uint16 public constant MAX_PURCHASABLE_GHOSTS = 4;
    uint16 public nextTokenId = 1;
    uint gasForDestinationLzReceive = 350000;
    uint16 public totalDevGhosts;
    bool private saleIsActive;
    bool private presaleIsActive; 
    address payable public treasury;
    address wsgSigner;
    string private _baseURIExtended;

    address public _owner;

    mapping(address => uint16) public purchased;

    constructor(string memory baseURI_, address _layerZeroEndpoint) ERC721('WeSeeGhosts Genesis Collection', 'GHOST') {
        _owner = msg.sender;
        endpoint = ILayerZeroEndpoint(_layerZeroEndpoint);
        _baseURIExtended = baseURI_;
    }

    function flipSaleState() public onlyOwner {
        require(!presaleIsActive, "WeSeeGhosts: Sale and Presale cannot be active at the same time");
        
        saleIsActive = !saleIsActive;
    }

    function flipPresaleState() public onlyOwner {
        require(!saleIsActive, "WeSeeGhosts: Presale and Sale cannot be active at the same time");
        require(wsgSigner != address(0), "WeSeeGhosts: Signer has not been set");
        presaleIsActive = !presaleIsActive;
    }

    function setWSGSigner(address _wsgSigner) external onlyOwner {
        require(_wsgSigner != address(0), "WeSeeGhosts: Must use valid address for WeSeeGhosts game signer");
        
        wsgSigner = _wsgSigner;
    }

    // Sets base URI for all tokens, only able to be called by contract owner
    function updateBaseUri(string memory newBaseURI) external onlyOwner {
        _baseURIExtended = newBaseURI;
    }

    function _baseURI() internal view virtual override returns (string memory) {
        return _baseURIExtended;
    }
    
    function setTreasury(address payable _treasury) external onlyOwner {
        treasury = _treasury;
    }

    // Non Presale Regular Mint
    function mint(uint256 numberOfGhosts) public payable {
        uint16 _nextTokenId = nextTokenId;
        uint256 totalCost;

        require(treasury != address(0), "WeSeeGhosts: Treasury has not been set");
        require(numberOfGhosts > 0, "WeSeeGhosts: Number of Ghosts can not be less than or equal to 0");
        require(saleIsActive, "WeSeeGhosts: Can only mint during public sale");
        require(_nextTokenId.add(numberOfGhosts-1) < MAX_GHOSTS, "WeSeeGhosts: Purchase would exceed max supply");
        require((numberOfGhosts-1) < MAX_PURCHASABLE_GHOSTS, "WeSeeGhosts: Number of Ghosts requested exceeds max number of Ghosts per address");
        require(purchased[msg.sender].add(numberOfGhosts-1) < MAX_PURCHASABLE_GHOSTS, 'WeSeeGhosts: Purchase would exceed max Ghosts purchasable per address');
        
        totalCost = GHOST_PRICE.mul(numberOfGhosts);
        
        require(msg.value == totalCost, "WeSeeGhosts: Sent ether value is incorrect");
        purchased[msg.sender] = uint16(purchased[msg.sender].add(numberOfGhosts));
        treasury.transfer(msg.value);

        for (uint i = 0; i < numberOfGhosts; i++) {
            _safeMint(msg.sender, _nextTokenId.add(i));
        }

        nextTokenId = uint16(_nextTokenId.add(numberOfGhosts));
        
        emit SaleMint(msg.sender, numberOfGhosts, msg.value, block.number);
    }

     // Presale and Discounted Mint
    function mintCoupon(uint256 numberOfGhosts,
        Coupon memory discountCoupon, 
        Coupon memory whitelistCoupon,
        uint _type
        ) public payable {
        uint16 _nextTokenId = nextTokenId;
        uint256 totalCost;

        require(treasury != address(0), "WeSeeGhosts: Treasury has not been set");
        require(numberOfGhosts > 0, "WeSeeGhosts: Number of Ghosts can not be less than or equal to 0");
        require(presaleIsActive || saleIsActive, "WeSeeGhosts: Can only mint during an active sale");
        require(_nextTokenId.add(numberOfGhosts-1) < MAX_GHOSTS, "WeSeeGhosts: Purchase would exceed max supply");
        require((numberOfGhosts-1) < MAX_PURCHASABLE_GHOSTS, "WeSeeGhosts: Number of Ghosts requested exceeds max number of Ghosts per address");
        require(purchased[msg.sender].add(numberOfGhosts-1) < MAX_PURCHASABLE_GHOSTS, 'WeSeeGhosts: Purchase would exceed max Ghosts purchasable per address');
        require((_type == 0) || (_type == 1) || (_type == 2), "WeSeeGhosts: CouponType not accepted");
        require(wsgSigner != address(0), "WeSeeGhosts: Signer has not been set");

        // validate whitelist
        if (presaleIsActive) {            
            bool isWhitelisted = _isValidCoupon(whitelistCoupon, msg.sender, 2);
            require(isWhitelisted, "WeSeeGhosts: The wallet address is not whitelisted");
        } 
        
        bool isValid = _isValidCoupon(discountCoupon, msg.sender, _type);        
        require(isValid, "WeSeeGhosts: This is not a valid coupon");

        if(_type == uint(CouponType.FREE)){
            uint256 freeQty = 1;
            // if user attempts to reuse a free coupon set, act as a reucedCoupon
            if (purchased[msg.sender] != 0)
                freeQty = 0;
            totalCost = DISCOUNT_GHOST_PRICE.mul(numberOfGhosts - freeQty);
        } else if(_type == uint(CouponType.REDUCED)){
            totalCost = DISCOUNT_GHOST_PRICE.mul(numberOfGhosts);
        } else {
            totalCost = GHOST_PRICE.mul(numberOfGhosts);
        }

        require(msg.value == totalCost, "WeSeeGhosts: Sent ether value is incorrect");
        purchased[msg.sender] = uint16(purchased[msg.sender].add(numberOfGhosts));
        treasury.transfer(msg.value);

        for (uint i = 0; i < numberOfGhosts; i++) {
            _safeMint(msg.sender, _nextTokenId.add(i));
        }

        nextTokenId = uint16(_nextTokenId.add(numberOfGhosts));

        if (presaleIsActive) {
            emit PresaleMint(msg.sender, numberOfGhosts, msg.value, block.number);
        } else {
            emit SaleMint(msg.sender, numberOfGhosts, msg.value, block.number);
        }
    }

    function mintDev(address recipient, uint256 numberOfGhosts) external onlyOwner {
        uint16 _nextTokenId = nextTokenId;

        require(treasury != address(0), "Treasury not set");
        require(recipient != address(0), "Cannot mint dev supply to zero address");
        require(_nextTokenId.add(numberOfGhosts-1) < MAX_GHOSTS, "WeSeeGhosts: Purchase would exceed max supply");
        require(totalDevGhosts.add(numberOfGhosts-1) < MAX_DEV_GHOSTS, "WeSeeGhosts: Purchase would exceed max dev supply");
        
        for (uint i = 0; i < numberOfGhosts; i++) {
            _safeMint(recipient, _nextTokenId.add(i));
        }
        nextTokenId = uint16(_nextTokenId.add(numberOfGhosts));
        totalDevGhosts = uint16(totalDevGhosts.add(numberOfGhosts));

        emit DevMint(recipient, numberOfGhosts);
    }

    // This function transfers the nft from your address on the 
    // source chain to the same address on the destination chain
    function traverseChains(uint16 _chainId, uint tokenId) public payable {
        require(msg.sender == ownerOf(tokenId), "You must own the token to traverse");
        require(trustedRemoteLookup[_chainId].length > 0, "This chain is currently unavailable for travel");

        // burn NFT, eliminating it from circulation on src chain
        _burn(tokenId);

        // abi.encode() the payload with the values to send
        bytes memory payload = abi.encode(msg.sender, tokenId);

        // encode adapterParams to specify more gas for the destination
        uint16 version = 1;
        bytes memory adapterParams = abi.encodePacked(version, gasForDestinationLzReceive);

        // get the fees we need to pay to LayerZero + Relayer to cover message delivery
        // you will be refunded for extra gas paid
        (uint messageFee, ) = endpoint.estimateFees(_chainId, address(this), payload, false, adapterParams);
        
        require(msg.value >= messageFee, "WSG: msg.value not enough to cover messageFee. Send gas for message fees");

        endpoint.send{value: msg.value}(
            _chainId,                           // destination chainId
            trustedRemoteLookup[_chainId],      // destination address of nft contract
            payload,                            // abi.encoded()'ed bytes
            payable(msg.sender),                // refund address
            address(0x0),                       // 'zroPaymentAddress' unused for this
            adapterParams                       // txParameters 
        );
    }

    // just in case this fixed variable limits us from future integrations
    function setGasForDestinationLzReceive(uint newVal) external onlyOwner {
        gasForDestinationLzReceive = newVal;
    }

    function totalDevMints() external view onlyOwner returns (uint16) {
        return totalDevGhosts;
    }

    function withdraw() public onlyOwner {
        uint256 balance = address(this).balance;
        payable(msg.sender).transfer(balance);
    }

    // ------------------
    // Internal Functions
    // ------------------

    

    function _isValidCoupon(Coupon memory coupon, address userAddress, uint _type)
        internal
        view
        returns (bool)
    {
        CouponType couponType; 
        bytes memory prefix = "\x19Ethereum Signed Message:\n32";

        if(_type == uint(CouponType.FREE)){
            couponType = CouponType.FREE;
        }else if (_type == uint(CouponType.REDUCED)){
            couponType = CouponType.REDUCED;
        }else if (_type == uint(CouponType.WHITELIST)){
            couponType = CouponType.WHITELIST;
        }
        
        bytes32 baseMsg = keccak256(abi.encode(couponType, userAddress));
        bytes32 prefixedMsg = keccak256(abi.encodePacked(prefix, baseMsg));
        address decodedSigner = ecrecover(prefixedMsg, coupon.v, coupon.r, coupon.s);

        if(decodedSigner != address(0) && decodedSigner == wsgSigner){
            return true;
        }

        return false;
    }

    function _LzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) override internal {
        // decode
        (address toAddr, uint tokenId) = abi.decode(_payload, (address, uint));

        // mint the tokens back into existence on destination chain
        _safeMint(toAddr, tokenId);
    }
    

}