// File: openzeppelin-solidity/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

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 () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: openzeppelin-solidity/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT

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

    /**
     * @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 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);

    /**
      * @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;
}

// File: openzeppelin-solidity/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT

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 `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
}

// File: openzeppelin-solidity/contracts/token/ERC721/extensions/IERC721Enumerable.sol



// SPDX-License-Identifier: MIT

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 tokenId);

    /**
     * @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-solidity/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT

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-solidity/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 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");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private 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

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: openzeppelin-solidity/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: openzeppelin-solidity/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant alphabet = "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] = alphabet[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

}

// File: openzeppelin-solidity/contracts/utils/cryptography/ECDSA.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        // Divide the signature in r, s and v variables
        bytes32 r;
        bytes32 s;
        uint8 v;

        // Check the signature length
        // - case 65: r,s,v signature (standard)
        // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
        if (signature.length == 65) {
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            // solhint-disable-next-line no-inline-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
        } else if (signature.length == 64) {
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            // solhint-disable-next-line no-inline-assembly
            assembly {
                let vs := mload(add(signature, 0x40))
                r := mload(add(signature, 0x20))
                s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                v := add(shr(255, vs), 27)
            }
        } else {
            revert("ECDSA: invalid signature length");
        }

        return recover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
        require(v == 27 || v == 28, "ECDSA: invalid signature 'v' value");

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        require(signer != address(0), "ECDSA: invalid signature");

        return signer;
    }

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

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
    }
}

// File: openzeppelin-solidity/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT

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-solidity/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT

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-solidity/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT

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 no longer needed starting with Solidity 0.8. 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 substraction 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. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * 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: /contracts/GeneticChain721.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

//------------------------------------------------------------------------------
// geneticchain.io - NextGen Generative NFT Platform
//------------------------------------------------------------------------------
//________________________________________________________________   .¿yy¿.   __
//MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM```````/MMM\\\\\  \\$$$$$$S/  .
//MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM``   `/  yyyy    ` _____J$$$*^^*/%#//
//MMMMMMMMMMMMMMMMMMMYYYMMM````      `\/  .¿yü  /  $ùpüüü%%% | ``|//|` __
//MMMMMYYYYMMMMMMM/`     `| ___.¿yüy¿.  .d$$$$  /  $$$$SSSSM |   | ||  MMNNNNNNM
//M/``      ``\/`  .¿ù%%/.  |.d$$$$$$$b.$$$*°^  /  o$$$  __  |   | ||  MMMMMMMMM
//M   .¿yy¿.     .dX$$$$$$7.|$$$$"^"$$$$$$o`  /MM  o$$$  MM  |   | ||  MMYYYYYYM
//  \\$$$$$$S/  .S$$o"^"4$$$$$$$` _ `SSSSS\        ____  MM  |___|_||  MM  ____
// J$$$*^^*/%#//oSSS`    YSSSSSS  /  pyyyüüü%%%XXXÙ$$$$  MM  pyyyyyyy, `` ,$$$o
//.$$$` ___     pyyyyyyyyyyyy//+  /  $$$$$$SSSSSSSÙM$$$. `` .S&&T$T$$$byyd$$$$\
//\$$7  ``     //o$$SSXMMSSSS  |  /  $$/&&X  _  ___ %$$$byyd$$$X\$`/S$$$$$$$S\
//o$$l   .\\YS$$X>$X  _  ___|  |  /  $$/%$$b.,.d$$$\`7$$$$$$$$7`.$   `"***"`  __
//o$$l  __  7$$$X>$$b.,.d$$$\  |  /  $$.`7$$$$$$$$%`  `*+SX+*|_\\$  /.     ..\MM
//o$$L  MM  !$$$$\$$$$$$$$$%|__|  /  $$// `*+XX*\'`  `____           ` `/MMMMMMM
///$$X, `` ,S$$$$\ `*+XX*\'`____  /  %SXX .      .,   NERV   ___.¿yüy¿.   /MMMMM
// 7$$$byyd$$$>$X\  .,,_    $$$$  `    ___ .y%%ü¿.  _______  $.d$$$$$$$S.  `MMMM
// `/S$$$$$$$\\$J`.\\$$$ :  $\`.¿yüy¿. `\\  $$$$$$S.//XXSSo  $$$$$"^"$$$$.  /MMM
//y   `"**"`"Xo$7J$$$$$\    $.d$$$$$$$b.    ^``/$$$$.`$$$$o  $$$$\ _ 'SSSo  /MMM
//M/.__   .,\Y$$$\\$$O` _/  $d$$$*°\ pyyyüüü%%%W $$$o.$$$$/  S$$$. `  S$To   MMM
//MMMM`  \$P*$$X+ b$$l  MM  $$$$` _  $$$$$$SSSSM $$$X.$T&&X  o$$$. `  S$To   MMM
//MMMX`  $<.\X\` -X$$l  MM  $$$$  /  $$/&&X      X$$$/$/X$$dyS$$>. `  S$X%/  `MM
//MMMM/   `"`  . -$$$l  MM  yyyy  /  $$/%$$b.__.d$$$$/$.'7$$$$$$$. `  %SXXX.  MM
//MMMMM//   ./M  .<$$S, `` ,S$$>  /  $$.`7$$$$$$$$$$$/S//_'*+%%XX\ `._       /MM
//MMMMMMMMMMMMM\  /$$$$byyd$$$$\  /  $$// `*+XX+*XXXX      ,.      .\MMMMMMMMMMM
//GENETIC/MMMMM\.  /$$$$$$$$$$\|  /  %SXX  ,_  .      .\MMMMMMMMMMMMMMMMMMMMMMMM
//CHAIN/MMMMMMMM/__  `*+YY+*`_\|  /_______//MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
//------------------------------------------------------------------------------
// Genetic Chain: GeneticChain721
//------------------------------------------------------------------------------
// Author: papaver (@tronicdreams)
//------------------------------------------------------------------------------

import "openzeppelin-solidity/contracts/access/Ownable.sol";
import "openzeppelin-solidity/contracts/utils/cryptography/ECDSA.sol";
import "openzeppelin-solidity/contracts/utils/Strings.sol";

import "./common/meta-transactions/ContentMixin.sol";
import "./common/meta-transactions/NativeMetaTransaction.sol";
import "./geneticchain/ERC721Sequential.sol";
import "./geneticchain/ERC721SeqEnumerable.sol";
import "./libraries/State.sol";

//------------------------------------------------------------------------------
// helper contracts
//------------------------------------------------------------------------------

contract OwnableDelegateProxy {}

//------------------------------------------------------------------------------

contract ProxyRegistry {
    mapping(address => OwnableDelegateProxy) public proxies;
}

//------------------------------------------------------------------------------
// GeneticChain721
//------------------------------------------------------------------------------

/**
 * @title GeneticChain721
 *
 * ERC721 contract with various features:
 *  - low-gas implmentation
 *  - off-chain whitelist verify (secure minting)
 *  - dynamic token allocation
 *  - artist allocation
 *  - gallery allocation
 *  - protected controlled burns
 *  - opensea proxy setup
 */
abstract contract GeneticChain721 is
    ContextMixin,
    ERC721SeqEnumerable,
    NativeMetaTransaction,
    Ownable
{
    using ECDSA for bytes32;
    using State for State.Data;

    //-------------------------------------------------------------------------
    // fields
    //-------------------------------------------------------------------------

    // erc721 metadata
    string constant private __name   = "Skell Yeah";
    string constant private __symbol = "SKELLYEAH";

    // verification address
    address constant private _signer = 0xc1f40b4438d66a736E9246c0c0B3fD5354F1402a;

    // token limits
    uint256 public immutable publicMax;
    uint256 public immutable artistMax;
    uint256 public immutable galleryMax;

    // opensea proxy
    address private immutable _proxyRegistryAddress;

    // contract state
    State.Data private _state;

    // roles
    mapping (address => bool) private _burnerAddress;
    address private _artistAddress = 0x00f630965f882298219edBB1B96e0409EC6C8698;

    // track mint count per address
    mapping (address => uint256) private _mints;

    //-------------------------------------------------------------------------
    // modifiers
    //-------------------------------------------------------------------------

    modifier validTokenId(uint256 tokenId) {
        require(_exists(tokenId), "invalid token");
        _;
    }

    //-------------------------------------------------------------------------

    modifier isArtist() {
        require(_msgSender() == _artistAddress, "caller not artist");
        _;
    }

    //-------------------------------------------------------------------------

    modifier isBurner() {
        require(_burnerAddress[_msgSender()], "caller not burner");
        _;
    }

    //-------------------------------------------------------------------------

    modifier notLocked() {
        require(_state._locked == 0, "contract is locked");
        _;
    }

    //-------------------------------------------------------------------------
    // ctor
    //-------------------------------------------------------------------------

    constructor(
        uint256[3] memory tokenMax_,
        address proxyRegistryAddress)
        ERC721Sequential(__name, __symbol)
    {
        publicMax             = tokenMax_[0];
        artistMax             = tokenMax_[1];
        galleryMax            = tokenMax_[2];
        _proxyRegistryAddress = proxyRegistryAddress;

        _initializeEIP712(__name);
        _state.setMaxPublic(1);

        // start tokens at 1 index
        _owners.push();
    }

    //-------------------------------------------------------------------------
    // accessors
    //-------------------------------------------------------------------------

    /**
     * Check if public minting is live.
     */
    function publicLive()
        public
        view
        returns (bool)
    {
        return _state._live == 1;
    }

    //-------------------------------------------------------------------------

    /**
     * Check if contract is locked.
     */
    function isLocked()
        public
        view
        returns (bool)
    {
        return _state._locked == 1;
    }

    //-------------------------------------------------------------------------

    /**
     * Get total gallery has minted.
     */
    function galleryMinted()
        public view
        returns (uint256)
    {
        return _state._gallery;
    }

    //-------------------------------------------------------------------------

    /**
     * Get total artist has minted.
     */
    function artistMinted()
        public view
        returns (uint256)
    {
        return _state._artist;
    }

    //-------------------------------------------------------------------------

    /**
     * Get total public has minted.
     */
    function publicMinted()
        public view
        returns (uint256)
    {
        return _state._public;
    }

    //-------------------------------------------------------------------------

    /**
     * Get max count allowed to mint per transaction.
     */
    function maxPublic()
        public view
        returns (uint256)
    {
        return _state._maxPublic;
    }

    //-------------------------------------------------------------------------
    // admin
    //-------------------------------------------------------------------------

    /**
     * Set artist address.
     */
    function setArtistAddress(address artistAddress)
        public
        onlyOwner
    {
        _artistAddress = artistAddress;
    }

    //-------------------------------------------------------------------------

    /**
     * Authorize artist address.
     */
    function registerBurnerAddress(address burner)
        public
        onlyOwner
    {
        require(!_burnerAddress[burner], "address already registered");
        _burnerAddress[burner] = true;
    }

    //-------------------------------------------------------------------------

    /**
     * Remove burner address.
     */
    function revokeBurnerAddress(address burner)
        public
        onlyOwner
    {
        require(_burnerAddress[burner], "address not registered");
        delete _burnerAddress[burner];
    }

    //-------------------------------------------------------------------------

    /**
     * Enable/disable public/member minting.
     */
    function toggleLock()
        public
        onlyOwner
    {
        _state.setLocked(_state._locked == 0 ? 1 : 0);
    }

    //-------------------------------------------------------------------------

    /**
     * Enable/disable public minting.
     */
    function togglePublicMint()
        public
        onlyOwner
    {
        _state.setLive(_state._live == 0 ? 1 : 0);
    }

    //-------------------------------------------------------------------------

    /**
     * Set max public mint per transaction.
     */
    function setMaxPublic(uint256 max)
        public
        onlyOwner
    {
        _state.setMaxPublic(max);
    }

    //-------------------------------------------------------------------------
    // security
    //-------------------------------------------------------------------------

    /**
     * Generate hash from input data.
     */
    function generateHash(uint256 allocation, uint256 count)
        private view
        returns(bytes32)
    {
        return ECDSA.toEthSignedMessageHash(
            keccak256(abi.encodePacked(address(this), msg.sender, allocation, count)));
    }

    //-------------------------------------------------------------------------

    /**
     * Validate message was signed by signer.
     */
    function validateSigner(bytes32 msgHash, bytes memory signature, address signer)
        private pure
        returns(bool)
    {
        return msgHash.recover(signature) == signer;
    }

    //-------------------------------------------------------------------------
    // minting
    //-------------------------------------------------------------------------

    /**
     * Allow anyone to mint tokens.
     */
    function mint(uint256 count)
        public
        notLocked
    {
        require(_state._live == 1, "public mint not live");
        require(count <= _state._maxPublic, "exceed allocation");
        require(_state._public + count <= publicMax, "exceed public supply");

        // track public supply
        _state.addPublic(count);

        // mint
        for (uint256 i = 0; i < count; ++i) {
            _safeMint(msg.sender);
        }
    }

    //-------------------------------------------------------------------------

    /**
     * Mint count tokens using securely signed message.
     */
    function secureMint(bytes calldata signature, uint256 allocation, uint256 count)
        external
        notLocked
    {
        bytes32 msgHash = generateHash(allocation, count);
        require(_state._public + count <= publicMax, "exceed public supply");
        require(_mints[msg.sender] + count <= allocation, "exceed allocation");
        require(validateSigner(msgHash, signature, _signer), "invalid sig");

        // track public supply
        _state.addPublic(count);

        // track user mints
        unchecked {
            _mints[msg.sender] += count;
        }

        // mint
        for (uint256 i = 0; i < count; ++i) {
            _safeMint(msg.sender);
        }
    }

    //-------------------------------------------------------------------------

    /**
     * @dev Mint from gallery's token allocation.
     */
    function galleryMintTo(address wallet, uint256 count)
        public
        onlyOwner
    {
        require(_state._gallery + count <= galleryMax, "exceed gallery supply");
        _state.addGallery(count);
        for (uint256 i = 0; i < count; ++i) {
            _safeMint(wallet);
        }
    }

    //-------------------------------------------------------------------------

    /**
     * @dev Mint from artist's token allocation.
     */
    function artistMintTo(address wallet, uint256 count)
        public
        isArtist
    {
        require(_state._artist + count <= artistMax, "exceed artist supply");
        _state.addArtist(count);
        for (uint256 i = 0; i < count; ++i) {
            _safeMint(wallet);
        }
    }

    //-------------------------------------------------------------------------

    /**
     * @dev Allow extending contract for later burns. See {ERC721-_burn}.
     */
    function burn(uint256 tokenId)
        public
        isBurner
    {
        _burn(tokenId);
    }

    //-------------------------------------------------------------------------
    // money
    //-------------------------------------------------------------------------

    /**
     * Pull money out of this contract.
     */
    function withdraw(address to, uint256 amount)
        public
        onlyOwner
    {
        require(amount > 0, "amount empty");
        require(amount <= address(this).balance, "amount exceeds balance");
        require(to != address(0), "address null");
        payable(to).transfer(amount);
    }

    //-------------------------------------------------------------------------
    // approval
    //-------------------------------------------------------------------------

    /**
     * Override isApprovedForAll to whitelist user's OpenSea proxy accounts
     *  to enable gas-less listings.
     */
    function isApprovedForAll(address owner, address operator)
        override(ERC721Sequential, IERC721)
        public
        view
        returns (bool)
    {
        // whitelist OpenSea proxy contract for easy trading
        ProxyRegistry proxyRegistry = ProxyRegistry(_proxyRegistryAddress);
        if (address(proxyRegistry.proxies(owner)) == operator) {
            return true;
        }

        return super.isApprovedForAll(owner, operator);
    }

    //-------------------------------------------------------------------------

    /**
     * This is used instead of msg.sender as transactions won't be sent by
     *  the original token owner, but by OpenSea.
     */
    function _msgSender()
        override
        internal
        view
        returns (address sender)
    {
        return ContextMixin.msgSender();
    }

}

// File: /contracts/SkellYeah.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

//-----------------------------------------------------------------------------
// geneticchain.io - NextGen Generative NFT Platform
//-----------------------------------------------------------------------------
 /*\_____________________________________________________________   .¿yy¿.   __
 MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM```````/MMM\\\\\  \\$$$$$$S/  .
 MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM``   `/  yyyy    ` _____J$$$^^^^/%#//
 MMMMMMMMMMMMMMMMMMMYYYMMM````      `\/  .¿yü  /  $ùpüüü%%% | ``|//|` __
 MMMMMYYYYMMMMMMM/`     `| ___.¿yüy¿.  .d$$$$  /  $$$$SSSSM |   | ||  MMNNNNNNM
 M/``      ``\/`  .¿ù%%/.  |.d$$$$$$$b.$$$*°^  /  o$$$  __  |   | ||  MMMMMMMMM
 M   .¿yy¿.     .dX$$$$$$7.|$$$$"^"$$$$$$o`  /MM  o$$$  MM  |   | ||  MMYYYYYYM
   \\$$$$$$S/  .S$$o"^"4$$$$$$$` _ `SSSSS\        ____  MM  |___|_||  MM  ____
  J$$$^^^^/%#//oSSS`    YSSSSSS  /  pyyyüüü%%%XXXÙ$$$$  MM  pyyyyyyy, `` ,$$$o
 .$$$` ___     pyyyyyyyyyyyy//+  /  $$$$$$SSSSSSSÙM$$$. `` .S&&T$T$$$byyd$$$$\
 \$$7  ``     //o$$SSXMMSSSS  |  /  $$/&&X  _  ___ %$$$byyd$$$X\$`/S$$$$$$$S\
 o$$l   .\\YS$$X>$X  _  ___|  |  /  $$/%$$b.,.d$$$\`7$$$$$$$$7`.$   `"***"`  __
 o$$l  __  7$$$X>$$b.,.d$$$\  |  /  $$.`7$$$$$$$$%`  `*+SX+*|_\\$  /.     ..\MM
 o$$L  MM  !$$$$\$$$$$$$$$%|__|  /  $$// `*+XX*\'`  `____           ` `/MMMMMMM
 /$$X, `` ,S$$$$\ `*+XX*\'`____  /  %SXX .      .,   NERV   ___.¿yüy¿.   /MMMMM
  7$$$byyd$$$>$X\  .,,_    $$$$  `    ___ .y%%ü¿.  _______  $.d$$$$$$$S.  `MMMM
  `/S$$$$$$$\\$J`.\\$$$ :  $\`.¿yüy¿. `\\  $$$$$$S.//XXSSo  $$$$$"^"$$$$.  /MMM
 y   `"**"`"Xo$7J$$$$$\    $.d$$$$$$$b.    ^``/$$$$.`$$$$o  $$$$\ _ 'SSSo  /MMM
 M/.__   .,\Y$$$\\$$O` _/  $d$$$*°\ pyyyüüü%%%W $$$o.$$$$/  S$$$. `  S$To   MMM
 MMMM`  \$P*$$X+ b$$l  MM  $$$$` _  $$$$$$SSSSM $$$X.$T&&X  o$$$. `  S$To   MMM
 MMMX`  $<.\X\` -X$$l  MM  $$$$  /  $$/&&X      X$$$/$/X$$dyS$$>. `  S$X%/  `MM
 MMMM/   `"`  . -$$$l  MM  yyyy  /  $$/%$$b.__.d$$$$/$.'7$$$$$$$. `  %SXXX.  MM
 MMMMM//   ./M  .<$$S, `` ,S$$>  /  $$.`7$$$$$$$$$$$/S//_'*+%%XX\ `._       /MM
 MMMMMMMMMMMMM\  /$$$$byyd$$$$\  /  $$// `*+XX+*XXXX      ,.      .\MMMMMMMMMMM
 GENETIC/MMMMM\.  /$$$$$$$$$$\|  /  %SXX  ,_  .      .\MMMMMMMMMMMMMMMMMMMMMMMM
 CHAIN/MMMMMMMM/__  `*+YY+*`_\|  /_______//MMMMMMMMMMMMMMMMMMMMMMMMMMM/-/-/-\*/
//-----------------------------------------------------------------------------
// Genetic Chain: Skell Yeah
//-----------------------------------------------------------------------------
// Author: papaver (@tronicdreams)
//-----------------------------------------------------------------------------

import "./GeneticChain721.sol";

//------------------------------------------------------------------------------
// SkellYeah
//------------------------------------------------------------------------------

/**
 * @title GeneticChain - Project #15 - Skell Yeah
 */
contract SkellYeah is GeneticChain721
{

    //-------------------------------------------------------------------------
    // fields
    //-------------------------------------------------------------------------

    // token info
    string private _baseUri;
    string private _tokenIpfsHash;

    // contract info
    string public _contractUri;

    //-------------------------------------------------------------------------
    // ctor
    //-------------------------------------------------------------------------

    constructor(
        string memory baseUri_,
        string memory ipfsHash_,
        string memory contractUri_,
        uint256[3] memory tokenMax_,
        address proxyRegistryAddress)
        GeneticChain721(
          tokenMax_,
          proxyRegistryAddress)
    {
        _baseUri       = baseUri_;
        _tokenIpfsHash = ipfsHash_;
        _contractUri   = contractUri_;
    }

    //-------------------------------------------------------------------------
    // accessors
    //-------------------------------------------------------------------------

    function setTokenIpfsHash(string memory hash)
        public
        onlyOwner
    {
        if (bytes(hash).length == 0) {
            delete _tokenIpfsHash;
        } else {
            _tokenIpfsHash = hash;
        }
    }

    //-------------------------------------------------------------------------

    function setBaseTokenURI(string memory baseUri)
        public
        onlyOwner
    {
        _baseUri = baseUri;
    }

    //-------------------------------------------------------------------------
    // ERC721Metadata
    //-------------------------------------------------------------------------

    function baseTokenURI()
        public
        view
        returns (string memory)
    {
        return _baseUri;
    }

    //-------------------------------------------------------------------------

    /**
     * @dev Returns uri of a token.  Not guarenteed token exists.
     */
    function tokenURI(uint256 tokenId)
        override
        public
        view
        returns (string memory)
    {
        return bytes(_tokenIpfsHash).length == 0
            ? string(abi.encodePacked(
                baseTokenURI(), "/", Strings.toString(tokenId)))
            : string(abi.encodePacked(
                baseTokenURI(),
                    "/", _tokenIpfsHash,
                    "/", Strings.toString(tokenId)));
    }

    //-------------------------------------------------------------------------
    // contractUri
    //-------------------------------------------------------------------------

    function setContractURI(string memory contractUri)
        public
        onlyOwner
    {
        _contractUri = contractUri;
    }

    //-------------------------------------------------------------------------

    function contractURI()
        public view
        returns (string memory)
    {
        return _contractUri;
    }

}

// File: /contracts/common/meta-transactions/ContentMixin.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

abstract contract ContextMixin {
    function msgSender()
        internal
        view
        returns (address payable sender)
    {
        if (msg.sender == address(this)) {
            bytes memory array = msg.data;
            uint256 index = msg.data.length;
            assembly {
                // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
                sender := and(
                    mload(add(array, index)),
                    0xffffffffffffffffffffffffffffffffffffffff
                )
            }
        } else {
            sender = payable(msg.sender);
        }
        return sender;
    }
}

// File: /contracts/common/meta-transactions/EIP712Base.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

contract EIP712Base is Initializable {
    struct EIP712Domain {
        string name;
        string version;
        address verifyingContract;
        bytes32 salt;
    }

    string constant public ERC712_VERSION = "1";

    bytes32 internal constant EIP712_DOMAIN_TYPEHASH = keccak256(
        bytes(
            "EIP712Domain(string name,string version,address verifyingContract,bytes32 salt)"
        )
    );
    bytes32 internal domainSeperator;

    // supposed to be called once while initializing.
    // one of the contracts that inherits this contract follows proxy pattern
    // so it is not possible to do this in a constructor
    function _initializeEIP712(
        string memory name
    )
        internal
        initializer
    {
        _setDomainSeperator(name);
    }

    function _setDomainSeperator(string memory name) internal {
        domainSeperator = keccak256(
            abi.encode(
                EIP712_DOMAIN_TYPEHASH,
                keccak256(bytes(name)),
                keccak256(bytes(ERC712_VERSION)),
                address(this),
                bytes32(getChainId())
            )
        );
    }

    function getDomainSeperator() public view returns (bytes32) {
        return domainSeperator;
    }

    function getChainId() public view returns (uint256) {
        uint256 id;
        assembly {
            id := chainid()
        }
        return id;
    }

    /**
     * Accept message hash and returns hash message in EIP712 compatible form
     * So that it can be used to recover signer from signature signed using EIP712 formatted data
     * https://eips.ethereum.org/EIPS/eip-712
     * "\\x19" makes the encoding deterministic
     * "\\x01" is the version byte to make it compatible to EIP-191
     */
    function toTypedMessageHash(bytes32 messageHash)
        internal
        view
        returns (bytes32)
    {
        return
            keccak256(
                abi.encodePacked("\x19\x01", getDomainSeperator(), messageHash)
            );
    }
}
// File: /contracts/common/meta-transactions/Initializable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Initializable {
    bool inited = false;

    modifier initializer() {
        require(!inited, "already inited");
        _;
        inited = true;
    }
}

// File: /contracts/common/meta-transactions/NativeMetaTransaction.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {SafeMath} from  "openzeppelin-solidity/contracts/utils/math/SafeMath.sol";
import {EIP712Base} from "./EIP712Base.sol";

contract NativeMetaTransaction is EIP712Base {
    using SafeMath for uint256;
    bytes32 private constant META_TRANSACTION_TYPEHASH = keccak256(
        bytes(
            "MetaTransaction(uint256 nonce,address from,bytes functionSignature)"
        )
    );
    event MetaTransactionExecuted(
        address userAddress,
        address payable relayerAddress,
        bytes functionSignature
    );
    mapping(address => uint256) nonces;

    /*
     * Meta transaction structure.
     * No point of including value field here as if user is doing value transfer then he has the funds to pay for gas
     * He should call the desired function directly in that case.
     */
    struct MetaTransaction {
        uint256 nonce;
        address from;
        bytes functionSignature;
    }

    function executeMetaTransaction(
        address userAddress,
        bytes memory functionSignature,
        bytes32 sigR,
        bytes32 sigS,
        uint8 sigV
    ) public payable returns (bytes memory) {
        MetaTransaction memory metaTx = MetaTransaction({
            nonce: nonces[userAddress],
            from: userAddress,
            functionSignature: functionSignature
        });

        require(
            verify(userAddress, metaTx, sigR, sigS, sigV),
            "Signer and signature do not match"
        );

        // increase nonce for user (to avoid re-use)
        nonces[userAddress] = nonces[userAddress].add(1);

        emit MetaTransactionExecuted(
            userAddress,
            payable(msg.sender),
            functionSignature
        );

        // Append userAddress and relayer address at the end to extract it from calling context
        (bool success, bytes memory returnData) = address(this).call(
            abi.encodePacked(functionSignature, userAddress)
        );
        require(success, "Function call not successful");

        return returnData;
    }

    function hashMetaTransaction(MetaTransaction memory metaTx)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(
                    META_TRANSACTION_TYPEHASH,
                    metaTx.nonce,
                    metaTx.from,
                    keccak256(metaTx.functionSignature)
                )
            );
    }

    function getNonce(address user) public view returns (uint256 nonce) {
        nonce = nonces[user];
    }

    function verify(
        address signer,
        MetaTransaction memory metaTx,
        bytes32 sigR,
        bytes32 sigS,
        uint8 sigV
    ) internal view returns (bool) {
        require(signer != address(0), "NativeMetaTransaction: INVALID_SIGNER");
        return
            signer ==
            ecrecover(
                toTypedMessageHash(hashMetaTransaction(metaTx)),
                sigV,
                sigR,
                sigS
            );
    }
}

// File: /contracts/geneticchain/ERC721SeqEnumerable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

//------------------------------------------------------------------------------
// geneticchain.io - NextGen Generative NFT Platform
//------------------------------------------------------------------------------
//    _______                   __   __        ______ __          __
//   |     __|-----.-----.-----|  |_|__|----. |      |  |--.---.-|__|-----.
//   |    |  |  -__|     |  -__|   _|  |  __| |   ---|     |  _  |  |     |
//   |_______|_____|__|__|_____|____|__|____| |______|__|__|___._|__|__|__|
//
//------------------------------------------------------------------------------
// Genetic Chain: ERC721SeqEnumerable
//------------------------------------------------------------------------------
// Author: papaver (@tronicdreams)
//------------------------------------------------------------------------------

import "openzeppelin-solidity/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
import "./ERC721Sequential.sol";

/**
 * @dev This is a no storage implemntation of the optional extension {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. These functions
 * are mainly for convienence and should NEVER be called from inside a
 * contract on the chain.
 */
abstract contract ERC721SeqEnumerable is ERC721Sequential, IERC721Enumerable {

    address constant zero = address(0);

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(
        bytes4 interfaceId
    ) public view virtual override(IERC165, ERC721Sequential) 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 tokenId) {
        uint256 length = _owners.length;

        unchecked {
            for (; tokenId < length; ++tokenId) {
                if (_owners[tokenId] == owner) {
                    if (index-- == 0) {
                        break;
                    }
                }
            }
        }

        require(tokenId < length, "ERC721Enumerable: owner index out of bounds");
    }

    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256 supply) {
        unchecked {
            uint256 length = _owners.length;
            for (uint256 tokenId = 0; tokenId < length; ++tokenId) {
                if (_owners[tokenId] != zero) {
                    ++supply;
                }
            }
        }
    }

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(
        uint256 index
    ) public view virtual override returns (uint256 tokenId) {
        uint256 length = _owners.length;

        unchecked {
            for (; tokenId < length; ++tokenId) {
                if (_owners[tokenId] != zero) {
                    if (index-- == 0) {
                        break;
                    }
                }
            }
        }

        require(tokenId < length, "ERC721Enumerable: global index out of bounds");
    }

    /**
     * @dev Get all tokens owned by owner.
     */
    function ownerTokens(
        address owner
    ) public view returns (uint256[] memory) {
        uint256 tokenCount = ERC721Sequential.balanceOf(owner);
        require(tokenCount != 0, "ERC721Enumerable: owner owns no tokens");

        uint256 length = _owners.length;
        uint256[] memory tokenIds = new uint256[](tokenCount);
        unchecked {
            uint256 i = 0;
            for (uint256 tokenId = 0; tokenId < length; ++tokenId) {
                if (_owners[tokenId] == owner) {
                    tokenIds[i++] = tokenId;
                }
            }
        }

        return tokenIds;
    }

}

// File: /contracts/geneticchain/ERC721Sequential.sol



// SPDX-License-Identifier: MIT
// Forked from: OpenZeppelin Contracts v4.4.0 (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

//------------------------------------------------------------------------------
// geneticchain.io - NextGen Generative NFT Platform
//------------------------------------------------------------------------------
//    _______                   __   __        ______ __          __
//   |     __|-----.-----.-----|  |_|__|----. |      |  |--.---.-|__|-----.
//   |    |  |  -__|     |  -__|   _|  |  __| |   ---|     |  _  |  |     |
//   |_______|_____|__|__|_____|____|__|____| |______|__|__|___._|__|__|__|
//
//------------------------------------------------------------------------------
// Genetic Chain: ERC721Sequential
//------------------------------------------------------------------------------
// Author: papaver (@tronicdreams)
//------------------------------------------------------------------------------

import "openzeppelin-solidity/contracts/token/ERC721/IERC721.sol";
import "openzeppelin-solidity/contracts/token/ERC721/IERC721Receiver.sol";
import "openzeppelin-solidity/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "openzeppelin-solidity/contracts/utils/Address.sol";
import "openzeppelin-solidity/contracts/utils/Context.sol";
import "openzeppelin-solidity/contracts/utils/Strings.sol";
import "openzeppelin-solidity/contracts/utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721
 *  [ERC721] Non-Fungible Token Standard
 *
 *  This implmentation of ERC721 assumes sequencial token creation to provide
 *  efficient minting.  Storage for balance are no longer required reducing
 *  gas significantly.  This comes at the price of calculating the balance by
 *  iterating through the entire array.  The balanceOf function should NOT
 *  be used inside a contract.  Gas usage will explode as the size of tokens
 *  increase.  A convenience function is provided which returns the entire
 *  list of owners whose index maps tokenIds to thier owners.  Zero addresses
 *  indicate burned tokens.
 *
 */
contract ERC721Sequential 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
    address[] _owners;

    // 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 balance) {
        require(owner != address(0), "ERC721: balance query for the zero address");

        unchecked {
            uint256 length = _owners.length;
            for (uint256 i = 0; i < length; ++i) {
                if (_owners[i] == owner) {
                    ++balance;
                }
            }
        }

    }

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

    /**
     * @dev Returns entire list of owner enumerated by thier tokenIds.  Burned tokens
     * will have a zero address.
     */
    function owners() public view returns (address[] memory) {
        address[] memory owners_ = _owners;
        return owners_;
    }

    /**
     * @dev Return largest tokenId minted.
     */
    function maxTokenId() public view returns (uint256) {
        return _owners.length - 1;
    }

    /**
     * @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 = ERC721Sequential.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 tokenId < _owners.length && _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 = ERC721Sequential.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, 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) internal virtual returns (uint256 tokenId) {
        tokenId = _safeMint(to, "");
    }

    /**
     * @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,
        bytes memory _data
    ) internal virtual returns (uint256 tokenId) {
        tokenId = _mint(to);
        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) internal virtual returns (uint256 tokenId) {
        require(to != address(0), "ERC721: mint to the zero address");
        tokenId = _owners.length;

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

        _owners.push(to);

        emit Transfer(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 = ERC721Sequential.ownerOf(tokenId);

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

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

        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(ERC721Sequential.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);

        _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(ERC721Sequential.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 {}
}

// File: /contracts/libraries/State.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

//------------------------------------------------------------------------------
// geneticchain.io - NextGen Generative NFT Platform
//------------------------------------------------------------------------------
//    _______                   __   __        ______ __          __
//   |     __|-----.-----.-----|  |_|__|----. |      |  |--.---.-|__|-----.
//   |    |  |  -__|     |  -__|   _|  |  __| |   ---|     |  _  |  |     |
//   |_______|_____|__|__|_____|____|__|____| |______|__|__|___._|__|__|__|
//
//------------------------------------------------------------------------------
// Genetic Chain: library/State
//------------------------------------------------------------------------------
// Author: papaver (@tronicdreams)
//------------------------------------------------------------------------------

/**
 * @dev Handle contract state efficiently as possbile.
 */
library State {

    //-------------------------------------------------------------------------
    // fields
    //-------------------------------------------------------------------------

    struct Data {
        uint16  _gallery;
        uint16  _artist;
        uint16  _public;
        uint16  _live;
        uint16  _locked;
        uint16  _maxPublic;
    }

    //-------------------------------------------------------------------------
    // methods
    //-------------------------------------------------------------------------

    function addGallery(Data storage data, uint256 count)
        internal
     {
        unchecked {
            data._gallery += uint16(count);
        }
    }

    //-------------------------------------------------------------------------

    function addArtist(Data storage data, uint256 count)
        internal
     {
        unchecked {
            data._artist += uint16(count);
        }
    }

    //-------------------------------------------------------------------------

    function addPublic(Data storage data, uint256 count)
        internal
     {
        unchecked {
            data._public += uint16(count);
        }
    }

    //-------------------------------------------------------------------------

    function setLive(Data storage data, uint256 enable)
        internal
     {
        data._live = uint16(enable);
    }

    //-------------------------------------------------------------------------

    function setLocked(Data storage data, uint256 enable)
        internal
    {
        data._locked = uint16(enable);
    }

    //-------------------------------------------------------------------------

    function setMaxPublic(Data storage data, uint256 maxPublic)
        internal
    {
        data._maxPublic = uint16(maxPublic);
    }

    //-------------------------------------------------------------------------

    function set(Data storage data, uint256 _gallery, uint256 _artist, uint256 _public)
        internal
    {
        data._gallery = uint16(_gallery);
        data._artist  = uint16(_artist);
        data._public  = uint16(_public);
    }

}