Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./interfaces/IGateway.sol";
import "./interfaces/IBasicERC721.sol";
import "./management/GatewayGuardedOwnable.sol";
import "@limitbreak/creator-token-contracts/contracts/erc721c/ERC721C.sol";
import "@limitbreak/creator-token-contracts/contracts/access/OwnableBasic.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/metatx/ERC2771Context.sol";

/**
 * @title BasicERC721C
 * @author Libeccio Inc.
 * @notice Extension of ERC721C that adds access control through TokenGateway.
 */
contract BasicERC721C is
    IBasicERC721,
    ERC2771Context,
    ERC721C,
    OwnableBasic,
    GatewayGuardedOwnable,
    Pausable
{
    using Counters for Counters.Counter;

    uint256 public constant VERSION_BasicERC721C = 20231019;

    Counters.Counter private _tokenIdCounter;

    string private __baseURI;

    /**
     * @param name the NFT contract name
     * @param symbol the NFT contract symbol
     * @param baseURI the base uri for nft meta. Note that the meta uri for the speicied token will be "{baseURI}/{contractAddress}/{tokenId}"
     * @param gateway the NFTGateway contract address
     * @param trustedForwarder the trusted forwarder contract address used for ERC2771
     */
    constructor(
        string memory name,
        string memory symbol,
        string memory baseURI,
        address gateway,
        address trustedForwarder
    )
        ERC2771Context(trustedForwarder)
        ERC721OpenZeppelin(name, symbol)
        GatewayGuarded(gateway)
    {
        __baseURI = baseURI;
    }

    /**
     * Mint `tokenId` to `to`. If `tokenId` is 0, use auto-increment id.
     */
    function mint(
        address to,
        uint256 tokenId
    ) external override onlyGatewayOrOwner {
        if (tokenId == 0) {
            uint256 id;
            while (true) {
                _tokenIdCounter.increment();
                id = _tokenIdCounter.current();
                if (!_exists(id)) {
                    tokenId = id;
                    break;
                }
            }
        }
        _safeMint(to, tokenId);
    }

    /**
     * Batch mint `tokenId` to `to`.
     */
    function mintBatch(
        address to,
        uint256[] calldata tokenId
    ) external override onlyGatewayOrOwner {
        for (uint256 i = 0; i < tokenId.length; i++) {
            _safeMint(to, tokenId[i]);
        }
    }

    /**
     * @dev Burns `tokenId`. See {ERC721-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) public virtual {
        require(
            _isApprovedOrOwner(_msgSender(), tokenId),
            "ERC721: caller is not token owner or approved"
        );
        _burn(tokenId);
    }

    function tokenURI(
        uint256 tokenId
    ) public view override returns (string memory) {
        return
            string(
                abi.encodePacked(
                    __baseURI,
                    "/",
                    Strings.toHexString(uint160(address(this)), 20),
                    "/",
                    Strings.toHexString(tokenId, 32)
                )
            );
    }

    function contractURI() public view returns (string memory) {
        return
            string(
                abi.encodePacked(
                    __baseURI,
                    "/",
                    Strings.toHexString(uint160(address(this)), 20)
                )
            );
    }

    function setURI(
        string calldata newBaseURI
    ) external override onlyGatewayOrOwner {
        __baseURI = newBaseURI;
    }

    function pause() external onlyGatewayOrOwner {
        _pause();
    }

    function unpause() external onlyGatewayOrOwner {
        _unpause();
    }

    function supportsInterface(
        bytes4 interfaceId
    ) public view virtual override returns (bool) {
        return
            interfaceId == type(IBasicERC721).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual override {
        _requireNotPaused();
        super._beforeTokenTransfer(from, to, firstTokenId, batchSize);
    }

    function _msgSender()
        internal
        view
        virtual
        override(ERC2771Context, Context)
        returns (address sender)
    {
        return ERC2771Context._msgSender();
    }

    function _msgData()
        internal
        view
        virtual
        override(ERC2771Context, Context)
        returns (bytes calldata)
    {
        return ERC2771Context._msgData();
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

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

pragma solidity ^0.8.0;

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

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

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

pragma solidity ^0.8.0;

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

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

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

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

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

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

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

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

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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

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

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

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

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

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

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

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

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

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

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

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

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

pragma solidity ^0.8.0;

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

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./IERC721Gateway.sol";
import "./IERC1155Gateway.sol";
import "./IERC20Gateway.sol";

interface IGateway is IERC721Gateway, IERC1155Gateway, IERC20Gateway {
    function operatorWhitelist(address _operator) external view returns (bool);

    function setManagerOf(address _nftContract, address _manager) external;

    function nftManager(address _nftContract) external view returns (address);

    function isInManagement(
        address _x,
        address _tokenContract
    ) external view returns (bool);

    function pause(address _contract) external;

    function unpause(address _contract) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

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

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

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

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

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

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

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

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

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: address zero is not a valid owner");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _ownerOf(tokenId);
        require(owner != address(0), "ERC721: invalid token ID");
        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) {
        _requireMinted(tokenId);

        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 token owner or approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);

        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: caller is not token owner or 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: caller is not token owner or 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 the owner of the `tokenId`. Does NOT revert if token doesn't exist
     */
    function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
        return _owners[tokenId];
    }

    /**
     * @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 _ownerOf(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) {
        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, 1);

        // Check that tokenId was not minted by `_beforeTokenTransfer` hook
        require(!_exists(tokenId), "ERC721: token already minted");

        unchecked {
            // Will not overflow unless all 2**256 token ids are minted to the same owner.
            // Given that tokens are minted one by one, it is impossible in practice that
            // this ever happens. Might change if we allow batch minting.
            // The ERC fails to describe this case.
            _balances[to] += 1;
        }

        _owners[tokenId] = to;

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

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

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     * This is an internal function that does not check if the sender is authorized to operate on the token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId, 1);

        // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
        owner = ERC721.ownerOf(tokenId);

        // Clear approvals
        delete _tokenApprovals[tokenId];

        unchecked {
            // Cannot overflow, as that would require more tokens to be burned/transferred
            // out than the owner initially received through minting and transferring in.
            _balances[owner] -= 1;
        }
        delete _owners[tokenId];

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

        _afterTokenTransfer(owner, address(0), tokenId, 1);
    }

    /**
     * @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, 1);

        // Check that tokenId was not transferred by `_beforeTokenTransfer` hook
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");

        // Clear approvals from the previous owner
        delete _tokenApprovals[tokenId];

        unchecked {
            // `_balances[from]` cannot overflow for the same reason as described in `_burn`:
            // `from`'s balance is the number of token held, which is at least one before the current
            // transfer.
            // `_balances[to]` could overflow in the conditions described in `_mint`. That would require
            // all 2**256 token ids to be minted, which in practice is impossible.
            _balances[from] -= 1;
            _balances[to] += 1;
        }
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

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

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {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 an {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 Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }

    /**
     * @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 {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
     * - When `from` is zero, the tokens will be minted for `to`.
     * - When `to` is zero, ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal virtual {}

    /**
     * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
     * - When `from` is zero, the tokens were minted for `to`.
     * - When `to` is zero, ``from``'s tokens were burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 firstTokenId, uint256 batchSize) internal virtual {}

    /**
     * @dev Unsafe write access to the balances, used by extensions that "mint" tokens using an {ownerOf} override.
     *
     * WARNING: Anyone calling this MUST ensure that the balances remain consistent with the ownership. The invariant
     * being that for any address `a` the value returned by `balanceOf(a)` must be equal to the number of tokens such
     * that `ownerOf(tokenId)` is `a`.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __unsafe_increaseBalance(address account, uint256 amount) internal {
        _balances[account] += amount;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * 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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (metatx/ERC2771Context.sol)

pragma solidity ^0.8.9;

import "../utils/Context.sol";

/**
 * @dev Context variant with ERC2771 support.
 */
abstract contract ERC2771Context is Context {
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable
    address private immutable _trustedForwarder;

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor(address trustedForwarder) {
        _trustedForwarder = trustedForwarder;
    }

    function isTrustedForwarder(address forwarder) public view virtual returns (bool) {
        return forwarder == _trustedForwarder;
    }

    function _msgSender() internal view virtual override returns (address sender) {
        if (isTrustedForwarder(msg.sender) && msg.data.length >= 20) {
            // The assembly code is more direct than the Solidity version using `abi.decode`.
            /// @solidity memory-safe-assembly
            assembly {
                sender := shr(96, calldataload(sub(calldatasize(), 20)))
            }
        } else {
            return super._msgSender();
        }
    }

    function _msgData() internal view virtual override returns (bytes calldata) {
        if (isTrustedForwarder(msg.sender) && msg.data.length >= 20) {
            return msg.data[:msg.data.length - 20];
        } else {
            return super._msgData();
        }
    }
}

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

pragma solidity ^0.8.0;

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

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

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

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

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IBasicERC721 {
    function mint(address to, uint256 tokenId) external;

    function mintBatch(address to, uint256[] calldata tokenId) external;

    function setURI(string calldata newBaseURI) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC20Gateway {
    /********************************************************************
     *                         ERC20 interfaces                         *
     ********************************************************************/

    /**
     * @dev Mint some ERC20 tokens to the recipient address.
     * @notice Only gateway contract is authorized to mint.
     * @param recipient The recipient of the minted ERC20 tokens.
     * @param amount The amount to be minted.
     */
    function ERC20_mint(
        address erc20Contract,
        address recipient,
        uint256 amount
    ) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC721Gateway {
    /********************************************************************
     *                        ERC721 interfaces                         *
     ********************************************************************/

    /**
     * @dev Mint an ERC721 token to the given address.
     * @notice Only gateway contract is authorized to mint.
     * @param recipient The recipient of the minted NFT.
     * @param tokenId The tokenId to be minted.
     */
    function ERC721_mint(
        address nftContract,
        address recipient,
        uint256 tokenId
    ) external;

    function ERC721_mintBatch(
        address nftContract,
        address recipient,
        uint256[] calldata tokenId
    ) external;

    /**
     * @dev Set `baseURI` of the ERC721 token. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`.
     */
    function ERC721_setURI(address nftContract, string memory newURI) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "../interfaces/IGatewayGuarded.sol";

/**
 * The management interface exposed to gateway.
 */
abstract contract GatewayGuarded is IGatewayGuarded {
    
    address public gateway;

    modifier onlyGateway() {
        _checkGateway();
        _;
    }

    constructor(address _gateway) {
        gateway = _gateway;
    }

    /**
     * @dev Throws if the sender is not the gateway contract.
     */
    function _checkGateway() internal view virtual {
        require(gateway == msg.sender, "GatewayGuarded: caller is not the gateway");
    }

    /**
     * @inheritdoc IGatewayGuarded
     */
    function setGateway(address _gateway) external override onlyGateway {
        gateway = _gateway;
    }

}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC1155Gateway {
    /********************************************************************
     *                        ERC1155 interfaces                        *
     ********************************************************************/

    /**
     * @dev Mint ERC1155 tokens.
     * @param account receiver of the minted tokens
     * @param id id of tokens to be minted
     * @param amount amount of tokens to be minted
     */
    function ERC1155_mint(
        address nftContract,
        address account,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) external;

    /**
     * @dev Mint a batch of ERC1155 tokens.
     *
     * See {ERC1155_mint}
     */
    function ERC1155_mintBatch(
        address nftContract,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) external;

    /**
     * @dev Sets a new URI for all token types, by relying on the token type ID
     * substitution mechanism
     * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
     *
     * By this mechanism, any occurrence of the `\{id\}` substring in either the
     * URI or any of the amounts in the JSON file at said URI will be replaced by
     * clients with the token type ID.
     *
     * For example, the `https://token-cdn-domain/\{id\}.json` URI would be
     * interpreted by clients as
     * `https://token-cdn-domain/000000000000000000000000000000000000000000000000000000000004cce0.json`
     * for token type ID 0x4cce0.
     *
     * See {uri}.
     *
     * Because these URIs cannot be meaningfully represented by the {URI} event,
     * this function emits no events.
     */
    function ERC1155_setURI(address nftContract, string memory newuri) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * The management interface exposed to gateway.
 */
interface IGatewayGuarded {
    /**
     * @dev Set the gateway contract address.
     * @notice Only gateway contract is authorized to set a
     * new gateway address.
     * @notice This function should be rarely used.
     * @param gateway The new gateway address.
     */
    function setGateway(address gateway) external;
}

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

pragma solidity ^0.8.0;

import "./IERC165.sol";

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

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

pragma solidity ^0.8.0;

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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

/**
 * The management interface exposed to gateway.
 */
abstract contract GatewayGuardedOwnable is GatewayGuarded, Ownable {
    
    modifier onlyGatewayOrOwner() {
        _checkGatewayOrOwner();
        _;
    }

    /**
     * @dev Throws if the sender is neither the gateway contract nor the owner.
     */
    function _checkGatewayOrOwner() internal view virtual {
        address sender = _msgSender();
        require(gateway == sender || owner() == sender, "GatewayGuardedOwnable: caller is neither the gateway nor the owner");
    }

    function resetOwner(address _newOwner) external onlyGateway {
        _transferOwnership(_newOwner);
    }

}

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

import "../utils/CreatorTokenBase.sol";
import "../token/erc721/ERC721OpenZeppelin.sol";

/**
 * @title ERC721C
 * @author Limit Break, Inc.
 * @notice Extends OpenZeppelin's ERC721 implementation with Creator Token functionality, which
 *         allows the contract owner to update the transfer validation logic by managing a security policy in
 *         an external transfer validation security policy registry.  See {CreatorTokenTransferValidator}.
 */
abstract contract ERC721C is ERC721OpenZeppelin, CreatorTokenBase {

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

    /// @dev Ties the open-zeppelin _beforeTokenTransfer hook to more granular transfer validation logic
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize) internal virtual override {
        for (uint256 i = 0; i < batchSize;) {
            _validateBeforeTransfer(from, to, firstTokenId + i);
            unchecked {
                ++i;
            }
        }
    }

    /// @dev Ties the open-zeppelin _afterTokenTransfer hook to more granular transfer validation logic
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize) internal virtual override {
        for (uint256 i = 0; i < batchSize;) {
            _validateAfterTransfer(from, to, firstTokenId + i);
            unchecked {
                ++i;
            }
        }
    }
}

/**
 * @title ERC721CInitializable
 * @author Limit Break, Inc.
 * @notice Initializable implementation of ERC721C to allow for EIP-1167 proxy clones.
 */
abstract contract ERC721CInitializable is ERC721OpenZeppelinInitializable, CreatorTokenBase {
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(ICreatorToken).interfaceId || super.supportsInterface(interfaceId);
    }

    /// @dev Ties the open-zeppelin _beforeTokenTransfer hook to more granular transfer validation logic
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize) internal virtual override {
        for (uint256 i = 0; i < batchSize;) {
            _validateBeforeTransfer(from, to, firstTokenId + i);
            unchecked {
                ++i;
            }
        }
    }

    /// @dev Ties the open-zeppelin _afterTokenTransfer hook to more granular transfer validation logic
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize) internal virtual override {
        for (uint256 i = 0; i < batchSize;) {
            _validateAfterTransfer(from, to, firstTokenId + i);
            unchecked {
                ++i;
            }
        }
    }
}

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

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

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

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

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

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

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

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

enum AllowlistTypes {
    Operators,
    PermittedContractReceivers
}

enum ReceiverConstraints {
    None,
    NoCode,
    EOA
}

enum CallerConstraints {
    None,
    OperatorWhitelistEnableOTC,
    OperatorWhitelistDisableOTC
}

enum StakerConstraints {
    None,
    CallerIsTxOrigin,
    EOA
}

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

struct TransferSecurityPolicy {
    CallerConstraints callerConstraints;
    ReceiverConstraints receiverConstraints;
}

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

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

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

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

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

    ICreatorTokenTransferValidator private transferValidator;

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

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

        setTransferValidator(validator);

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

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

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

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

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

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

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

        bool isValidTransferValidator = false;

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

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

        emit TransferValidatorUpdated(address(transferValidator), transferValidator_);

        transferValidator = ICreatorTokenTransferValidator(transferValidator_);
    }

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

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

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

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

        return new address[](0);
    }

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

        return new address[](0);
    }

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

        return false;
    }

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

        return false;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "../../access/OwnablePermissions.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

abstract contract ERC721OpenZeppelinBase is ERC721 {

    // Token name
    string internal _contractName;

    // Token symbol
    string internal _contractSymbol;

    function name() public view virtual override returns (string memory) {
        return _contractName;
    }

    function symbol() public view virtual override returns (string memory) {
        return _contractSymbol;
    }

    function _setNameAndSymbol(string memory name_, string memory symbol_) internal {
        _contractName = name_;
        _contractSymbol = symbol_;
    }
}

abstract contract ERC721OpenZeppelin is ERC721OpenZeppelinBase {
    constructor(string memory name_, string memory symbol_) ERC721("", "") {
        _setNameAndSymbol(name_, symbol_);
    }
}

abstract contract ERC721OpenZeppelinInitializable is OwnablePermissions, ERC721OpenZeppelinBase {

    error ERC721OpenZeppelinInitializable__AlreadyInitializedERC721();

    /// @notice Specifies whether or not the contract is initialized
    bool private _erc721Initialized;

    /// @dev Initializes parameters of ERC721 tokens.
    /// These cannot be set in the constructor because this contract is optionally compatible with EIP-1167.
    function initializeERC721(string memory name_, string memory symbol_) public {
        _requireCallerIsContractOwner();

        if(_erc721Initialized) {
            revert ERC721OpenZeppelinInitializable__AlreadyInitializedERC721();
        }

        _erc721Initialized = true;

        _setNameAndSymbol(name_, symbol_);
    }
}

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

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

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

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

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

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

interface ICreatorTokenTransferValidator is ITransferSecurityRegistry, ITransferValidator, IEOARegistry {}