Contract Address Details

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

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

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



pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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



pragma solidity ^0.8.0;

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

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

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

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



pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

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



pragma solidity ^0.8.0;

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

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

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



pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

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

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

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

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



pragma solidity ^0.8.0;

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

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



pragma solidity ^0.8.0;







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

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        _approve(to, tokenId);
    }

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

        return _tokenApprovals[tokenId];
    }

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

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

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

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

        _transfer(from, to, tokenId);
    }

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

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

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

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

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

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

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

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

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

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

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

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

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

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

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

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

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

        _beforeTokenTransfer(from, to, tokenId);

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

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

        emit Transfer(from, to, tokenId);
    }

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

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

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

// File: @openzeppelin/contracts/token/ERC1155/IERC1155.sol



pragma solidity ^0.8.0;

/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(
        address indexed operator,
        address indexed from,
        address indexed to,
        uint256[] ids,
        uint256[] values
    );

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
        external
        view
        returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes calldata data
    ) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] calldata ids,
        uint256[] calldata amounts,
        bytes calldata data
    ) external;
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol



pragma solidity ^0.8.0;

/**
 * @dev _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {
    /**
        @dev Handles the receipt of a single ERC1155 token type. This function is
        called at the end of a `safeTransferFrom` after the balance has been updated.
        To accept the transfer, this must return
        `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
        (i.e. 0xf23a6e61, or its own function selector).
        @param operator The address which initiated the transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param id The ID of the token being transferred
        @param value The amount of tokens being transferred
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
    */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    ) external returns (bytes4);

    /**
        @dev Handles the receipt of a multiple ERC1155 token types. This function
        is called at the end of a `safeBatchTransferFrom` after the balances have
        been updated. To accept the transfer(s), this must return
        `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
        (i.e. 0xbc197c81, or its own function selector).
        @param operator The address which initiated the batch transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param ids An array containing ids of each token being transferred (order and length must match values array)
        @param values An array containing amounts of each token being transferred (order and length must match ids array)
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
    */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Receiver.sol



pragma solidity ^0.8.0;


/**
 * @dev _Available since v3.1._
 */
abstract contract ERC1155Receiver is ERC165, IERC1155Receiver {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC1155Receiver).interfaceId || super.supportsInterface(interfaceId);
    }
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol



pragma solidity ^0.8.0;

/**
 * @dev _Available since v3.1._
 */
contract ERC1155Holder is ERC1155Receiver {
    function onERC1155Received(
        address,
        address,
        uint256,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    function onERC1155BatchReceived(
        address,
        address,
        uint256[] memory,
        uint256[] memory,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}

// File: @openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol



pragma solidity ^0.8.0;

/**
 * @dev Implementation of the {IERC721Receiver} interface.
 *
 * Accepts all token transfers.
 * Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.
 */
contract ERC721Holder is IERC721Receiver {
    /**
     * @dev See {IERC721Receiver-onERC721Received}.
     *
     * Always returns `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address,
        address,
        uint256,
        bytes memory
    ) public virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
}

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



pragma solidity ^0.8.0;

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

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

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

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol



pragma solidity ^0.8.0;

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

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

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

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

        _;

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

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



pragma solidity ^0.8.0;

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

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

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

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

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

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/interfaces/IMarketPlaceFeeContract.sol


pragma solidity 0.8.10;

interface IMarketPlaceFeeContract {
    /**
     * @notice Collects and pays marketplace fees for a transaction
     * @param _user         Address of the user performing the transaction
     * @param _totalPrice   Total transaction value
     * @return transaction value left after fee deduction
     */
    function _collectMarketFee(address _user, uint256 _totalPrice)
        external
        returns (uint256);

    /**
     * @notice Returns the market fees for a user
     * @param _user         Address of the user performing the transaction
     * @return Fee percentage
     */
    function _getMarketFee(address _user) external view returns (uint256);
}

// File: contracts/interfaces/IOwnableNFT.sol


pragma solidity 0.8.10;

interface IOwnableNFT {
    /**
     * @notice Returns the owner of an NFT Collection
     * @return address of the owner
     */
    function owner() external view returns (address);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol



pragma solidity ^0.8.0;


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: contracts/libraries/CustomOwnable.sol



pragma solidity ^0.8.0;

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

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor(address owner_) {
        _owner = owner_;
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

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

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/NFT.sol


pragma solidity 0.8.10;



contract NFT is ERC721Enumerable, CustomOwnable {
    using Strings for uint256;
    bool public publicMinting;

    string public baseExtension = ".json";
    uint256 public cost = 0 ether;
    uint256 public maxSupply;
    uint256 public maxMintAmount;
    uint256 public timeDeployed;
    uint256 public allowMintingAfter = 0;
    bool public isPaused = false;
    bool public isRevealed = true;
    uint256 public maxMintsPerAccount;
    mapping(uint256 => string) public tokenURIs;

    event PublicMintingEnabled(
        uint256 _revealTime,
        uint256 _maxSupply,
        uint256 _maxMintAmount,
        uint256 _cost,
        uint256 _maxMintsPerAccount
    );

    event Withdrawal(address payee, uint256 amount);

    /**
     * @notice Initiates an NFT collection
     * @param _name     Name of the collection
     * @param _symbol   Symbol of the collection
     * @param _owner    Address of the contract owner
     */
    constructor(
        string memory _name,
        string memory _symbol,
        address _owner
    ) ERC721(_name, _symbol) CustomOwnable(_owner) {
        timeDeployed = block.timestamp;
    }

    /**
     * @notice Enables Public minting with time and max mint conditions
     * @param _revealTime           Time at which the URI for tokens are available to view
     * @param _revealed             True if the URI is revealed and False if not
     * @param _maxSupply            Maximum supply that can be minted
     * @param _maxMintAmount        Maximum mints per account per mint
     * @param _cost                 Cost of minting a token
     * @param _maxMintsPerAccount   Maximum number of mints per account
     */
    function enablePublicMinting(
        uint256 _revealTime,
        bool _revealed,
        uint256 _maxSupply,
        uint256 _maxMintAmount,
        uint256 _cost,
        uint256 _maxMintsPerAccount
    ) public onlyOwner {
        publicMinting = true;
        if (_revealTime > block.timestamp) {
            allowMintingAfter = _revealTime - block.timestamp;
        }
        maxSupply = _maxSupply;
        maxMintAmount = _maxMintAmount;
        cost = _cost;
        isRevealed = _revealed;
        maxMintsPerAccount = _maxMintsPerAccount;
        emit PublicMintingEnabled(
            _revealTime,
            _maxSupply,
            _maxMintAmount,
            _cost,
            _maxMintsPerAccount
        );
    }

    /**
     * @notice Mints a new token for the msg.sender
     * @param uri       Metadata URI of the new token
     * @param _owner    Address the token should be minted to
     * @return total supply of the tokens
     */
    function createToken(string memory uri, address _owner)
        public
        onlyOwner
        returns (uint256)
    {
        uint256 supply = totalSupply();
        _safeMint(_owner, supply + 1);
        tokenURIs[supply + 1] = uri;
        return totalSupply();
    }

    /**
     * @notice Mints multiple new tokens for the msg.sender
     * @param uris          Metadata URIs of the new token
     * @param _mintAmount   Number of tokens to be minted
     */
    function batchCreateTokens(uint256 _mintAmount, string[] memory uris)
        public
        onlyOwner
    {
        uint256 supply = totalSupply();
        require(!isPaused, "CONTRACT_PAUSED");
        require(_mintAmount > 0, "INVALID_MINT_AMOUNT");
        require(supply + _mintAmount <= maxSupply, "EXCEEDS_MAX_SUPPLY");
        require(_mintAmount == uris.length, "URI_COUNT_MISMATCH");

        for (uint256 i = 1; i <= _mintAmount; i++) {
            _safeMint(msg.sender, supply + i);
            tokenURIs[supply + i] = uris[i];
        }
    }

    // PUBLIC FUNCTIONS

    /**
     * @notice Mints a new token for the msg.sender
     * @param _mintAmount   Number of tokens to be minted
     * @param uris          Metadata URIs of the new token
     */
    function mint(uint256 _mintAmount, string[] memory uris) public payable {
        require(publicMinting, "PUBLIC_MINTING_NOT_ENABLED");
        require(
            block.timestamp >= timeDeployed + allowMintingAfter,
            "MINTING_NOT_ALLOWED_YET"
        );

        require(
            balanceOf(msg.sender) < maxMintsPerAccount,
            "MAX_MINTS_PER_ACCOUNT_EXCEEDED"
        );

        uint256 supply = totalSupply();
        require(!isPaused, "CONTRACT_PAUSED");
        require(
            _mintAmount > 0 && _mintAmount <= maxMintAmount,
            "INVALID_MINT_AMOUNT"
        );
        require(supply + _mintAmount <= maxSupply, "EXCEEDS_MAX_SUPPLY");
        require(_mintAmount == uris.length, "URI_COUNT_MISMATCH");

        if (msg.sender != owner()) {
            require(
                msg.value >= cost * _mintAmount,
                "MSG_VALUE_LESS_THEN_COST"
            );
        }

        for (uint256 i = 1; i <= _mintAmount; i++) {
            _safeMint(msg.sender, supply + i);
            tokenURIs[supply + i] = uris[i];
        }
    }

    /**
     * @notice Returns the token ids held by a user
     * @param _owner Wallet to be tested for
     * @return token Ids held by the user
     */
    function walletOfOwner(address _owner)
        public
        view
        returns (uint256[] memory)
    {
        uint256 ownerTokenCount = balanceOf(_owner);
        uint256[] memory tokenIds = new uint256[](ownerTokenCount);
        for (uint256 i; i < ownerTokenCount; i++) {
            tokenIds[i] = tokenOfOwnerByIndex(_owner, i);
        }
        return tokenIds;
    }

    /**
     * @notice Returns the token URI of a token
     * @param tokenId Token ID for which URI is to be revealed
     * @return tokenId - URI of the token
     */
    function tokenURI(uint256 tokenId)
        public
        view
        virtual
        override
        returns (string memory)
    {
        require(_exists(tokenId), "URI_QUERY_FOR_NON_EXISTENT_TOKEN");

        return tokenURIs[tokenId];
    }

    /**
     * @notice Revelas the number of seconds until public minting goes live
     * @return Number of seconds until public minting starts
     */
    function getSecondsUntilMinting() public view returns (uint256) {
        if (block.timestamp < timeDeployed + allowMintingAfter) {
            return (timeDeployed + allowMintingAfter) - block.timestamp;
        } else {
            return 0;
        }
    }

    // ONLY OWNER FUNCTIONS

    /**
     * @notice Sets reveal status for the collection
     * @param _state New state of reveal
     */
    function setIsRevealed(bool _state) public onlyOwner {
        isRevealed = _state;
    }

    /**
     * @notice Sets cost of minting new token
     * @param _newCost New cost of minting
     */
    function setCost(uint256 _newCost) public onlyOwner {
        cost = _newCost;
    }

    /**
     * @notice Sets maximum mint amount
     * @param _newmaxMintAmount New maximum mint amount
     */
    function setmaxMintAmount(uint256 _newmaxMintAmount) public onlyOwner {
        maxMintAmount = _newmaxMintAmount;
    }

    /**
     * @notice Sets the paused status of the collection
     * @param _state New paused state of the collection
     */
    function setIsPaused(bool _state) public onlyOwner {
        isPaused = _state;
    }

    /**
     * @notice enables admin withdrawal of funds from the protocol
     */
    function withdraw() public payable onlyOwner {
        uint256 balance = address(this).balance;
        payable(msg.sender).transfer(balance);
        require(address(this).balance == 0, "TRANSFER_FAILED");
        emit Withdrawal(msg.sender, balance);
    }
}

// File: @openzeppelin/contracts/token/ERC1155/extensions/IERC1155MetadataURI.sol



pragma solidity ^0.8.0;

/**
 * @dev Interface of the optional ERC1155MetadataExtension interface, as defined
 * in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155MetadataURI is IERC1155 {
    /**
     * @dev Returns the URI for token type `id`.
     *
     * If the `\{id\}` substring is present in the URI, it must be replaced by
     * clients with the actual token type ID.
     */
    function uri(uint256 id) external view returns (string memory);
}

// File: @openzeppelin/contracts/token/ERC1155/ERC1155.sol



pragma solidity ^0.8.0;






/**
 * @dev Implementation of the basic standard multi-token.
 * See https://eips.ethereum.org/EIPS/eip-1155
 * Originally based on code by Enjin: https://github.com/enjin/erc-1155
 *
 * _Available since v3.1._
 */
contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI {
    using Address for address;

    // Mapping from token ID to account balances
    mapping(uint256 => mapping(address => uint256)) private _balances;

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

    // Used as the URI for all token types by relying on ID substitution, e.g. https://token-cdn-domain/{id}.json
    string private _uri;

    /**
     * @dev See {_setURI}.
     */
    constructor(string memory uri_) {
        _setURI(uri_);
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC1155).interfaceId ||
            interfaceId == type(IERC1155MetadataURI).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC1155MetadataURI-uri}.
     *
     * This implementation returns the same URI for *all* token types. It relies
     * on the token type ID substitution mechanism
     * https://eips.ethereum.org/EIPS/eip-1155#metadata[defined in the EIP].
     *
     * Clients calling this function must replace the `\{id\}` substring with the
     * actual token type ID.
     */
    function uri(uint256) public view virtual override returns (string memory) {
        return _uri;
    }

    /**
     * @dev See {IERC1155-balanceOf}.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) public view virtual override returns (uint256) {
        require(account != address(0), "ERC1155: balance query for the zero address");
        return _balances[id][account];
    }

    /**
     * @dev See {IERC1155-balanceOfBatch}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] memory accounts, uint256[] memory ids)
        public
        view
        virtual
        override
        returns (uint256[] memory)
    {
        require(accounts.length == ids.length, "ERC1155: accounts and ids length mismatch");

        uint256[] memory batchBalances = new uint256[](accounts.length);

        for (uint256 i = 0; i < accounts.length; ++i) {
            batchBalances[i] = balanceOf(accounts[i], ids[i]);
        }

        return batchBalances;
    }

    /**
     * @dev See {IERC1155-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        require(_msgSender() != operator, "ERC1155: setting approval status for self");

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

    /**
     * @dev See {IERC1155-isApprovedForAll}.
     */
    function isApprovedForAll(address account, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[account][operator];
    }

    /**
     * @dev See {IERC1155-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) public virtual override {
        require(
            from == _msgSender() || isApprovedForAll(from, _msgSender()),
            "ERC1155: caller is not owner nor approved"
        );
        _safeTransferFrom(from, to, id, amount, data);
    }

    /**
     * @dev See {IERC1155-safeBatchTransferFrom}.
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) public virtual override {
        require(
            from == _msgSender() || isApprovedForAll(from, _msgSender()),
            "ERC1155: transfer caller is not owner nor approved"
        );
        _safeBatchTransferFrom(from, to, ids, amounts, data);
    }

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function _safeTransferFrom(
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) internal virtual {
        require(to != address(0), "ERC1155: transfer to the zero address");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, from, to, _asSingletonArray(id), _asSingletonArray(amount), data);

        uint256 fromBalance = _balances[id][from];
        require(fromBalance >= amount, "ERC1155: insufficient balance for transfer");
        unchecked {
            _balances[id][from] = fromBalance - amount;
        }
        _balances[id][to] += amount;

        emit TransferSingle(operator, from, to, id, amount);

        _doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data);
    }

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function _safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) internal virtual {
        require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");
        require(to != address(0), "ERC1155: transfer to the zero address");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, from, to, ids, amounts, data);

        for (uint256 i = 0; i < ids.length; ++i) {
            uint256 id = ids[i];
            uint256 amount = amounts[i];

            uint256 fromBalance = _balances[id][from];
            require(fromBalance >= amount, "ERC1155: insufficient balance for transfer");
            unchecked {
                _balances[id][from] = fromBalance - amount;
            }
            _balances[id][to] += amount;
        }

        emit TransferBatch(operator, from, to, ids, amounts);

        _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, amounts, data);
    }

    /**
     * @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 _setURI(string memory newuri) internal virtual {
        _uri = newuri;
    }

    /**
     * @dev Creates `amount` tokens of token type `id`, and assigns them to `account`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - If `account` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function _mint(
        address account,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) internal virtual {
        require(account != address(0), "ERC1155: mint to the zero address");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, address(0), account, _asSingletonArray(id), _asSingletonArray(amount), data);

        _balances[id][account] += amount;
        emit TransferSingle(operator, address(0), account, id, amount);

        _doSafeTransferAcceptanceCheck(operator, address(0), account, id, amount, data);
    }

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_mint}.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function _mintBatch(
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) internal virtual {
        require(to != address(0), "ERC1155: mint to the zero address");
        require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, address(0), to, ids, amounts, data);

        for (uint256 i = 0; i < ids.length; i++) {
            _balances[ids[i]][to] += amounts[i];
        }

        emit TransferBatch(operator, address(0), to, ids, amounts);

        _doSafeBatchTransferAcceptanceCheck(operator, address(0), to, ids, amounts, data);
    }

    /**
     * @dev Destroys `amount` tokens of token type `id` from `account`
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens of token type `id`.
     */
    function _burn(
        address account,
        uint256 id,
        uint256 amount
    ) internal virtual {
        require(account != address(0), "ERC1155: burn from the zero address");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, account, address(0), _asSingletonArray(id), _asSingletonArray(amount), "");

        uint256 accountBalance = _balances[id][account];
        require(accountBalance >= amount, "ERC1155: burn amount exceeds balance");
        unchecked {
            _balances[id][account] = accountBalance - amount;
        }

        emit TransferSingle(operator, account, address(0), id, amount);
    }

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {_burn}.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     */
    function _burnBatch(
        address account,
        uint256[] memory ids,
        uint256[] memory amounts
    ) internal virtual {
        require(account != address(0), "ERC1155: burn from the zero address");
        require(ids.length == amounts.length, "ERC1155: ids and amounts length mismatch");

        address operator = _msgSender();

        _beforeTokenTransfer(operator, account, address(0), ids, amounts, "");

        for (uint256 i = 0; i < ids.length; i++) {
            uint256 id = ids[i];
            uint256 amount = amounts[i];

            uint256 accountBalance = _balances[id][account];
            require(accountBalance >= amount, "ERC1155: burn amount exceeds balance");
            unchecked {
                _balances[id][account] = accountBalance - amount;
            }
        }

        emit TransferBatch(operator, account, address(0), ids, amounts);
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning, as well as batched variants.
     *
     * The same hook is called on both single and batched variants. For single
     * transfers, the length of the `id` and `amount` arrays will be 1.
     *
     * Calling conditions (for each `id` and `amount` pair):
     *
     * - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * of token type `id` will be  transferred to `to`.
     * - When `from` is zero, `amount` tokens of token type `id` will be minted
     * for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens of token type `id`
     * will be burned.
     * - `from` and `to` are never both zero.
     * - `ids` and `amounts` have the same, non-zero length.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address operator,
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) internal virtual {}

    function _doSafeTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) private {
        if (to.isContract()) {
            try IERC1155Receiver(to).onERC1155Received(operator, from, id, amount, data) returns (bytes4 response) {
                if (response != IERC1155Receiver.onERC1155Received.selector) {
                    revert("ERC1155: ERC1155Receiver rejected tokens");
                }
            } catch Error(string memory reason) {
                revert(reason);
            } catch {
                revert("ERC1155: transfer to non ERC1155Receiver implementer");
            }
        }
    }

    function _doSafeBatchTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) private {
        if (to.isContract()) {
            try IERC1155Receiver(to).onERC1155BatchReceived(operator, from, ids, amounts, data) returns (
                bytes4 response
            ) {
                if (response != IERC1155Receiver.onERC1155BatchReceived.selector) {
                    revert("ERC1155: ERC1155Receiver rejected tokens");
                }
            } catch Error(string memory reason) {
                revert(reason);
            } catch {
                revert("ERC1155: transfer to non ERC1155Receiver implementer");
            }
        }
    }

    function _asSingletonArray(uint256 element) private pure returns (uint256[] memory) {
        uint256[] memory array = new uint256[](1);
        array[0] = element;

        return array;
    }
}

// File: @openzeppelin/contracts/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;
    }
}

// File: contracts/FractionalNFT.sol


pragma solidity 0.8.10;




contract FractionalNFT is ERC1155, CustomOwnable {
    using Counters for Counters.Counter;
    Counters.Counter public _tokenIds;

    // NFT name
    string public name;

    // NFT symbol
    string public symbol;

    // Mapping from token ID to token supply
    mapping(uint256 => uint256) private tokenSupply;

    // Mapping from token ID to token existence
    mapping(uint256 => bool) private exists;

    // Mapping from token ID to token URI
    mapping(uint256 => string) private tokenURI;

    /**
     * @notice Initiates a Fractional NFT collection
     * @param _name     Name of the collection
     * @param _symbol   Symbol of the collection
     * @param _owner    Address of the contract owner
     */
    constructor(
        string memory _name,
        string memory _symbol,
        address _owner
    ) ERC1155("") CustomOwnable(_owner) {
        name = _name;
        symbol = _symbol;
    }

    /**
     * @notice Mints a new token in the collection
     * @param quantity  Quantity of tokens to be created
     * @param _uri      Metadata URI of the new token
     * @param _owner    Address the token should be minted to
     * @return token id of the new token created
     */
    function createToken(
        uint256 quantity,
        string memory _uri,
        address _owner
    ) public onlyOwner returns (uint256) {
        _tokenIds.increment();
        uint256 newItemId = _tokenIds.current();

        require(!exists[newItemId], "INVALID_ID");

        super._mint(_owner, newItemId, quantity, new bytes(0));
        tokenURI[newItemId] = _uri;
        tokenSupply[newItemId] += quantity;
        return newItemId;
    }

    /**
     * @notice Mints multiple new tokens in the collection
     * @param quantities    Quantities corresponding to the new tokens
     * @param uris          Metadata URIs of the new tokens
     * @return token ids of the new tokens created
     */
    function batchCreateTokens(
        uint256[] memory quantities,
        string[] memory uris
    ) public onlyOwner returns (uint256[] memory) {
        uint256[] memory ids;
        for (uint256 i = 0; i < quantities.length; i++) {
            _tokenIds.increment();
            ids[i] = _tokenIds.current();
        }

        require(ids.length == quantities.length, "MISMATCHED_ARRAY_LENGTHS");

        super._mintBatch(msg.sender, ids, quantities, new bytes(0));

        for (uint256 i = 0; i < ids.length; i++) {
            tokenSupply[ids[i]] += quantities[i];
            tokenURI[ids[i]] = uris[i];
        }
        return ids;
    }

    /**
     * @notice Returns the URI of a token given its ID
     * @param id ID of the token to query
     * @return uri of the token or an empty string if it does not exist
     */
    function uri(uint256 id) public view override returns (string memory) {
        require(exists[id], "URI_QUERY_FOR_NON_EXISTENT_TOKEN");

        return tokenURI[id];
    }

    /**
     * @notice Returns the total quantity for a token ID
     * @param id ID of the token to query
     * @return amount of token in existence
     */
    function totalSupply(uint256 id) public view returns (uint256) {
        return tokenSupply[id];
    }
}

// File: contracts/NFTMarket.sol


pragma solidity 0.8.10;











/// @author Velas Art Team
/// @title  NFT Marketplace on Velas Blockchain
contract NFTMarket is ReentrancyGuard, Ownable, ERC1155Holder, ERC721Holder {
    // STATE VARIABLES
    uint16 constant HUNDRED = 10000;
    IMarketPlaceFeeContract public feeContract;
    address private creatorContractAddress;

    mapping(address => uint256) public escrow;
    mapping(address => uint256) public allowedToWithdraw;

    mapping(address => Collection) public addressToCollection;
    mapping(address => uint256[]) public tokenIdsInCollection;

    mapping(address => Creator[]) public creatorFees;
    mapping(address => mapping(uint256 => Ask[])) public asks;
    mapping(address => mapping(uint256 => Bid[])) public bids;
    mapping(address => mapping(uint256 => uint256)) public lastTradedPrice;
    mapping(address => mapping(uint256 => SaleLog[])) public priceHistory;

    address[] public collections;

    address payable public beneficiary;

    struct Collection {
        bool isFractional;
        bool mintedOnMarketPlace;
        address createdBy;
        string name;
        string symbol;
        string description;
        string collectionSlug;
        uint16 creatorRoyaltyInPercentage;
        uint256 totalSupply;
        uint256 listedTime;
        uint256 volumeTraded;
    }

    struct Ask {
        bool exists;
        address seller;
        uint256 price;
        uint256 quantity;
        uint256 timestamp;
    }

    struct Bid {
        bool exists;
        address buyer;
        uint256 price;
        uint256 quantity;
        uint256 timestamp;
    }

    struct Creator {
        uint16 shareInPercentage;
        address payable creator;
    }

    struct UserAsk {
        address nftContract;
        uint256 tokenId;
        uint256 askIndex;
        uint256 price;
        uint256 quantity;
        uint256 timestamp;
    }

    struct UserBid {
        address nftContract;
        uint256 tokenId;
        uint256 bidIndex;
        uint256 price;
        uint256 quantity;
        uint256 timestamp;
    }

    struct SaleLog {
        address seller;
        address buyer;
        uint256 price;
        uint256 timestamp;
    }

    // EVENTS

    event CollectionCreated(
        uint256 collectionId,
        address _nftContract,
        string _name,
        string _symbol,
        uint256 timestamp
    );

    event AskCreated(
        address indexed nft,
        uint256 indexed tokenID,
        uint256 price,
        address indexed seller,
        uint256 quantity
    );

    event AskDeleted(
        address indexed nft,
        uint256 indexed tokenID,
        address indexed seller,
        uint256 price
    );

    event AskAccepted(
        address indexed nft,
        uint256 indexed tokenID,
        uint256 price,
        uint256 quantity,
        address indexed buyer
    );

    event BidCreated(
        address indexed nft,
        uint256 indexed tokenID,
        address indexed buyer,
        uint256 price,
        uint256 quantity
    );

    event BidDeleted(
        address indexed nft,
        uint256 indexed tokenID,
        address indexed buyer,
        uint256 price
    );

    event BidAccepted(
        address indexed nft,
        uint256 indexed tokenID,
        uint256 price,
        uint256 quantity,
        address indexed seller
    );

    event BidPayment(bool isCredit, address indexed user, Bid bid);

    event AskPayment(bool isCredit, address indexed user, Ask ask);

    event RoyaltyPayment(
        address indexed user,
        uint256 amount,
        address indexed nftContract,
        uint256 tokenId
    );

    event Withdrawal(address indexed payee, uint256 amount);

    // CONSTRUCTOR
    /**
     * @notice Initiates the contract with feeContract and creatorContractAddress
     * @param _feeContract              The instance of MarketPlaceFeeContract which is used by the marketplace for fee calculations
     * @param _creatorContractAddress   The collection creator contract used by the marketplace
     * @param _beneficiary              The beneficiary of Marketplace Fees
     */
    constructor(
        IMarketPlaceFeeContract _feeContract,
        address _creatorContractAddress,
        address payable _beneficiary
    ) {
        feeContract = _feeContract;
        creatorContractAddress = _creatorContractAddress;
        beneficiary = _beneficiary;
    }

    // EXTERNAL FUNCTIONS

    /**
     * @notice Imports a verified contract with creator royalties - Only callable by the creatorContract
     * @param _nftContract                  The address of NFT contract imported
     * @param _name                         Name of the NFT Contract
     * @param _symbol                       Symbol of the NFT Contract
     * @param _description                  Description of the NFT Contract
     * @param _collectionSlug               Slug of the collection
     * @param _isFractional                 True if the contract is ERC1155 compatible and False if ERC721
     * @param _creatorRoyaltyInPercentage   Creator Royalty in percentage scaled to 10^2
     * @param _creators                     Array of creator addresses that share the royalty
     * @param _percentages                  Array of percentages corresponding to the creators above
     * @param _createdBy                    Creator of the contract
     */
    function createCollection(
        address _nftContract,
        string memory _name,
        string memory _symbol,
        string memory _description,
        string memory _collectionSlug,
        bool _isFractional,
        uint16 _creatorRoyaltyInPercentage,
        address payable[] memory _creators,
        uint16[] memory _percentages,
        address _createdBy
    ) public {
        require(
            msg.sender == creatorContractAddress || msg.sender == owner(),
            "UNAUTHORIZED"
        );
        require(
            addressToCollection[_nftContract].listedTime == 0,
            "EXISTING_COLLECTION"
        ); // Checks if collection already exists
        uint16 totalPercentage;
        for (uint256 i = 0; i < _percentages.length; i++) {
            totalPercentage += _percentages[i];
        }
        require(
            totalPercentage == 10000 || totalPercentage == 0,
            "TOTAL_PERCENTAGE_NOT_VALID"
        );
        Collection memory _tempCollection;

        uint256 totalSupply;
        if (msg.sender == creatorContractAddress) {
            totalSupply = 0;
            _tempCollection.mintedOnMarketPlace = true;
        } else {
            try IERC721Enumerable(_nftContract).totalSupply() returns (
                uint256 _totalSupply
            ) {
                totalSupply = _totalSupply;
            } catch {
                totalSupply = 0;
            }
            _tempCollection.mintedOnMarketPlace = false;
        }

        _tempCollection.name = _name;
        _tempCollection.symbol = _symbol;
        _tempCollection.description = _description;
        _tempCollection.collectionSlug = _collectionSlug;
        _tempCollection.isFractional = _isFractional;
        _tempCollection.totalSupply = totalSupply;
        _tempCollection.listedTime = block.timestamp;
        _tempCollection.createdBy = _createdBy;
        _tempCollection
            .creatorRoyaltyInPercentage = _creatorRoyaltyInPercentage;

        addressToCollection[_nftContract] = _tempCollection;
        collections.push(_nftContract);

        addCreatorFees(_nftContract, _creators, _percentages);

        emit CollectionCreated(
            collections.length, // array index will be the collectionId
            _nftContract,
            _name,
            _symbol,
            block.timestamp
        );
    }

    /**
     * @notice Creates an ask for (`nft`, `tokenID`) tuple for `price` and `quantity`
     * @dev Creating an ask requires msg.sender to have at least one qty of (`nft`, `tokenID`)
     * @param _nftContract  An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId      Token Ids of the NFTs msg.sender wishes to sell
     * @param _price        Prices at which the seller is willing to sell the NFTs
     * @param _quantity     Number of tokens the seller is willing to sell. 1 if the NFT is ERC721 standard
     */
    function ask(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _price,
        uint256[] memory _quantity
    ) public {
        require(
            _nftContract.length == _tokenId.length &&
                _nftContract.length == _price.length &&
                _nftContract.length == _quantity.length,
            "ARRAY_LENGTHS_MISMATCH"
        );
        for (uint256 i = 0; i < _nftContract.length; i++) {
            address nftContract = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 price = _price[i];
            uint256 quantity = _quantity[i];
            require(price > 0, "PRICE_LT_ZERO");
            require(
                quantityOf(nftContract, msg.sender, tokenId) > 0,
                "NOT_OWNER_OF_TOKEN"
            );
            require(isApproved(_nftContract[i]), "NOT_APPROVED_FOR_TRANSFER");

            if (!tokenIdExists(nftContract, tokenId)) {
                tokenIdsInCollection[nftContract].push(tokenId);
            }

            // There can be multiple asks for a tokenId in case of ERC1155 tokens
            asks[nftContract][tokenId].push(
                Ask({
                    exists: true,
                    seller: msg.sender,
                    price: price,
                    quantity: quantity,
                    timestamp: block.timestamp
                })
            );
            bool success = safeTransferFrom_(
                nftContract,
                tokenId,
                msg.sender,
                address(this),
                quantity,
                new bytes(0)
            );
            require(success, "REVERT_NFT_NOT_SENT");

            emit AskCreated({
                nft: address(nftContract),
                tokenID: tokenId,
                price: price,
                seller: msg.sender,
                quantity: quantity
            });
        }
    }

    /**
     * @notice Creates a bid on (`nft`, `tokenID`) tuple for `price`.
     * @dev Creating a bid requires msg.sender to pay the (bid amount - escrow balance) to the contract
     * @param _nftContract  An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId      Token Ids of the NFTs msg.sender wishes to buy
     * @param _price        Prices at which the buyer is willing to buy the NFTs
     * @param _quantity     Number of tokens the buyer is willing to buy. 1 if the NFT is ERC721 standard
     */
    function bid(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _price,
        uint256[] memory _quantity
    ) public payable nonReentrant {
        require(
            _nftContract.length == _tokenId.length &&
                _nftContract.length == _price.length &&
                _nftContract.length == _quantity.length,
            "ARRAY_LENGTHS_MISMATCH"
        );
        uint256 totalPrice;

        for (uint256 i = 0; i < _nftContract.length; i++) {
            address nftContract = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 price = _price[i];
            uint256 quantity = _quantity[i];

            if (!tokenIdExists(nftContract, tokenId)) {
                tokenIdsInCollection[nftContract].push(tokenId);
            }

            bids[nftContract][tokenId].push(
                Bid({
                    exists: true,
                    buyer: msg.sender,
                    price: price,
                    quantity: quantity,
                    timestamp: block.timestamp
                })
            );

            emit BidCreated({
                nft: nftContract,
                tokenID: tokenId,
                buyer: msg.sender,
                price: price,
                quantity: quantity
            });

            totalPrice += price * quantity;
            emit BidPayment(
                false,
                msg.sender,
                Bid({
                    exists: true,
                    buyer: msg.sender,
                    price: price,
                    quantity: quantity,
                    timestamp: block.timestamp
                })
            );
        }

        require(msg.value >= totalPrice, "REVERT_INSUFFICIENT_ETHER");
        escrow[msg.sender] += (totalPrice);
        payable(msg.sender).transfer(msg.value - totalPrice);
    }

    /**
     * @notice Cancels ask(s) that the seller previously created
     * @param _nftContract      An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId          Token Ids of the NFTs msg.sender wishes to cancel the asks on
     * @param _askIndex         Index of this particular ask in the asks array
     */
    function cancelAsk(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _askIndex
    ) public {
        for (uint256 i = 0; i < _nftContract.length; i++) {
            address nftContract = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 askIndex = _askIndex[i];
            address seller = asks[nftContract][tokenId][askIndex].seller;
            uint256 price = asks[nftContract][tokenId][askIndex].price;
            uint256 quantity = asks[nftContract][tokenId][askIndex].quantity;
            require(seller == msg.sender, "REVERT_NOT_A_CREATOR_OF_ASK");
            bool success = safeTransferFrom_(
                nftContract,
                tokenId,
                address(this),
                msg.sender,
                quantity,
                new bytes(0)
            );
            require(success, "TRANSFER_FAILED");

            delete asks[nftContract][tokenId][askIndex];

            emit AskDeleted({
                nft: nftContract,
                tokenID: tokenId,
                seller: seller,
                price: price
            });
        }
    }

    /**
     * @notice Cancels bid(s) that the msg.sender previously created
     * @param _nftContract      An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId          Token Ids of the NFTs msg.sender wishes to cancel the bids on
     * @param _bidIndex         Index of this particular bid in the bids array
     */
    function cancelBid(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _bidIndex
    ) public nonReentrant {
        for (uint256 i = 0; i < _nftContract.length; i++) {
            address nftAddress = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 bidIndex = _bidIndex[i];
            address buyer = bids[nftAddress][tokenId][bidIndex].buyer;
            uint256 price = bids[nftAddress][tokenId][bidIndex].price;
            uint256 quantity = bids[nftAddress][tokenId][bidIndex].quantity;
            require(buyer == msg.sender, "REVERT_NOT_A_CREATOR_OF_BID");

            escrow[msg.sender] -= (price * quantity);
            emit BidPayment(
                true,
                msg.sender,
                bids[nftAddress][tokenId][bidIndex]
            );

            delete bids[nftAddress][tokenId][bidIndex];

            emit BidDeleted({
                nft: nftAddress,
                tokenID: tokenId,
                buyer: buyer,
                price: price
            });
            payable(msg.sender).transfer(price * quantity);
        }
    }

    /**
     * @notice Seller placed ask(s), you (buyer) are fine with the terms. You accept
     * their ask by sending the required msg.value and indicating the id of the
     * token(s) you are purchasing.
     *
     * @param _nftContract      An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId          Token Ids of the NFTs msg.sender wishes to accept the asks on
     * @param _quantity         Number of tokens the buyer is willing to buy. 1 if the NFT is ERC721 standard
     * @param _askIndex         Index of this particular ask in the asks array
     */
    function acceptAsk(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _quantity,
        uint256[] memory _askIndex
    ) public payable nonReentrant {
        require(
            _nftContract.length == _tokenId.length &&
                _nftContract.length == _askIndex.length &&
                _nftContract.length == _quantity.length,
            "ARRAY_LENGTHS_MISMATCH"
        );
        uint256 totalPrice;
        for (uint256 i = 0; i < _nftContract.length; i++) {
            address nftContract = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 askIndex = _askIndex[i];
            uint256 quantity = _quantity[i];
            bool exists = asks[nftContract][tokenId][askIndex].exists;
            address seller = asks[nftContract][tokenId][askIndex].seller;
            uint256 price = asks[nftContract][tokenId][askIndex].price;

            require(exists, "REVERT_ASK_DOES_NOT_EXIST");
            require(seller != msg.sender, "REVERT_CANT_ACCEPT_OWN_ASK");
            require(
                quantity <= asks[nftContract][tokenId][askIndex].quantity,
                "QUANTITY_EXCEEDS_ASK"
            );

            totalPrice += (price * quantity);

            uint256 creatorRoyalty = payRoyalty(
                nftContract,
                price,
                quantity,
                tokenId
            );

            allowedToWithdraw[beneficiary] += feeContract._collectMarketFee(
                seller,
                price * quantity
            );

            emit AskPayment(true, seller, asks[nftContract][tokenId][askIndex]);

            // Quantity will reduce in case of ERC1155 tokens and deleted in case of ERC721 tokens
            if (quantity < asks[nftContract][tokenId][askIndex].quantity) {
                asks[nftContract][tokenId][askIndex].quantity -= quantity;
            } else {
                delete asks[nftContract][tokenId][askIndex];
            }
            addressToCollection[nftContract].volumeTraded += (price * quantity);
            lastTradedPrice[nftContract][tokenId] = price;
            SaleLog memory tempLog;
            tempLog.price = price;
            tempLog.timestamp = block.timestamp;
            tempLog.seller = seller;
            tempLog.buyer = msg.sender;
            priceHistory[nftContract][tokenId].push(tempLog);
            bool success = safeTransferFrom_(
                nftContract,
                tokenId,
                address(this),
                msg.sender,
                quantity,
                new bytes(0)
            );
            require(success, "REVERT_NFT_NOT_SENT");
            emit AskAccepted({
                nft: nftContract,
                tokenID: tokenId,
                price: price,
                quantity: quantity,
                buyer: msg.sender
            });
            emit AskPayment(
                false,
                msg.sender,
                asks[nftContract][tokenId][askIndex]
            );
            payable(seller).transfer(
                (price * quantity) -
                    feeContract._collectMarketFee(seller, price * quantity) -
                    creatorRoyalty
            );
        }
        require(msg.value >= totalPrice, "REVERT_INSUFFICIENT_ETHER");
        payable(msg.sender).transfer(msg.value - totalPrice);
    }

    /**
     * @notice You are the owner of the NFTs, someone submitted the bids on them.
     * You accept one or more of these bids.
     *
     * @param _nftContract      An array of ERC-721 and / or ERC-1155 addresses
     * @param _tokenId          Token Ids of the NFTs msg.sender wishes to accept the bids on
     * @param _quantity         Number of tokens the buyer is willing to buy. 1 if the NFT is ERC721 standard
     * @param _bidIndex         Index of this particular bid in the bids array
     */
    function acceptBid(
        address[] memory _nftContract,
        uint256[] memory _tokenId,
        uint256[] memory _quantity,
        uint256[] memory _bidIndex
    ) public nonReentrant {
        require(
            _nftContract.length == _tokenId.length &&
                _nftContract.length == _bidIndex.length &&
                _nftContract.length == _quantity.length,
            "ARRAY_LENGTHS_MISMATCH"
        );

        for (uint256 i = 0; i < _nftContract.length; i++) {
            require(
                quantityOf(_nftContract[i], msg.sender, _tokenId[i]) > 0,
                "REVERT_NOT_OWNER_OF_TOKEN_ID"
            );

            address nftContract = _nftContract[i];
            uint256 tokenId = _tokenId[i];
            uint256 bidIndex = _bidIndex[i];
            uint256 quantity = _quantity[i];
            uint256 price = bids[nftContract][tokenId][bidIndex].price;
            address buyer = bids[nftContract][tokenId][bidIndex].buyer;

            require(isApproved(_nftContract[i]), "NOT_APPROVED_FOR_TRANSFER");

            uint256 creatorRoyalty = payRoyalty(
                nftContract,
                price,
                quantity,
                tokenId
            );

            allowedToWithdraw[beneficiary] += feeContract._collectMarketFee(
                msg.sender,
                price * quantity
            );

            emit BidPayment(
                true,
                msg.sender,
                bids[nftContract][tokenId][bidIndex]
            );
            // delete ask if ERC721
            if (!addressToCollection[nftContract].isFractional) {
                for (
                    uint256 j = 0;
                    j < asks[nftContract][tokenId].length;
                    j++
                ) {
                    Ask memory _ask = asks[nftContract][tokenId][j];
                    if (_ask.seller == msg.sender) {
                        delete asks[nftContract][tokenId][j];
                    }
                }
            }
            Bid memory tempBid = bids[nftContract][tokenId][bidIndex]; // For event emit
            // Quantity will reduce in case of ERC1155 tokens and deleted in case of ERC721 tokens
            if (quantity < bids[nftContract][tokenId][bidIndex].quantity) {
                bids[nftContract][tokenId][bidIndex].quantity -= quantity;
            } else {
                delete bids[nftContract][tokenId][bidIndex];
            }
            addressToCollection[nftContract].volumeTraded += price * quantity;
            lastTradedPrice[nftContract][tokenId] = price;
            SaleLog memory tempLog;
            tempLog.price = price;
            tempLog.timestamp = block.timestamp;
            tempLog.seller = msg.sender;
            tempLog.buyer = buyer;
            priceHistory[nftContract][tokenId].push(tempLog);

            uint256 balancePayable = price * quantity;
            require(escrow[buyer] >= balancePayable, "LOW_BUYER_BALANCE");
            escrow[buyer] -= balancePayable;
            bool success = safeTransferFrom_(
                nftContract,
                tokenId,
                msg.sender,
                buyer,
                quantity,
                new bytes(0)
            );
            require(success, "REVERT_NFT_NOT_SENT");

            emit BidPayment(false, buyer, tempBid);

            emit BidAccepted({
                nft: nftContract,
                tokenID: tokenId,
                price: price,
                quantity: quantity,
                seller: msg.sender
            });

            payable(msg.sender).transfer(
                (price * quantity) -
                    feeContract._collectMarketFee(
                        msg.sender,
                        price * quantity
                    ) -
                    creatorRoyalty
            );
        }
    }

    /**
     * @notice Withdrawal of accumulated funds from escrow account
     * @param amount    Amount to be withdrawn
     */
    function withdraw(int256 amount) public nonReentrant {
        // Enter amount = -1 for MAX withdrawal
        uint256 transferAmount;
        if (amount == -1) {
            transferAmount = allowedToWithdraw[msg.sender];
        } else {
            transferAmount = uint256(amount);
        }
        require(
            transferAmount <= allowedToWithdraw[msg.sender],
            "AMOUNT_EXCEEDS_BALANCE"
        );
        allowedToWithdraw[msg.sender] -= transferAmount;
        payable(address(msg.sender)).transfer(transferAmount);

        emit Withdrawal(msg.sender, transferAmount);
    }

    /**
     * @notice Change the Collection creator and Fee contract address
     * @dev Can only be called by the owner of the marketplace
     * @param _newCreatorContract   Address of the new creatorContract
     * @param _newFeeContract   Address of the new feeContract
     */
    function changeCreatorAndFeeContract(
        address _newCreatorContract,
        address _newFeeContract,
        address payable _beneficiary
    ) public onlyOwner {
        creatorContractAddress = _newCreatorContract;
        feeContract = IMarketPlaceFeeContract(_newFeeContract);
        beneficiary = _beneficiary;
    }

    /**
     * @notice Rejects a Creator Royalty payment request
     * @dev Can only be called by the owner of the marketplace
     * @param _nftContract Address of the NFT collection
     * @param _newOwner Address of the new owner of the collection
     */
    function changeCollectionOwner(address _nftContract, address _newOwner)
        public
        onlyOwner
    {
        addressToCollection[_nftContract].createdBy = _newOwner;
    }

    /**
     * @notice Returns the floorPrice of a collection
     * @param nftContract   Address of the collection
     * @return floor price of a collection
     */
    function floorPrice(address nftContract) public view returns (uint256) {
        uint256 _floorPrice;
        uint256[] memory _tokenIds = tokenIdsInCollection[nftContract];
        if (_tokenIds.length == 0) {
            return 0;
        } else {
            _floorPrice = asks[nftContract][_tokenIds[0]][0].price;
        }
        for (uint256 i = 0; i < _tokenIds.length; i++) {
            Ask[] memory askArray = asks[nftContract][_tokenIds[i]];
            for (uint256 j = 0; j < askArray.length; j++) {
                if (askArray[j].price < _floorPrice || _floorPrice == 0) {
                    _floorPrice = askArray[j].price;
                }
            }
        }
        return _floorPrice;
    }

    /**
     * @notice Returns the tokenIds in a collection
     * @param nftContract   Address of the collection
     * @return tokenIds array of tokenIds
     */
    function fetchTokensInCollection(address nftContract)
        public
        view
        returns (uint256[] memory tokenIds)
    {
        return tokenIdsInCollection[nftContract];
    }

    // PUBLIC FUNCTIONS

    /**
     * @notice Returns the list of collections in the marketplace
     * @return collectionsList An array of collections
     */
    function fetchCollectionsList()
        public
        view
        returns (address[] memory collectionsList)
    {
        return collections;
    }

    /**
     * @notice Returns all NFTs held by the user
     * @param _user User address whose NFTs are requested
     * @return userNFTAddresses userNFTIds - An array of collections and the corresponding tokenIds owned by the user
     */
    function fetchUserNFTs(address _user)
        public
        view
        returns (address[] memory userNFTAddresses, uint256[] memory userNFTIds)
    {
        uint256 counter;

        for (uint256 i = 0; i < collections.length; i++) {
            if (collections[i] == address(0)) {
                continue;
            }
            address tempCollectionAddress = collections[i];
            for (
                uint256 j = 0;
                j < tokenIdsInCollection[tempCollectionAddress].length;
                j++
            ) {
                if (addressToCollection[tempCollectionAddress].isFractional) {
                    if (
                        IERC1155(tempCollectionAddress).balanceOf(
                            _user,
                            tokenIdsInCollection[tempCollectionAddress][j]
                        ) > 0
                    ) {
                        userNFTAddresses[counter] = tempCollectionAddress;
                        userNFTIds[counter] = tokenIdsInCollection[
                            tempCollectionAddress
                        ][j];
                        counter++;
                    }
                } else {
                    if (
                        ERC721(tempCollectionAddress).ownerOf(
                            tokenIdsInCollection[tempCollectionAddress][j]
                        ) == msg.sender
                    ) {
                        userNFTAddresses[counter] = tempCollectionAddress;
                        userNFTIds[counter] = tokenIdsInCollection[
                            tempCollectionAddress
                        ][j];
                        counter++;
                    }
                }
            }
        }
    }

    /**
     * @notice Returns all Asks and Bids for a token
     * @param nftContract nft contract address whose Asks and Bids are requested
     * @param tokenId token id whose Asks and Bids are requested
     * @return Asks Bids - Asks and Bids for a token id
     */
    function fetchTokenAsksAndBids(address nftContract, uint256 tokenId)
        public
        view
        returns (Ask[] memory Asks, Bid[] memory Bids)
    {
        return (asks[nftContract][tokenId], bids[nftContract][tokenId]);
    }

    /**
     * @notice Returns the lowest ask for a token
     * @param nftContract     NFT address
     * @param tokenId         id of the token
     * @return Lowest ask and corresponding quantity
     */
    function lowestAsk(address nftContract, uint256 tokenId)
        public
        view
        returns (uint256, uint256)
    {
        uint256 lowestAskPrice;
        uint256 correspondingQuantity;
        Ask[] memory currentAsk = asks[nftContract][tokenId];
        if (currentAsk.length == 0) {
            return (0, 0);
        } else {
            lowestAskPrice = currentAsk[0].price;
            correspondingQuantity = currentAsk[0].quantity;
        }
        for (uint256 i = 0; i < currentAsk.length; i++) {
            if (currentAsk[i].price < lowestAskPrice || lowestAskPrice == 0) {
                lowestAskPrice = currentAsk[i].price;
                correspondingQuantity = currentAsk[i].quantity;
            }
            if (currentAsk[i].price == lowestAskPrice || lowestAskPrice == 0) {
                correspondingQuantity += currentAsk[i].quantity;
            }
        }
        return (lowestAskPrice, correspondingQuantity);
    }

    /**
     * @notice Returns the highest bid for a token
     * @param nftContract     NFT address
     * @param tokenId         id of the token
     * @return Highest bid and corresponding quantity
     */
    function highestBid(address nftContract, uint256 tokenId)
        public
        view
        returns (uint256, uint256)
    {
        uint256 highestBidPrice;
        uint256 correspondingQuantity;
        Bid[] memory currentBid = bids[nftContract][tokenId];
        if (currentBid.length == 0) {
            return (0, 0);
        } else {
            highestBidPrice = currentBid[0].price;
            correspondingQuantity = currentBid[0].quantity;
        }
        for (uint256 i = 0; i < currentBid.length; i++) {
            if (currentBid[i].price > highestBidPrice || highestBidPrice == 0) {
                highestBidPrice = currentBid[i].price;
                correspondingQuantity = currentBid[i].quantity;
            }
            if (
                currentBid[i].price == highestBidPrice || highestBidPrice == 0
            ) {
                correspondingQuantity += currentBid[i].quantity;
            }
        }
        return (highestBidPrice, correspondingQuantity);
    }

    /**
     * @notice Returns the creators for a collection
     * @param nftContract     NFT address
     * @return creators array
     */
    function fetchCreators(address nftContract)
        public
        view
        returns (Creator[] memory creators)
    {
        return creatorFees[nftContract];
    }

    /**
     * @notice Returns if the marketplace is approved by the msg.sender for transfers
     * @param nftContract   Address of ERC721 or ERC1155 contract
     * @return approved True if approved and False if not
     */
    function isApproved(address nftContract)
        public
        view
        returns (bool approved)
    {
        return IERC721(nftContract).isApprovedForAll(msg.sender, address(this));
    }

    /**
     * @notice Returns the price history of the tokenId
     * @param _nftContract  Address of the collection
     * @param _tokenId      Token Id of the requested token
     * @return Array of price history for the token
     */
    function fetchPriceHistory(address _nftContract, uint256 _tokenId)
        public
        view
        returns (SaleLog[] memory)
    {
        return priceHistory[_nftContract][_tokenId];
    }

    // INTERNAL FUNCTIONS

    /**
     * @notice Transfers the NFT tokenID from to
     * @dev safeTransferFrom_ name to avoid collision with the interface signature definitions. The reason it is implemented the way it is,
     *  is because some NFT contracts implement both the 721 and 1155 standard at the same time. Sometimes, 721 or 1155 function does not work.
     *  So instead of relying on the user's input, or asking the contract what interface it implements, it is best to just make a good assumption
     *  about what NFT type it is (here we guess it is 721 first), and if that fails, we use the 1155 function to tranfer the NFT.
     * @param nftContract    NFT address
     * @param from           Source address
     * @param to             Target address
     * @param tokenId        ID of the token type
     * @param quantity       Quantity of tokens
     * @param data           Additional data with no specified format, MUST be sent unaltered in call to `onERC1155Received` on `_to`
     */
    function safeTransferFrom_(
        address nftContract,
        uint256 tokenId,
        address from,
        address to,
        uint256 quantity,
        bytes memory data
    ) internal returns (bool) {
        // most are 721s, so we assume that that is what the NFT type is
        try IERC721(nftContract).safeTransferFrom(from, to, tokenId, data) {
            return true;
            // on fail, use 1155s format
        } catch (bytes memory) {
            try
                IERC1155(nftContract).safeTransferFrom(
                    from,
                    to,
                    tokenId,
                    quantity,
                    data
                )
            {
                return true;
            } catch (bytes memory) {
                return false;
            }
        }
    }

    /**
     * @notice Determines if potentialOwner is in fact an owner of at least 1 qty of NFT token ID.
     * @param nftContract     NFT address
     * @param potentialOwner  suspected owner of the NFT token ID
     * @param tokenId         id of the token
     * @return quantity of held token, possibly zero
     */
    function quantityOf(
        address nftContract,
        address potentialOwner,
        uint256 tokenId
    ) internal view returns (uint256) {
        try IERC721(nftContract).ownerOf(tokenId) returns (address owner) {
            if (owner == potentialOwner) {
                return 1;
            } else {
                return 0;
            }
        } catch (bytes memory) {
            try
                IERC1155(nftContract).balanceOf(potentialOwner, tokenId)
            returns (uint256 amount) {
                return amount;
            } catch (bytes memory) {
                return 0;
            }
        }
    }

    // PRIVATE FUNCTIONS

    /**
     * @notice Adds creator royalties to creators of an NFT collection
     * @param _nftContract  NFT address
     * @param _creators     Array of creator addresses that share the royalty
     * @param _percentages  Array of percentages corresponding to the creators above
     */
    function addCreatorFees(
        address _nftContract,
        address payable[] memory _creators,
        uint16[] memory _percentages
    ) private {
        for (uint256 j = 0; j < _creators.length; j++) {
            Creator memory _creatorFees;
            _creatorFees.creator = _creators[j];
            _creatorFees.shareInPercentage = _percentages[j];
            creatorFees[_nftContract].push(_creatorFees);
        }
    }

    /**
     * @notice Calculates royalty fees for creators of a collection during acceptAsk or acceptBid operations
     * @param _nftContract  NFT address
     * @param _price        Price of the token
     * @param _quantity     Quantity of the token
     * @param _tokenId      Token Id of the NFT
     * @return Royalty fees calculated
     */
    function payRoyalty(
        address _nftContract,
        uint256 _price,
        uint256 _quantity,
        uint256 _tokenId
    ) private returns (uint256) {
        uint256 creatorRoyalty;
        if (addressToCollection[_nftContract].creatorRoyaltyInPercentage > 0) {
            for (uint256 j = 0; j < creatorFees[_nftContract].length; j++) {
                uint256 total = _price * _quantity;
                uint256 share = (((total *
                    addressToCollection[_nftContract]
                        .creatorRoyaltyInPercentage) / HUNDRED) *
                    creatorFees[_nftContract][j].shareInPercentage) / HUNDRED;
                allowedToWithdraw[
                    creatorFees[_nftContract][j].creator
                ] += share;
                creatorRoyalty += share;
                emit RoyaltyPayment(
                    creatorFees[_nftContract][j].creator,
                    share,
                    _nftContract,
                    _tokenId
                );
            }
        }
        return creatorRoyalty;
    }

    /**
     * @notice Checks if a tokenId exists within a collection
     * @param _nftContract  NFT contract address
     * @param _tokenId      Token Id of the NFT
     * @return True if exists and False if not
     */
    function tokenIdExists(address _nftContract, uint256 _tokenId)
        private
        view
        returns (bool)
    {
        for (
            uint256 i = 0;
            i < tokenIdsInCollection[_nftContract].length;
            i++
        ) {
            if (tokenIdsInCollection[_nftContract][i] == _tokenId) {
                return true;
            }
        }
        return false;
    }

    /**
     * @notice Deletes a collection from the contract
     * @param _nftContract  NFT contract address
     */
    function deleteCollection(address _nftContract) external onlyOwner {
        Collection memory _tempCollection;
        addressToCollection[_nftContract] = _tempCollection;
        for (uint256 i = 0; i < collections.length; i++) {
            if (collections[i] == _nftContract) {
                delete collections[i];
                break;
            }
        }
    }
}