GenFrens

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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);
            }
        }
    }
}

pragma solidity ^0.8.0;

library AnonymiceLibrary {
    string internal constant TABLE =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    function encode(bytes memory data) internal pure returns (string memory) {
        if (data.length == 0) return "";

        // load the table into memory
        string memory table = TABLE;

        // multiply by 4/3 rounded up
        uint256 encodedLen = 4 * ((data.length + 2) / 3);

        // add some extra buffer at the end required for the writing
        string memory result = new string(encodedLen + 32);

        assembly {
            // set the actual output length
            mstore(result, encodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

            // result ptr, jump over length
            let resultPtr := add(result, 32)

            // run over the input, 3 bytes at a time
            for {

            } lt(dataPtr, endPtr) {

            } {
                dataPtr := add(dataPtr, 3)

                // read 3 bytes
                let input := mload(dataPtr)

                // write 4 characters
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(input, 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
            }

            // padding with '='
            switch mod(mload(data), 3)
            case 1 {
                mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
            }
            case 2 {
                mstore(sub(resultPtr, 1), shl(248, 0x3d))
            }
        }

        return result;
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        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);
    }

    function parseInt(string memory _a)
        internal
        pure
        returns (uint8 _parsedInt)
    {
        bytes memory bresult = bytes(_a);
        uint8 mint = 0;
        for (uint8 i = 0; i < bresult.length; i++) {
            if (
                (uint8(uint8(bresult[i])) >= 48) &&
                (uint8(uint8(bresult[i])) <= 57)
            ) {
                mint *= 10;
                mint += uint8(bresult[i]) - 48;
            }
        }
        return mint;
    }

    function substring(
        string memory str,
        uint256 startIndex,
        uint256 endIndex
    ) internal pure returns (string memory) {
        bytes memory strBytes = bytes(str);
        bytes memory result = new bytes(endIndex - startIndex);
        for (uint256 i = startIndex; i < endIndex; i++) {
            result[i - startIndex] = strBytes[i];
        }
        return string(result);
    }

    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;
    }
}

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

pragma solidity ^0.8.0;

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

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

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

pragma solidity ^0.8.0;

import "./IERC165.sol";

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

// SPDX-License-Identifier: MIT
// Creators: locationtba.eth, 2pmflow.eth

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints.
 *
 * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..).
 *
 * Does not support burning tokens to address(0).
 */
contract ERC721A is
    Context,
    ERC165,
    IERC721,
    IERC721Metadata,
    IERC721Enumerable
{
    using Address for address;
    using Strings for uint256;

    struct TokenOwnership {
        address addr;
        uint64 startTimestamp;
    }

    struct AddressData {
        uint128 balance;
        uint128 numberMinted;
    }

    uint256 private currentIndex = 0;

    uint256 internal immutable maxBatchSize;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to ownership details
    // An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
    mapping(uint256 => TokenOwnership) private _ownerships;

    // Mapping owner address to address data
    mapping(address => AddressData) private _addressData;

    // 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
     * `maxBatchSize` refers to how much a minter can mint at a time.
     */
    constructor(
        string memory name_,
        string memory symbol_,
        uint256 maxBatchSize_
    ) {
        require(maxBatchSize_ > 0, "ERC721A: max batch size must be nonzero");
        _name = name_;
        _symbol = symbol_;
        maxBatchSize = maxBatchSize_;
    }

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

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index)
        public
        view
        override
        returns (uint256)
    {
        require(index < totalSupply(), "ERC721A: global index out of bounds");
        return index;
    }

    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     * This read function is O(totalSupply). If calling from a separate contract, be sure to test gas first.
     * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index)
        public
        view
        override
        returns (uint256)
    {
        require(index < balanceOf(owner), "ERC721A: owner index out of bounds");
        uint256 numMintedSoFar = totalSupply();
        uint256 tokenIdsIdx = 0;
        address currOwnershipAddr = address(0);
        for (uint256 i = 0; i < numMintedSoFar; i++) {
            TokenOwnership memory ownership = _ownerships[i];
            if (ownership.addr != address(0)) {
                currOwnershipAddr = ownership.addr;
            }
            if (currOwnershipAddr == owner) {
                if (tokenIdsIdx == index) {
                    return i;
                }
                tokenIdsIdx++;
            }
        }
        revert("ERC721A: unable to get token of owner by index");
    }

    /**
     * @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 ||
            interfaceId == type(IERC721Enumerable).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view override returns (uint256) {
        require(
            owner != address(0),
            "ERC721A: balance query for the zero address"
        );
        return uint256(_addressData[owner].balance);
    }

    function _numberMinted(address owner) internal view returns (uint256) {
        require(
            owner != address(0),
            "ERC721A: number minted query for the zero address"
        );
        return uint256(_addressData[owner].numberMinted);
    }

    function ownershipOf(uint256 tokenId)
        internal
        view
        returns (TokenOwnership memory)
    {
        require(_exists(tokenId), "ERC721A: owner query for nonexistent token");

        uint256 lowestTokenToCheck;
        if (tokenId >= maxBatchSize) {
            lowestTokenToCheck = tokenId - maxBatchSize + 1;
        }

        for (uint256 curr = tokenId; curr >= lowestTokenToCheck; curr--) {
            TokenOwnership memory ownership = _ownerships[curr];
            if (ownership.addr != address(0)) {
                return ownership;
            }
        }

        revert("ERC721A: unable to determine the owner of token");
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view override returns (address) {
        return ownershipOf(tokenId).addr;
    }

    /**
     * @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 override {
        address owner = ERC721A.ownerOf(tokenId);
        require(to != owner, "ERC721A: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721A: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId, owner);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId)
        public
        view
        override
        returns (address)
    {
        require(
            _exists(tokenId),
            "ERC721A: approved query for nonexistent token"
        );

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved)
        public
        override
    {
        require(operator != _msgSender(), "ERC721A: 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 override {
        _transfer(from, to, tokenId);
    }

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

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public override {
        _transfer(from, to, tokenId);
        require(
            _checkOnERC721Received(from, to, tokenId, _data),
            "ERC721A: 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`),
     */
    function _exists(uint256 tokenId) internal view returns (bool) {
        return tokenId < currentIndex;
    }

    function _safeMint(address to, uint256 quantity) internal {
        _safeMint(to, quantity, "");
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` cannot be larger than the max batch size.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal {
        uint256 startTokenId = currentIndex;
        require(to != address(0), "ERC721A: mint to the zero address");
        // We know if the first token in the batch doesn't exist, the other ones don't as well, because of serial ordering.
        require(!_exists(startTokenId), "ERC721A: token already minted");
        require(quantity <= maxBatchSize, "ERC721A: quantity to mint too high");

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        AddressData memory addressData = _addressData[to];
        _addressData[to] = AddressData(
            addressData.balance + uint128(quantity),
            addressData.numberMinted + uint128(quantity)
        );
        _ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp));

        uint256 updatedIndex = startTokenId;

        for (uint256 i = 0; i < quantity; i++) {
            emit Transfer(address(0), to, updatedIndex);
            require(
                _checkOnERC721Received(address(0), to, updatedIndex, _data),
                "ERC721A: transfer to non ERC721Receiver implementer"
            );
            updatedIndex++;
        }

        currentIndex = updatedIndex;
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * 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
    ) private {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);

        bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
            getApproved(tokenId) == _msgSender() ||
            isApprovedForAll(prevOwnership.addr, _msgSender()));

        require(
            isApprovedOrOwner,
            "ERC721A: transfer caller is not owner nor approved"
        );

        require(
            prevOwnership.addr == from,
            "ERC721A: transfer from incorrect owner"
        );
        require(to != address(0), "ERC721A: transfer to the zero address");

        _beforeTokenTransfers(from, to, tokenId, 1);

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

        _addressData[from].balance -= 1;
        _addressData[to].balance += 1;
        _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));

        // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
        // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
        uint256 nextTokenId = tokenId + 1;
        if (_ownerships[nextTokenId].addr == address(0)) {
            if (_exists(nextTokenId)) {
                _ownerships[nextTokenId] = TokenOwnership(
                    prevOwnership.addr,
                    prevOwnership.startTimestamp
                );
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

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

    uint256 public nextOwnerToExplicitlySet = 0;

    /**
     * @dev Explicitly set `owners` to eliminate loops in future calls of ownerOf().
     */
    function _setOwnersExplicit(uint256 quantity) internal {
        uint256 oldNextOwnerToSet = nextOwnerToExplicitlySet;
        require(quantity > 0, "quantity must be nonzero");
        uint256 endIndex = oldNextOwnerToSet + quantity - 1;
        if (endIndex > currentIndex - 1) {
            endIndex = currentIndex - 1;
        }
        // We know if the last one in the group exists, all in the group exist, due to serial ordering.
        require(_exists(endIndex), "not enough minted yet for this cleanup");
        for (uint256 i = oldNextOwnerToSet; i <= endIndex; i++) {
            if (_ownerships[i].addr == address(0)) {
                TokenOwnership memory ownership = ownershipOf(i);
                _ownerships[i] = TokenOwnership(
                    ownership.addr,
                    ownership.startTimestamp
                );
            }
        }
        nextOwnerToExplicitlySet = endIndex + 1;
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try
                IERC721Receiver(to).onERC721Received(
                    _msgSender(),
                    from,
                    tokenId,
                    _data
                )
            returns (bytes4 retval) {
                return retval == IERC721Receiver(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert(
                        "ERC721A: transfer to non ERC721Receiver implementer"
                    );
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * 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`.
     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
     * minting.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
}

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

import "./AnonymiceLibrary.sol";
import "./ERC721A.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract GenFrens is ERC721A, Ownable {
    using AnonymiceLibrary for uint8;

    struct Trait {
        string traitName;
        string traitType;
    }

    //Mappings
    mapping(uint256 => Trait[]) public traitTypes;
    mapping(string => bool) hashToMinted;
    mapping(uint256 => string) internal tokenIdToHash;
    mapping(address => bool) addressMinted;

    //uint256s
    uint256 MAX_SUPPLY = 444;
    uint256 SEED_NONCE = 0;
    uint256 MINT_COST = 0.01 ether;

    //minting flag
    bool public MINTING_LIVE = false;

    //uint arrays
    uint16[][6] TIERS;

    //p5js url
    string p5jsUrl;
    string p5jsIntegrity;
    string imageUrl;
    string externalUrl;

    constructor() ERC721A("GenFrens", "GENF", 2) {
        //Declare all the rarity tiers

        //pCol
        TIERS[0] = [1400, 1400, 1800, 700, 700, 1800, 1100, 1100];
        //sCol
        TIERS[1] = [1500, 1800, 900, 900, 1200, 1800, 1500, 400];
        //noise Max
        TIERS[2] = [4000, 3000, 2000, 1000];
        //eyeSize
        TIERS[3] = [2500, 5000, 2500];
        //Thickness
        TIERS[4] = [6000, 2500, 1500];
        //eyeLevel
        TIERS[5] = [6000, 4000];
    }

    /*
  __  __ _     _   _             ___             _   _             
 |  \/  (_)_ _| |_(_)_ _  __ _  | __|  _ _ _  __| |_(_)___ _ _  ___
 | |\/| | | ' \  _| | ' \/ _` | | _| || | ' \/ _|  _| / _ \ ' \(_-<
 |_|  |_|_|_||_\__|_|_||_\__, | |_| \_,_|_||_\__|\__|_\___/_||_/__/
                         |___/                                     
   */

    /**
     * @dev Converts a digit from 0 - 10000 into its corresponding rarity based on the given rarity tier.
     * @param _randinput The input from 0 - 10000 to use for rarity gen.
     * @param _rarityTier The tier to use.
     */
    function rarityGen(uint256 _randinput, uint8 _rarityTier)
        internal
        view
        returns (uint8)
    {
        uint16 currentLowerBound = 0;
        for (uint8 i = 0; i < TIERS[_rarityTier].length; i++) {
            uint16 thisPercentage = TIERS[_rarityTier][i];
            if (
                _randinput >= currentLowerBound &&
                _randinput < currentLowerBound + thisPercentage
            ) return i;
            currentLowerBound = currentLowerBound + thisPercentage;
        }

        revert();
    }

    /**
     * @dev Generates a 11 digit hash from a tokenId, address, and random number.
     * @param _t The token id to be used within the hash.
     * @param _a The address to be used within the hash.
     * @param _c The custom nonce to be used within the hash.
     */
    function hash(
        uint256 _t,
        address _a,
        uint256 _c
    ) internal returns (string memory) {
        require(_c < 11);

        // This will generate a 11 character string.
        // The first 2 digits are the palette.
        string memory currentHash = "";

        for (uint8 i = 0; i < 6; i++) {
            SEED_NONCE++;
            uint16 _randinput = uint16(
                uint256(
                    keccak256(
                        abi.encodePacked(
                            block.timestamp,
                            block.difficulty,
                            _t,
                            _a,
                            _c,
                            SEED_NONCE
                        )
                    )
                ) % 10000
            );
            currentHash = string(
                abi.encodePacked(
                    currentHash,
                    rarityGen(_randinput, i).toString()
                )
            );
        }

        if (hashToMinted[currentHash]) return hash(_t, _a, _c + 1);

        return currentHash;
    }

    /**
     * @dev Mint internal, this is to avoid code duplication.
     */
    function mintInternal(uint8 mintAmount) internal {
        require(
            MINTING_LIVE == true || msg.sender == owner(),
            "Minting not live"
        );
        uint256 _totalSupply = totalSupply();
        require(_totalSupply < MAX_SUPPLY);
        require(!AnonymiceLibrary.isContract(msg.sender));
        require(addressMinted[msg.sender] != true, "Address already minted");
        require(msg.value >= MINT_COST * mintAmount, "Insufficient ETH sent");

        for (uint8 i = 0; i < mintAmount; i++) {
            uint256 thisTokenId = _totalSupply + i;

            tokenIdToHash[thisTokenId] = hash(thisTokenId, msg.sender, 0);

            hashToMinted[tokenIdToHash[thisTokenId]] = true;
        }
        addressMinted[msg.sender] = true;
        _safeMint(msg.sender, mintAmount);
    }

    /**
     * @dev Mints new tokens.
     */
    function mintFren(uint8 mintAmount) public payable {
        return mintInternal(mintAmount);
    }

    /*
 ____     ___   ____  ___        _____  __ __  ____     __ ______  ____  ___   ____   _____
|    \   /  _] /    ||   \      |     ||  |  ||    \   /  ]      ||    |/   \ |    \ / ___/
|  D  ) /  [_ |  o  ||    \     |   __||  |  ||  _  | /  /|      | |  ||     ||  _  (   \_ 
|    / |    _]|     ||  D  |    |  |_  |  |  ||  |  |/  / |_|  |_| |  ||  O  ||  |  |\__  |
|    \ |   [_ |  _  ||     |    |   _] |  :  ||  |  /   \_  |  |   |  ||     ||  |  |/  \ |
|  .  \|     ||  |  ||     |    |  |   |     ||  |  \     | |  |   |  ||     ||  |  |\    |
|__|\_||_____||__|__||_____|    |__|    \__,_||__|__|\____| |__|  |____|\___/ |__|__| \___|
                                                                                           
*/

    /**
     * @dev Hash to HTML function
     */
    function hashToHTML(string memory _hash, uint256 _tokenId)
        public
        view
        returns (string memory)
    {
        string memory htmlString = string(
            abi.encodePacked(
                "data:text/html,%3Chtml%3E%3Chead%3E%3Cscript%20src%3D%22",
                p5jsUrl,
                "%22%20integrity%3D%22",
                p5jsIntegrity,
                "%22%20crossorigin%3D%22anonymous%22%3E%3C%2Fscript%3E%3C%2Fhead%3E%3Cbody%3E%3Cscript%3Evar%20tokenId%3D",
                AnonymiceLibrary.toString(_tokenId),
                "%3Bvar%20hash%3D%22",
                _hash,
                "%22%3B"
            )
        );

        htmlString = string(
            abi.encodePacked(
                htmlString,
                "xo%3D1%2Csd%3D21%2AtokenId%2CpCs%3D%5B0%2C30%2C80%2C120%2C180%2C225%2C270%2C300%5D%2CsCs%3D%5B0%2C30%2C120%2C180%2C225%2C270%2C300%2C330%5D%2CnMV%3D%5B.5%2C1%2C2%2C3%5D%2CeSs%3D%5B.26%2C.33%2C.4%5D%2CtV%3D%5B10%2C25%2C70%5D%2CeLs%3D%5B0%2C15%5D%3Bfunction%20setup%28%29%7BcreateCanvas%28500%2C500%29%2CcolorMode%28HSB%2C360%2C100%2C100%29%2CstrokeCap%28ROUND%29%2CnoiseSeed%28sd%29%2CrandomSeed%28sd%29%2CpC%3DparseInt%28hash.substring%280%2C1%29%29%2CsC%3DparseInt%28hash.substring%281%2C2%29%29%2CnM%3DparseInt%28hash.substring%282%2C3%29%29%2CeS%3DparseInt%28hash.substring%283%2C4%29%29%2Ct%3DparseInt%28hash.substring%284%2C5%29%29%2CeL%3DparseInt%28hash.substring%285%2C6%29%29%2C330%3D%3DsCs%5BsC%5D%3Fk%3DpCs%5BpC%5D%3Ak%3DsCs%5BsC%5D%2CwP%3Drandom%285%2C10%29%2ChP%3Drandom%285%2C10%29%7Dfunction%20draw%28%29%7Bbackground%28255%29%3Bfor%28let%20s%3D25%3Bs%3C500%3Bs%2B%3D50%29for%28let%20e%3D25%3Be%3C500%3Be%2B%3D50%29noStroke%28%29%2Cf%3DsCs%5BsC%5D%2C330%3D%3Df%3FrC%3Drandom%28360%29%3ArC%3Dk%2Cfill%28rC%2Crandom%2825%29%2C100%29%2Cc%3Dnew%20C1%2Cpush%28%29%2Ctranslate%28s%2Ce%29%2Cscale%28.14%2C.14%29%2Cc.s%28%29%2Cpop%28%29%3Bc1%3Dnew%20C2%28pCs%5BpC%5D%2C40%2C100%2C0%29%2Cpush%28%29%2Ctranslate%28250%2C500%29%2Crotate%283.14%29%2Cscale%28.55%2C1.25%29%2Cc1.s%28%29%2Cpop%28%29%2Cpush%28%29%2Ctranslate%28250%2C250%29%2Cc1.s%28%29%2Cpop%28%29%2CnoStroke%28%29%2Ce1%3Dnew%20C2%280%2C0%2C100%2C1%29%2Cpush%28%29%2Ctranslate%28200%2C200%29%2Cscale%28.33%29%2Ce1.s%28%29%2Cpop%28%29%2Ce2%3Dnew%20C2%280%2C0%2C100%2C1%29%2Cpush%28%29%2Cpush%28%29%2Ctranslate%28300%2C200%29%2Cscale%28eSs%5BeS%5D%29%2Crotate%28PI%29%2Ce2.s%28%29%2Cpop%28%29%2Cp1%3Dnew%20C2%28k%2C100%2C100%2C1%29%2Cpush%28%29%2Ctranslate%28200%2C200%2BeLs%5BeL%5D%29%2Cscale%28.1%29%2Cp1.s%28%29%2Cpop%28%29%2Cp2%3Dnew%20C2%28k%2C100%2C100%2C1%29%2Cpush%28%29%2Ctranslate%28300%2C200-eLs%5BeL%5D%29%2Cscale%28.1%29%2Crotate%28PI%29%2Cp2.s%28%29%2Cpop%28%29%3Bfor%28let%20s%3D200%3Bs%3C%3D300%3Bs%2B%2B%29sats%3Dmap%28noise%28xo%29%2C0%2C1%2C30%2C100%29%2Cfill%28k%2Csats%2C95%29%2Cr%3Dmap%28noise%28xo%29%2C0%2C1%2C.53%2C.77%29%2Cellipse%28s%2C500%2Ar%2C28%29%2Cxo%2B%3D.015%3BnoLoop%28%29%7Dclass%20C1%7Bs%28%29%7BbeginShape%28%29%3Bfor%28let%20s%3D0%3Bs%3CTWO_PI%3Bs%2B%3D.16%29%7Blet%20e%3Dmap%28cos%28s%29%2C-1%2C1%2C0%2CnMV%5BnM%5D%29%2Ct%3Dmap%28sin%28s%29%2C-1%2C1%2C0%2CnMV%5BnM%5D%29%2Cn%3Dmap%28noise%28e%2Ct%29%2C0%2C1%2C100%2C200%29%2Ca%3Dn%2Acos%28s%29%2Cp%3Dn%2Asin%28s%29%3Bvertex%28a%2Cp%29%2Ce%2B%3D.004%7DendShape%28%29%7D%7Dclass%20C2%7Bconstructor%28s%2Ce%2Ct%2Cn%29%7Bthis.h%3Ds%2Cthis.z%3De%2Cthis.l%3Dt%2Cthis.b%3Dn%7Ds%28%29%7BbeginShape%28%29%2CnoFill%28%29%3Bfor%28let%20s%3D0%3Bs%3CTWO_PI%3Bs%2B%3D.045%29%7Blet%20e%3Dmap%28sin%28s%29%2C-1%2C1%2C0%2CnMV%5BnM%5D%29%2Cn%3Dmap%28cos%28s%29%2C-1%2C1%2C0%2CnMV%5BnM%5D%29%2Ca%3Dmap%28noise%28n%2Ce%29%2C0%2C1%2C100%2C200%29%2Cp%3Da%2Acos%28s%29%2Co%3Da%2Asin%28s%29%3B0%3D%3Dthis.b%26%26%28stroke%28this.h%2Cthis.z%2Cthis.l-25%29%2CstrokeWeight%28tV%5Bt%5D%29%29%2Cvertex%28p%2Co%29%2CendShape%28%29%2Cpush%28%29%2Cstroke%28this.h%2Cthis.z%2Cthis.l%29%2CstrokeWeight%286%29%2Cline%28p%2B7.5%2Co%2B10%2C500%2FwP%2C500%2FhP%29%2Cpop%28%29%2Cn%2B%3D.04%2Ce%2B%3D.001%7DendShape%28%29%7D%7D%3C%2Fscript%3E%3C%2Fbody%3E%3C%2Fhtml%3E"
            )
        );

        return htmlString;
    }

    /**
     * @dev Hash to metadata function
     */
    function hashToMetadata(string memory _hash)
        public
        view
        returns (string memory)
    {
        string memory metadataString;

        for (uint8 i = 0; i < 6; i++) {
            uint8 thisTraitIndex = AnonymiceLibrary.parseInt(
                AnonymiceLibrary.substring(_hash, i, i + 1)
            );

            metadataString = string(
                abi.encodePacked(
                    metadataString,
                    '{"trait_type":"',
                    traitTypes[i][thisTraitIndex].traitType,
                    '","value":"',
                    traitTypes[i][thisTraitIndex].traitName,
                    '"}'
                )
            );

            if (i != 5)
                metadataString = string(abi.encodePacked(metadataString, ","));
        }

        return string(abi.encodePacked("[", metadataString, "]"));
    }

    /**
     * @dev Returns the SVG and metadata for a token Id
     * @param _tokenId The tokenId to return the SVG and metadata for.
     */
    function tokenURI(uint256 _tokenId)
        public
        view
        override
        returns (string memory)
    {
        require(_exists(_tokenId));

        string memory tokenHash = _tokenIdToHash(_tokenId);

        string
            memory description = '", "description": "444 GenFrens to keep you company. Metadata & images mirrored on chain permanently. Your GenFren will never leave you <3",';

        string memory encodedTokenId = AnonymiceLibrary.encode(
            bytes(string(abi.encodePacked(AnonymiceLibrary.toString(_tokenId))))
        );
        string memory encodedHash = AnonymiceLibrary.encode(
            bytes(string(abi.encodePacked(tokenHash)))
        );

        return
            string(
                abi.encodePacked(
                    "data:application/json;base64,",
                    AnonymiceLibrary.encode(
                        bytes(
                            string(
                                abi.encodePacked(
                                    '{"name": "GenFrens #',
                                    AnonymiceLibrary.toString(_tokenId),
                                    description,
                                    '"external_url":"',
                                    externalUrl,
                                    encodedTokenId,
                                    "&t=",
                                    encodedHash,
                                    '","image":"',
                                    imageUrl,
                                    AnonymiceLibrary.toString(_tokenId),
                                    "&t=",
                                    tokenHash,
                                    '","attributes":',
                                    hashToMetadata(tokenHash),
                                    "}"
                                )
                            )
                        )
                    )
                )
            );
    }

    /**
     * @dev Returns a hash for a given tokenId
     * @param _tokenId The tokenId to return the hash for.
     */
    function _tokenIdToHash(uint256 _tokenId)
        public
        view
        returns (string memory)
    {
        string memory tokenHash = tokenIdToHash[_tokenId];

        return tokenHash;
    }

    /*
  ___   __    __  ____     ___  ____       _____  __ __  ____     __ ______  ____  ___   ____   _____
 /   \ |  |__|  ||    \   /  _]|    \     |     ||  |  ||    \   /  ]      ||    |/   \ |    \ / ___/
|     ||  |  |  ||  _  | /  [_ |  D  )    |   __||  |  ||  _  | /  /|      | |  ||     ||  _  (   \_ 
|  O  ||  |  |  ||  |  ||    _]|    /     |  |_  |  |  ||  |  |/  / |_|  |_| |  ||  O  ||  |  |\__  |
|     ||  `  '  ||  |  ||   [_ |    \     |   _] |  :  ||  |  /   \_  |  |   |  ||     ||  |  |/  \ |
|     | \      / |  |  ||     ||  .  \    |  |   |     ||  |  \     | |  |   |  ||     ||  |  |\    |
 \___/   \_/\_/  |__|__||_____||__|\_|    |__|    \__,_||__|__|\____| |__|  |____|\___/ |__|__| \___|
                                                                                                     
    /**
     * @dev Add a trait type
     * @param _traitTypeIndex The trait type index
     * @param traits Array of traits to add
     */

    function addTraitType(uint256 _traitTypeIndex, Trait[] memory traits)
        public
        onlyOwner
    {
        for (uint256 i = 0; i < traits.length; i++) {
            traitTypes[_traitTypeIndex].push(
                Trait(traits[i].traitName, traits[i].traitType)
            );
        }

        return;
    }

    function flipMintingSwitch() public onlyOwner {
        MINTING_LIVE = !MINTING_LIVE;
    }

    /**
     * @dev Sets the p5js url
     * @param _p5jsUrl The address of the p5js file hosted on CDN
     */

    function setJsAddress(string memory _p5jsUrl) public onlyOwner {
        p5jsUrl = _p5jsUrl;
    }

    /**
     * @dev Sets the p5js resource integrity
     * @param _p5jsIntegrity The hash of the p5js file (to protect w subresource integrity)
     */

    function setJsIntegrity(string memory _p5jsIntegrity) public onlyOwner {
        p5jsIntegrity = _p5jsIntegrity;
    }

    /**
     * @dev Sets the base image url
     * @param _imageUrl The base url for image field
     */

    function setImageUrl(string memory _imageUrl) public onlyOwner {
        imageUrl = _imageUrl;
    }

    function setExternalUrl(string memory _externalUrl) public onlyOwner {
        externalUrl = _externalUrl;
    }

    function withdraw() public payable onlyOwner {
        (bool success, ) = payable(msg.sender).call{
            value: address(this).balance
        }("");
        require(success);
    }
}

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

pragma solidity ^0.8.0;

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, 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;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

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

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

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

pragma solidity ^0.8.0;

import "../IERC721.sol";

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

pragma solidity ^0.8.0;

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

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

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

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

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

{
  "compilationTarget": {
    "contracts/GenFrens.sol": "GenFrens"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}