// File: @openzeppelin-4.5/contracts/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

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

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

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

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

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

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

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

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

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

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: 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 {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

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

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

        _transfer(from, to, tokenId);
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

        _beforeTokenTransfer(from, to, tokenId);

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

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

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId);
    }

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

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

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

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

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin-4.5/contracts/token/ERC721/extensions/IERC721Metadata.sol



// 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);
}

// File: @openzeppelin-4.5/contracts/token/ERC721/IERC721.sol



// 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;
}

// File: @openzeppelin-4.5/contracts/token/ERC721/IERC721Receiver.sol



// 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);
}

// File: @openzeppelin-4.5/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: @openzeppelin-4.5/contracts/utils/Context.sol



// 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;
    }
}

// File: @openzeppelin-4.5/contracts/utils/introspection/ERC165.sol



// 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;
    }
}

// File: @openzeppelin-4.5/contracts/utils/introspection/IERC165.sol



// 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);
}

// File: @openzeppelin-4.5/contracts/utils/Strings.sol



// 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);
    }
}

// File: contracts/engine/GenArt721CoreV2_ENGINE_FLEX.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

import "../interfaces/0.8.x/IRandomizer.sol";
import "../interfaces/0.8.x/IGenArt721CoreV2_PBAB.sol";
import "@openzeppelin-4.5/contracts/utils/Strings.sol";
import "@openzeppelin-4.5/contracts/token/ERC721/ERC721.sol";

pragma solidity 0.8.9;

/**
 * @title Art Blocks Engine ERC-721 core contract with FLEX integration.
 * Allows for projects to specify external asset dependencies from either IPFS or ARWEAVE.
 * @author Art Blocks Inc.
 */
contract GenArt721CoreV2_ENGINE_FLEX is ERC721, IGenArt721CoreV2_PBAB {
    /// randomizer contract
    IRandomizer public randomizerContract;

    /// version & type of this core contract
    string public constant coreVersion = "v2.0.0";
    string public constant coreType = "GenArt721CoreV2_ENGINE_FLEX";

    struct Project {
        string name;
        string artist;
        string description;
        string website;
        string license;
        string projectBaseURI;
        uint256 invocations;
        uint256 maxInvocations;
        string scriptJSON;
        mapping(uint256 => string) scripts;
        uint256 scriptCount;
        string ipfsHash;
        bool active;
        bool locked;
        bool paused;
        bool externalAssetDependenciesLocked;
        uint24 externalAssetDependencyCount;
        mapping(uint256 => ExternalAssetDependency) externalAssetDependencies;
    }

    event ExternalAssetDependencyUpdated(
        uint256 indexed _projectId,
        uint256 indexed _index,
        string _cid,
        ExternalAssetDependencyType _dependencyType,
        uint24 _externalAssetDependencyCount
    );

    event ExternalAssetDependencyRemoved(
        uint256 indexed _projectId,
        uint256 indexed _index
    );

    event GatewayUpdated(
        ExternalAssetDependencyType indexed _dependencyType,
        string _gatewayAddress
    );

    event ProjectExternalAssetDependenciesLocked(uint256 indexed _projectId);

    enum ExternalAssetDependencyType {
        IPFS,
        ARWEAVE
    }
    struct ExternalAssetDependency {
        string cid;
        ExternalAssetDependencyType dependencyType;
    }

    string public preferredIPFSGateway;
    string public preferredArweaveGateway;

    uint256 constant ONE_MILLION = 1_000_000;
    mapping(uint256 => Project) projects;

    //All financial functions are stripped from struct for visibility
    mapping(uint256 => address payable) public projectIdToArtistAddress;
    mapping(uint256 => string) public projectIdToCurrencySymbol;
    mapping(uint256 => address) public projectIdToCurrencyAddress;
    mapping(uint256 => uint256) public projectIdToPricePerTokenInWei;
    mapping(uint256 => address payable) public projectIdToAdditionalPayee;
    mapping(uint256 => uint256) public projectIdToAdditionalPayeePercentage;
    mapping(uint256 => uint256)
        public projectIdToSecondaryMarketRoyaltyPercentage;

    address payable public renderProviderAddress;
    /// Percentage of mint revenue allocated to render provider
    uint256 public renderProviderPercentage = 10;

    mapping(uint256 => uint256) public tokenIdToProjectId;
    mapping(uint256 => bytes32) public tokenIdToHash;
    mapping(bytes32 => uint256) public hashToTokenId;

    /// admin for contract
    address public admin;
    /// true if address is whitelisted
    mapping(address => bool) public isWhitelisted;
    /// true if minter is whitelisted
    mapping(address => bool) public isMintWhitelisted;

    /// next project ID to be created
    uint256 public nextProjectId = 0;

    modifier onlyValidTokenId(uint256 _tokenId) {
        require(_exists(_tokenId), "Token ID does not exist");
        _;
    }

    modifier onlyUnlockedProjectExternalAssetDependencies(uint256 _projectId) {
        require(
            !projects[_projectId].externalAssetDependenciesLocked,
            "Project external asset dependencies are locked"
        );
        _;
    }

    modifier onlyUnlocked(uint256 _projectId) {
        require(!projects[_projectId].locked, "Only if unlocked");
        _;
    }

    modifier onlyArtist(uint256 _projectId) {
        require(
            msg.sender == projectIdToArtistAddress[_projectId],
            "Only artist"
        );
        _;
    }

    modifier onlyAdmin() {
        require(msg.sender == admin, "Only admin");
        _;
    }

    modifier onlyWhitelisted() {
        require(isWhitelisted[msg.sender], "Only whitelisted");
        _;
    }

    modifier onlyArtistOrWhitelisted(uint256 _projectId) {
        require(
            isWhitelisted[msg.sender] ||
                msg.sender == projectIdToArtistAddress[_projectId],
            "Only artist or whitelisted"
        );
        _;
    }

    /**
     * @notice Initializes contract.
     * @param _tokenName Name of token.
     * @param _tokenSymbol Token symbol.
     * @param _randomizerContract Randomizer contract.
     */
    constructor(
        string memory _tokenName,
        string memory _tokenSymbol,
        address _randomizerContract
    ) ERC721(_tokenName, _tokenSymbol) {
        admin = msg.sender;
        isWhitelisted[msg.sender] = true;
        renderProviderAddress = payable(msg.sender);
        randomizerContract = IRandomizer(_randomizerContract);
    }

    /**
     * @notice Mints a token from project `_projectId` and sets the
     * token's owner to `_to`.
     * @param _to Address to be the minted token's owner.
     * @param _projectId Project ID to mint a token on.
     * @param _by Purchaser of minted token.
     * @dev sender must be a whitelisted minter
     */
    function mint(
        address _to,
        uint256 _projectId,
        address _by
    ) external returns (uint256 _tokenId) {
        require(
            isMintWhitelisted[msg.sender],
            "Must mint from whitelisted minter contract."
        );
        require(
            projects[_projectId].invocations + 1 <=
                projects[_projectId].maxInvocations,
            "Must not exceed max invocations"
        );
        require(
            projects[_projectId].active ||
                _by == projectIdToArtistAddress[_projectId],
            "Project must exist and be active"
        );
        require(
            !projects[_projectId].paused ||
                _by == projectIdToArtistAddress[_projectId],
            "Purchases are paused."
        );

        uint256 tokenId = _mintToken(_to, _projectId);

        return tokenId;
    }

    function _mintToken(
        address _to,
        uint256 _projectId
    ) internal returns (uint256 _tokenId) {
        uint256 tokenIdToBe = (_projectId * ONE_MILLION) +
            projects[_projectId].invocations;

        projects[_projectId].invocations = projects[_projectId].invocations + 1;

        bytes32 hash = keccak256(
            abi.encodePacked(
                projects[_projectId].invocations,
                block.number,
                blockhash(block.number - 1),
                randomizerContract.returnValue()
            )
        );
        tokenIdToHash[tokenIdToBe] = hash;
        hashToTokenId[hash] = tokenIdToBe;

        _mint(_to, tokenIdToBe);

        tokenIdToProjectId[tokenIdToBe] = _projectId;

        emit Mint(_to, tokenIdToBe, _projectId);

        return tokenIdToBe;
    }

    /**
     * @notice Updates preferredIPFSGateway to `_gateway`.
     */
    function updateIPFSGateway(
        string calldata _gateway
    ) public onlyWhitelisted {
        preferredIPFSGateway = _gateway;
        emit GatewayUpdated(ExternalAssetDependencyType.IPFS, _gateway);
    }

    /**
     * @notice Updates preferredArweaveGateway to `_gateway`.
     */
    function updateArweaveGateway(
        string calldata _gateway
    ) public onlyWhitelisted {
        preferredArweaveGateway = _gateway;
        emit GatewayUpdated(ExternalAssetDependencyType.ARWEAVE, _gateway);
    }

    /**
     * @notice Updates contract admin to `_adminAddress`.
     */
    function updateAdmin(address _adminAddress) public onlyAdmin {
        admin = _adminAddress;
    }

    /**
     * @notice Updates render provider address to `_renderProviderAddress`.
     */
    function updateRenderProviderAddress(
        address payable _renderProviderAddress
    ) public onlyAdmin {
        renderProviderAddress = _renderProviderAddress;
    }

    /**
     * @notice Updates render provider mint revenue percentage to
     * `_renderProviderPercentage`.
     */
    function updateRenderProviderPercentage(
        uint256 _renderProviderPercentage
    ) public onlyAdmin {
        require(_renderProviderPercentage <= 25, "Max of 25%");
        renderProviderPercentage = _renderProviderPercentage;
    }

    /**
     * @notice Whitelists `_address`.
     */
    function addWhitelisted(address _address) public onlyAdmin {
        isWhitelisted[_address] = true;
    }

    /**
     * @notice Revokes whitelisting of `_address`.
     */
    function removeWhitelisted(address _address) public onlyAdmin {
        isWhitelisted[_address] = false;
    }

    /**
     * @notice Whitelists minter `_address`.
     */
    function addMintWhitelisted(address _address) public onlyAdmin {
        isMintWhitelisted[_address] = true;
    }

    /**
     * @notice Revokes whitelisting of minter `_address`.
     */
    function removeMintWhitelisted(address _address) public onlyAdmin {
        isMintWhitelisted[_address] = false;
    }

    /**
     * @notice Updates randomizer to `_randomizerAddress`.
     */
    function updateRandomizerAddress(
        address _randomizerAddress
    ) public onlyWhitelisted {
        randomizerContract = IRandomizer(_randomizerAddress);
    }

    /**
     * @notice Locks project `_projectId`.
     */
    function toggleProjectIsLocked(
        uint256 _projectId
    ) public onlyWhitelisted onlyUnlocked(_projectId) {
        projects[_projectId].locked = true;
    }

    /**
     * @notice Locks external asset dependencies for project `_projectId`.
     */
    function lockProjectExternalAssetDependencies(
        uint256 _projectId
    )
        external
        onlyArtistOrWhitelisted(_projectId)
        onlyUnlockedProjectExternalAssetDependencies(_projectId)
    {
        projects[_projectId].externalAssetDependenciesLocked = true;
        emit ProjectExternalAssetDependenciesLocked(_projectId);
    }

    /**
     * @notice Toggles project `_projectId` as active/inactive.
     */
    function toggleProjectIsActive(uint256 _projectId) public onlyWhitelisted {
        projects[_projectId].active = !projects[_projectId].active;
    }

    /**
     * @notice Updates artist of project `_projectId` to `_artistAddress`.
     */
    function updateProjectArtistAddress(
        uint256 _projectId,
        address payable _artistAddress
    ) public onlyArtistOrWhitelisted(_projectId) {
        projectIdToArtistAddress[_projectId] = _artistAddress;
    }

    /**
     * @notice Toggles paused state of project `_projectId`.
     */
    function toggleProjectIsPaused(
        uint256 _projectId
    ) public onlyArtist(_projectId) {
        projects[_projectId].paused = !projects[_projectId].paused;
    }

    /**
     * @notice Adds new project `_projectName` by `_artistAddress`.
     * @param _projectName Project name.
     * @param _artistAddress Artist's address.
     * @param _pricePerTokenInWei Price to mint a token, in Wei.
     */
    function addProject(
        string memory _projectName,
        address payable _artistAddress,
        uint256 _pricePerTokenInWei
    ) public onlyWhitelisted {
        uint256 projectId = nextProjectId;
        projectIdToArtistAddress[projectId] = _artistAddress;
        projects[projectId].name = _projectName;
        projectIdToCurrencySymbol[projectId] = "ETH";
        projectIdToPricePerTokenInWei[projectId] = _pricePerTokenInWei;
        projects[projectId].paused = true;
        projects[projectId].maxInvocations = ONE_MILLION;
        nextProjectId = nextProjectId + 1;
    }

    /**
     * @notice Updates payment currency of project `_projectId` to be
     * `_currencySymbol`.
     * @param _projectId Project ID to update.
     * @param _currencySymbol Currency symbol.
     * @param _currencyAddress Currency address.
     */
    function updateProjectCurrencyInfo(
        uint256 _projectId,
        string memory _currencySymbol,
        address _currencyAddress
    ) public onlyArtist(_projectId) {
        projectIdToCurrencySymbol[_projectId] = _currencySymbol;
        projectIdToCurrencyAddress[_projectId] = _currencyAddress;
    }

    /**
     * @notice Updates price per token of project `_projectId` to be
     * '_pricePerTokenInWei`, in Wei.
     */
    function updateProjectPricePerTokenInWei(
        uint256 _projectId,
        uint256 _pricePerTokenInWei
    ) public onlyArtist(_projectId) {
        projectIdToPricePerTokenInWei[_projectId] = _pricePerTokenInWei;
    }

    /**
     * @notice Updates name of project `_projectId` to be `_projectName`.
     */
    function updateProjectName(
        uint256 _projectId,
        string memory _projectName
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].name = _projectName;
    }

    /**
     * @notice Updates artist name for project `_projectId` to be
     * `_projectArtistName`.
     */
    function updateProjectArtistName(
        uint256 _projectId,
        string memory _projectArtistName
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].artist = _projectArtistName;
    }

    /**
     * @notice Updates additional payee for project `_projectId` to be
     * `_additionalPayee`, receiving `_additionalPayeePercentage` percent
     * of artist mint and royalty revenues.
     */
    function updateProjectAdditionalPayeeInfo(
        uint256 _projectId,
        address payable _additionalPayee,
        uint256 _additionalPayeePercentage
    ) public onlyArtist(_projectId) {
        require(_additionalPayeePercentage <= 100, "Max of 100%");
        projectIdToAdditionalPayee[_projectId] = _additionalPayee;
        projectIdToAdditionalPayeePercentage[
            _projectId
        ] = _additionalPayeePercentage;
    }

    /**
     * @notice Updates artist secondary market royalties for project
     * `_projectId` to be `_secondMarketRoyalty` percent.
     */
    function updateProjectSecondaryMarketRoyaltyPercentage(
        uint256 _projectId,
        uint256 _secondMarketRoyalty
    ) public onlyArtist(_projectId) {
        require(_secondMarketRoyalty <= 100, "Max of 100%");
        projectIdToSecondaryMarketRoyaltyPercentage[
            _projectId
        ] = _secondMarketRoyalty;
    }

    /**
     * @notice Updates description of project `_projectId`.
     */
    function updateProjectDescription(
        uint256 _projectId,
        string memory _projectDescription
    ) public onlyArtist(_projectId) {
        projects[_projectId].description = _projectDescription;
    }

    /**
     * @notice Updates website of project `_projectId` to be `_projectWebsite`.
     */
    function updateProjectWebsite(
        uint256 _projectId,
        string memory _projectWebsite
    ) public onlyArtist(_projectId) {
        projects[_projectId].website = _projectWebsite;
    }

    /**
     * @notice Updates license for project `_projectId`.
     */
    function updateProjectLicense(
        uint256 _projectId,
        string memory _projectLicense
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].license = _projectLicense;
    }

    /**
     * @notice Updates maximum invocations for project `_projectId` to
     * `_maxInvocations`.
     */
    function updateProjectMaxInvocations(
        uint256 _projectId,
        uint256 _maxInvocations
    ) public onlyArtist(_projectId) {
        require(
            (!projects[_projectId].locked ||
                _maxInvocations < projects[_projectId].maxInvocations),
            "Only if unlocked"
        );
        require(
            _maxInvocations > projects[_projectId].invocations,
            "You must set max invocations greater than current invocations"
        );
        require(_maxInvocations <= ONE_MILLION, "Cannot exceed 1000000");
        projects[_projectId].maxInvocations = _maxInvocations;
    }

    /**
     * @notice Adds a script to project `_projectId`.
     * @param _projectId Project to be updated.
     * @param _script Script to be added.
     */
    function addProjectScript(
        uint256 _projectId,
        string memory _script
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].scripts[
            projects[_projectId].scriptCount
        ] = _script;
        projects[_projectId].scriptCount = projects[_projectId].scriptCount + 1;
    }

    /**
     * @notice Updates script for project `_projectId` at script ID `_scriptId`.
     * @param _projectId Project to be updated.
     * @param _scriptId Script ID to be updated.
     * @param _script Script to be added.
     */
    function updateProjectScript(
        uint256 _projectId,
        uint256 _scriptId,
        string memory _script
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        require(
            _scriptId < projects[_projectId].scriptCount,
            "scriptId out of range"
        );
        projects[_projectId].scripts[_scriptId] = _script;
    }

    /**
     * @notice Updates external asset dependency for project `_projectId`.
     * @param _projectId Project to be updated.
     * @param _index Asset index.
     * @param _cid Asset cid (Content identifier).
     * @param _dependencyType Asset dependency type.
     *  0 - IPFS
     *  1 - ARWEAVE
     */
    function updateProjectExternalAssetDependency(
        uint256 _projectId,
        uint256 _index,
        string calldata _cid,
        ExternalAssetDependencyType _dependencyType
    )
        external
        onlyUnlockedProjectExternalAssetDependencies(_projectId)
        onlyArtistOrWhitelisted(_projectId)
    {
        uint24 assetCount = projects[_projectId].externalAssetDependencyCount;
        require(_index < assetCount, "Asset index out of range");
        projects[_projectId].externalAssetDependencies[_index].cid = _cid;
        projects[_projectId]
            .externalAssetDependencies[_index]
            .dependencyType = _dependencyType;
        emit ExternalAssetDependencyUpdated(
            _projectId,
            _index,
            _cid,
            _dependencyType,
            assetCount
        );
    }

    /**
     * @notice Removes external asset dependency for project `_projectId` at index `_index`.
     * Removal is done by swapping the element to be removed with the last element in the array, then deleting this last element.
     * Assets with indices higher than `_index` can have their indices adjusted as a result of this operation.
     * @param _projectId Project to be updated.
     * @param _index Asset index
     */
    function removeProjectExternalAssetDependency(
        uint256 _projectId,
        uint256 _index
    )
        external
        onlyUnlockedProjectExternalAssetDependencies(_projectId)
        onlyArtistOrWhitelisted(_projectId)
    {
        uint24 assetCount = projects[_projectId].externalAssetDependencyCount;
        require(_index < assetCount, "Asset index out of range");

        uint24 lastElementIndex = assetCount - 1;

        projects[_projectId].externalAssetDependencies[_index] = projects[
            _projectId
        ].externalAssetDependencies[lastElementIndex];
        delete projects[_projectId].externalAssetDependencies[lastElementIndex];

        projects[_projectId].externalAssetDependencyCount = lastElementIndex;

        emit ExternalAssetDependencyRemoved(_projectId, _index);
    }

    /**
     * @notice Adds external asset dependency for project `_projectId`.
     * @param _projectId Project to be updated.
     * @param _cid Asset cid (Content identifier).
     * @param _dependencyType Asset dependency type.
     *  0 - IPFS
     *  1 - ARWEAVE
     */
    function addProjectExternalAssetDependency(
        uint256 _projectId,
        string calldata _cid,
        ExternalAssetDependencyType _dependencyType
    )
        external
        onlyUnlockedProjectExternalAssetDependencies(_projectId)
        onlyArtistOrWhitelisted(_projectId)
    {
        uint24 assetCount = projects[_projectId].externalAssetDependencyCount;
        ExternalAssetDependency memory asset = ExternalAssetDependency({
            cid: _cid,
            dependencyType: _dependencyType
        });
        projects[_projectId].externalAssetDependencies[assetCount] = asset;
        projects[_projectId].externalAssetDependencyCount = assetCount + 1;

        emit ExternalAssetDependencyUpdated(
            _projectId,
            assetCount,
            _cid,
            _dependencyType,
            assetCount + 1
        );
    }

    /**
     * @notice Removes last script from project `_projectId`.
     */
    function removeProjectLastScript(
        uint256 _projectId
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        require(
            projects[_projectId].scriptCount > 0,
            "there are no scripts to remove"
        );
        delete projects[_projectId].scripts[
            projects[_projectId].scriptCount - 1
        ];
        projects[_projectId].scriptCount = projects[_projectId].scriptCount - 1;
    }

    /**
     * @notice Updates script json for project `_projectId`.
     */
    function updateProjectScriptJSON(
        uint256 _projectId,
        string memory _projectScriptJSON
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].scriptJSON = _projectScriptJSON;
    }

    /**
     * @notice Updates ipfs hash for project `_projectId`.
     */
    function updateProjectIpfsHash(
        uint256 _projectId,
        string memory _ipfsHash
    ) public onlyUnlocked(_projectId) onlyArtistOrWhitelisted(_projectId) {
        projects[_projectId].ipfsHash = _ipfsHash;
    }

    /**
     * @notice Updates base URI for project `_projectId` to `_newBaseURI`.
     */
    function updateProjectBaseURI(
        uint256 _projectId,
        string memory _newBaseURI
    ) public onlyArtist(_projectId) {
        projects[_projectId].projectBaseURI = _newBaseURI;
    }

    /**
     * @notice Returns project details for project `_projectId`.
     * @param _projectId Project to be queried.
     * @return projectName Name of project
     * @return artist Artist of project
     * @return description Project description
     * @return website Project website
     * @return license Project license
     */
    function projectDetails(
        uint256 _projectId
    )
        public
        view
        returns (
            string memory projectName,
            string memory artist,
            string memory description,
            string memory website,
            string memory license
        )
    {
        projectName = projects[_projectId].name;
        artist = projects[_projectId].artist;
        description = projects[_projectId].description;
        website = projects[_projectId].website;
        license = projects[_projectId].license;
    }

    /**
     * @notice Returns project token information for project `_projectId`.
     * @param _projectId Project to be queried.
     * @return artistAddress Project Artist's address
     * @return pricePerTokenInWei Price to mint a token, in Wei
     * @return invocations Current number of invocations
     * @return maxInvocations Maximum allowed invocations
     * @return active Boolean representing if project is currently active
     * @return additionalPayee Additional payee address
     * @return additionalPayeePercentage Percentage of artist revenue
     * to be sent to the additional payee's address
     * @return currency Symbol of project's currency
     * @return currencyAddress Address of project's currency
     */
    function projectTokenInfo(
        uint256 _projectId
    )
        public
        view
        returns (
            address artistAddress,
            uint256 pricePerTokenInWei,
            uint256 invocations,
            uint256 maxInvocations,
            bool active,
            address additionalPayee,
            uint256 additionalPayeePercentage,
            string memory currency,
            address currencyAddress
        )
    {
        artistAddress = projectIdToArtistAddress[_projectId];
        pricePerTokenInWei = projectIdToPricePerTokenInWei[_projectId];
        invocations = projects[_projectId].invocations;
        maxInvocations = projects[_projectId].maxInvocations;
        active = projects[_projectId].active;
        additionalPayee = projectIdToAdditionalPayee[_projectId];
        additionalPayeePercentage = projectIdToAdditionalPayeePercentage[
            _projectId
        ];
        currency = projectIdToCurrencySymbol[_projectId];
        currencyAddress = projectIdToCurrencyAddress[_projectId];
    }

    /**
     * @notice Returns script information for project `_projectId`.
     * @param _projectId Project to be queried.
     * @return scriptJSON Project's script json
     * @return scriptCount Count of scripts for project
     * @return ipfsHash IPFS hash for project
     * @return locked Boolean representing if project is locked
     * @return paused Boolean representing if project is paused
     */
    function projectScriptInfo(
        uint256 _projectId
    )
        public
        view
        returns (
            string memory scriptJSON,
            uint256 scriptCount,
            string memory ipfsHash,
            bool locked,
            bool paused
        )
    {
        scriptJSON = projects[_projectId].scriptJSON;
        scriptCount = projects[_projectId].scriptCount;
        ipfsHash = projects[_projectId].ipfsHash;
        locked = projects[_projectId].locked;
        paused = projects[_projectId].paused;
    }

    /**
     * @notice Returns script for project `_projectId` at script index `_index`

     */
    function projectScriptByIndex(
        uint256 _projectId,
        uint256 _index
    ) public view returns (string memory) {
        return projects[_projectId].scripts[_index];
    }

    /**
     * @notice Returns external asset dependency for project `_projectId` at index `_index`.
     */
    function projectExternalAssetDependencyByIndex(
        uint256 _projectId,
        uint256 _index
    ) public view returns (ExternalAssetDependency memory) {
        return projects[_projectId].externalAssetDependencies[_index];
    }

    /**
     * @notice Returns external asset dependency count for project `_projectId` at index `_index`.
     */
    function projectExternalAssetDependencyCount(
        uint256 _projectId
    ) public view returns (uint256) {
        return uint256(projects[_projectId].externalAssetDependencyCount);
    }

    /**
     * @notice Returns base URI for project `_projectId`.
     */
    function projectURIInfo(
        uint256 _projectId
    ) public view returns (string memory projectBaseURI) {
        projectBaseURI = projects[_projectId].projectBaseURI;
    }

    /**
     * @notice Gets royalty data for token ID `_tokenId`.
     * @param _tokenId Token ID to be queried.
     * @return artistAddress Artist's payment address
     * @return additionalPayee Additional payee's payment address
     * @return additionalPayeePercentage Percentage of artist revenue
     * to be sent to the additional payee's address
     * @return royaltyFeeByID Total royalty percentage to be sent to
     * combination of artist and additional payee
     */
    function getRoyaltyData(
        uint256 _tokenId
    )
        public
        view
        returns (
            address artistAddress,
            address additionalPayee,
            uint256 additionalPayeePercentage,
            uint256 royaltyFeeByID
        )
    {
        artistAddress = projectIdToArtistAddress[tokenIdToProjectId[_tokenId]];
        additionalPayee = projectIdToAdditionalPayee[
            tokenIdToProjectId[_tokenId]
        ];
        additionalPayeePercentage = projectIdToAdditionalPayeePercentage[
            tokenIdToProjectId[_tokenId]
        ];
        royaltyFeeByID = projectIdToSecondaryMarketRoyaltyPercentage[
            tokenIdToProjectId[_tokenId]
        ];
    }

    /**
     * @notice Gets token URI for token ID `_tokenId`.
     */
    function tokenURI(
        uint256 _tokenId
    ) public view override onlyValidTokenId(_tokenId) returns (string memory) {
        return
            string(
                abi.encodePacked(
                    projects[tokenIdToProjectId[_tokenId]].projectBaseURI,
                    Strings.toString(_tokenId)
                )
            );
    }
}

// File: contracts/interfaces/0.8.x/IGenArt721CoreV2_PBAB.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Created By: Art Blocks Inc.

pragma solidity ^0.8.0;

interface IGenArt721CoreV2_PBAB {
    /**
     * @notice Token ID `_tokenId` minted on project ID `_projectId` to `_to`.
     */
    event Mint(
        address indexed _to,
        uint256 indexed _tokenId,
        uint256 indexed _projectId
    );

    // getter function of public variable
    function admin() external view returns (address);

    // getter function of public variable
    function nextProjectId() external view returns (uint256);

    // getter function of public mapping
    function tokenIdToProjectId(
        uint256 tokenId
    ) external view returns (uint256 projectId);

    function isWhitelisted(address sender) external view returns (bool);

    function projectIdToCurrencySymbol(
        uint256 _projectId
    ) external view returns (string memory);

    function projectIdToCurrencyAddress(
        uint256 _projectId
    ) external view returns (address);

    function projectIdToArtistAddress(
        uint256 _projectId
    ) external view returns (address payable);

    function projectIdToPricePerTokenInWei(
        uint256 _projectId
    ) external view returns (uint256);

    function projectIdToAdditionalPayee(
        uint256 _projectId
    ) external view returns (address payable);

    function projectIdToAdditionalPayeePercentage(
        uint256 _projectId
    ) external view returns (uint256);

    function projectTokenInfo(
        uint256 _projectId
    )
        external
        view
        returns (
            address,
            uint256,
            uint256,
            uint256,
            bool,
            address,
            uint256,
            string memory,
            address
        );

    function renderProviderAddress() external view returns (address payable);

    function renderProviderPercentage() external view returns (uint256);

    function mint(
        address _to,
        uint256 _projectId,
        address _by
    ) external returns (uint256 tokenId);

    function getRoyaltyData(
        uint256 _tokenId
    )
        external
        view
        returns (
            address artistAddress,
            address additionalPayee,
            uint256 additionalPayeePercentage,
            uint256 royaltyFeeByID
        );
}

// File: contracts/interfaces/0.8.x/IRandomizer.sol



// SPDX-License-Identifier: LGPL-3.0-only
// Creatd By: Art Blocks Inc.

pragma solidity ^0.8.0;

interface IRandomizer {
    function returnValue() external view returns (bytes32);
}