diff --git a/contract/SimpleNft.sol b/contract/SimpleNft.sol
index 7977bfc..73f2e1f 100644
--- a/contract/SimpleNft.sol
+++ b/contract/SimpleNft.sol
@@ -1,3 +1,7 @@
+/**
+ *Submitted for verification at polygonscan.com on 2022-03-06
+*/
+
// SPDX-License-Identifier: MIT
// Amended by HashLips
@@ -13,20 +17,1234 @@
to the best of the developers' knowledge to work as intended.
*/
-pragma solidity >=0.7.0 <0.9.0;
+// File: @openzeppelin/contracts/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/contracts/token/ERC721/IERC721.sol
+pragma solidity ^0.8.0;
+/**
+ * @dev Required interface of an ERC721 compliant contract.
+ */
+interface IERC721 is IERC165 {
+ /**
+ * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
+ */
+ event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
+
+ /**
+ * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
+ */
+ event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
+
+ /**
+ * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
+ */
+ event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
+
+ /**
+ * @dev Returns the number of tokens in ``owner``'s account.
+ */
+ function balanceOf(address owner) external view returns (uint256 balance);
+
+ /**
+ * @dev Returns the owner of the `tokenId` token.
+ *
+ * Requirements:
+ *
+ * - `tokenId` must exist.
+ */
+ function ownerOf(uint256 tokenId) external view returns (address owner);
+
+ /**
+ * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
+ * are aware of the ERC721 protocol to prevent tokens from being forever locked.
+ *
+ * Requirements:
+ *
+ * - `from` cannot be the zero address.
+ * - `to` cannot be the zero address.
+ * - `tokenId` token must exist and be owned by `from`.
+ * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
+ * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
+ *
+ * Emits a {Transfer} event.
+ */
+ function safeTransferFrom(
+ address from,
+ address to,
+ uint256 tokenId
+ ) external;
+
+ /**
+ * @dev Transfers `tokenId` token from `from` to `to`.
+ *
+ * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
+ *
+ * Requirements:
+ *
+ * - `from` cannot be the zero address.
+ * - `to` cannot be the zero address.
+ * - `tokenId` token must be owned by `from`.
+ * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
+ *
+ * Emits a {Transfer} event.
+ */
+ function transferFrom(
+ address from,
+ address to,
+ uint256 tokenId
+ ) external;
+
+ /**
+ * @dev Gives permission to `to` to transfer `tokenId` token to another account.
+ * The approval is cleared when the token is transferred.
+ *
+ * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
+ *
+ * Requirements:
+ *
+ * - The caller must own the token or be an approved operator.
+ * - `tokenId` must exist.
+ *
+ * Emits an {Approval} event.
+ */
+ function approve(address to, uint256 tokenId) external;
+
+ /**
+ * @dev Returns the account approved for `tokenId` token.
+ *
+ * Requirements:
+ *
+ * - `tokenId` must exist.
+ */
+ function getApproved(uint256 tokenId) external view returns (address operator);
+
+ /**
+ * @dev Approve or remove `operator` as an operator for the caller.
+ * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
+ *
+ * Requirements:
+ *
+ * - The `operator` cannot be the caller.
+ *
+ * Emits an {ApprovalForAll} event.
+ */
+ function setApprovalForAll(address operator, bool _approved) external;
+
+ /**
+ * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
+ *
+ * See {setApprovalForAll}
+ */
+ function isApprovedForAll(address owner, address operator) external view returns (bool);
+
+ /**
+ * @dev Safely transfers `tokenId` token from `from` to `to`.
+ *
+ * Requirements:
+ *
+ * - `from` cannot be the zero address.
+ * - `to` cannot be the zero address.
+ * - `tokenId` token must exist and be owned by `from`.
+ * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
+ * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
+ *
+ * Emits a {Transfer} event.
+ */
+ function safeTransferFrom(
+ address from,
+ address to,
+ uint256 tokenId,
+ bytes calldata data
+ ) external;
+}
+
+
+// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol
+pragma solidity ^0.8.0;
+/**
+ * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
+ * @dev See https://eips.ethereum.org/EIPS/eip-721
+ */
+interface IERC721Enumerable is IERC721 {
+ /**
+ * @dev Returns the total amount of tokens stored by the contract.
+ */
+ function totalSupply() external view returns (uint256);
+
+ /**
+ * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
+ * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
+ */
+ function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
+
+ /**
+ * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
+ * Use along with {totalSupply} to enumerate all tokens.
+ */
+ function tokenByIndex(uint256 index) external view returns (uint256);
+}
+
+
+// File: @openzeppelin/contracts/utils/introspection/ERC165.sol
+pragma solidity ^0.8.0;
+/**
+ * @dev Implementation of the {IERC165} interface.
+ *
+ * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
+ * for the additional interface id that will be supported. For example:
+ *
+ * ```solidity
+ * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
+ * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
+ * }
+ * ```
+ *
+ * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
+ */
+abstract contract ERC165 is IERC165 {
+ /**
+ * @dev See {IERC165-supportsInterface}.
+ */
+ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
+ return interfaceId == type(IERC165).interfaceId;
+ }
+}
+
+// File: @openzeppelin/contracts/utils/Strings.sol
+
+
+
+pragma solidity ^0.8.0;
+
+/**
+ * @dev String operations.
+ */
+library Strings {
+ bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
+
+ /**
+ * @dev Converts a `uint256` to its ASCII `string` decimal representation.
+ */
+ function toString(uint256 value) internal pure returns (string memory) {
+ // Inspired by OraclizeAPI's implementation - MIT licence
+ // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
+
+ if (value == 0) {
+ return "0";
+ }
+ uint256 temp = value;
+ uint256 digits;
+ while (temp != 0) {
+ digits++;
+ temp /= 10;
+ }
+ bytes memory buffer = new bytes(digits);
+ while (value != 0) {
+ digits -= 1;
+ buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
+ value /= 10;
+ }
+ return string(buffer);
+ }
+
+ /**
+ * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
+ */
+ function toHexString(uint256 value) internal pure returns (string memory) {
+ if (value == 0) {
+ return "0x00";
+ }
+ uint256 temp = value;
+ uint256 length = 0;
+ while (temp != 0) {
+ length++;
+ temp >>= 8;
+ }
+ return toHexString(value, length);
+ }
+
+ /**
+ * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
+ */
+ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
+ bytes memory buffer = new bytes(2 * length + 2);
+ buffer[0] = "0";
+ buffer[1] = "x";
+ for (uint256 i = 2 * length + 1; i > 1; --i) {
+ buffer[i] = _HEX_SYMBOLS[value & 0xf];
+ value >>= 4;
+ }
+ require(value == 0, "Strings: hex length insufficient");
+ return string(buffer);
+ }
+}
+
+// File: @openzeppelin/contracts/utils/Address.sol
+
+
+
+pragma solidity ^0.8.0;
+
+/**
+ * @dev Collection of functions related to the address type
+ */
+library Address {
+ /**
+ * @dev Returns true if `account` is a contract.
+ *
+ * [IMPORTANT]
+ * ====
+ * It is unsafe to assume that an address for which this function returns
+ * false is an externally-owned account (EOA) and not a contract.
+ *
+ * Among others, `isContract` will return false for the following
+ * types of addresses:
+ *
+ * - an externally-owned account
+ * - a contract in construction
+ * - an address where a contract will be created
+ * - an address where a contract lived, but was destroyed
+ * ====
+ */
+ function isContract(address account) internal view returns (bool) {
+ // This method relies on extcodesize, which returns 0 for contracts in
+ // construction, since the code is only stored at the end of the
+ // constructor execution.
+
+ uint256 size;
+ assembly {
+ size := extcodesize(account)
+ }
+ return size > 0;
+ }
+
+ /**
+ * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
+ * `recipient`, forwarding all available gas and reverting on errors.
+ *
+ * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
+ * of certain opcodes, possibly making contracts go over the 2300 gas limit
+ * imposed by `transfer`, making them unable to receive funds via
+ * `transfer`. {sendValue} removes this limitation.
+ *
+ * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
+ *
+ * IMPORTANT: because control is transferred to `recipient`, care must be
+ * taken to not create reentrancy vulnerabilities. Consider using
+ * {ReentrancyGuard} or the
+ * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
+ */
+ function sendValue(address payable recipient, uint256 amount) internal {
+ require(address(this).balance >= amount, "Address: insufficient balance");
+
+ (bool success, ) = recipient.call{value: amount}("");
+ require(success, "Address: unable to send value, recipient may have reverted");
+ }
+
+ /**
+ * @dev Performs a Solidity function call using a low level `call`. A
+ * plain `call` is an unsafe replacement for a function call: use this
+ * function instead.
+ *
+ * If `target` reverts with a revert reason, it is bubbled up by this
+ * function (like regular Solidity function calls).
+ *
+ * Returns the raw returned data. To convert to the expected return value,
+ * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
+ *
+ * Requirements:
+ *
+ * - `target` must be a contract.
+ * - calling `target` with `data` must not revert.
+ *
+ * _Available since v3.1._
+ */
+ function functionCall(address target, bytes memory data) internal returns (bytes memory) {
+ return functionCall(target, data, "Address: low-level call failed");
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
+ * `errorMessage` as a fallback revert reason when `target` reverts.
+ *
+ * _Available since v3.1._
+ */
+ function functionCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ return functionCallWithValue(target, data, 0, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but also transferring `value` wei to `target`.
+ *
+ * Requirements:
+ *
+ * - the calling contract must have an ETH balance of at least `value`.
+ * - the called Solidity function must be `payable`.
+ *
+ * _Available since v3.1._
+ */
+ function functionCallWithValue(
+ address target,
+ bytes memory data,
+ uint256 value
+ ) internal returns (bytes memory) {
+ return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
+ * with `errorMessage` as a fallback revert reason when `target` reverts.
+ *
+ * _Available since v3.1._
+ */
+ function functionCallWithValue(
+ address target,
+ bytes memory data,
+ uint256 value,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ require(address(this).balance >= value, "Address: insufficient balance for call");
+ require(isContract(target), "Address: call to non-contract");
+
+ (bool success, bytes memory returndata) = target.call{value: value}(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but performing a static call.
+ *
+ * _Available since v3.3._
+ */
+ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
+ return functionStaticCall(target, data, "Address: low-level static call failed");
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+ * but performing a static call.
+ *
+ * _Available since v3.3._
+ */
+ function functionStaticCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal view returns (bytes memory) {
+ require(isContract(target), "Address: static call to non-contract");
+
+ (bool success, bytes memory returndata) = target.staticcall(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but performing a delegate call.
+ *
+ * _Available since v3.4._
+ */
+ function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
+ return functionDelegateCall(target, data, "Address: low-level delegate call failed");
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+ * but performing a delegate call.
+ *
+ * _Available since v3.4._
+ */
+ function functionDelegateCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ require(isContract(target), "Address: delegate call to non-contract");
+
+ (bool success, bytes memory returndata) = target.delegatecall(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
+ * revert reason using the provided one.
+ *
+ * _Available since v4.3._
+ */
+ function verifyCallResult(
+ bool success,
+ bytes memory returndata,
+ string memory errorMessage
+ ) internal pure returns (bytes memory) {
+ if (success) {
+ return returndata;
+ } else {
+ // Look for revert reason and bubble it up if present
+ if (returndata.length > 0) {
+ // The easiest way to bubble the revert reason is using memory via assembly
+
+ assembly {
+ let returndata_size := mload(returndata)
+ revert(add(32, returndata), returndata_size)
+ }
+ } else {
+ revert(errorMessage);
+ }
+ }
+ }
+}
+
+// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol
+
+
+
+pragma solidity ^0.8.0;
+
+
+/**
+ * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
+ * @dev See https://eips.ethereum.org/EIPS/eip-721
+ */
+interface IERC721Metadata is IERC721 {
+ /**
+ * @dev Returns the token collection name.
+ */
+ function name() external view returns (string memory);
+
+ /**
+ * @dev Returns the token collection symbol.
+ */
+ function symbol() external view returns (string memory);
+
+ /**
+ * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
+ */
+ function tokenURI(uint256 tokenId) external view returns (string memory);
+}
+
+// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol
+
+
+
+pragma solidity ^0.8.0;
+
+/**
+ * @title ERC721 token receiver interface
+ * @dev Interface for any contract that wants to support safeTransfers
+ * from ERC721 asset contracts.
+ */
+interface IERC721Receiver {
+ /**
+ * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
+ * by `operator` from `from`, this function is called.
+ *
+ * It must return its Solidity selector to confirm the token transfer.
+ * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
+ *
+ * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
+ */
+ function onERC721Received(
+ address operator,
+ address from,
+ uint256 tokenId,
+ bytes calldata data
+ ) external returns (bytes4);
+}
+
+// File: @openzeppelin/contracts/utils/Context.sol
+pragma solidity ^0.8.0;
+/**
+ * @dev Provides information about the current execution context, including the
+ * sender of the transaction and its data. While these are generally available
+ * via msg.sender and msg.data, they should not be accessed in such a direct
+ * manner, since when dealing with meta-transactions the account sending and
+ * paying for execution may not be the actual sender (as far as an application
+ * is concerned).
+ *
+ * This contract is only required for intermediate, library-like contracts.
+ */
+abstract contract Context {
+ function _msgSender() internal view virtual returns (address) {
+ return msg.sender;
+ }
+
+ function _msgData() internal view virtual returns (bytes calldata) {
+ return msg.data;
+ }
+}
+
+
+// File: @openzeppelin/contracts/token/ERC721/ERC721.sol
+pragma solidity ^0.8.0;
+/**
+ * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
+ * the Metadata extension, but not including the Enumerable extension, which is available separately as
+ * {ERC721Enumerable}.
+ */
+contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
+ using Address for address;
+ using Strings for uint256;
+
+ // Token name
+ string private _name;
+
+ // Token symbol
+ string private _symbol;
+
+ // Mapping from token ID to owner address
+ mapping(uint256 => address) private _owners;
+
+ // Mapping owner address to token count
+ mapping(address => uint256) private _balances;
+
+ // Mapping from token ID to approved address
+ mapping(uint256 => address) private _tokenApprovals;
+
+ // Mapping from owner to operator approvals
+ mapping(address => mapping(address => bool)) private _operatorApprovals;
+
+ /**
+ * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
+ */
+ constructor(string memory name_, string memory symbol_) {
+ _name = name_;
+ _symbol = symbol_;
+ }
+
+ /**
+ * @dev See {IERC165-supportsInterface}.
+ */
+ function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
+ return
+ interfaceId == type(IERC721).interfaceId ||
+ interfaceId == type(IERC721Metadata).interfaceId ||
+ super.supportsInterface(interfaceId);
+ }
+
+ /**
+ * @dev See {IERC721-balanceOf}.
+ */
+ function balanceOf(address owner) public view virtual override returns (uint256) {
+ require(owner != address(0), "ERC721: balance query for the zero address");
+ return _balances[owner];
+ }
+
+ /**
+ * @dev See {IERC721-ownerOf}.
+ */
+ function ownerOf(uint256 tokenId) public view virtual override returns (address) {
+ address owner = _owners[tokenId];
+ require(owner != address(0), "ERC721: owner query for nonexistent token");
+ return owner;
+ }
-import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
-import "@openzeppelin/contracts/access/Ownable.sol";
+ /**
+ * @dev See {IERC721Metadata-name}.
+ */
+ function name() public view virtual override returns (string memory) {
+ return _name;
+ }
+
+ /**
+ * @dev See {IERC721Metadata-symbol}.
+ */
+ function symbol() public view virtual override returns (string memory) {
+ return _symbol;
+ }
+
+ /**
+ * @dev See {IERC721Metadata-tokenURI}.
+ */
+ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
+ require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
+
+ string memory baseURI = _baseURI();
+ return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
+ }
+
+ /**
+ * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
+ * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
+ * by default, can be overriden in child contracts.
+ */
+ function _baseURI() internal view virtual returns (string memory) {
+ return "";
+ }
+
+ /**
+ * @dev See {IERC721-approve}.
+ */
+ function approve(address to, uint256 tokenId) public virtual override {
+ address owner = ERC721.ownerOf(tokenId);
+ require(to != owner, "ERC721: approval to current owner");
+
+ require(
+ _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
+ "ERC721: approve caller is not owner nor approved for all"
+ );
+
+ _approve(to, tokenId);
+ }
+
+ /**
+ * @dev See {IERC721-getApproved}.
+ */
+ function getApproved(uint256 tokenId) public view virtual override returns (address) {
+ require(_exists(tokenId), "ERC721: approved query for nonexistent token");
+
+ return _tokenApprovals[tokenId];
+ }
+
+ /**
+ * @dev See {IERC721-setApprovalForAll}.
+ */
+ function setApprovalForAll(address operator, bool approved) public virtual override {
+ require(operator != _msgSender(), "ERC721: approve to caller");
+
+ _operatorApprovals[_msgSender()][operator] = approved;
+ emit ApprovalForAll(_msgSender(), operator, approved);
+ }
+
+ /**
+ * @dev See {IERC721-isApprovedForAll}.
+ */
+ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
+ return _operatorApprovals[owner][operator];
+ }
+
+ /**
+ * @dev See {IERC721-transferFrom}.
+ */
+ function transferFrom(
+ address from,
+ address to,
+ uint256 tokenId
+ ) public virtual override {
+ //solhint-disable-next-line max-line-length
+ require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
+
+ _transfer(from, to, tokenId);
+ }
+
+ /**
+ * @dev See {IERC721-safeTransferFrom}.
+ */
+ function safeTransferFrom(
+ address from,
+ address to,
+ uint256 tokenId
+ ) public virtual override {
+ safeTransferFrom(from, to, tokenId, "");
+ }
+
+ /**
+ * @dev See {IERC721-safeTransferFrom}.
+ */
+ function safeTransferFrom(
+ address from,
+ address to,
+ uint256 tokenId,
+ bytes memory _data
+ ) public virtual override {
+ require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
+ _safeTransfer(from, to, tokenId, _data);
+ }
+
+ /**
+ * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
+ * are aware of the ERC721 protocol to prevent tokens from being forever locked.
+ *
+ * `_data` is additional data, it has no specified format and it is sent in call to `to`.
+ *
+ * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
+ * implement alternative mechanisms to perform token transfer, such as signature-based.
+ *
+ * Requirements:
+ *
+ * - `from` cannot be the zero address.
+ * - `to` cannot be the zero address.
+ * - `tokenId` token must exist and be owned by `from`.
+ * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
+ *
+ * Emits a {Transfer} event.
+ */
+ function _safeTransfer(
+ address from,
+ address to,
+ uint256 tokenId,
+ bytes memory _data
+ ) internal virtual {
+ _transfer(from, to, tokenId);
+ require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
+ }
+
+ /**
+ * @dev Returns whether `tokenId` exists.
+ *
+ * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
+ *
+ * Tokens start existing when they are minted (`_mint`),
+ * and stop existing when they are burned (`_burn`).
+ */
+ function _exists(uint256 tokenId) internal view virtual returns (bool) {
+ return _owners[tokenId] != address(0);
+ }
+
+ /**
+ * @dev Returns whether `spender` is allowed to manage `tokenId`.
+ *
+ * Requirements:
+ *
+ * - `tokenId` must exist.
+ */
+ function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
+ require(_exists(tokenId), "ERC721: operator query for nonexistent token");
+ address owner = ERC721.ownerOf(tokenId);
+ return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
+ }
+
+ /**
+ * @dev Safely mints `tokenId` and transfers it to `to`.
+ *
+ * Requirements:
+ *
+ * - `tokenId` must not exist.
+ * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
+ *
+ * Emits a {Transfer} event.
+ */
+ function _safeMint(address to, uint256 tokenId) internal virtual {
+ _safeMint(to, tokenId, "");
+ }
+
+ /**
+ * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
+ * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
+ */
+ function _safeMint(
+ address to,
+ uint256 tokenId,
+ bytes memory _data
+ ) internal virtual {
+ _mint(to, tokenId);
+ require(
+ _checkOnERC721Received(address(0), to, tokenId, _data),
+ "ERC721: transfer to non ERC721Receiver implementer"
+ );
+ }
+
+ /**
+ * @dev Mints `tokenId` and transfers it to `to`.
+ *
+ * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
+ *
+ * Requirements:
+ *
+ * - `tokenId` must not exist.
+ * - `to` cannot be the zero address.
+ *
+ * Emits a {Transfer} event.
+ */
+ function _mint(address to, uint256 tokenId) internal virtual {
+ require(to != address(0), "ERC721: mint to the zero address");
+ require(!_exists(tokenId), "ERC721: token already minted");
+
+ _beforeTokenTransfer(address(0), to, tokenId);
+
+ _balances[to] += 1;
+ _owners[tokenId] = to;
+
+ emit Transfer(address(0), to, tokenId);
+ }
+
+ /**
+ * @dev Destroys `tokenId`.
+ * The approval is cleared when the token is burned.
+ *
+ * Requirements:
+ *
+ * - `tokenId` must exist.
+ *
+ * Emits a {Transfer} event.
+ */
+ function _burn(uint256 tokenId) internal virtual {
+ address owner = ERC721.ownerOf(tokenId);
+
+ _beforeTokenTransfer(owner, address(0), tokenId);
+
+ // Clear approvals
+ _approve(address(0), tokenId);
+
+ _balances[owner] -= 1;
+ delete _owners[tokenId];
+
+ emit Transfer(owner, address(0), tokenId);
+ }
+
+ /**
+ * @dev Transfers `tokenId` from `from` to `to`.
+ * As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
+ *
+ * Requirements:
+ *
+ * - `to` cannot be the zero address.
+ * - `tokenId` token must be owned by `from`.
+ *
+ * Emits a {Transfer} event.
+ */
+ function _transfer(
+ address from,
+ address to,
+ uint256 tokenId
+ ) internal virtual {
+ require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
+ require(to != address(0), "ERC721: transfer to the zero address");
+
+ _beforeTokenTransfer(from, to, tokenId);
+
+ // Clear approvals from the previous owner
+ _approve(address(0), tokenId);
+
+ _balances[from] -= 1;
+ _balances[to] += 1;
+ _owners[tokenId] = to;
+
+ emit Transfer(from, to, tokenId);
+ }
+
+ /**
+ * @dev Approve `to` to operate on `tokenId`
+ *
+ * Emits a {Approval} event.
+ */
+ function _approve(address to, uint256 tokenId) internal virtual {
+ _tokenApprovals[tokenId] = to;
+ emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
+ }
+
+ /**
+ * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
+ * The call is not executed if the target address is not a contract.
+ *
+ * @param from address representing the previous owner of the given token ID
+ * @param to target address that will receive the tokens
+ * @param tokenId uint256 ID of the token to be transferred
+ * @param _data bytes optional data to send along with the call
+ * @return bool whether the call correctly returned the expected magic value
+ */
+ function _checkOnERC721Received(
+ address from,
+ address to,
+ uint256 tokenId,
+ bytes memory _data
+ ) private returns (bool) {
+ if (to.isContract()) {
+ try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
+ return retval == IERC721Receiver.onERC721Received.selector;
+ } catch (bytes memory reason) {
+ if (reason.length == 0) {
+ revert("ERC721: transfer to non ERC721Receiver implementer");
+ } else {
+ assembly {
+ revert(add(32, reason), mload(reason))
+ }
+ }
+ }
+ } else {
+ return true;
+ }
+ }
+
+ /**
+ * @dev Hook that is called before any token transfer. This includes minting
+ * and burning.
+ *
+ * Calling conditions:
+ *
+ * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
+ * transferred to `to`.
+ * - When `from` is zero, `tokenId` will be minted for `to`.
+ * - When `to` is zero, ``from``'s `tokenId` will be burned.
+ * - `from` and `to` are never both zero.
+ *
+ * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
+ */
+ function _beforeTokenTransfer(
+ address from,
+ address to,
+ uint256 tokenId
+ ) internal virtual {}
+}
-contract NFT is ERC721Enumerable, Ownable {
+// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol
+
+
+
+pragma solidity ^0.8.0;
+
+
+
+/**
+ * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
+ * enumerability of all the token ids in the contract as well as all token ids owned by each
+ * account.
+ */
+abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
+ // Mapping from owner to list of owned token IDs
+ mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
+
+ // Mapping from token ID to index of the owner tokens list
+ mapping(uint256 => uint256) private _ownedTokensIndex;
+
+ // Array with all token ids, used for enumeration
+ uint256[] private _allTokens;
+
+ // Mapping from token id to position in the allTokens array
+ mapping(uint256 => uint256) private _allTokensIndex;
+
+ /**
+ * @dev See {IERC165-supportsInterface}.
+ */
+ function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
+ return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
+ }
+
+ /**
+ * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
+ */
+ function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
+ require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
+ return _ownedTokens[owner][index];
+ }
+
+ /**
+ * @dev See {IERC721Enumerable-totalSupply}.
+ */
+ function totalSupply() public view virtual override returns (uint256) {
+ return _allTokens.length;
+ }
+
+ /**
+ * @dev See {IERC721Enumerable-tokenByIndex}.
+ */
+ function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
+ require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
+ return _allTokens[index];
+ }
+
+ /**
+ * @dev Hook that is called before any token transfer. This includes minting
+ * and burning.
+ *
+ * Calling conditions:
+ *
+ * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
+ * transferred to `to`.
+ * - When `from` is zero, `tokenId` will be minted for `to`.
+ * - When `to` is zero, ``from``'s `tokenId` will be burned.
+ * - `from` cannot be the zero address.
+ * - `to` cannot be the zero address.
+ *
+ * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
+ */
+ function _beforeTokenTransfer(
+ address from,
+ address to,
+ uint256 tokenId
+ ) internal virtual override {
+ super._beforeTokenTransfer(from, to, tokenId);
+
+ if (from == address(0)) {
+ _addTokenToAllTokensEnumeration(tokenId);
+ } else if (from != to) {
+ _removeTokenFromOwnerEnumeration(from, tokenId);
+ }
+ if (to == address(0)) {
+ _removeTokenFromAllTokensEnumeration(tokenId);
+ } else if (to != from) {
+ _addTokenToOwnerEnumeration(to, tokenId);
+ }
+ }
+
+ /**
+ * @dev Private function to add a token to this extension's ownership-tracking data structures.
+ * @param to address representing the new owner of the given token ID
+ * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
+ */
+ function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
+ uint256 length = ERC721.balanceOf(to);
+ _ownedTokens[to][length] = tokenId;
+ _ownedTokensIndex[tokenId] = length;
+ }
+
+ /**
+ * @dev Private function to add a token to this extension's token tracking data structures.
+ * @param tokenId uint256 ID of the token to be added to the tokens list
+ */
+ function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
+ _allTokensIndex[tokenId] = _allTokens.length;
+ _allTokens.push(tokenId);
+ }
+
+ /**
+ * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
+ * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
+ * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
+ * This has O(1) time complexity, but alters the order of the _ownedTokens array.
+ * @param from address representing the previous owner of the given token ID
+ * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
+ */
+ function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
+ // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
+ // then delete the last slot (swap and pop).
+
+ uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
+ uint256 tokenIndex = _ownedTokensIndex[tokenId];
+
+ // When the token to delete is the last token, the swap operation is unnecessary
+ if (tokenIndex != lastTokenIndex) {
+ uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
+
+ _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
+ _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
+ }
+
+ // This also deletes the contents at the last position of the array
+ delete _ownedTokensIndex[tokenId];
+ delete _ownedTokens[from][lastTokenIndex];
+ }
+
+ /**
+ * @dev Private function to remove a token from this extension's token tracking data structures.
+ * This has O(1) time complexity, but alters the order of the _allTokens array.
+ * @param tokenId uint256 ID of the token to be removed from the tokens list
+ */
+ function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
+ // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
+ // then delete the last slot (swap and pop).
+
+ uint256 lastTokenIndex = _allTokens.length - 1;
+ uint256 tokenIndex = _allTokensIndex[tokenId];
+
+ // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
+ // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
+ // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
+ uint256 lastTokenId = _allTokens[lastTokenIndex];
+
+ _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
+ _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
+
+ // This also deletes the contents at the last position of the array
+ delete _allTokensIndex[tokenId];
+ _allTokens.pop();
+ }
+}
+
+
+// File: @openzeppelin/contracts/access/Ownable.sol
+pragma solidity ^0.8.0;
+/**
+ * @dev Contract module which provides a basic access control mechanism, where
+ * there is an account (an owner) that can be granted exclusive access to
+ * specific functions.
+ *
+ * By default, the owner account will be the one that deploys the contract. This
+ * can later be changed with {transferOwnership}.
+ *
+ * This module is used through inheritance. It will make available the modifier
+ * `onlyOwner`, which can be applied to your functions to restrict their use to
+ * the owner.
+ */
+abstract contract Ownable is Context {
+ address private _owner;
+
+ event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
+
+ /**
+ * @dev Initializes the contract setting the deployer as the initial owner.
+ */
+ constructor() {
+ _setOwner(_msgSender());
+ }
+
+ /**
+ * @dev Returns the address of the current owner.
+ */
+ function owner() public view virtual returns (address) {
+ return _owner;
+ }
+
+ /**
+ * @dev Throws if called by any account other than the owner.
+ */
+ modifier onlyOwner() {
+ require(owner() == _msgSender(), "Ownable: caller is not the owner");
+ _;
+ }
+
+ /**
+ * @dev Leaves the contract without owner. It will not be possible to call
+ * `onlyOwner` functions anymore. Can only be called by the current owner.
+ *
+ * NOTE: Renouncing ownership will leave the contract without an owner,
+ * thereby removing any functionality that is only available to the owner.
+ */
+ function renounceOwnership() public virtual onlyOwner {
+ _setOwner(address(0));
+ }
+
+ /**
+ * @dev Transfers ownership of the contract to a new account (`newOwner`).
+ * Can only be called by the current owner.
+ */
+ function transferOwnership(address newOwner) public virtual onlyOwner {
+ require(newOwner != address(0), "Ownable: new owner is the zero address");
+ _setOwner(newOwner);
+ }
+
+ function _setOwner(address newOwner) private {
+ address oldOwner = _owner;
+ _owner = newOwner;
+ emit OwnershipTransferred(oldOwner, newOwner);
+ }
+}
+
+pragma solidity >=0.7.0 <0.9.0;
+
+contract StrongElvesClub is ERC721Enumerable, Ownable {
using Strings for uint256;
string baseURI;
string public baseExtension = ".json";
- uint256 public cost = 0.05 ether;
+ uint256 public cost = 0.006 ether;
uint256 public maxSupply = 10000;
- uint256 public maxMintAmount = 20;
- bool public paused = false;
+ uint256 public maxMintAmount = 30;
+ bool public paused = true;
bool public revealed = false;
string public notRevealedUri;
@@ -98,15 +1316,15 @@ contract NFT is ERC721Enumerable, Ownable {
}
//only owner
- function reveal() public onlyOwner {
+ function reveal() public onlyOwner() {
revealed = true;
}
- function setCost(uint256 _newCost) public onlyOwner {
+ function setCost(uint256 _newCost) public onlyOwner() {
cost = _newCost;
}
- function setmaxMintAmount(uint256 _newmaxMintAmount) public onlyOwner {
+ function setmaxMintAmount(uint256 _newmaxMintAmount) public onlyOwner() {
maxMintAmount = _newmaxMintAmount;
}
@@ -127,18 +1345,7 @@ contract NFT is ERC721Enumerable, Ownable {
}
function withdraw() public payable onlyOwner {
- // This will pay HashLips 5% of the initial sale.
- // You can remove this if you want, or keep it in to support HashLips and his channel.
- // =============================================================================
- (bool hs, ) = payable(0x943590A42C27D08e3744202c4Ae5eD55c2dE240D).call{value: address(this).balance * 5 / 100}("");
- require(hs);
- // =============================================================================
-
- // This will payout the owner 95% of the contract balance.
- // Do not remove this otherwise you will not be able to withdraw the funds.
- // =============================================================================
- (bool os, ) = payable(owner()).call{value: address(this).balance}("");
- require(os);
- // =============================================================================
+ (bool success, ) = payable(msg.sender).call{value: address(this).balance}("");
+ require(success);
}
}