Contract Source Code:
File 1 of 1 : NFT
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
/*
* @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;
}
}
/**
* @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);
}
}
// Creator: Chiru Labs
/**
* @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;
}
/**
* @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);
}
/**
* @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);
}
/**
* @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);
}
/**
* @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);
}
function _verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) private 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);
}
}
}
}
/**
* @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;
}
}
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints.
*
* Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..).
*
* Does not support burning tokens to address(0).
*
* Assumes that an owner cannot have more than the 2**128 (max value of uint128) of supply
*/
contract ERC721A is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable {
using Address for address;
using Strings for uint256;
struct TokenOwnership {
address addr;
uint64 startTimestamp;
}
struct AddressData {
uint128 balance;
uint128 numberMinted;
}
uint256 internal currentIndex = 0;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to ownership details
// An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
mapping(uint256 => TokenOwnership) internal _ownerships;
// Mapping owner address to address data
mapping(address => AddressData) private _addressData;
// Mapping from token ID to approved address
mapping(uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view override returns (uint256) {
return currentIndex;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view override returns (uint256) {
require(index < totalSupply(), 'ERC721A: global index out of bounds');
return index;
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
* This read function is O(totalSupply). If calling from a separate contract, be sure to test gas first.
* It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view override returns (uint256) {
require(index < balanceOf(owner), 'ERC721A: owner index out of bounds');
uint256 numMintedSoFar = totalSupply();
uint256 tokenIdsIdx = 0;
address currOwnershipAddr = address(0);
for (uint256 i = 0; i < numMintedSoFar; i++) {
TokenOwnership memory ownership = _ownerships[i];
if (ownership.addr != address(0)) {
currOwnershipAddr = ownership.addr;
}
if (currOwnershipAddr == owner) {
if (tokenIdsIdx == index) {
return i;
}
tokenIdsIdx++;
}
}
revert('ERC721A: unable to get token of owner by index');
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
interfaceId == type(IERC721Enumerable).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view override returns (uint256) {
require(owner != address(0), 'ERC721A: balance query for the zero address');
return uint256(_addressData[owner].balance);
}
function _numberMinted(address owner) internal view returns (uint256) {
require(owner != address(0), 'ERC721A: number minted query for the zero address');
return uint256(_addressData[owner].numberMinted);
}
function ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
require(_exists(tokenId), 'ERC721A: owner query for nonexistent token');
for (uint256 curr = tokenId; ; curr--) {
TokenOwnership memory ownership = _ownerships[curr];
if (ownership.addr != address(0)) {
return ownership;
}
}
revert('ERC721A: unable to determine the owner of token');
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view override returns (address) {
return ownershipOf(tokenId).addr;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), 'ERC721Metadata: URI query for nonexistent token');
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
}
/**
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
* by default, can be overriden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return '';
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public override {
address owner = ERC721A.ownerOf(tokenId);
require(to != owner, 'ERC721A: approval to current owner');
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
'ERC721A: approve caller is not owner nor approved for all'
);
_approve(to, tokenId, owner);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view override returns (address) {
require(_exists(tokenId), 'ERC721A: approved query for nonexistent token');
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public override {
require(operator != _msgSender(), 'ERC721A: approve to caller');
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) public override {
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public override {
safeTransferFrom(from, to, tokenId, '');
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory _data
) public override {
_transfer(from, to, tokenId);
require(
_checkOnERC721Received(from, to, tokenId, _data),
'ERC721A: transfer to non ERC721Receiver implementer'
);
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
*/
function _exists(uint256 tokenId) internal view returns (bool) {
return tokenId < currentIndex;
}
function _safeMint(address to, uint256 quantity) internal {
_safeMint(to, quantity, '');
}
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` cannot be larger than the max batch size.
*
* Emits a {Transfer} event.
*/
function _safeMint(
address to,
uint256 quantity,
bytes memory _data
) internal {
uint256 startTokenId = currentIndex;
require(to != address(0), 'ERC721A: mint to the zero address');
// We know if the first token in the batch doesn't exist, the other ones don't as well, because of serial ordering.
require(!_exists(startTokenId), 'ERC721A: token already minted');
require(quantity > 0, 'ERC721A: quantity must be greater 0');
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
AddressData memory addressData = _addressData[to];
_addressData[to] = AddressData(
addressData.balance + uint128(quantity),
addressData.numberMinted + uint128(quantity)
);
_ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp));
uint256 updatedIndex = startTokenId;
for (uint256 i = 0; i < quantity; i++) {
emit Transfer(address(0), to, updatedIndex);
require(
_checkOnERC721Received(address(0), to, updatedIndex, _data),
'ERC721A: transfer to non ERC721Receiver implementer'
);
updatedIndex++;
}
currentIndex = updatedIndex;
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(
address from,
address to,
uint256 tokenId
) private {
TokenOwnership memory prevOwnership = ownershipOf(tokenId);
bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
getApproved(tokenId) == _msgSender() ||
isApprovedForAll(prevOwnership.addr, _msgSender()));
require(isApprovedOrOwner, 'ERC721A: transfer caller is not owner nor approved');
require(prevOwnership.addr == from, 'ERC721A: transfer from incorrect owner');
require(to != address(0), 'ERC721A: transfer to the zero address');
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner
_approve(address(0), tokenId, prevOwnership.addr);
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
unchecked {
_addressData[from].balance -= 1;
_addressData[to].balance += 1;
}
_ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp));
// If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
uint256 nextTokenId = tokenId + 1;
if (_ownerships[nextTokenId].addr == address(0)) {
if (_exists(nextTokenId)) {
_ownerships[nextTokenId] = TokenOwnership(prevOwnership.addr, prevOwnership.startTimestamp);
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/
function _approve(
address to,
uint256 tokenId,
address owner
) private {
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert('ERC721A: transfer to non ERC721Receiver implementer');
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
*/
function _beforeTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
/**
* @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
* minting.
*
* startTokenId - the first token id to be transferred
* quantity - the amount to be transferred
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero.
* - `from` and `to` are never both zero.
*/
function _afterTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
}
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
function reset(Counter storage counter) internal {
counter._value = 0;
}
}
/**
* @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);
}
}
// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.
/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler
* now has built in overflow checking.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
return a + b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
return a * b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a / b;
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
contract NFT is ERC721A, Ownable, ReentrancyGuard {
using Counters for Counters.Counter;
using SafeMath for uint256;
uint256 private _mintCost;
uint256 private _maxSupply;
bool private _isPublicMintEnabled;
uint256 private _freeSupply;
/**
* @dev Initializes the contract setting the `tokenName` and `symbol` of the nft, `cost` of each mint call, and maximum `supply` of the nft.
* Note: `cost` is in wei.
*/
constructor(string memory tokenName, string memory symbol, uint256 cost, uint256 supply) ERC721A(tokenName, symbol) Ownable() {
_mintCost = cost;
_maxSupply = supply;
_isPublicMintEnabled = false;
_freeSupply = 0;
}
/**
* @dev Changes contract state to enable public access to `mintTokens` function
* Can only be called by the current owner.
*/
function allowPublicMint()
public
onlyOwner{
_isPublicMintEnabled = true;
}
/**
* @dev Changes contract state to disable public access to `mintTokens` function
* Can only be called by the current owner.
*/
function denyPublicMint()
public
onlyOwner{
_isPublicMintEnabled = false;
}
/**
* @dev Mint `count` tokens if requirements are satisfied.
*
*/
function mintTokens(uint256 count)
public
payable
nonReentrant{
require(_isPublicMintEnabled, "Mint disabled");
require(count > 0 && count <= 100, "You can drop minimum 1, maximum 100 NFTs");
require(count.add(totalSupply()) < (_maxSupply+1), "Exceeds max supply");
require(owner() == msg.sender || msg.value >= _mintCost.mul(count),
"Ether value sent is below the price");
_mint(msg.sender, count);
}
/**
* @dev Mint a token to each Address of `recipients`.
* Can only be called if requirements are satisfied.
*/
function mintTokens(address[] calldata recipients)
public
payable
nonReentrant{
require(recipients.length>0,"Missing recipient addresses");
require(owner() == msg.sender || _isPublicMintEnabled, "Mint disabled");
require(recipients.length > 0 && recipients.length <= 100, "You can drop minimum 1, maximum 100 NFTs");
require(recipients.length.add(totalSupply()) < (_maxSupply+1), "Exceeds max supply");
require(owner() == msg.sender || msg.value >= _mintCost.mul(recipients.length),
"Ether value sent is below the price");
for(uint i=0; i<recipients.length; i++){
_mint(recipients[i], 1);
}
}
/**
* @dev Mint `count` tokens if requirements are satisfied.
*/
function freeMint(uint256 count)
public
payable
nonReentrant{
require(owner() == msg.sender || _isPublicMintEnabled, "Mint disabled");
require(totalSupply() + count <= _freeSupply, "Exceed max free supply");
require(count == 1, "Cant mint more than 1");
require(count > 0, "Must mint at least 1 token");
_safeMint(msg.sender, count);
}
/**
* @dev Update the cost to mint a token.
* Can only be called by the current owner.
*/
function setCost(uint256 cost) public onlyOwner{
_mintCost = cost;
}
/**
* @dev Update the max supply.
* Can only be called by the current owner.
*/
function setMaxSupply(uint256 max) public onlyOwner{
_maxSupply = max;
}
/**
* @dev Update the max free supply.
* Can only be called by the current owner.
*/
function setFreeSupply(uint256 max) public onlyOwner{
_freeSupply = max;
}
/**
* @dev Transfers contract balance to contract owner.
* Can only be called by the current owner.
*/
function withdraw() public onlyOwner{
payable(owner()).transfer(address(this).balance);
}
/**
* @dev Used by public mint functions and by owner functions.
* Can only be called internally by other functions.
*/
function _mint(address to, uint256 count) internal virtual returns (uint256){
_safeMint(to, count);
return count;
}
function getCost() public view returns (uint256){
return _mintCost;
}
function getMaxSupply() public view returns (uint256){
return _maxSupply;
}
function getCurrentSupply() public view returns (uint256){
return totalSupply();
}
function getMintStatus() public view returns (bool) {
return _isPublicMintEnabled;
}
function getFreeSupply() public view returns (uint256) {
return _freeSupply;
}
function _baseURI() override internal pure returns (string memory) {
return "https://mw9spidhbc.execute-api.us-east-1.amazonaws.com/dev/token/sekushi-girls/";
}
function contractURI() public pure returns (string memory) {
return "https://mw9spidhbc.execute-api.us-east-1.amazonaws.com/dev/contract/sekushi-girls";
}
}