Contract Name:
OnChainKevin
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "./OnChainKevinLib.sol";
import "./interfaces/IOnChainKevinRenderer.sol";
// ______ __ __ ______ __ __ ______ __ __ __ __ __ ______ __ __ __ __ __
// /\ __ \ /\ "-.\ \ /\ ___\ /\ \_\ \ /\ __ \ /\ \ /\ "-.\ \ /\ \/ / /\ ___\ /\ \ / / /\ \ /\ "-.\ \
// \ \ \/\ \ \ \ \-. \ \ \ \____ \ \ __ \ \ \ __ \ \ \ \ \ \ \-. \ \ \ _"-. \ \ __\ \ \ \'/ \ \ \ \ \ \-. \
// \ \_____\ \ \_\\"\_\ \ \_____\ \ \_\ \_\ \ \_\ \_\ \ \_\ \ \_\\"\_\ \ \_\ \_\ \ \_____\ \ \__| \ \_\ \ \_\\"\_\
// \/_____/ \/_/ \/_/ \/_____/ \/_/\/_/ \/_/\/_/ \/_/ \/_/ \/_/ \/_/\/_/ \/_____/ \/_/ \/_/ \/_/ \/_/
contract OnChainKevin is ERC721Enumerable, ReentrancyGuard {
using OnChainKevinLib for uint8;
using Counters for Counters.Counter;
Counters.Counter private tokenIds;
mapping(string => bool) internal hashToMinted;
mapping(uint256 => string) internal _tokenIdToHash;
mapping(address => uint256) public addressMintedCounts;
address public renderingContractAddress;
//uint256s
uint256 SEED_NONCE = 0;
uint256 private constant MAX_KEVINS = 2000;
uint256 private constant V1_FOUNDER_KEVINS = 50;
uint256 private constant MAX_PUBLIC_MINT = MAX_KEVINS - V1_FOUNDER_KEVINS;
uint256 private constant NUM_LAYERS = 9;
string[] private TRAIT_INDEX_NAME = [
"Lasers",
"Head Accessory",
"Mouth",
"Face Accessory",
"Eyes",
"Nose",
"Shirt",
"Skin",
"Background"
];
string public baseURI = "https://onchainkevin.com/api/v3/";
uint256 internal v1PublicKevins = 519;
uint256 internal maxPerAddress = 5;
uint16[][NUM_LAYERS] private TIERS;
bool public isMintingPaused = true;
address _owner;
constructor() ERC721("OnChainKevin", "DERP") {
_owner = msg.sender;
// *SHOUTOUT* to Anonymice and Chain Runners for the inspiration.
//Lasers
TIERS[0] = [2, 5, 10, 30, 40, 50, 1863];
//Head Accessory
TIERS[1] = [10, 15, 20, 35, 50, 60, 65, 70, 75, 80, 90, 95, 150, 170, 180, 190, 200, 215, 230];
//Mouth
TIERS[2] = [40, 80, 100, 120, 160, 200, 250, 300, 350, 400];
//Face Accessory
TIERS[3] = [10, 15, 20, 35, 50, 60, 70, 75, 80, 110, 115, 160, 220, 230, 240, 250, 260];
//Eyes
TIERS[4] = [200, 250, 280, 290, 300, 330, 350];
//Nose
TIERS[5] = [200, 300, 400, 500, 600];
//Shirt
TIERS[6] = [40, 45, 55, 65, 80, 85, 95, 100, 110, 115, 120, 150, 220, 230, 240, 250];
//Skin
TIERS[7] = [50, 750, 1200];
//Background
TIERS[8] = [10, 80, 100, 180, 200, 210, 220, 230, 240, 260, 270];
}
modifier whenPublicMintActive() {
require(isPublicMintActive(), "Public sale not open");
_;
}
/*
__ __ _ _ _ ___ _ _
| \/ (_)_ _| |_(_)_ _ __ _ | __| _ _ _ __| |_(_)___ _ _ ___
| |\/| | | ' \ _| | ' \/ _` | | _| || | ' \/ _| _| / _ \ ' \(_-<
|_| |_|_|_||_\__|_|_||_\__, | |_| \_,_|_||_\__|\__|_\___/_||_/__/
|___/
*/
function rarityGen(uint256 _randinput, uint8 _rarityTier)
internal
view
returns (uint8)
{
uint16 currentLowerBound = 0;
for (uint8 i = 0; i < TIERS[_rarityTier].length; i++) {
uint16 thisPercentage = TIERS[_rarityTier][i];
if (
_randinput >= currentLowerBound &&
_randinput < currentLowerBound + thisPercentage
) return i;
currentLowerBound = currentLowerBound + thisPercentage;
}
revert();
}
function hash(
uint256 _t,
address _a,
uint256 _c
) internal returns (string memory) {
require(_c < 19, "Too many layers");
// This will generate a 18 character string.
string memory currentHash = "";
for (uint8 i = 0; i < NUM_LAYERS; i++) {
SEED_NONCE++;
uint16 _randinput = uint16(
uint256(
keccak256(
abi.encodePacked(
block.timestamp,
block.difficulty,
_t,
_a,
_c,
SEED_NONCE
)
)
) % MAX_KEVINS
);
uint8 rarity = rarityGen(_randinput, i);
if (rarity < 10) {
currentHash = string(
abi.encodePacked(currentHash, "0", rarity)
);
} else {
currentHash = string(
abi.encodePacked(currentHash, rarity)
);
}
}
if (hashToMinted[currentHash]) return hash(_t, _a, _c + 1);
return currentHash;
}
function mint(uint256 tokenId) internal {
_tokenIdToHash[tokenId] = hash(tokenId, msg.sender, 0);
hashToMinted[_tokenIdToHash[tokenId]] = true;
_safeMint(msg.sender, tokenId);
}
function mintKevin(uint256 _count) external whenPublicMintActive returns (uint256, uint256) {
require(_count > 0, "Invalid Kevin count");
require(tokenIds.current() + v1PublicKevins + _count <= MAX_PUBLIC_MINT, "All OnChainKevins are gone");
uint256 userMintedAmount = addressMintedCounts[msg.sender] + _count;
require(userMintedAmount <= maxPerAddress, "Exceeded max mints allowed.");
uint256 firstMintedId = tokenIds.current() + v1PublicKevins + 1;
for (uint256 i = 0; i < _count; i++) {
tokenIds.increment();
mint(tokenIds.current() + v1PublicKevins);
}
addressMintedCounts[msg.sender] = userMintedAmount;
return (firstMintedId, _count);
}
/*
____ ___ ____ ___ _____ __ __ ____ __ ______ ____ ___ ____ _____
| \ / _] / || \ | || | || \ / ] || |/ \ | \ / ___/
| D ) / [_ | o || \ | __|| | || _ | / /| | | || || _ ( \_
| / | _]| || D | | |_ | | || | |/ / |_| |_| | || O || | |\__ |
| \ | [_ | _ || | | _] | : || | / \_ | | | || || | |/ \ |
| . \| || | || | | | | || | \ | | | | || || | |\ |
|__|\_||_____||__|__||_____| |__| \__,_||__|__|\____| |__| |____|\___/ |__|__| \___|
*/
function isPublicMintActive() public view returns (bool) {
return tokenIds.current() + v1PublicKevins + V1_FOUNDER_KEVINS < MAX_PUBLIC_MINT && isMintingPaused == false;
}
function hashToSVG(string memory _hash)
public
view
returns (string memory)
{
if (renderingContractAddress == address(0)) {
return '';
}
IOnChainKevinRenderer renderer = IOnChainKevinRenderer(renderingContractAddress);
return renderer.hashToSVG(_hash);
}
function hashToMetadata(string memory _hash)
public
view
returns (string memory)
{
if (renderingContractAddress == address(0)) {
return '';
}
IOnChainKevinRenderer renderer = IOnChainKevinRenderer(renderingContractAddress);
return renderer.hashToMetadata(_hash);
}
function tokenURI(uint256 _tokenId)
public
view
override
returns (string memory)
{
require(_exists(_tokenId), "Invalid token");
if (_tokenId > v1PublicKevins && _tokenId <= MAX_KEVINS - V1_FOUNDER_KEVINS) {
return string(abi.encodePacked(baseURI, OnChainKevinLib.toString(_tokenId), "?dna=", _tokenIdToHash[_tokenId]));
}
if (renderingContractAddress == address(0)) {
return '';
}
IOnChainKevinRenderer renderer = IOnChainKevinRenderer(renderingContractAddress);
return string(abi.encodePacked(baseURI, OnChainKevinLib.toString(_tokenId), "?dna=", renderer._tokenIdToHash(_tokenId)));
}
function tokenIdToHash(uint256 _tokenId)
public
view
returns (string memory)
{
if (_tokenId > v1PublicKevins && _tokenId <= MAX_KEVINS - V1_FOUNDER_KEVINS) {
return _tokenIdToHash[_tokenId];
}
if (renderingContractAddress == address(0)) {
return '';
}
IOnChainKevinRenderer renderer = IOnChainKevinRenderer(renderingContractAddress);
return renderer._tokenIdToHash(_tokenId);
}
function walletOfOwner(address _wallet)
public
view
returns (uint256[] memory)
{
uint256 tokenCount = balanceOf(_wallet);
uint256[] memory tokensId = new uint256[](tokenCount);
for (uint256 i; i < tokenCount; i++) {
tokensId[i] = tokenOfOwnerByIndex(_wallet, i);
}
return tokensId;
}
/*
___ __ __ ____ ___ ____ _____ __ __ ____ __ ______ ____ ___ ____ _____
/ \ | |__| || \ / _]| \ | || | || \ / ] || |/ \ | \ / ___/
| || | | || _ | / [_ | D ) | __|| | || _ | / /| | | || || _ ( \_
| O || | | || | || _]| / | |_ | | || | |/ / |_| |_| | || O || | |\__ |
| || ` ' || | || [_ | \ | _] | : || | / \_ | | | || || | |/ \ |
| | \ / | | || || . \ | | | || | \ | | | | || || | |\ |
\___/ \_/\_/ |__|__||_____||__|\_| |__| \__,_||__|__|\____| |__| |____|\___/ |__|__| \___|
*/
function setRenderingContractAddress(address _renderingContractAddress) external onlyOwner {
renderingContractAddress = _renderingContractAddress;
}
function changeMaxPerAddress(uint256 _maxPerAddress) external onlyOwner {
maxPerAddress = _maxPerAddress;
}
function changeBaseURI(string memory _baseURI) external onlyOwner {
baseURI = _baseURI;
}
function changeV1PublicKevins(uint256 _v1PublicKevins) external onlyOwner {
v1PublicKevins = _v1PublicKevins;
}
function airdropKevins(address[] memory _to, uint256[] memory _tokenIds, string[] memory _hashes)
external
onlyOwner
returns (uint256) {
uint256 length = _to.length;
for (uint256 i = 0; i < length; i++) {
hashToMinted[_hashes[i]] = true;
_mint(_to[i], _tokenIds[i]);
}
return length;
}
function toggleMinting() external onlyOwner {
isMintingPaused = !isMintingPaused;
}
function transferOwnership(address _newOwner) external onlyOwner {
_owner = _newOwner;
}
modifier onlyOwner() {
require(_owner == msg.sender);
_;
}
function withdraw() external onlyOwner nonReentrant {
(bool success,) = msg.sender.call{value : address(this).balance}('');
require(success, "Withdrawal failed");
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.12;
interface IOnChainKevinRenderer {
function _tokenIdToHash(uint256 tokenId) external view returns (string memory);
function hashToSVG(string memory _hash) external view returns (string memory);
function hashToMetadata(string memory _hash) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;
library OnChainKevinLib {
string internal constant TABLE =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
function encode(bytes memory data) internal pure returns (string memory) {
if (data.length == 0) return "";
// load the table into memory
string memory table = TABLE;
// multiply by 4/3 rounded up
uint256 encodedLen = 4 * ((data.length + 2) / 3);
// add some extra buffer at the end required for the writing
string memory result = new string(encodedLen + 32);
assembly {
// set the actual output length
mstore(result, encodedLen)
// prepare the lookup table
let tablePtr := add(table, 1)
// input ptr
let dataPtr := data
let endPtr := add(dataPtr, mload(data))
// result ptr, jump over length
let resultPtr := add(result, 32)
// run over the input, 3 bytes at a time
for {
} lt(dataPtr, endPtr) {
} {
dataPtr := add(dataPtr, 3)
// read 3 bytes
let input := mload(dataPtr)
// write 4 characters
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
)
resultPtr := add(resultPtr, 1)
mstore(
resultPtr,
shl(248, mload(add(tablePtr, and(input, 0x3F))))
)
resultPtr := add(resultPtr, 1)
}
// padding with '='
switch mod(mload(data), 3)
case 1 {
mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
}
case 2 {
mstore(sub(resultPtr, 1), shl(248, 0x3d))
}
}
return result;
}
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
function parseInt(string memory _a)
internal
pure
returns (uint8 _parsedInt)
{
bytes memory bresult = bytes(_a);
uint8 mint = 0;
for (uint8 i = 0; i < bresult.length; i++) {
if (
(uint8(uint8(bresult[i])) >= 48) &&
(uint8(uint8(bresult[i])) <= 57)
) {
mint *= 10;
mint += uint8(bresult[i]) - 48;
}
}
return mint;
}
function _substring(
string memory str,
uint256 startIndex,
uint256 endIndex
) internal pure returns (string memory) {
bytes memory strBytes = bytes(str);
bytes memory result = new bytes(endIndex - startIndex);
for (uint256 i = startIndex; i < endIndex; i++) {
result[i - startIndex] = strBytes[i];
}
return string(result);
}
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
pragma solidity ^0.8.0;
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
function reset(Counter storage counter) internal {
counter._value = 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making 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;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../ERC721.sol";
import "./IERC721Enumerable.sol";
/**
* @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();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (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 {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// 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);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (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);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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);
}