Transaction Hash:
Block:
19677029 at Apr-17-2024 06:37:35 PM +UTC
Transaction Fee:
0.00049144797726557 ETH
$1.20
Gas Used:
24,322 Gas / 20.205903185 Gwei
Emitted Events:
237 |
KumaVerse.ApprovalForAll( owner=[Sender] 0xc0e447582f03e9388c7003b7d48ebb8bea45416d, operator=0x482016a6...d6D67a90d, approved=False )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x4838B106...B0BAD5f97
Miner
| (Titan Builder) | 5.299412988983042131 Eth | 5.299413342020763651 Eth | 0.00000035303772152 | |
0x6CC8e06D...4FD67f3e4 | |||||
0xC0E44758...BEa45416D |
0.015115468087905784 Eth
Nonce: 257
|
0.014624020110640214 Eth
Nonce: 258
| 0.00049144797726557 |
Execution Trace
KumaVerse.setApprovalForAll( operator=0x482016a669AeE5D62A61808787F4e50d6D67a90d, approved=False )
setApprovalForAll[ERC721ACustom (ln:549)]
_msgSender[ERC721ACustom (ln:550)]
ApproveToCaller[ERC721ACustom (ln:550)]
_msgSender[ERC721ACustom (ln:551)]
ApprovalForAll[ERC721ACustom (ln:552)]
_msgSender[ERC721ACustom (ln:552)]
// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "@openzeppelin/contracts/access/Ownable.sol"; import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol"; import "./ERC721ACustom.sol"; import '@openzeppelin/contracts/token/ERC1155/IERC1155.sol'; import "./Interfaces.sol"; /// @title Kumaverse NFT contract /// @author agonist (https://github.com/agonist) contract KumaVerse is ERC721ACustom, Ownable { struct KumaHistory { string name; string lore; } uint256 public immutable maxSupply; uint256 public maxMintAtOnce; uint256 public maxMintWhitelist; uint256 public price = 0.05 ether; uint256 public changeLorePrice = 10 ** 18; bool public trackerSaleActive; bool public presaleActive; bool public saleActive; string public baseTokenURI; bytes32 public whitelistMerkleRoot = 0x0; bool private ancestorUnlocked; mapping(address => uint256) public claimed; mapping(address => uint256) public claimedTracker; mapping(address => bool) public trackerFreeClaimed; mapping(uint256 => KumaHistory) public kumaHistories; IERC1155 trackerContract; IPaw pawContract; constructor( string memory name_, string memory symbol_, string memory baseTokenURI_, uint256 maxSupply_, uint256 maxMintAtOnce_, uint256 maxMintWhitelist_, address trackerContract_ ) ERC721ACustom(name_, symbol_){ baseTokenURI = baseTokenURI_; maxSupply = maxSupply_; maxMintAtOnce = maxMintAtOnce_; maxMintWhitelist = maxMintWhitelist_; trackerContract = IERC1155(trackerContract_); } function mint( uint256 _quantity ) external payable { require(saleActive, "Sale inactive"); require(totalSupply() + _quantity <= maxSupply, "Mint exceed max supply"); require(_quantity <= maxMintAtOnce, "Max mint exceeded"); require(price * _quantity == msg.value, "Value sent is incorrect"); _safeMint(msg.sender, _quantity); pawContract.updateReward(msg.sender); } function mintPresale(uint256 _quantity, bytes32[] calldata _merkleProof) external payable { require(presaleActive, "Presale inactive"); require(totalSupply() + _quantity <= maxSupply, "Mint exceed max supply"); bytes32 leaf = keccak256(abi.encodePacked(msg.sender)); require(MerkleProof.verify(_merkleProof, whitelistMerkleRoot, leaf), "Not whitelisted"); require(claimed[msg.sender] + _quantity <= maxMintWhitelist, "Whitelist mint exceeded"); require(price * _quantity == msg.value, "Value sent is incorrect"); claimed[msg.sender] += _quantity; _safeMint(msg.sender, _quantity); pawContract.updateReward(msg.sender); } function mintTracker(uint256 _quantity) external payable { require(trackerSaleActive, "TrackerSale inactive"); require(totalSupply() + _quantity <= maxSupply, "Mint exceed max supply"); uint256 trackerBalance = trackerContract.balanceOf(msg.sender, 1); require(trackerBalance > 0, "You don't own a tracker"); require(claimedTracker[msg.sender] + _quantity <= trackerBalance * 2, "Tracker mint exceeded"); require(price * _quantity == msg.value, "Value sent is incorrect"); uint256 trackerExtra = 0; if (trackerBalance > 0) { if (!trackerFreeClaimed[msg.sender]) { trackerExtra += trackerBalance; trackerFreeClaimed[msg.sender] = true; } } claimedTracker[msg.sender] += _quantity; _safeMint(msg.sender, _quantity + trackerExtra); pawContract.updateReward(msg.sender); } function claimFreeKuma() external { require(trackerSaleActive, "TrackerSale inactive"); require(!trackerFreeClaimed[msg.sender], "Already claimed"); uint256 trackerBalance = trackerContract.balanceOf(msg.sender, 1); require(trackerBalance > 0, "You don't own a tracker"); require(totalSupply() + trackerBalance <= maxSupply, "Mint exceed max supply"); trackerFreeClaimed[msg.sender] = true; _safeMint(msg.sender, trackerBalance); pawContract.updateReward(msg.sender); } /// @notice Check if someone is whitelisted function isWhitelisted(bytes32[] calldata _merkleProof, address _address) external view returns (bool) { bytes32 leaf = keccak256(abi.encodePacked(_address)); return MerkleProof.verify(_merkleProof, whitelistMerkleRoot, leaf); } function changeLore(uint256 _id, string calldata _lore) external { require(this.ownerOf(_id) == msg.sender, "You are not the owner"); require(pawContract.transferFrom(msg.sender, address(this), changeLorePrice), "PAW transfer failed"); kumaHistories[_id].lore = _lore; } function renameKuma(uint256 _id, string calldata _newName) external { require(this.ownerOf(_id) == msg.sender, "You are not the owner"); require(pawContract.transferFrom(msg.sender, address(this), changeLorePrice), "PAW transfer failed"); kumaHistories[_id].name = _newName; } function updateHistory(uint256 _id, string calldata _newName, string calldata _lore) external { require(this.ownerOf(_id) == msg.sender, "You are not the owner"); require(pawContract.transferFrom(msg.sender, address(this), changeLorePrice * 2), "PAW transfer failed"); kumaHistories[_id] = KumaHistory(_newName, _lore); } // ADMIN /// @notice mint 10 extra NFTs that are the Ancestors that will be auctioned by the project. /// to use only after soldout function unlockAncestors() external onlyOwner { require(!ancestorUnlocked, "Ancestor already unlocked"); _safeMint(msg.sender, 10); pawContract.updateReward(msg.sender); ancestorUnlocked = true; } function toggleSale() external onlyOwner { saleActive = !saleActive; } function togglePresale() external onlyOwner { presaleActive = !presaleActive; } function toggleTrackerSale() external onlyOwner { trackerSaleActive = !trackerSaleActive; } /// @notice for marketing / team /// @param _quantity Amount to mint function reserve(uint256 _quantity) external onlyOwner { require(totalSupply() + _quantity <= maxSupply, "Mint exceed max supply"); _safeMint(msg.sender, _quantity); pawContract.updateReward(msg.sender); } function _baseURI() internal view override returns (string memory) { return baseTokenURI; } function setBaseURI( string calldata _baseTokenURI ) external onlyOwner { baseTokenURI = _baseTokenURI; } function setWhitelistMerkleRoot(bytes32 _merkleRoot) external onlyOwner { whitelistMerkleRoot = _merkleRoot; } function _startTokenId() internal pure override returns (uint256) { return 1; } function _yieldTransferHook(address _from, address _to) internal { pawContract.updateReward(_from); pawContract.updateReward(_to); } function transferFrom(address from_, address to_, uint256 tokenId_) public override { _yieldTransferHook(from_, to_); _transfer(from_, to_, tokenId_); } function safeTransferFrom(address from_, address to_, uint256 tokenId_, bytes memory data_) public override { _yieldTransferHook(from_, to_); ERC721ACustom.safeTransferFrom(from_, to_, tokenId_, data_); } function setChangeLorePrice(uint256 _price) external onlyOwner { changeLorePrice = _price ** 18; } function setPaw(address _address) public onlyOwner { pawContract = IPaw(_address); } function setTracker(address _address) public onlyOwner { trackerContract = IERC1155(_address); } function withdraw() public onlyOwner { address payable to = payable(msg.sender); to.transfer(address(this).balance); } function withdrawPaw() external onlyOwner { uint256 balance = pawContract.balanceOf(address(this)); pawContract.transfer(msg.sender, balance); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/Context.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract Ownable is Context { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor() { _transferOwnership(_msgSender()); } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { require(owner() == _msgSender(), "Ownable: caller is not the owner"); _; } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol) pragma solidity ^0.8.0; /** * @dev These functions deal with verification of Merkle Trees proofs. * * The proofs can be generated using the JavaScript library * https://github.com/miguelmota/merkletreejs[merkletreejs]. * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled. * * See `test/utils/cryptography/MerkleProof.test.js` for some examples. */ library MerkleProof { /** * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree * defined by `root`. For this, a `proof` must be provided, containing * sibling hashes on the branch from the leaf to the root of the tree. Each * pair of leaves and each pair of pre-images are assumed to be sorted. */ function verify( bytes32[] memory proof, bytes32 root, bytes32 leaf ) internal pure returns (bool) { return processProof(proof, leaf) == root; } /** * @dev Returns the rebuilt hash obtained by traversing a Merklee tree up * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt * hash matches the root of the tree. When processing the proof, the pairs * of leafs & pre-images are assumed to be sorted. * * _Available since v4.4._ */ function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) { bytes32 computedHash = leaf; for (uint256 i = 0; i < proof.length; i++) { bytes32 proofElement = proof[i]; if (computedHash <= proofElement) { // Hash(current computed hash + current element of the proof) computedHash = _efficientHash(computedHash, proofElement); } else { // Hash(current element of the proof + current computed hash) computedHash = _efficientHash(proofElement, computedHash); } } return computedHash; } function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) { assembly { mstore(0x00, a) mstore(0x20, b) value := keccak256(0x00, 0x40) } } } // SPDX-License-Identifier: MIT // Creator: Chiru Labs pragma solidity ^0.8.4; import '@openzeppelin/contracts/token/ERC721/IERC721.sol'; import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol'; import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol'; import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol'; import '@openzeppelin/contracts/utils/Address.sol'; import '@openzeppelin/contracts/utils/Context.sol'; import '@openzeppelin/contracts/utils/Strings.sol'; import '@openzeppelin/contracts/utils/introspection/ERC165.sol'; error ApprovalCallerNotOwnerNorApproved(); error ApprovalQueryForNonexistentToken(); error ApproveToCaller(); error ApprovalToCurrentOwner(); error BalanceQueryForZeroAddress(); error MintedQueryForZeroAddress(); error BurnedQueryForZeroAddress(); error AuxQueryForZeroAddress(); error MintToZeroAddress(); error MintZeroQuantity(); error OwnerIndexOutOfBounds(); error OwnerQueryForNonexistentToken(); error TokenIndexOutOfBounds(); error TransferCallerNotOwnerNorApproved(); error TransferFromIncorrectOwner(); error TransferToNonERC721ReceiverImplementer(); error TransferToZeroAddress(); error URIQueryForNonexistentToken(); /** * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including * the Metadata extension. Built to optimize for lower gas during batch mints. * * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..). * * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply. * * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256). */ contract ERC721ACustom is Context, ERC165, IERC721, IERC721Metadata { using Address for address; using Strings for uint256; // Compiler will pack this into a single 256bit word. struct TokenOwnership { // The address of the owner. address addr; // Keeps track of the start time of ownership with minimal overhead for tokenomics. uint64 startTimestamp; // Whether the token has been burned. bool burned; } // Compiler will pack this into a single 256bit word. struct AddressData { // Realistically, 2**64-1 is more than enough. uint64 balance; // Keeps track of mint count with minimal overhead for tokenomics. uint64 numberMinted; // Keeps track of burn count with minimal overhead for tokenomics. uint64 numberBurned; // For miscellaneous variable(s) pertaining to the address // (e.g. number of whitelist mint slots used). // If there are multiple variables, please pack them into a uint64. uint64 aux; } // The tokenId of the next token to be minted. uint256 internal _currentIndex; // The number of tokens burned. uint256 internal _burnCounter; // 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_; _currentIndex = _startTokenId(); } /** * To change the starting tokenId, please override this function. */ function _startTokenId() internal view virtual returns (uint256) { return 0; } /** * @dev See {IERC721Enumerable-totalSupply}. * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens. */ function totalSupply() public view returns (uint256) { // Counter underflow is impossible as _burnCounter cannot be incremented // more than _currentIndex - _startTokenId() times unchecked { return _currentIndex - _burnCounter - _startTokenId(); } } /** * Returns the total amount of tokens minted in the contract. */ function _totalMinted() internal view returns (uint256) { // Counter underflow is impossible as _currentIndex does not decrement, // and it is initialized to _startTokenId() unchecked { return _currentIndex - _startTokenId(); } } /** * @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 override returns (uint256) { if (owner == address(0)) revert BalanceQueryForZeroAddress(); return uint256(_addressData[owner].balance); } /** * Returns the number of tokens minted by `owner`. */ function _numberMinted(address owner) internal view returns (uint256) { if (owner == address(0)) revert MintedQueryForZeroAddress(); return uint256(_addressData[owner].numberMinted); } /** * Returns the number of tokens burned by or on behalf of `owner`. */ function _numberBurned(address owner) internal view returns (uint256) { if (owner == address(0)) revert BurnedQueryForZeroAddress(); return uint256(_addressData[owner].numberBurned); } /** * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used). */ function _getAux(address owner) internal view returns (uint64) { if (owner == address(0)) revert AuxQueryForZeroAddress(); return _addressData[owner].aux; } /** * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used). * If there are multiple variables, please pack them into a uint64. */ function _setAux(address owner, uint64 aux) internal { if (owner == address(0)) revert AuxQueryForZeroAddress(); _addressData[owner].aux = aux; } /** * Gas spent here starts off proportional to the maximum mint batch size. * It gradually moves to O(1) as tokens get transferred around in the collection over time. */ function ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) { uint256 curr = tokenId; unchecked { if (_startTokenId() <= curr && curr < _currentIndex) { TokenOwnership memory ownership = _ownerships[curr]; if (!ownership.burned) { if (ownership.addr != address(0)) { return ownership; } // Invariant: // There will always be an ownership that has an address and is not burned // before an ownership that does not have an address and is not burned. // Hence, curr will not underflow. while (true) { curr--; ownership = _ownerships[curr]; if (ownership.addr != address(0)) { return ownership; } } } } } revert OwnerQueryForNonexistentToken(); } /** * @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) { if (!_exists(tokenId)) revert URIQueryForNonexistentToken(); 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 = ERC721ACustom.ownerOf(tokenId); if (to == owner) revert ApprovalToCurrentOwner(); if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) { revert ApprovalCallerNotOwnerNorApproved(); } _approve(to, tokenId, owner); } /** * @dev See {IERC721-getApproved}. */ function getApproved(uint256 tokenId) public view override returns (address) { if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken(); return _tokenApprovals[tokenId]; } /** * @dev See {IERC721-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public override { if (operator == _msgSender()) revert ApproveToCaller(); _operatorApprovals[_msgSender()][operator] = approved; emit ApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC721-isApprovedForAll}. */ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { return _operatorApprovals[owner][operator]; } /** * @dev See {IERC721-transferFrom}. */ function transferFrom( address from, address to, uint256 tokenId ) public virtual override { _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 { _transfer(from, to, tokenId); if (to.isContract() && !_checkContractOnERC721Received(from, to, tokenId, _data)) { revert TransferToNonERC721ReceiverImplementer(); } } /** * @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 _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned; } function _safeMint(address to, uint256 quantity) internal { _safeMint(to, quantity, ''); } /** * @dev Safely mints `quantity` tokens and transfers them to `to`. * * Requirements: * * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer. * - `quantity` must be greater than 0. * * Emits a {Transfer} event. */ function _safeMint( address to, uint256 quantity, bytes memory _data ) internal { _mint(to, quantity, _data, true); } /** * @dev Mints `quantity` tokens and transfers them to `to`. * * Requirements: * * - `to` cannot be the zero address. * - `quantity` must be greater than 0. * * Emits a {Transfer} event. */ function _mint( address to, uint256 quantity, bytes memory _data, bool safe ) internal { uint256 startTokenId = _currentIndex; if (to == address(0)) revert MintToZeroAddress(); if (quantity == 0) revert MintZeroQuantity(); _beforeTokenTransfers(address(0), to, startTokenId, quantity); // Overflows are incredibly unrealistic. // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1 // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1 unchecked { _addressData[to].balance += uint64(quantity); _addressData[to].numberMinted += uint64(quantity); _ownerships[startTokenId].addr = to; _ownerships[startTokenId].startTimestamp = uint64(block.timestamp); uint256 updatedIndex = startTokenId; uint256 end = updatedIndex + quantity; if (safe && to.isContract()) { do { emit Transfer(address(0), to, updatedIndex); if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) { revert TransferToNonERC721ReceiverImplementer(); } } while (updatedIndex != end); // Reentrancy protection if (_currentIndex != startTokenId) revert(); } else { do { emit Transfer(address(0), to, updatedIndex++); } while (updatedIndex != end); } _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 ) internal { TokenOwnership memory prevOwnership = ownershipOf(tokenId); bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr || isApprovedForAll(prevOwnership.addr, _msgSender()) || getApproved(tokenId) == _msgSender()); if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved(); if (prevOwnership.addr != from) revert TransferFromIncorrectOwner(); if (to == address(0)) revert TransferToZeroAddress(); _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. // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256. unchecked { _addressData[from].balance -= 1; _addressData[to].balance += 1; _ownerships[tokenId].addr = to; _ownerships[tokenId].startTimestamp = 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)) { // This will suffice for checking _exists(nextTokenId), // as a burned slot cannot contain the zero address. if (nextTokenId < _currentIndex) { _ownerships[nextTokenId].addr = prevOwnership.addr; _ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp; } } } emit Transfer(from, to, tokenId); _afterTokenTransfers(from, to, tokenId, 1); } /** * @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 { TokenOwnership memory prevOwnership = ownershipOf(tokenId); _beforeTokenTransfers(prevOwnership.addr, address(0), 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. // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256. unchecked { _addressData[prevOwnership.addr].balance -= 1; _addressData[prevOwnership.addr].numberBurned += 1; // Keep track of who burned the token, and the timestamp of burning. _ownerships[tokenId].addr = prevOwnership.addr; _ownerships[tokenId].startTimestamp = uint64(block.timestamp); _ownerships[tokenId].burned = true; // If the ownership slot of tokenId+1 is not explicitly set, that means the burn 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)) { // This will suffice for checking _exists(nextTokenId), // as a burned slot cannot contain the zero address. if (nextTokenId < _currentIndex) { _ownerships[nextTokenId].addr = prevOwnership.addr; _ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp; } } } emit Transfer(prevOwnership.addr, address(0), tokenId); _afterTokenTransfers(prevOwnership.addr, address(0), tokenId, 1); // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times. unchecked { _burnCounter++; } } /** * @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 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 _checkContractOnERC721Received( address from, address to, uint256 tokenId, bytes memory _data ) private returns (bool) { 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 TransferToNonERC721ReceiverImplementer(); } else { assembly { revert(add(32, reason), mload(reason)) } } } } /** * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting. * And also called before burning one token. * * 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`. * - When `to` is zero, `tokenId` will be burned by `from`. * - `from` and `to` are never both zero. */ 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. * And also called after one token has been burned. * * 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` has been * transferred to `to`. * - When `from` is zero, `tokenId` has been minted for `to`. * - When `to` is zero, `tokenId` has been burned by `from`. * - `from` and `to` are never both zero. */ function _afterTokenTransfers( address from, address to, uint256 startTokenId, uint256 quantity ) internal virtual {} /// @dev Returns the tokenIds of the address. O(totalSupply) in complexity. function tokensOfOwner(address owner) external view returns (uint256[] memory) { unchecked { uint256[] memory a = new uint256[](balanceOf(owner)); uint256 end = _currentIndex; uint256 tokenIdsIdx; address currOwnershipAddr; for (uint256 i; i < end; i++) { TokenOwnership memory ownership = _ownerships[i]; if (ownership.burned) { continue; } if (ownership.addr != address(0)) { currOwnershipAddr = ownership.addr; } if (currOwnershipAddr == owner) { a[tokenIdsIdx++] = i; } } return a; } } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC1155/IERC1155.sol) pragma solidity ^0.8.0; import "../../utils/introspection/IERC165.sol"; /** * @dev Required interface of an ERC1155 compliant contract, as defined in the * https://eips.ethereum.org/EIPS/eip-1155[EIP]. * * _Available since v3.1._ */ interface IERC1155 is IERC165 { /** * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`. */ event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value); /** * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all * transfers. */ event TransferBatch( address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values ); /** * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to * `approved`. */ event ApprovalForAll(address indexed account, address indexed operator, bool approved); /** * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI. * * If an {URI} event was emitted for `id`, the standard * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value * returned by {IERC1155MetadataURI-uri}. */ event URI(string value, uint256 indexed id); /** * @dev Returns the amount of tokens of token type `id` owned by `account`. * * Requirements: * * - `account` cannot be the zero address. */ function balanceOf(address account, uint256 id) external view returns (uint256); /** * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}. * * Requirements: * * - `accounts` and `ids` must have the same length. */ function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids) external view returns (uint256[] memory); /** * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`, * * Emits an {ApprovalForAll} event. * * Requirements: * * - `operator` cannot be the caller. */ function setApprovalForAll(address operator, bool approved) external; /** * @dev Returns true if `operator` is approved to transfer ``account``'s tokens. * * See {setApprovalForAll}. */ function isApprovedForAll(address account, address operator) external view returns (bool); /** * @dev Transfers `amount` tokens of token type `id` from `from` to `to`. * * Emits a {TransferSingle} event. * * Requirements: * * - `to` cannot be the zero address. * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}. * - `from` must have a balance of tokens of type `id` of at least `amount`. * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the * acceptance magic value. */ function safeTransferFrom( address from, address to, uint256 id, uint256 amount, bytes calldata data ) external; /** * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}. * * Emits a {TransferBatch} event. * * Requirements: * * - `ids` and `amounts` must have the same length. * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the * acceptance magic value. */ function safeBatchTransferFrom( address from, address to, uint256[] calldata ids, uint256[] calldata amounts, bytes calldata data ) external; } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import '@openzeppelin/contracts/token/ERC20/IERC20.sol'; import '@openzeppelin/contracts/token/ERC721/IERC721.sol'; import '@openzeppelin/contracts/token/ERC1155/IERC1155.sol'; interface IPaw is IERC20 { function updateReward(address _address) external; } interface IKumaVerse is IERC721 { } interface IKumaTracker is IERC1155 {} // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract Context { function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol) pragma solidity ^0.8.0; import "../../utils/introspection/IERC165.sol"; /** * @dev Required interface of an ERC721 compliant contract. */ interface IERC721 is IERC165 { /** * @dev Emitted when `tokenId` token is transferred from `from` to `to`. */ event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token. */ event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets. */ event ApprovalForAll(address indexed owner, address indexed operator, bool approved); /** * @dev Returns the number of tokens in ``owner``'s account. */ function balanceOf(address owner) external view returns (uint256 balance); /** * @dev Returns the owner of the `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function ownerOf(uint256 tokenId) external view returns (address owner); /** * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients * are aware of the ERC721 protocol to prevent tokens from being forever locked. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom( address from, address to, uint256 tokenId ) external; /** * @dev Transfers `tokenId` token from `from` to `to`. * * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * * Emits a {Transfer} event. */ function transferFrom( address from, address to, uint256 tokenId ) external; /** * @dev Gives permission to `to` to transfer `tokenId` token to another account. * The approval is cleared when the token is transferred. * * Only a single account can be approved at a time, so approving the zero address clears previous approvals. * * Requirements: * * - The caller must own the token or be an approved operator. * - `tokenId` must exist. * * Emits an {Approval} event. */ function approve(address to, uint256 tokenId) external; /** * @dev Returns the account approved for `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function getApproved(uint256 tokenId) external view returns (address operator); /** * @dev Approve or remove `operator` as an operator for the caller. * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller. * * Requirements: * * - The `operator` cannot be the caller. * * Emits an {ApprovalForAll} event. */ function setApprovalForAll(address operator, bool _approved) external; /** * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`. * * See {setApprovalForAll} */ function isApprovedForAll(address owner, address operator) external view returns (bool); /** * @dev Safely transfers `tokenId` token from `from` to `to`. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom( address from, address to, uint256 tokenId, bytes calldata data ) external; } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/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 (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 (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) (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 (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/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/introspection/IERC165.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the amount of tokens owned by `account`. */ function balanceOf(address account) external view returns (uint256); /** * @dev Moves `amount` tokens from the caller's account to `to`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address to, uint256 amount) external returns (bool); /** * @dev Returns the remaining number of tokens that `spender` will be * allowed to spend on behalf of `owner` through {transferFrom}. This is * zero by default. * * This value changes when {approve} or {transferFrom} are called. */ function allowance(address owner, address spender) external view returns (uint256); /** * @dev Sets `amount` as the allowance of `spender` over the caller's tokens. * * Returns a boolean value indicating whether the operation succeeded. * * IMPORTANT: Beware that changing an allowance with this method brings the risk * that someone may use both the old and the new allowance by unfortunate * transaction ordering. One possible solution to mitigate this race * condition is to first reduce the spender's allowance to 0 and set the * desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * * Emits an {Approval} event. */ function approve(address spender, uint256 amount) external returns (bool); /** * @dev Moves `amount` tokens from `from` to `to` using the * allowance mechanism. `amount` is then deducted from the caller's * allowance. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transferFrom( address from, address to, uint256 amount ) external returns (bool); /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); }