Transaction Hash:
Block:
14819975 at May-21-2022 11:00:14 PM +UTC
Transaction Fee:
0.000908772492555408 ETH
$2.26
Gas Used:
46,171 Gas / 19.682755248 Gwei
Emitted Events:
40 |
BaoSociety.ApprovalForAll( owner=[Sender] 0x8a1681d693ef30ca9c330ab5b5e52c2174e83a6b, operator=0x51D7e371...fece53540, approved=True )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x8A1681d6...174e83a6B |
0.244597085912653671 Eth
Nonce: 62
|
0.243688313420098263 Eth
Nonce: 63
| 0.000908772492555408 | ||
0xba033D82...5dfE6e706 | |||||
0xEA674fdD...16B898ec8
Miner
| (Ethermine) | 1,352.90150301308178833 Eth | 1,352.90157226958178833 Eth | 0.0000692565 |
Execution Trace
BaoSociety.setApprovalForAll( operator=0x51D7e3713Dc5eB06974A93C1F755724fece53540, approved=True )
//SPDX-License-Identifier: MIT pragma solidity ^0.8.13; import '@openzeppelin/contracts/token/ERC20/IERC20.sol'; import '@openzeppelin/contracts/access/Ownable.sol'; import '@openzeppelin/contracts/utils/cryptography/ECDSA.sol'; import {VRFBaseMainnet as VRFBase} from './VRFBase.sol'; import './ERC721A.sol'; error PublicSaleNotActive(); error ExceedsLimit(); error SignatureExceedsLimit(); error IncorrectValue(); error InvalidSignature(); error ContractCallNotAllowed(); contract BaoSociety is ERC721A, Ownable, VRFBase { using ECDSA for bytes32; using Strings for uint256; event SaleStateUpdate(); bool public publicSaleActive; string public baseURI; string private unrevealedURI = 'ipfs://QmRuQYxmdzqfVfy8ZhZNTvXsmbN9yLnBFPDeczFvWUS2HU/'; uint256 constant MAX_SUPPLY = 3888; uint256 constant MAX_PER_WALLET = 20; uint256 constant price = 0.0888 ether; uint256 constant PURCHASE_LIMIT = 10; uint256 constant whitelistPrice = 0.0777 ether; uint256 constant WHITELIST_PURCHASE_LIMIT = 10; address public signerAddress = 0x63B14a4D433d9ed70176cF7ed1f322790F0d5F89; address public treasuryAddress = 0x69D8004d527d72eFe1a4d5eECFf4A7f38f5b2B69; constructor() ERC721A('BaoSociety', 'BAOSOC', MAX_SUPPLY, 1, MAX_PER_WALLET) {} /* ------------- External ------------- */ function mint(uint256 amount) external payable noContract { if (!publicSaleActive) revert PublicSaleNotActive(); if (PURCHASE_LIMIT < amount) revert ExceedsLimit(); if (msg.value != price * amount) revert IncorrectValue(); _mint(msg.sender, amount); } function whitelistMint( uint256 amount, uint256 limit, bytes calldata signature ) external payable noContract { if (!validSignature(signature, limit)) revert InvalidSignature(); if (WHITELIST_PURCHASE_LIMIT < limit) revert SignatureExceedsLimit(); if (msg.value != whitelistPrice * amount) revert IncorrectValue(); uint256 numMinted = numMinted(msg.sender); if (numMinted + amount > limit) revert ExceedsLimit(); _mint(msg.sender, amount); } /* ------------- Private ------------- */ function validSignature(bytes memory signature, uint256 limit) private view returns (bool) { bytes32 msgHash = keccak256(abi.encode(address(this), msg.sender, limit)); return msgHash.toEthSignedMessageHash().recover(signature) == signerAddress; } /* ------------- Owner ------------- */ function setPublicSaleActive(bool active) external onlyOwner { publicSaleActive = active; emit SaleStateUpdate(); } function giveAway(address[] calldata users, uint256[] calldata amounts) external onlyOwner { for (uint256 i; i < users.length; i++) _mint(users[i], amounts[i]); } function setBaseURI(string calldata _baseURI) external onlyOwner { baseURI = _baseURI; } function setUnrevealedURI(string calldata _uri) external onlyOwner { unrevealedURI = _uri; } function setSignerAddress(address _address) external onlyOwner { signerAddress = _address; } function withdraw() external onlyOwner { uint256 balance = address(this).balance; payable(treasuryAddress).transfer(balance); } function recoverToken(IERC20 token) external onlyOwner { uint256 balance = token.balanceOf(address(this)); token.transfer(treasuryAddress, balance); } /* ------------- Modifier ------------- */ modifier noContract() { if (tx.origin != msg.sender) revert ContractCallNotAllowed(); _; } /* ------------- ERC721 ------------- */ function tokenURI(uint256 tokenId) public view override returns (string memory) { if (!_exists(tokenId)) revert QueryForNonexistentToken(); if (bytes(baseURI).length == 0 || !randomSeedSet()) return string.concat(unrevealedURI, tokenId.toString(), '.json'); uint256 metadataId = _getShiftedId(tokenId, startingIndex(), MAX_SUPPLY); return string.concat(baseURI, metadataId.toString(), '.json'); } } // 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); } // 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/ECDSA.sol) pragma solidity ^0.8.0; import "../Strings.sol"; /** * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations. * * These functions can be used to verify that a message was signed by the holder * of the private keys of a given address. */ library ECDSA { enum RecoverError { NoError, InvalidSignature, InvalidSignatureLength, InvalidSignatureS, InvalidSignatureV } function _throwError(RecoverError error) private pure { if (error == RecoverError.NoError) { return; // no error: do nothing } else if (error == RecoverError.InvalidSignature) { revert("ECDSA: invalid signature"); } else if (error == RecoverError.InvalidSignatureLength) { revert("ECDSA: invalid signature length"); } else if (error == RecoverError.InvalidSignatureS) { revert("ECDSA: invalid signature 's' value"); } else if (error == RecoverError.InvalidSignatureV) { revert("ECDSA: invalid signature 'v' value"); } } /** * @dev Returns the address that signed a hashed message (`hash`) with * `signature` or error string. This address can then be used for verification purposes. * * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures: * this function rejects them by requiring the `s` value to be in the lower * half order, and the `v` value to be either 27 or 28. * * IMPORTANT: `hash` _must_ be the result of a hash operation for the * verification to be secure: it is possible to craft signatures that * recover to arbitrary addresses for non-hashed data. A safe way to ensure * this is by receiving a hash of the original message (which may otherwise * be too long), and then calling {toEthSignedMessageHash} on it. * * Documentation for signature generation: * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js] * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers] * * _Available since v4.3._ */ function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) { // Check the signature length // - case 65: r,s,v signature (standard) // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._ if (signature.length == 65) { bytes32 r; bytes32 s; uint8 v; // ecrecover takes the signature parameters, and the only way to get them // currently is to use assembly. assembly { r := mload(add(signature, 0x20)) s := mload(add(signature, 0x40)) v := byte(0, mload(add(signature, 0x60))) } return tryRecover(hash, v, r, s); } else if (signature.length == 64) { bytes32 r; bytes32 vs; // ecrecover takes the signature parameters, and the only way to get them // currently is to use assembly. assembly { r := mload(add(signature, 0x20)) vs := mload(add(signature, 0x40)) } return tryRecover(hash, r, vs); } else { return (address(0), RecoverError.InvalidSignatureLength); } } /** * @dev Returns the address that signed a hashed message (`hash`) with * `signature`. This address can then be used for verification purposes. * * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures: * this function rejects them by requiring the `s` value to be in the lower * half order, and the `v` value to be either 27 or 28. * * IMPORTANT: `hash` _must_ be the result of a hash operation for the * verification to be secure: it is possible to craft signatures that * recover to arbitrary addresses for non-hashed data. A safe way to ensure * this is by receiving a hash of the original message (which may otherwise * be too long), and then calling {toEthSignedMessageHash} on it. */ function recover(bytes32 hash, bytes memory signature) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, signature); _throwError(error); return recovered; } /** * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately. * * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures] * * _Available since v4.3._ */ function tryRecover( bytes32 hash, bytes32 r, bytes32 vs ) internal pure returns (address, RecoverError) { bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff); uint8 v = uint8((uint256(vs) >> 255) + 27); return tryRecover(hash, v, r, s); } /** * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately. * * _Available since v4.2._ */ function recover( bytes32 hash, bytes32 r, bytes32 vs ) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, r, vs); _throwError(error); return recovered; } /** * @dev Overload of {ECDSA-tryRecover} that receives the `v`, * `r` and `s` signature fields separately. * * _Available since v4.3._ */ function tryRecover( bytes32 hash, uint8 v, bytes32 r, bytes32 s ) internal pure returns (address, RecoverError) { // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most // signatures from current libraries generate a unique signature with an s-value in the lower half order. // // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept // these malleable signatures as well. if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) { return (address(0), RecoverError.InvalidSignatureS); } if (v != 27 && v != 28) { return (address(0), RecoverError.InvalidSignatureV); } // If the signature is valid (and not malleable), return the signer address address signer = ecrecover(hash, v, r, s); if (signer == address(0)) { return (address(0), RecoverError.InvalidSignature); } return (signer, RecoverError.NoError); } /** * @dev Overload of {ECDSA-recover} that receives the `v`, * `r` and `s` signature fields separately. */ function recover( bytes32 hash, uint8 v, bytes32 r, bytes32 s ) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, v, r, s); _throwError(error); return recovered; } /** * @dev Returns an Ethereum Signed Message, created from a `hash`. This * produces hash corresponding to the one signed with the * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] * JSON-RPC method as part of EIP-191. * * See {recover}. */ function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) { // 32 is the length in bytes of hash, // enforced by the type signature above return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\ 32", hash)); } /** * @dev Returns an Ethereum Signed Message, created from `s`. This * produces hash corresponding to the one signed with the * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] * JSON-RPC method as part of EIP-191. * * See {recover}. */ function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) { return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\ ", Strings.toString(s.length), s)); } /** * @dev Returns an Ethereum Signed Typed Data, created from a * `domainSeparator` and a `structHash`. This produces hash corresponding * to the one signed with the * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] * JSON-RPC method as part of EIP-712. * * See {recover}. */ function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) { return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash)); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import '@chainlink/contracts/src/v0.8/VRFConsumerBase.sol'; import '@openzeppelin/contracts/access/Ownable.sol'; error RandomSeedNotSet(); error RandomSeedAlreadySet(); contract VRFBase is VRFConsumerBase, Ownable { bytes32 private immutable keyHash; uint256 private immutable fee; uint256 private constant ceilGap = 100_000; uint256 public randomSeed; constructor( bytes32 keyHash_, uint256 fee_, address vrfCoordinator_, address link_ ) VRFConsumerBase(vrfCoordinator_, link_) { keyHash = keyHash_; fee = fee_; } /* ------------- External ------------- */ function requestRandomSeed() external virtual onlyOwner whenRandomSeedUnset { requestRandomness(keyHash, fee); } // this function should not be needed and is just an emergency fail-safe if // for some reason chainlink is not able to fulfill the randomness callback function forceFulfillRandomness() external virtual onlyOwner whenRandomSeedUnset { uint256 randomNumber = uint256(blockhash(block.number - 1)); setRandomSeed(randomNumber); } /* ------------- Internal ------------- */ function fulfillRandomness(bytes32, uint256 randomNumber) internal virtual override { setRandomSeed(randomNumber); } function _getShiftedId( uint256 index, uint256 startId, uint256 n ) internal view returns (uint256) { return startId + ((randomSeed + index) % n); } function setRandomSeed(uint256 randomNumber) private { randomSeed = (randomNumber > type(uint256).max - ceilGap) ? randomNumber - ceilGap : randomNumber; } /* ------------- View ------------- */ function randomSeedSet() public view returns (bool) { return randomSeed > 0; } /* ------------- Modifier ------------- */ modifier whenRandomSeedSet() { if (!randomSeedSet()) revert RandomSeedNotSet(); _; } modifier whenRandomSeedUnset() { if (randomSeedSet()) revert RandomSeedAlreadySet(); _; } } contract VRFBaseMainnet is VRFBase( 0xAA77729D3466CA35AE8D28B3BBAC7CC36A5031EFDC430821C02BC31A238AF445, 2 * 1e18, 0xf0d54349aDdcf704F77AE15b96510dEA15cb7952, 0x514910771AF9Ca656af840dff83E8264EcF986CA ) {} contract VRFBaseRinkeby is VRFBase( 0x2ed0feb3e7fd2022120aa84fab1945545a9f2ffc9076fd6156fa96eaff4c1311, 0.1 * 1e18, 0xb3dCcb4Cf7a26f6cf6B120Cf5A73875B7BBc655B, 0x01BE23585060835E02B77ef475b0Cc51aA1e0709 ) {} contract VRFBaseMumbai is VRFBase( 0x6e75b569a01ef56d18cab6a8e71e6600d6ce853834d4a5748b720d06f878b3a4, 0.0001 * 1e18, 0x8C7382F9D8f56b33781fE506E897a4F1e2d17255, 0x326C977E6efc84E512bB9C30f76E30c160eD06FB ) {} // SPDX-License-Identifier: MIT // Creator: Chiru Labs pragma solidity ^0.8.0; 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/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 ApproveToCaller(); error ApprovalToCurrentOwner(); error BalanceQueryForZeroAddress(); error MintToZeroAddress(); error MintZeroQuantity(); error MintExceedsLimit(); error MintExceedsMaxPerWallet(); error TransferCallerNotOwnerNorApproved(); error TransferFromIncorrectOwner(); error TransferToNonERC721ReceiverImplementer(); error TransferToZeroAddress(); error QueryForNonexistentToken(); /** * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints. * * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..). * * Does not support burning tokens to address(0). */ contract ERC721A is Context, ERC165, IERC721, IERC721Metadata { using Address for address; using Strings for uint256; struct TokenOwnership { address addr; uint56 startTimestamp; bool nextTokenOwnerShipSet; } struct UserData { uint128 balance; uint128 numMinted; } uint256 private immutable _startingIndex; uint256 private immutable _collectionSize; uint256 private immutable _maxPerWallet; uint256 private _totalSupply; // 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) private _tokenData; // Mapping owner address to address data mapping(address => UserData) private _userData; // 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 * `maxBatchSize` refers to how much a minter can mint at a time. */ constructor( string memory name_, string memory symbol_, uint256 collectionSize_, uint256 startingIndex_, uint256 maxPerWallet_ ) { _name = name_; _symbol = symbol_; _collectionSize = collectionSize_; _startingIndex = startingIndex_; _maxPerWallet = maxPerWallet_; } /** * @dev See {IERC721Enumerable-totalSupply}. */ function totalSupply() external view returns (uint256) { return _totalSupply; } function startingIndex() public view returns (uint256) { return _startingIndex; } function tokenIdsOf(address owner) external view returns (uint256[] memory) { uint256 balance = balanceOf(owner); uint256[] memory tokenIds = new uint256[](balance); if (balance == 0) return tokenIds; uint256 totalSupply_ = _totalSupply; uint256 count; for (uint256 i = _startingIndex; i < _startingIndex + totalSupply_; i++) { if (owner == ownerOf(i)) { tokenIds[count++] = i; if (balance == count) return tokenIds; } } return tokenIds; } /** * @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 _userData[owner].balance; } function numMinted(address owner) public view returns (uint256) { return _userData[owner].numMinted; } function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) { if (!_exists(tokenId)) revert QueryForNonexistentToken(); for (uint256 curr = tokenId; ; curr--) { TokenOwnership memory ownership = _tokenData[curr]; if (ownership.addr != address(0)) { return ownership; } } revert QueryForNonexistentToken(); } /** * @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 QueryForNonexistentToken(); string memory baseURI = _baseURI(); return bytes(baseURI).length != 0 ? string.concat(baseURI, tokenId.toString()) : ''; } /** * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each * token will be the concatenation of the `baseURI` and the `tokenId`. Empty * by default, can be overriden in child contracts. */ function _baseURI() internal view virtual returns (string memory) { return ''; } /** * @dev See {IERC721-approve}. */ function approve(address to, uint256 tokenId) public override { address owner = ERC721A.ownerOf(tokenId); if (to == owner) revert ApprovalToCurrentOwner(); if (msg.sender != owner && !isApprovedForAll(owner, msg.sender)) revert ApprovalCallerNotOwnerNorApproved(); _approve(to, tokenId, owner); } /** * @dev See {IERC721-getApproved}. */ function getApproved(uint256 tokenId) public view override returns (address) { if (!_exists(tokenId)) revert QueryForNonexistentToken(); return _tokenApprovals[tokenId]; } /** * @dev See {IERC721-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public override { if (operator == msg.sender) revert ApproveToCaller(); _operatorApprovals[msg.sender][operator] = approved; emit ApprovalForAll(msg.sender, operator, approved); } /** * @dev See {IERC721-isApprovedForAll}. */ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { return _operatorApprovals[owner][operator]; } /** * @dev See {IERC721-transferFrom}. */ function transferFrom( address from, address to, uint256 tokenId ) public override { _transfer(from, to, tokenId); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId ) public override { safeTransferFrom(from, to, tokenId, ''); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId, bytes memory data ) public override { _transfer(from, to, tokenId); if ( to.code.length != 0 && IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, data) != IERC721Receiver(to).onERC721Received.selector ) 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 _startingIndex <= tokenId && tokenId < _startingIndex + _totalSupply; } /** * @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) internal { unchecked { uint256 supply = _totalSupply; uint256 startTokenId = _startingIndex + supply; if (to == address(0)) revert MintToZeroAddress(); if (quantity == 0) revert MintZeroQuantity(); if (supply + quantity > _collectionSize) revert MintExceedsLimit(); UserData memory userData = _userData[to]; if (userData.numMinted + quantity > _maxPerWallet && to == msg.sender && address(this).code.length != 0) revert MintExceedsMaxPerWallet(); _userData[to] = UserData(userData.balance + uint128(quantity), userData.numMinted + uint128(quantity)); _tokenData[startTokenId] = TokenOwnership(to, uint56(block.timestamp), false); for (uint256 i; i < quantity; ++i) emit Transfer(address(0), to, startTokenId + i); _totalSupply += quantity; } } /** * @dev Transfers `tokenId` from `from` to `to`. * * Requirements: * * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * * Emits a {Transfer} event. */ function _transfer( address from, address to, uint256 tokenId ) private { TokenOwnership memory prevOwnership = _ownershipOf(tokenId); if (prevOwnership.addr != from) revert TransferFromIncorrectOwner(); bool isApprovedOrOwner = (msg.sender == from || isApprovedForAll(from, msg.sender) || getApproved(tokenId) == msg.sender); if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved(); if (to == address(0)) revert TransferToZeroAddress(); // Clear approvals from the previous owner delete _tokenApprovals[tokenId]; unchecked { --_userData[from].balance; ++_userData[to].balance; _tokenData[tokenId] = TokenOwnership(to, uint56(block.timestamp), true); // 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 ( !prevOwnership.nextTokenOwnerShipSet && _tokenData[nextTokenId].addr == address(0) && nextTokenId < _startingIndex + _collectionSize // it's ok to check collectionSize instead of totalSupply, because unminted tokenOwnerships will be overwritten ) { _tokenData[nextTokenId] = TokenOwnership(from, prevOwnership.startTimestamp, false); } } emit Transfer(from, to, tokenId); } /** * @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); } } // 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 (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 pragma solidity ^0.8.0; import "./interfaces/LinkTokenInterface.sol"; import "./VRFRequestIDBase.sol"; /** **************************************************************************** * @notice Interface for contracts using VRF randomness * ***************************************************************************** * @dev PURPOSE * * @dev Reggie the Random Oracle (not his real job) wants to provide randomness * @dev to Vera the verifier in such a way that Vera can be sure he's not * @dev making his output up to suit himself. Reggie provides Vera a public key * @dev to which he knows the secret key. Each time Vera provides a seed to * @dev Reggie, he gives back a value which is computed completely * @dev deterministically from the seed and the secret key. * * @dev Reggie provides a proof by which Vera can verify that the output was * @dev correctly computed once Reggie tells it to her, but without that proof, * @dev the output is indistinguishable to her from a uniform random sample * @dev from the output space. * * @dev The purpose of this contract is to make it easy for unrelated contracts * @dev to talk to Vera the verifier about the work Reggie is doing, to provide * @dev simple access to a verifiable source of randomness. * ***************************************************************************** * @dev USAGE * * @dev Calling contracts must inherit from VRFConsumerBase, and can * @dev initialize VRFConsumerBase's attributes in their constructor as * @dev shown: * * @dev contract VRFConsumer { * @dev constuctor(<other arguments>, address _vrfCoordinator, address _link) * @dev VRFConsumerBase(_vrfCoordinator, _link) public { * @dev <initialization with other arguments goes here> * @dev } * @dev } * * @dev The oracle will have given you an ID for the VRF keypair they have * @dev committed to (let's call it keyHash), and have told you the minimum LINK * @dev price for VRF service. Make sure your contract has sufficient LINK, and * @dev call requestRandomness(keyHash, fee, seed), where seed is the input you * @dev want to generate randomness from. * * @dev Once the VRFCoordinator has received and validated the oracle's response * @dev to your request, it will call your contract's fulfillRandomness method. * * @dev The randomness argument to fulfillRandomness is the actual random value * @dev generated from your seed. * * @dev The requestId argument is generated from the keyHash and the seed by * @dev makeRequestId(keyHash, seed). If your contract could have concurrent * @dev requests open, you can use the requestId to track which seed is * @dev associated with which randomness. See VRFRequestIDBase.sol for more * @dev details. (See "SECURITY CONSIDERATIONS" for principles to keep in mind, * @dev if your contract could have multiple requests in flight simultaneously.) * * @dev Colliding `requestId`s are cryptographically impossible as long as seeds * @dev differ. (Which is critical to making unpredictable randomness! See the * @dev next section.) * * ***************************************************************************** * @dev SECURITY CONSIDERATIONS * * @dev A method with the ability to call your fulfillRandomness method directly * @dev could spoof a VRF response with any random value, so it's critical that * @dev it cannot be directly called by anything other than this base contract * @dev (specifically, by the VRFConsumerBase.rawFulfillRandomness method). * * @dev For your users to trust that your contract's random behavior is free * @dev from malicious interference, it's best if you can write it so that all * @dev behaviors implied by a VRF response are executed *during* your * @dev fulfillRandomness method. If your contract must store the response (or * @dev anything derived from it) and use it later, you must ensure that any * @dev user-significant behavior which depends on that stored value cannot be * @dev manipulated by a subsequent VRF request. * * @dev Similarly, both miners and the VRF oracle itself have some influence * @dev over the order in which VRF responses appear on the blockchain, so if * @dev your contract could have multiple VRF requests in flight simultaneously, * @dev you must ensure that the order in which the VRF responses arrive cannot * @dev be used to manipulate your contract's user-significant behavior. * * @dev Since the ultimate input to the VRF is mixed with the block hash of the * @dev block in which the request is made, user-provided seeds have no impact * @dev on its economic security properties. They are only included for API * @dev compatability with previous versions of this contract. * * @dev Since the block hash of the block which contains the requestRandomness * @dev call is mixed into the input to the VRF *last*, a sufficiently powerful * @dev miner could, in principle, fork the blockchain to evict the block * @dev containing the request, forcing the request to be included in a * @dev different block with a different hash, and therefore a different input * @dev to the VRF. However, such an attack would incur a substantial economic * @dev cost. This cost scales with the number of blocks the VRF oracle waits * @dev until it calls responds to a request. */ abstract contract VRFConsumerBase is VRFRequestIDBase { /** * @notice fulfillRandomness handles the VRF response. Your contract must * @notice implement it. See "SECURITY CONSIDERATIONS" above for important * @notice principles to keep in mind when implementing your fulfillRandomness * @notice method. * * @dev VRFConsumerBase expects its subcontracts to have a method with this * @dev signature, and will call it once it has verified the proof * @dev associated with the randomness. (It is triggered via a call to * @dev rawFulfillRandomness, below.) * * @param requestId The Id initially returned by requestRandomness * @param randomness the VRF output */ function fulfillRandomness(bytes32 requestId, uint256 randomness) internal virtual; /** * @dev In order to keep backwards compatibility we have kept the user * seed field around. We remove the use of it because given that the blockhash * enters later, it overrides whatever randomness the used seed provides. * Given that it adds no security, and can easily lead to misunderstandings, * we have removed it from usage and can now provide a simpler API. */ uint256 private constant USER_SEED_PLACEHOLDER = 0; /** * @notice requestRandomness initiates a request for VRF output given _seed * * @dev The fulfillRandomness method receives the output, once it's provided * @dev by the Oracle, and verified by the vrfCoordinator. * * @dev The _keyHash must already be registered with the VRFCoordinator, and * @dev the _fee must exceed the fee specified during registration of the * @dev _keyHash. * * @dev The _seed parameter is vestigial, and is kept only for API * @dev compatibility with older versions. It can't *hurt* to mix in some of * @dev your own randomness, here, but it's not necessary because the VRF * @dev oracle will mix the hash of the block containing your request into the * @dev VRF seed it ultimately uses. * * @param _keyHash ID of public key against which randomness is generated * @param _fee The amount of LINK to send with the request * * @return requestId unique ID for this request * * @dev The returned requestId can be used to distinguish responses to * @dev concurrent requests. It is passed as the first argument to * @dev fulfillRandomness. */ function requestRandomness(bytes32 _keyHash, uint256 _fee) internal returns (bytes32 requestId) { LINK.transferAndCall(vrfCoordinator, _fee, abi.encode(_keyHash, USER_SEED_PLACEHOLDER)); // This is the seed passed to VRFCoordinator. The oracle will mix this with // the hash of the block containing this request to obtain the seed/input // which is finally passed to the VRF cryptographic machinery. uint256 vRFSeed = makeVRFInputSeed(_keyHash, USER_SEED_PLACEHOLDER, address(this), nonces[_keyHash]); // nonces[_keyHash] must stay in sync with // VRFCoordinator.nonces[_keyHash][this], which was incremented by the above // successful LINK.transferAndCall (in VRFCoordinator.randomnessRequest). // This provides protection against the user repeating their input seed, // which would result in a predictable/duplicate output, if multiple such // requests appeared in the same block. nonces[_keyHash] = nonces[_keyHash] + 1; return makeRequestId(_keyHash, vRFSeed); } LinkTokenInterface internal immutable LINK; address private immutable vrfCoordinator; // Nonces for each VRF key from which randomness has been requested. // // Must stay in sync with VRFCoordinator[_keyHash][this] mapping(bytes32 => uint256) /* keyHash */ /* nonce */ private nonces; /** * @param _vrfCoordinator address of VRFCoordinator contract * @param _link address of LINK token contract * * @dev https://docs.chain.link/docs/link-token-contracts */ constructor(address _vrfCoordinator, address _link) { vrfCoordinator = _vrfCoordinator; LINK = LinkTokenInterface(_link); } // rawFulfillRandomness is called by VRFCoordinator when it receives a valid VRF // proof. rawFulfillRandomness then calls fulfillRandomness, after validating // the origin of the call function rawFulfillRandomness(bytes32 requestId, uint256 randomness) external { require(msg.sender == vrfCoordinator, "Only VRFCoordinator can fulfill"); fulfillRandomness(requestId, randomness); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; interface LinkTokenInterface { function allowance(address owner, address spender) external view returns (uint256 remaining); function approve(address spender, uint256 value) external returns (bool success); function balanceOf(address owner) external view returns (uint256 balance); function decimals() external view returns (uint8 decimalPlaces); function decreaseApproval(address spender, uint256 addedValue) external returns (bool success); function increaseApproval(address spender, uint256 subtractedValue) external; function name() external view returns (string memory tokenName); function symbol() external view returns (string memory tokenSymbol); function totalSupply() external view returns (uint256 totalTokensIssued); function transfer(address to, uint256 value) external returns (bool success); function transferAndCall( address to, uint256 value, bytes calldata data ) external returns (bool success); function transferFrom( address from, address to, uint256 value ) external returns (bool success); } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; contract VRFRequestIDBase { /** * @notice returns the seed which is actually input to the VRF coordinator * * @dev To prevent repetition of VRF output due to repetition of the * @dev user-supplied seed, that seed is combined in a hash with the * @dev user-specific nonce, and the address of the consuming contract. The * @dev risk of repetition is mostly mitigated by inclusion of a blockhash in * @dev the final seed, but the nonce does protect against repetition in * @dev requests which are included in a single block. * * @param _userSeed VRF seed input provided by user * @param _requester Address of the requesting contract * @param _nonce User-specific nonce at the time of the request */ function makeVRFInputSeed( bytes32 _keyHash, uint256 _userSeed, address _requester, uint256 _nonce ) internal pure returns (uint256) { return uint256(keccak256(abi.encode(_keyHash, _userSeed, _requester, _nonce))); } /** * @notice Returns the id for this request * @param _keyHash The serviceAgreement ID to be used for this request * @param _vRFInputSeed The seed to be passed directly to the VRF * @return The id for this request * * @dev Note that _vRFInputSeed is not the seed passed by the consuming * @dev contract, but the one generated by makeVRFInputSeed */ function makeRequestId(bytes32 _keyHash, uint256 _vRFInputSeed) internal pure returns (bytes32) { return keccak256(abi.encodePacked(_keyHash, _vRFInputSeed)); } } // 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) (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/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); }