Transaction Hash:
Block:
14964487 at Jun-14-2022 11:44:16 PM +UTC
Transaction Fee:
0.001913110412137707 ETH
$3.63
Gas Used:
46,141 Gas / 41.462265927 Gwei
Emitted Events:
72 |
LaidBackLlamas.ApprovalForAll( owner=[Sender] 0x4bf6c2894358f9ab9d5824fea80e86da9c872226, operator=0x1E004978...d54003c71, approved=True )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x2DaA3596...79C930E5e
Miner
| (Poolin 2) | 3,179.321052230864310325 Eth | 3,179.321167583364310325 Eth | 0.0001153525 | |
0x40A0f793...f978ECBF3 | |||||
0x4Bf6C289...A9C872226 |
0.047757816400296818 Eth
Nonce: 94
|
0.045844705988159111 Eth
Nonce: 95
| 0.001913110412137707 |
Execution Trace
LaidBackLlamas.setApprovalForAll( operator=0x1E0049783F008A0085193E00003D00cd54003c71, approved=True )
setApprovalForAll[ERC721 (ln:1571)]
_setApprovalForAll[ERC721 (ln:1572)]
ApprovalForAll[ERC721 (ln:1778)]
_msgSender[ERC721 (ln:1572)]
/*** * ██╗ █████╗ ██╗██████╗ ██████╗ █████╗ ██████╗██╗ ██╗ * ██║ ██╔══██╗██║██╔══██╗ ██╔══██╗██╔══██╗██╔════╝██║ ██╔╝ * ██║ ███████║██║██║ ██║ ██████╔╝███████║██║ █████╔╝ * ██║ ██╔══██║██║██║ ██║ ██╔══██╗██╔══██║██║ ██╔═██╗ * ███████╗██║ ██║██║██████╔╝ ██████╔╝██║ ██║╚██████╗██║ ██╗ * ╚══════╝╚═╝ ╚═╝╚═╝╚═════╝ ╚═════╝ ╚═╝ ╚═╝ ╚═════╝╚═╝ ╚═╝ * * ██╗ ██╗ █████╗ ███╗ ███╗ █████╗ ███████╗ * ██║ ██║ ██╔══██╗████╗ ████║██╔══██╗██╔════╝ * ██║ ██║ ███████║██╔████╔██║███████║███████╗ * ██║ ██║ ██╔══██║██║╚██╔╝██║██╔══██║╚════██║ * ███████╗███████╗██║ ██║██║ ╚═╝ ██║██║ ██║███████║ * ╚══════╝╚══════╝╚═╝ ╚═╝╚═╝ ╚═╝╚═╝ ╚═╝╚══════╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] * */ // SPDX-License-Identifier: MIT pragma solidity 0.8.11; import "@openzeppelin/contracts/utils/introspection/ERC165Storage.sol"; import "@openzeppelin/contracts/token/ERC721/ERC721.sol"; import "@openzeppelin/contracts/token/ERC721/IERC721.sol"; import "@openzeppelin/contracts/security/ReentrancyGuard.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; import "./access/Developer.sol"; import "@openzeppelin/contracts/utils/Counters.sol"; import "./interface/IMAX721.sol"; import "./modules/Whitelist.sol"; import "./interface/IMAX721Whitelist.sol"; import "./modules/PaymentSplitter.sol"; import "./modules/BAYC.sol"; import "./modules/ContractURI.sol"; contract LaidBackLlamas is ERC721, BAYC, ContractURI, IMAX721, IMAX721Whitelist, Whitelist, ERC165Storage, ReentrancyGuard, PaymentSplitter, Developer, Ownable { using Counters for Counters.Counter; Counters.Counter private _tokenIdCounter; Counters.Counter private _teamMintCounter; uint private mintStartID; uint private constant MINT_FEES = 0.1 ether; uint private constant PRESALE_MINT_FEES = 0.07 ether; uint private endOfPresale; uint private constant MINT_SIZE = 7000; uint private teamMintSize; string private base; bool private enableMinter; bool private enableWhiteList; bool private lockedProvenance; bool private lockedPayees; event UpdatedBaseURI(string _old, string _new); event UpdatedMintSize(uint _old, uint _new); event UpdatedMintStatus(bool _old, bool _new); event UpdatedTeamMintSize(uint _old, uint _new); event UpdatedWhitelistStatus(bool _old, bool _new); event UpdatedPresaleEnd(uint _old, uint _new); event ProvenanceLocked(bool _status); event PayeesLocked(bool _status); // bytes4 constants for ERC165 bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd; bytes4 private constant _INTERFACE_ID_IBAYC = 0xdee68dd1; bytes4 private constant _INTERFACE_ID_IContractURI = 0xe8a3d485; bytes4 private constant _INTERFACE_ID_IMAX721 = 0x29499a25; bytes4 private constant _INTERFACE_ID_IMAX721Whitelist = 0x22699a34; bytes4 private constant _INTERFACE_ID_Whitelist = 0xc683630d; bytes4 private constant _INTERFACE_ID_Developer = 0x18f19aba; bytes4 private constant _INTERFACE_ID_PaymentSplitter = 0x4a7f18f2; constructor() ERC721("Laid Back Llamas", "LBL") { // ECR165 Interfaces Supported _registerInterface(_INTERFACE_ID_ERC721); _registerInterface(_INTERFACE_ID_IBAYC); _registerInterface(_INTERFACE_ID_IContractURI); _registerInterface(_INTERFACE_ID_IMAX721); _registerInterface(_INTERFACE_ID_IMAX721Whitelist); _registerInterface(_INTERFACE_ID_Whitelist); _registerInterface(_INTERFACE_ID_Developer); _registerInterface(_INTERFACE_ID_PaymentSplitter); } /*** * ███╗ ███╗██╗███╗ ██╗████████╗ * ████╗ ████║██║████╗ ██║╚══██╔══╝ * ██╔████╔██║██║██╔██╗ ██║ ██║ * ██║╚██╔╝██║██║██║╚██╗██║ ██║ * ██║ ╚═╝ ██║██║██║ ╚████║ ██║ * ╚═╝ ╚═╝╚═╝╚═╝ ╚═══╝ ╚═╝ */ function publicMint(uint amount) public payable nonReentrant(){ require(lockedProvenance, "Set Providence hashes"); require(enableMinter, "Minter not active"); require(_tokenIdCounter.current() + amount <= MINT_SIZE, "Can not mint that many"); uint yourBalance = IERC721(address(this)).balanceOf(msg.sender); if(enableWhiteList) { require(msg.value == PRESALE_MINT_FEES * amount, "Wrong amount of Native Token"); require(isWhitelist[msg.sender], "You are not Whitelisted"); require(yourBalance < 3 && amount + yourBalance <= 3, "You can not get that many!"); checkTime(); // locks them out of whitelist, soft reentrancy guard _removeWhitelist(msg.sender); for (uint i = 0; i < amount; i++) { _safeMint(msg.sender, mintID()); _tokenIdCounter.increment(); } } else { require(msg.value == MINT_FEES * amount, "Wrong amount of Native Token"); require(yourBalance < 5 && amount + yourBalance <= 5, "You can not get that many!"); for (uint i = 0; i < amount; i++) { _safeMint(msg.sender, mintID()); _tokenIdCounter.increment(); } } } function teamMint(address _address) public onlyOwner { require(lockedProvenance, "Set Providence hashes"); require(teamMintSize != 0, "Team minting not enabled"); require(_tokenIdCounter.current() < MINT_SIZE, "Can not mint that many"); require(_teamMintCounter.current() < teamMintSize, "Can not team mint anymore"); _safeMint(_address, mintID()); _tokenIdCounter.increment(); _teamMintCounter.increment(); } // @notice this shifts the _tokenIdCounter to proper mint number function mintID() internal view returns (uint) { return (mintStartID + _tokenIdCounter.current()) % MINT_SIZE; } // @notice this will check time and set whitelist to disabled function checkTime() private { if(endOfPresale <= block.timestamp) { enableWhiteList = !enableWhiteList; } } // Function to receive ether, msg.data must be empty receive() external payable { // From PaymentSplitter.sol, 99% of the time won't register emit PaymentReceived(msg.sender, msg.value); } // Function to receive ether, msg.data is not empty fallback() external payable { // From PaymentSplitter.sol, 99% of the time won't register emit PaymentReceived(msg.sender, msg.value); } function getBalance() external view returns (uint) { return address(this).balance; } /*** * ██████╗ ██╗ ██╗███╗ ██╗███████╗██████╗ * ██╔═══██╗██║ ██║████╗ ██║██╔════╝██╔══██╗ * ██║ ██║██║ █╗ ██║██╔██╗ ██║█████╗ ██████╔╝ * ██║ ██║██║███╗██║██║╚██╗██║██╔══╝ ██╔══██╗ * ╚██████╔╝╚███╔███╔╝██║ ╚████║███████╗██║ ██║ * ╚═════╝ ╚══╝╚══╝ ╚═╝ ╚═══╝╚══════╝╚═╝ ╚═╝ * This section will have all the internals set to onlyOwner */ // @notice click this to start it up initally, for ease by onlyOwner function startMinting() public onlyOwner { require(lockedProvenance && lockedPayees, "Prerequisites not met"); // This is the initial setting // Set Presale end time and emit uint prevEndOfPresale = endOfPresale; endOfPresale = block.timestamp + 1 days; emit UpdatedPresaleEnd(prevEndOfPresale, endOfPresale); // Set Whitelist status and emit bool prevWhitelist = enableWhiteList; enableWhiteList = true; emit UpdatedWhitelistStatus(prevWhitelist, enableWhiteList); // Set Minter Status and emit bool prevMintStatus = enableMinter; enableMinter = true; emit UpdatedMintStatus(prevMintStatus, enableMinter); } // @notice this will enable publicMint() function enableMinting() public onlyOwner { bool old = enableMinter; enableMinter = true; emit UpdatedMintStatus(old, enableMinter); } // @notice this will disable publicMint() function disableMinting() public onlyOwner { bool old = enableMinter; enableMinter = false; emit UpdatedMintStatus(old, enableMinter); } // @notice this will enable whitelist or "if" in publicMint() function enableWhitelist() public onlyOwner { // Set Presale end time and emit uint prevEndOfPresale = endOfPresale; endOfPresale = block.timestamp + 1 days; emit UpdatedPresaleEnd(prevEndOfPresale, endOfPresale); // Set Whitelist status and emit bool prevWhitelist = enableWhiteList; enableWhiteList = true; emit UpdatedWhitelistStatus(prevWhitelist, enableWhiteList); } // @notice this will disable whitelist or "else" in publicMint() function disableWhitelist() public onlyOwner { bool old = enableWhiteList; enableWhiteList = false; emit UpdatedWhitelistStatus(old, enableWhiteList); } // @notice adding functions to mapping function addWhitelistBatch(address [] memory _addresses) public onlyOwner { _addWhitelistBatch(_addresses); } // @notice adding functions to mapping function addWhitelist(address _address) public onlyOwner { _addWhitelist(_address); } // @notice removing functions to mapping function removeWhitelistBatch(address [] memory _addresses) public onlyOwner { _removeWhitelistBatch(_addresses); } // @notice removing functions to mapping function removeWhitelist(address _address) public onlyOwner { _removeWhitelist(_address); } /*** * ██████╗ ███████╗██╗ ██╗ * ██╔══██╗██╔════╝██║ ██║ * ██║ ██║█████╗ ██║ ██║ * ██║ ██║██╔══╝ ╚██╗ ██╔╝ * ██████╔╝███████╗ ╚████╔╝ * ╚═════╝ ╚══════╝ ╚═══╝ * This section will have all the internals set to onlyDev * also contains all overrides required for funtionality */ // @notice will add an address to PaymentSplitter by onlyDev role function addPayee(address newAddy, uint newShares) public onlyDev { require(!lockedPayees, "Can not set, payees locked"); _addPayee(newAddy, newShares); } // @notice will lock payees on PaymentSplitter.sol function lockPayees() public onlyDev { require(!lockedPayees, "Can not set, payees locked"); lockedPayees = true; emit PayeesLocked(lockedPayees); } // @notice will update _baseURI() by onlyDev role function setBaseURI(string memory _base) public onlyDev { string memory old = base; base = _base; emit UpdatedBaseURI(old, base); } // @notice will set the ContractURI for OpenSea function setContractURI(string memory _contractURI) public onlyDev { _setContractURI(_contractURI); } // @notice will set "team minting" by onlyDev role function setTeamMinting(uint _amount) public onlyDev { uint old = teamMintSize; teamMintSize = _amount; emit UpdatedTeamMintSize(old, teamMintSize); } // @notice this will set the Provenance Hashes // This will also set the starting order as well! // Only one shot to do this, otherwise it shows as invalid function setProvenance(string memory _images, string memory _json) public onlyDev { require(lockedPayees, "Can not set, payees unlocked"); require(!lockedProvenance, "Already Set!"); // This is the initial setting _setProvenanceImages(_images); _setProvenanceJSON(_json); // Now to psuedo-random the starting number // Your API should be a random before this step! mintStartID = uint(keccak256(abi.encodePacked(block.timestamp, msg.sender, _images, _json, block.difficulty))) % MINT_SIZE; _setStartNumber(mintStartID); // @notice Locks sequence lockedProvenance = true; emit ProvenanceLocked(lockedProvenance); } // @notice this will set the reveal timestamp // This is more for your API and not on chain... function setRevealTimestamp(uint _time) public onlyDev { _setRevealTimestamp(_time); } // @notice function useful for accidental ETH transfers to contract (to user address) // wraps _user in payable to fix address -> address payable // Set to onlyOwner, this is case of a foulup on PaymentSplitter or minting function sweepEthToAddress(address _user, uint _amount) public onlyOwner { payable(_user).transfer(_amount); } /// /// Developer, these are the overrides /// // @notice solidity required override for _baseURI() function _baseURI() internal view override returns (string memory) { return base; } // @notice solidity required override for supportsInterface(bytes4) function supportsInterface(bytes4 interfaceId) public view override(ERC721, ERC165Storage, IERC165) returns (bool) { return super.supportsInterface(interfaceId); } // @notice will return status of Minter function minterStatus() external view override(IMAX721) returns (bool) { return enableMinter; } // @notice will return minting fees function minterFees() external pure override(IMAX721) returns (uint) { return MINT_FEES; } // @notice will return presale minting fees function presaleMinterFees() external pure returns (uint) { return PRESALE_MINT_FEES; } // @notice will return maximum mint capacity function minterMaximumCapacity() external pure override(IMAX721) returns (uint) { return MINT_SIZE; } // @notice will return maximum "team minting" capacity function minterMaximumTeamMints() external view override(IMAX721) returns (uint) { return teamMintSize; } // @notice will return "team mints" left function minterTeamMintsRemaining() external view override(IMAX721) returns (uint) { return teamMintSize - _teamMintCounter.current(); } // @notice will return "team mints" count function minterTeamMintsCount() external view override(IMAX721) returns (uint) { return _teamMintCounter.current(); } // @notice will return current token count function totalSupply() external view override(IMAX721) returns (uint) { return _tokenIdCounter.current(); } // @notice will return whitelist end timestamp function whitelistEnd() external view override(IMAX721Whitelist) returns (uint256) { return endOfPresale; } // @notice will return whitelist status of Minter function whitelistStatus() external view override(IMAX721Whitelist) returns (bool) { return enableWhiteList; } } /*** * ██╗ ██╗██╗ ██╗██╗████████╗███████╗██╗ ██╗███████╗████████╗ * ██║ ██║██║ ██║██║╚══██╔══╝██╔════╝██║ ██║██╔════╝╚══██╔══╝ * ██║ █╗ ██║███████║██║ ██║ █████╗ ██║ ██║███████╗ ██║ * ██║███╗██║██╔══██║██║ ██║ ██╔══╝ ██║ ██║╚════██║ ██║ * ╚███╔███╔╝██║ ██║██║ ██║ ███████╗███████╗██║███████║ ██║ * ╚══╝╚══╝ ╚═╝ ╚═╝╚═╝ ╚═╝ ╚══════╝╚══════╝╚═╝╚══════╝ ╚═╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; abstract contract Whitelist { // ERC165 data // Public getter isWhitelist(address) => 0xc683630d // Whitelist is 0xc683630d // set contract mapping mapping(address => bool) public isWhitelist; // only event needed event ChangeToWhitelist(address _address, bool old, bool update); // adding functions to mapping function _addWhitelistBatch(address [] memory _addresses) internal { for (uint i = 0; i < _addresses.length; i++) { _addWhitelist(_addresses[i]); } } function _addWhitelist(address _address) internal { require(!isWhitelist[_address], "Already on Whitelist"); bool old = isWhitelist[_address]; isWhitelist[_address] = true; emit ChangeToWhitelist(_address, old, isWhitelist[_address]); } // removing functions to mapping function _removeWhitelistBatch(address [] memory _addresses) internal { for (uint i = 0; i < _addresses.length; i++) { _removeWhitelist(_addresses[i]); } } function _removeWhitelist(address _address) internal { require(isWhitelist[_address], "Already off Whitelist"); bool old = isWhitelist[_address]; isWhitelist[_address] = false; emit ChangeToWhitelist(_address, old, isWhitelist[_address]); } } /*** * ██████╗ █████╗ ██╗ ██╗███╗ ███╗███████╗███╗ ██╗████████╗ * ██╔══██╗██╔══██╗╚██╗ ██╔╝████╗ ████║██╔════╝████╗ ██║╚══██╔══╝ * ██████╔╝███████║ ╚████╔╝ ██╔████╔██║█████╗ ██╔██╗ ██║ ██║ * ██╔═══╝ ██╔══██║ ╚██╔╝ ██║╚██╔╝██║██╔══╝ ██║╚██╗██║ ██║ * ██║ ██║ ██║ ██║ ██║ ╚═╝ ██║███████╗██║ ╚████║ ██║ * ╚═╝ ╚═╝ ╚═╝ ╚═╝ ╚═╝ ╚═╝╚══════╝╚═╝ ╚═══╝ ╚═╝ * * ███████╗██████╗ ██╗ ██╗████████╗████████╗███████╗██████╗ * ██╔════╝██╔══██╗██║ ██║╚══██╔══╝╚══██╔══╝██╔════╝██╔══██╗ * ███████╗██████╔╝██║ ██║ ██║ ██║ █████╗ ██████╔╝ * ╚════██║██╔═══╝ ██║ ██║ ██║ ██║ ██╔══╝ ██╔══██╗ * ███████║██║ ███████╗██║ ██║ ██║ ███████╗██║ ██║ * ╚══════╝╚═╝ ╚══════╝╚═╝ ╚═╝ ╚═╝ ╚══════╝╚═╝ ╚═╝ * This is a re-write of @openzeppelin/contracts/finance/PaymentSplitter.sol * Rewritten by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/Address.sol"; import "@openzeppelin/contracts/utils/Context.sol"; // Removal of SafeMath due to ^0.8.0 standards, not needed /** * @title PaymentSplitter * @dev This contract allows to split Ether payments among a group of accounts. The sender does not need to be aware * that the Ether will be split in this way, since it is handled transparently by the contract. * * The split can be in equal parts or in any other arbitrary proportion. The way this is specified is by assigning each * account to a number of shares. Of all the Ether that this contract receives, each account will then be able to claim * an amount proportional to the percentage of total shares they were assigned. * * `PaymentSplitter` follows a _pull payment_ model. This means that payments are not automatically forwarded to the * accounts but kept in this contract, and the actual transfer is triggered as a separate step by calling the {release} * function. */ abstract contract PaymentSplitter is Context { // ERC165 data // totalShares() => 0x3a98ef39 // totalReleased() => 0xe33b7de3 // shares(address) => 0xce7c2ac2 // released(address) => 0x9852595c // payee(uint256) => 0x8b83209b // claim() => 0x4e71d92d // PaymentSplitter => 0x4a7f18f2 event PayeeAdded(address account, uint256 shares); event PaymentReleased(address to, uint256 amount); event PaymentReceived(address from, uint256 amount); uint256 private _totalShares; uint256 private _totalReleased; mapping(address => uint256) private _shares; mapping(address => uint256) private _released; address[] private _payees; /** * @dev The Ether received will be logged with {PaymentReceived} events. Note that these events are not fully * reliable: it's possible for a contract to receive Ether without triggering this function. This only affects the * reliability of the events, and not the actual splitting of Ether. * * To learn more about this see the Solidity documentation for * https://solidity.readthedocs.io/en/latest/contracts.html#fallback-function[fallback * functions]. * * receive() external payable virtual { * emit PaymentReceived(_msgSender(), msg.value); * } * * // Fallback function is called when msg.data is not empty * // Added to PaymentSplitter.sol * fallback() external payable { * emit PaymentReceived(_msgSender(), msg.value); * } * * receive() and fallback() to be handled at final contract */ /** * @dev Getter for the total shares held by payees. */ // totalShares() => 0x3a98ef39 function totalShares() public view returns (uint256) { return _totalShares; } /** * @dev Getter for the total amount of Ether already released. */ // totalReleased() => 0xe33b7de3 function totalReleased() public view returns (uint256) { return _totalReleased; } /** * @dev Getter for the amount of shares held by an account. */ // shares(address) => 0xce7c2ac2 function shares(address account) public view returns (uint256) { return _shares[account]; } /** * @dev Getter for the amount of Ether already released to a payee. */ // released(address) => 0x9852595c function released(address account) public view returns (uint256) { return _released[account]; } /** * @dev Getter for the address of the payee number `index`. */ // payee(uint256) => 0x8b83209b function payee(uint256 index) public view returns (address) { return _payees[index]; } /** * @dev Triggers a transfer to `account` of the amount of Ether they are owed, according to their percentage of the * total shares and their previous withdrawals. */ // This function was updated from "account" to msg.sender // claim() => 0x4e71d92d function claim() public virtual { require(_shares[msg.sender] > 0, "PaymentSplitter: msg.sender has no shares"); uint256 totalReceived = address(this).balance + _totalReleased; uint256 payment = (totalReceived * _shares[msg.sender]) / _totalShares - _released[msg.sender]; require(payment != 0, "PaymentSplitter: msg.sender is not due payment"); _released[msg.sender] = _released[msg.sender] + payment; _totalReleased = _totalReleased + payment; Address.sendValue(payable(msg.sender), payment); emit PaymentReleased(msg.sender, payment); } /** * @dev Add a new payee to the contract. * @param account The address of the payee to add. * @param shares_ The number of shares owned by the payee. */ // This function was updated to internal function _addPayee(address account, uint256 shares_) internal { require(account != address(0), "PaymentSplitter: account is the zero address"); require(shares_ > 0, "PaymentSplitter: shares are 0"); require(_shares[account] == 0, "PaymentSplitter: account already has shares"); _payees.push(account); _shares[account] = shares_; _totalShares = _totalShares + shares_; emit PayeeAdded(account, shares_); } } /*** * ██████╗ ██████╗ ███╗ ██╗████████╗██████╗ █████╗ ██████╗████████╗ ██╗ ██╗██████╗ ██╗ * ██╔════╝██╔═══██╗████╗ ██║╚══██╔══╝██╔══██╗██╔══██╗██╔════╝╚══██╔══╝ ██║ ██║██╔══██╗██║ * ██║ ██║ ██║██╔██╗ ██║ ██║ ██████╔╝███████║██║ ██║ ██║ ██║██████╔╝██║ * ██║ ██║ ██║██║╚██╗██║ ██║ ██╔══██╗██╔══██║██║ ██║ ██║ ██║██╔══██╗██║ * ╚██████╗╚██████╔╝██║ ╚████║ ██║ ██║ ██║██║ ██║╚██████╗ ██║ ╚██████╔╝██║ ██║██║ * ╚═════╝ ╚═════╝ ╚═╝ ╚═══╝ ╚═╝ ╚═╝ ╚═╝╚═╝ ╚═╝ ╚═════╝ ╚═╝ ╚═════╝ ╚═╝ ╚═╝╚═╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] * * Purpose: OpenSea compliance on chain ID #1-5 */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "../interface/IContractURI.sol"; abstract contract ContractURI is IContractURI { // ERC165 stuff to be added // all internals are not calculated // contractURI() => 0xe8a3d485 // ContractURI => 0xe8a3d485 event ContractURIChange(string _old, string _new); string private thisContractURI; // @notice this sets the contractURI function _setContractURI(string memory newURI) internal { string memory old = thisContractURI; thisContractURI = newURI; emit ContractURIChange(old, thisContractURI); } // @notice will return string _ContractURI // contractURI() => 0xe8a3d485 function contractURI() external view override(IContractURI) returns (string memory) { return thisContractURI; } } /*** * ██████╗ █████╗ ██╗ ██╗ ██████╗ * ██╔══██╗██╔══██╗╚██╗ ██╔╝██╔════╝ * ██████╔╝███████║ ╚████╔╝ ██║ * ██╔══██╗██╔══██║ ╚██╔╝ ██║ * ██████╔╝██║ ██║ ██║ ╚██████╗ * ╚═════╝ ╚═╝ ╚═╝ ╚═╝ ╚═════╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] * * Purpose: Insipired by BAYC on Ethereum, Sets Provential Hashes and More * Source: https://etherscan.io/address/0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d#code */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "../interface/IBAYC.sol"; abstract contract BAYC is IBAYC { // ERC165 // RevealTimestamp() => 0x83ba7c1d // RevealProvenanceImages() => 0xd792d2a0 // RevealProvenanceJSON() => 0x94352676 // RevealStartNumber() => 0x1efb051a // BAYC => 0xdee68dd1 event SetProvenanceImages(string _old, string _new); event SetProvenanceJSON(string _old, string _new); event SetTimestamp(uint _old, uint _new); event SetStartNumber(uint _old, uint _new); uint256 private timestamp; uint256 private startNumber; string private ProvenanceImages; string private ProvenanceJSON; // @notice will set reveal timestamp // _setRevealTimestamp(uint256) => 0x20add1a4 function _setRevealTimestamp(uint256 _timestamp) internal { uint256 old = timestamp; timestamp = _timestamp; emit SetTimestamp(old, timestamp); } // @notice will set start number // _setStartNumber(uint256) => 0x4266377e function _setStartNumber(uint256 _startNumber) internal { uint256 old = startNumber; startNumber = _startNumber; emit SetStartNumber(old, startNumber); } // @notice will set JSON Provenance // _setProvenanceJSON(string) => 0xf3808eb1 function _setProvenanceJSON(string memory _ProvenanceJSON) internal { string memory old = ProvenanceJSON; ProvenanceJSON = _ProvenanceJSON; emit SetProvenanceJSON(old, ProvenanceJSON); } // @notice will set Images Provenance // _setProvenanceImages(string) => 0x1ef799c6 function _setProvenanceImages(string memory _ProvenanceImages) internal { string memory old = ProvenanceImages; ProvenanceImages = _ProvenanceImages; emit SetProvenanceImages(old, ProvenanceImages); } // @notice will return timestamp of reveal // RevealTimestamp() => 0x83ba7c1d function RevealTimestamp() external view override(IBAYC) returns (uint256) { return timestamp; } // @notice will return Provenance hash of images // RevealProvenanceImages() => 0xd792d2a0 function RevealProvenanceImages() external view override(IBAYC) returns (string memory) { return ProvenanceImages; } // @notice will return Provenance hash of metadata // RevealProvenanceJSON() => 0x94352676 function RevealProvenanceJSON() external view override(IBAYC) returns (string memory) { return ProvenanceJSON; } // @notice will return starting number for mint // RevealStartNumber() => 0x1efb051a function RevealStartNumber() external view override(IBAYC) returns (uint256) { return startNumber; } } /*** * ██╗███╗ ██╗████████╗███████╗██████╗ ███████╗ █████╗ ██████╗███████╗ * ██║████╗ ██║╚══██╔══╝██╔════╝██╔══██╗██╔════╝██╔══██╗██╔════╝██╔════╝ * ██║██╔██╗ ██║ ██║ █████╗ ██████╔╝█████╗ ███████║██║ █████╗ * ██║██║╚██╗██║ ██║ ██╔══╝ ██╔══██╗██╔══╝ ██╔══██║██║ ██╔══╝ * ██║██║ ╚████║ ██║ ███████╗██║ ██║██║ ██║ ██║╚██████╗███████╗ * ╚═╝╚═╝ ╚═══╝ ╚═╝ ╚══════╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚═╝ ╚═════╝╚══════╝ * * ███╗ ███╗ █████╗ ██╗ ██╗ ███████╗██████╗ ██╗ * ████╗ ████║██╔══██╗╚██╗██╔╝ ╚════██║╚════██╗███║ * ██╔████╔██║███████║ ╚███╔╝█████╗ ██╔╝ █████╔╝╚██║ * ██║╚██╔╝██║██╔══██║ ██╔██╗╚════╝██╔╝ ██╔═══╝ ██║ * ██║ ╚═╝ ██║██║ ██║██╔╝ ██╗ ██║ ███████╗ ██║ * ╚═╝ ╚═╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚═╝ ╚══════╝ ╚═╝ * * ██╗ ██╗██╗ ██╗██╗████████╗███████╗██╗ ██╗███████╗████████╗ * ██║ ██║██║ ██║██║╚══██╔══╝██╔════╝██║ ██║██╔════╝╚══██╔══╝ * ██║ █╗ ██║███████║██║ ██║ █████╗ ██║ ██║███████╗ ██║ * ██║███╗██║██╔══██║██║ ██║ ██╔══╝ ██║ ██║╚════██║ ██║ * ╚███╔███╔╝██║ ██║██║ ██║ ███████╗███████╗██║███████║ ██║ * ╚══╝╚══╝ ╚═╝ ╚═╝╚═╝ ╚═╝ ╚══════╝╚══════╝╚═╝╚══════╝ ╚═╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/introspection/IERC165.sol"; /// /// Developer this is the standard interface for all ERC721's written by myself /// interface IMAX721Whitelist is IERC165 { // ERC165 data // whitelistStatus() => 0x9ddf7ad3 // whitelistEnd() => 0xbfb6e0e7 // IMAX721Whitelist => 0x22699a34 // @notice will return status of whitelist function whitelistStatus() external view returns (bool); // @notice will return whitelist end (quantity or time) function whitelistEnd() external view returns (uint256); } /*** * ██╗███╗ ██╗████████╗███████╗██████╗ ███████╗ █████╗ ██████╗███████╗ * ██║████╗ ██║╚══██╔══╝██╔════╝██╔══██╗██╔════╝██╔══██╗██╔════╝██╔════╝ * ██║██╔██╗ ██║ ██║ █████╗ ██████╔╝█████╗ ███████║██║ █████╗ * ██║██║╚██╗██║ ██║ ██╔══╝ ██╔══██╗██╔══╝ ██╔══██║██║ ██╔══╝ * ██║██║ ╚████║ ██║ ███████╗██║ ██║██║ ██║ ██║╚██████╗███████╗ * ╚═╝╚═╝ ╚═══╝ ╚═╝ ╚══════╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚═╝ ╚═════╝╚══════╝ * * ███╗ ███╗ █████╗ ██╗ ██╗ ███████╗██████╗ ██╗ * ████╗ ████║██╔══██╗╚██╗██╔╝ ╚════██║╚════██╗███║ * ██╔████╔██║███████║ ╚███╔╝█████╗ ██╔╝ █████╔╝╚██║ * ██║╚██╔╝██║██╔══██║ ██╔██╗╚════╝██╔╝ ██╔═══╝ ██║ * ██║ ╚═╝ ██║██║ ██║██╔╝ ██╗ ██║ ███████╗ ██║ * ╚═╝ ╚═╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚═╝ ╚══════╝ ╚═╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/introspection/IERC165.sol"; /// /// Developer this is the standard interface for all ERC721's written by myself /// interface IMAX721 is IERC165 { // ERC165 data // minterStatus() => 0x2ecd28ab // minterFees() => 0xd95ae162 // minterMaximumCapacity() => 0x78c5939b // minterMaximumTeamMints() => 0x049157bb // minterTeamMintsRemaining() => 0x5c17e370 // minterTeamMintsCount() => 0xe68b7961 // totalSupply() => 0x18160ddd // IMAX721 => 0x29499a25 // @notice will return status of Minter // minterStatus() => 0x2ecd28ab function minterStatus() external view returns (bool); // @notice will return minting fees // minterFees() => 0xd95ae162 function minterFees() external view returns (uint256); // @notice will return maximum mint capacity // minterMaximumCapacity() => 0x78c5939b function minterMaximumCapacity() external view returns (uint256); // @notice will return maximum "team minting" capacity // minterMaximumTeamMints() => 0x049157bb function minterMaximumTeamMints() external view returns (uint256); // @notice will return "team mints" left // minterTeamMintsRemaining() => 0x5c17e370 function minterTeamMintsRemaining() external view returns (uint256); // @notice will return "team mints" count // minterTeamMintsCount() => 0xe68b7961 function minterTeamMintsCount() external view returns (uint256); // @notice will return current token count // totalSupply() => 0x18160ddd function totalSupply() external view returns (uint256); } /*** * ██╗ ██████╗ ██████╗ ███╗ ██╗████████╗██████╗ █████╗ ██████╗████████╗ ██╗ ██╗██████╗ ██╗ * ██║██╔════╝██╔═══██╗████╗ ██║╚══██╔══╝██╔══██╗██╔══██╗██╔════╝╚══██╔══╝ ██║ ██║██╔══██╗██║ * ██║██║ ██║ ██║██╔██╗ ██║ ██║ ██████╔╝███████║██║ ██║ ██║ ██║██████╔╝██║ * ██║██║ ██║ ██║██║╚██╗██║ ██║ ██╔══██╗██╔══██║██║ ██║ ██║ ██║██╔══██╗██║ * ██║╚██████╗╚██████╔╝██║ ╚████║ ██║ ██║ ██║██║ ██║╚██████╗ ██║ ╚██████╔╝██║ ██║██║ * ╚═╝ ╚═════╝ ╚═════╝ ╚═╝ ╚═══╝ ╚═╝ ╚═╝ ╚═╝╚═╝ ╚═╝ ╚═════╝ ╚═╝ ╚═════╝ ╚═╝ ╚═╝╚═╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] * * Purpose: OpenSea compliance on chain ID #1-5 */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/introspection/IERC165.sol"; interface IContractURI is IERC165{ // contractURI() => 0xe8a3d485 // IContractURI => 0xe8a3d485 // @notice this is the contractURI() for OpeanSea compliance // contractURI() => 0xe8a3d485 function contractURI() external view returns (string memory); } /*** * ██╗██████╗ █████╗ ██╗ ██╗ ██████╗ * ██║██╔══██╗██╔══██╗╚██╗ ██╔╝██╔════╝ * ██║██████╔╝███████║ ╚████╔╝ ██║ * ██║██╔══██╗██╔══██║ ╚██╔╝ ██║ * ██║██████╔╝██║ ██║ ██║ ╚██████╗ * ╚═╝╚═════╝ ╚═╝ ╚═╝ ╚═╝ ╚═════╝ * Written by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] * * Purpose: Insipired by BAYC on Ethereum, Sets Provential Hashes and More * Source: https://etherscan.io/address/0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d#code */ // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/introspection/IERC165.sol"; interface IBAYC is IERC165{ // ERC165 // RevealTimestamp() => 0x83ba7c1d // RevealProvenanceImages() => 0xd792d2a0 // RevealProvenanceJSON() => 0x94352676 // RevealStartNumber() => 0x1efb051a // IBAYC => 0x515a7c7c // @notice will return timestamp of reveal // RevealTimestamp() => 0x83ba7c1d function RevealTimestamp() external view returns (uint256); // @notice will return Provenance hash of images // RevealProvenanceImages() => 0xd792d2a0 function RevealProvenanceImages() external view returns (string memory); // @notice will return Provenance hash of metadata // RevealProvenanceJSON() => 0x94352676 function RevealProvenanceJSON() external view returns (string memory); // @notice will return starting number for mint // RevealStartNumber() => 0x1efb051a function RevealStartNumber() external view returns (uint256); } /*** * ██████╗ ███████╗██╗ ██╗███████╗██╗ ██████╗ ██████╗ ███████╗██████╗ * ██╔══██╗██╔════╝██║ ██║██╔════╝██║ ██╔═══██╗██╔══██╗██╔════╝██╔══██╗ * ██║ ██║█████╗ ██║ ██║█████╗ ██║ ██║ ██║██████╔╝█████╗ ██████╔╝ * ██║ ██║██╔══╝ ╚██╗ ██╔╝██╔══╝ ██║ ██║ ██║██╔═══╝ ██╔══╝ ██╔══██╗ * ██████╔╝███████╗ ╚████╔╝ ███████╗███████╗╚██████╔╝██║ ███████╗██║ ██║ * ╚═════╝ ╚══════╝ ╚═══╝ ╚══════╝╚══════╝ ╚═════╝ ╚═╝ ╚══════╝╚═╝ ╚═╝ * This is a re-write of @openzeppelin/contracts/access/Ownable.sol * Rewritten by MaxFlowO2, Senior Developer and Partner of G&M² Labs * Follow me on https://github.com/MaxflowO2 or Twitter @MaxFlowO2 * email: [email protected] */ // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.3.2 // Rewritten for onlyDev modifier pragma solidity >=0.8.0 <0.9.0; import "@openzeppelin/contracts/utils/Context.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (a developer) that can be granted exclusive access to * specific functions. * * By default, the developer account will be the one that deploys the contract. This * can later be changed with {transferDeveloper}. * * This module is used through inheritance. It will make available the modifier * `onlyDev`, which can be applied to your functions to restrict their use to * the developer. */ abstract contract Developer is Context { // ERC165 // developer() => 0xca4b208b // renounceDeveloper() => 0xad6d9c17 // transferDeveloper(address) => 0xb671f4ea // Developer => 0x18f19aba address private _developer; event DeveloperTransferred(address indexed previousDeveloper, address indexed newDeveloper); /** * @dev Initializes the contract setting the deployer as the initial developer. */ constructor() { _transferDeveloper(_msgSender()); } /** * @dev Returns the address of the current developer. */ // developer() => 0xca4b208b function developer() public view virtual returns (address) { return _developer; } /** * @dev Throws if called by any account other than the developer. */ modifier onlyDev() { require(developer() == _msgSender(), "Developer: caller is not the developer"); _; } /** * @dev Leaves the contract without developer. It will not be possible to call * `onlyDev` functions anymore. Can only be called by the current developer. * * NOTE: Renouncing developership will leave the contract without an developer, * thereby removing any functionality that is only available to the developer. */ // renounceDeveloper() => 0xad6d9c17 function renounceDeveloper() public virtual onlyDev { _transferDeveloper(address(0)); } /** * @dev Transfers Developer of the contract to a new account (`newDeveloper`). * Can only be called by the current developer. */ // transferDeveloper(address) => 0x64cb4edb function transferDeveloper(address newDeveloper) public virtual onlyDev { require(newDeveloper != address(0), "Developer: new developer is the zero address"); _transferDeveloper(newDeveloper); } /** * @dev Transfers Developer of the contract to a new account (`newDeveloper`). * Internal function without access restriction. */ function _transferDeveloper(address newDeveloper) internal virtual { address oldDeveloper = _developer; _developer = newDeveloper; emit DeveloperTransferred(oldDeveloper, newDeveloper); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (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 v4.4.0 (utils/introspection/ERC165Storage.sol) pragma solidity ^0.8.0; import "./ERC165.sol"; /** * @dev Storage based implementation of the {IERC165} interface. * * Contracts may inherit from this and call {_registerInterface} to declare * their support of an interface. */ abstract contract ERC165Storage is ERC165 { /** * @dev Mapping of interface ids to whether or not it's supported. */ mapping(bytes4 => bool) private _supportedInterfaces; /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return super.supportsInterface(interfaceId) || _supportedInterfaces[interfaceId]; } /** * @dev Registers the contract as an implementer of the interface defined by * `interfaceId`. Support of the actual ERC165 interface is automatic and * registering its interface id is not required. * * See {IERC165-supportsInterface}. * * Requirements: * * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). */ function _registerInterface(bytes4 interfaceId) internal virtual { require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); _supportedInterfaces[interfaceId] = true; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (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 v4.4.0 (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 v4.4.0 (utils/Counters.sol) pragma solidity ^0.8.0; /** * @title Counters * @author Matt Condon (@shrugs) * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number * of elements in a mapping, issuing ERC721 ids, or counting request ids. * * Include with `using Counters for Counters.Counter;` */ library Counters { struct Counter { // This variable should never be directly accessed by users of the library: interactions must be restricted to // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add // this feature: see https://github.com/ethereum/solidity/issues/4637 uint256 _value; // default: 0 } function current(Counter storage counter) internal view returns (uint256) { return counter._value; } function increment(Counter storage counter) internal { unchecked { counter._value += 1; } } function decrement(Counter storage counter) internal { uint256 value = counter._value; require(value > 0, "Counter: decrement overflow"); unchecked { counter._value = value - 1; } } function reset(Counter storage counter) internal { counter._value = 0; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (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 v4.4.0 (utils/Address.sol) pragma solidity ^0.8.0; /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize, which returns 0 for contracts in // construction, since the code is only stored at the end of the // constructor execution. uint256 size; assembly { size := extcodesize(account) } return size > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); require(isContract(target), "Address: call to non-contract"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { require(isContract(target), "Address: static call to non-contract"); (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a delegate call. * * _Available since v3.4._ */ function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { return functionDelegateCall(target, data, "Address: low-level delegate call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a delegate call. * * _Available since v3.4._ */ function functionDelegateCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { require(isContract(target), "Address: delegate call to non-contract"); (bool success, bytes memory returndata) = target.delegatecall(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (token/ERC721/extensions/IERC721Metadata.sol) pragma solidity ^0.8.0; import "../IERC721.sol"; /** * @title ERC-721 Non-Fungible Token Standard, optional metadata extension * @dev See https://eips.ethereum.org/EIPS/eip-721 */ interface IERC721Metadata is IERC721 { /** * @dev Returns the token collection name. */ function name() external view returns (string memory); /** * @dev Returns the token collection symbol. */ function symbol() external view returns (string memory); /** * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token. */ function tokenURI(uint256 tokenId) external view returns (string memory); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (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 v4.4.0 (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 v4.4.0 (token/ERC721/ERC721.sol) pragma solidity ^0.8.0; import "./IERC721.sol"; import "./IERC721Receiver.sol"; import "./extensions/IERC721Metadata.sol"; import "../../utils/Address.sol"; import "../../utils/Context.sol"; import "../../utils/Strings.sol"; import "../../utils/introspection/ERC165.sol"; /** * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including * the Metadata extension, but not including the Enumerable extension, which is available separately as * {ERC721Enumerable}. */ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata { using Address for address; using Strings for uint256; // Token name string private _name; // Token symbol string private _symbol; // Mapping from token ID to owner address mapping(uint256 => address) private _owners; // Mapping owner address to token count mapping(address => uint256) private _balances; // Mapping from token ID to approved address mapping(uint256 => address) private _tokenApprovals; // Mapping from owner to operator approvals mapping(address => mapping(address => bool)) private _operatorApprovals; /** * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC721Metadata).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC721-balanceOf}. */ function balanceOf(address owner) public view virtual override returns (uint256) { require(owner != address(0), "ERC721: balance query for the zero address"); return _balances[owner]; } /** * @dev See {IERC721-ownerOf}. */ function ownerOf(uint256 tokenId) public view virtual override returns (address) { address owner = _owners[tokenId]; require(owner != address(0), "ERC721: owner query for nonexistent token"); return owner; } /** * @dev See {IERC721Metadata-name}. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev See {IERC721Metadata-symbol}. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev See {IERC721Metadata-tokenURI}. */ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); string memory baseURI = _baseURI(); return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : ""; } /** * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each * token will be the concatenation of the `baseURI` and the `tokenId`. Empty * by default, can be overriden in child contracts. */ function _baseURI() internal view virtual returns (string memory) { return ""; } /** * @dev See {IERC721-approve}. */ function approve(address to, uint256 tokenId) public virtual override { address owner = ERC721.ownerOf(tokenId); require(to != owner, "ERC721: approval to current owner"); require( _msgSender() == owner || isApprovedForAll(owner, _msgSender()), "ERC721: approve caller is not owner nor approved for all" ); _approve(to, tokenId); } /** * @dev See {IERC721-getApproved}. */ function getApproved(uint256 tokenId) public view virtual override returns (address) { require(_exists(tokenId), "ERC721: approved query for nonexistent token"); return _tokenApprovals[tokenId]; } /** * @dev See {IERC721-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public virtual override { _setApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC721-isApprovedForAll}. */ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { return _operatorApprovals[owner][operator]; } /** * @dev See {IERC721-transferFrom}. */ function transferFrom( address from, address to, uint256 tokenId ) public virtual override { //solhint-disable-next-line max-line-length require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); _transfer(from, to, tokenId); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId ) public virtual override { safeTransferFrom(from, to, tokenId, ""); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId, bytes memory _data ) public virtual override { require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); _safeTransfer(from, to, tokenId, _data); } /** * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients * are aware of the ERC721 protocol to prevent tokens from being forever locked. * * `_data` is additional data, it has no specified format and it is sent in call to `to`. * * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g. * implement alternative mechanisms to perform token transfer, such as signature-based. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function _safeTransfer( address from, address to, uint256 tokenId, bytes memory _data ) internal virtual { _transfer(from, to, tokenId); require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); } /** * @dev Returns whether `tokenId` exists. * * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}. * * Tokens start existing when they are minted (`_mint`), * and stop existing when they are burned (`_burn`). */ function _exists(uint256 tokenId) internal view virtual returns (bool) { return _owners[tokenId] != address(0); } /** * @dev Returns whether `spender` is allowed to manage `tokenId`. * * Requirements: * * - `tokenId` must exist. */ function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) { require(_exists(tokenId), "ERC721: operator query for nonexistent token"); address owner = ERC721.ownerOf(tokenId); return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender)); } /** * @dev Safely mints `tokenId` and transfers it to `to`. * * Requirements: * * - `tokenId` must not exist. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function _safeMint(address to, uint256 tokenId) internal virtual { _safeMint(to, tokenId, ""); } /** * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is * forwarded in {IERC721Receiver-onERC721Received} to contract recipients. */ function _safeMint( address to, uint256 tokenId, bytes memory _data ) internal virtual { _mint(to, tokenId); require( _checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer" ); } /** * @dev Mints `tokenId` and transfers it to `to`. * * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible * * Requirements: * * - `tokenId` must not exist. * - `to` cannot be the zero address. * * Emits a {Transfer} event. */ function _mint(address to, uint256 tokenId) internal virtual { require(to != address(0), "ERC721: mint to the zero address"); require(!_exists(tokenId), "ERC721: token already minted"); _beforeTokenTransfer(address(0), to, tokenId); _balances[to] += 1; _owners[tokenId] = to; emit Transfer(address(0), to, tokenId); } /** * @dev Destroys `tokenId`. * The approval is cleared when the token is burned. * * Requirements: * * - `tokenId` must exist. * * Emits a {Transfer} event. */ function _burn(uint256 tokenId) internal virtual { address owner = ERC721.ownerOf(tokenId); _beforeTokenTransfer(owner, address(0), tokenId); // Clear approvals _approve(address(0), tokenId); _balances[owner] -= 1; delete _owners[tokenId]; emit Transfer(owner, address(0), tokenId); } /** * @dev Transfers `tokenId` from `from` to `to`. * As opposed to {transferFrom}, this imposes no restrictions on msg.sender. * * Requirements: * * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * * Emits a {Transfer} event. */ function _transfer( address from, address to, uint256 tokenId ) internal virtual { require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); require(to != address(0), "ERC721: transfer to the zero address"); _beforeTokenTransfer(from, to, tokenId); // Clear approvals from the previous owner _approve(address(0), tokenId); _balances[from] -= 1; _balances[to] += 1; _owners[tokenId] = to; emit Transfer(from, to, tokenId); } /** * @dev Approve `to` to operate on `tokenId` * * Emits a {Approval} event. */ function _approve(address to, uint256 tokenId) internal virtual { _tokenApprovals[tokenId] = to; emit Approval(ERC721.ownerOf(tokenId), to, tokenId); } /** * @dev Approve `operator` to operate on all of `owner` tokens * * Emits a {ApprovalForAll} event. */ function _setApprovalForAll( address owner, address operator, bool approved ) internal virtual { require(owner != operator, "ERC721: approve to caller"); _operatorApprovals[owner][operator] = approved; emit ApprovalForAll(owner, operator, approved); } /** * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address. * The call is not executed if the target address is not a contract. * * @param from address representing the previous owner of the given token ID * @param to target address that will receive the tokens * @param tokenId uint256 ID of the token to be transferred * @param _data bytes optional data to send along with the call * @return bool whether the call correctly returned the expected magic value */ function _checkOnERC721Received( address from, address to, uint256 tokenId, bytes memory _data ) private returns (bool) { if (to.isContract()) { try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) { return retval == IERC721Receiver.onERC721Received.selector; } catch (bytes memory reason) { if (reason.length == 0) { revert("ERC721: transfer to non ERC721Receiver implementer"); } else { assembly { revert(add(32, reason), mload(reason)) } } } } else { return true; } } /** * @dev Hook that is called before any token transfer. This includes minting * and burning. * * Calling conditions: * * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be * transferred to `to`. * - When `from` is zero, `tokenId` will be minted for `to`. * - When `to` is zero, ``from``'s `tokenId` will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 tokenId ) internal virtual {} } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (security/ReentrancyGuard.sol) pragma solidity ^0.8.0; /** * @dev Contract module that helps prevent reentrant calls to a function. * * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier * available, which can be applied to functions to make sure there are no nested * (reentrant) calls to them. * * Note that because there is a single `nonReentrant` guard, functions marked as * `nonReentrant` may not call one another. This can be worked around by making * those functions `private`, and then adding `external` `nonReentrant` entry * points to them. * * TIP: If you would like to learn more about reentrancy and alternative ways * to protect against it, check out our blog post * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul]. */ abstract contract ReentrancyGuard { // Booleans are more expensive than uint256 or any type that takes up a full // word because each write operation emits an extra SLOAD to first read the // slot's contents, replace the bits taken up by the boolean, and then write // back. This is the compiler's defense against contract upgrades and // pointer aliasing, and it cannot be disabled. // The values being non-zero value makes deployment a bit more expensive, // but in exchange the refund on every call to nonReentrant will be lower in // amount. Since refunds are capped to a percentage of the total // transaction's gas, it is best to keep them low in cases like this one, to // increase the likelihood of the full refund coming into effect. uint256 private constant _NOT_ENTERED = 1; uint256 private constant _ENTERED = 2; uint256 private _status; constructor() { _status = _NOT_ENTERED; } /** * @dev Prevents a contract from calling itself, directly or indirectly. * Calling a `nonReentrant` function from another `nonReentrant` * function is not supported. It is possible to prevent this from happening * by making the `nonReentrant` function external, and making it call a * `private` function that does the actual work. */ modifier nonReentrant() { // On the first call to nonReentrant, _notEntered will be true require(_status != _ENTERED, "ReentrancyGuard: reentrant call"); // Any calls to nonReentrant after this point will fail _status = _ENTERED; _; // By storing the original value once again, a refund is triggered (see // https://eips.ethereum.org/EIPS/eip-2200) _status = _NOT_ENTERED; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.0 (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); } }