Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract SimpleNftLowerGas is ERC721, Ownable {
using Strings for uint256;
using Counters for Counters.Counter;
Counters.Counter private supply;
string public uriPrefix = "";
string public uriSuffix = ".json";
string public hiddenMetadataUri;
uint256 public cost = 0.01 ether;
uint256 public maxSupply = 10000;
uint256 public maxMintAmountPerTx = 5;
bool public paused = true;
bool public revealed = false;
constructor() ERC721("NAME", "SYMBOL") {
setHiddenMetadataUri("ipfs://__CID__/hidden.json");
}
modifier mintCompliance(uint256 _mintAmount) {
require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, "Invalid mint amount!");
require(supply.current() + _mintAmount <= maxSupply, "Max supply exceeded!");
_;
}
function totalSupply() public view returns (uint256) {
return supply.current();
}
function mint(uint256 _mintAmount) public payable mintCompliance(_mintAmount) {
require(!paused, "The contract is paused!");
require(msg.value >= cost * _mintAmount, "Insufficient funds!");
_mintLoop(msg.sender, _mintAmount);
}
function mintForAddress(uint256 _mintAmount, address _receiver) public mintCompliance(_mintAmount) onlyOwner {
_mintLoop(_receiver, _mintAmount);
}
function walletOfOwner(address _owner)
public
view
returns (uint256[] memory)
{
uint256 ownerTokenCount = balanceOf(_owner);
uint256[] memory ownedTokenIds = new uint256[](ownerTokenCount);
uint256 currentTokenId = 1;
uint256 ownedTokenIndex = 0;
while (ownedTokenIndex < ownerTokenCount && currentTokenId <= maxSupply) {
address currentTokenOwner = ownerOf(currentTokenId);
if (currentTokenOwner == _owner) {
ownedTokenIds[ownedTokenIndex] = currentTokenId;
ownedTokenIndex++;
}
currentTokenId++;
}
return ownedTokenIds;
}
function tokenURI(uint256 _tokenId)
public
view
virtual
override
returns (string memory)
{
require(
_exists(_tokenId),
"ERC721Metadata: URI query for nonexistent token"
);
if (revealed == false) {
return hiddenMetadataUri;
}
string memory currentBaseURI = _baseURI();
return bytes(currentBaseURI).length > 0
? string(abi.encodePacked(currentBaseURI, _tokenId.toString(), uriSuffix))
: "";
}
function setRevealed(bool _state) public onlyOwner {
revealed = _state;
}
function setCost(uint256 _cost) public onlyOwner {
cost = _cost;
}
function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx) public onlyOwner {
maxMintAmountPerTx = _maxMintAmountPerTx;
}
function setHiddenMetadataUri(string memory _hiddenMetadataUri) public onlyOwner {
hiddenMetadataUri = _hiddenMetadataUri;
}
function setUriPrefix(string memory _uriPrefix) public onlyOwner {
uriPrefix = _uriPrefix;
}
function setUriSuffix(string memory _uriSuffix) public onlyOwner {
uriSuffix = _uriSuffix;
}
function setPaused(bool _state) public onlyOwner {
paused = _state;
}
function withdraw() public onlyOwner {
// This will pay to CryptoValentin 5% of the initial sale.
// You can remove this if you want, or keep it in to support CryptoValentin and his channel.
// =============================================================================
(bool hs, ) = payable(0x8A1b7E7b50B8d68A3171eF5E7fee691DA01d9485).call{value: address(this).balance * 5 / 100}("");
require(hs);
// =============================================================================
// This will transfer the remaining contract balance to the owner.
// Do not remove this otherwise you will not be able to withdraw the funds.
// =============================================================================
(bool os, ) = payable(owner()).call{value: address(this).balance}("");
require(os);
// =============================================================================
}
function _mintLoop(address _receiver, uint256 _mintAmount) internal {
for (uint256 i = 0; i < _mintAmount; i++) {
supply.increment();
_safeMint(_receiver, supply.current());
}
}
function _baseURI() internal view virtual override returns (string memory) {
return uriPrefix;
}
}