Update error handling from NFTPort

contracts/contract

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.10;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "erc721a/contracts/ERC721A.sol";
+import "@openzeppelin/contracts/utils/Strings.sol";
+
+import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
+
+
+contract VampirestownNFT is ERC721A, Ownable, ReentrancyGuard {
+
+    using Strings for uint256;
+
+
+    uint256 price;
+    uint256 _maxSupply;
+    uint256 maxMintAmountPerTx; // change when free mint will run out
+    uint256 maxMintAmountPerWallet; //change when free mint will run out
+
+    string baseURL = "QmWAoaxG6xba8dGqLLu2FmHL1BQeHsUAkAZJH7pYfBhj6w";
+    string ExtensionURL = ".json";
+
+
+
+
+    bool paused = false;
+
+
+    constructor(uint256 __maxSupply, string memory _initBaseURI, uint256 _maxMintAmountPerTx, uint256 _maxMintAmountPerWallet) ERC721A("vampirestown", "VAMPIRE") {
+
+        baseURL = _initBaseURI;
+        price = 0.005 ether;
+        _maxSupply = __maxSupply;
+        maxMintAmountPerTx = _maxMintAmountPerTx;
+        maxMintAmountPerWallet = _maxMintAmountPerWallet;
+
+
+    }
+    function priceUpdate(uint256 _supply) internal pure returns (uint256 _price){
+        if(_supply < 25) {
+            return 0 ether;
+        }
+        else {
+            return 0.005 ether;
+        }
+ }
+    // ================== Mint Function =======================
+
+      function mint(address to, uint256 _mintAmount) public payable{
+          uint256 supply = totalSupply();
+          require(!paused, "The contract is paused!");
+          require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, "Invalid mint amount!");
+          require(supply + _mintAmount <= _maxSupply, "You want to suck too much blood. Max supply exceeded!");
+          require(msg.value >= priceUpdate(supply) * _mintAmount, "Are your fangs too short, or you dont have enough funds?");
+          require(balanceOf(msg.sender) + _mintAmount <= maxMintAmountPerWallet, "Dont be greedy! Max mint per wallet exceeded!");
+
+
+
+
+
+          _safeMint(to, _mintAmount);
+      }
+    // ================== Orange Functions (Owner Only) ===============
+
+    function pause(bool state) public onlyOwner {
+        paused = state;
+    }
+
+    function safeMint(address to, uint256 quantity) public onlyOwner {
+        _safeMint(to, quantity);
+    }
+
+    function setbaseURL(string memory uri) public onlyOwner{
+        baseURL = uri;
+    }
+
+    function setExtensionURL(string memory uri) public onlyOwner{
+        ExtensionURL = uri;
+    }
+
+    function setCostPrice(uint256 _cost) public onlyOwner{
+        price = _cost;
+    } 
+
+    function setSupply(uint256 supply) public onlyOwner{
+        _maxSupply = supply;
+    }
+
+    // ================================ Withdraw Function ====================
+
+    function withdraw() public onlyOwner nonReentrant{
+
+        uint256 CurrentContractBalance = address(this).balance;
+        (bool os, ) = payable(owner()).call{value: CurrentContractBalance}("");
+        require(os);
+
+    }
+
+    // =================== Blue Functions (View Only) ====================
+
+    function tokenURI(uint256 tokenId) public view override(ERC721A) returns (string memory){
+
+        require(_exists(tokenId),"ERC721Metadata: URI query for nonexistent token");
+
+        string memory currentBaseURI = _baseURI();
+        return bytes(currentBaseURI).length > 0
+            ? string(abi.encodePacked(currentBaseURI, tokenId.toString(), ExtensionURL))
+            : '';
+
+    }
+
+    function cost() public view returns (uint256){
+        return price;
+    }
+
+    function _baseURI() internal view virtual override returns (string memory) {
+        return baseURL;
+    }
+
+    function maxSupply() public view returns (uint256){
+        return _maxSupply;
+
+    }  
+}