Accesslists

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract Accesslist is ERC721, Ownable {
bytes32 public merkleRoot;
uint256 public nextTokenId;
mapping(address => bool) public claimed;

constructor() ERC721("ExampleNFT", "NFT") {
    merkleRoot = 0x0;
}

function isWhiteListed(bytes32[] memory proof, bytes32 leaf) public view returns(bool) {
        return MerkleProof.verify(proof, merkleRoot, leaf);
    }

function setMerkleRoot(bytes32 merkleRoot_) external onlyOwner{
    merkleRoot = merkleRoot_;
}

function mint(address to, bytes32[] calldata merkleProof) public payable {
    require(claimed[to] == false, "already claimed");
    claimed[to] = true;
    require(isWhiteListed(merkleProof, keccak256(abi.encodePacked(to))), "invalid merkle proof");
    nextTokenId++;
    _mint(to, nextTokenId);
}
}

mapping(address => uint256) public whitelistMapping;

function presale(address _to, uint256 _count) external payable {
// ensure _to address has tokens left to mint
require(whitelistMapping[_to] > 0, "no whitelist tokens for user");

// decrement mapping for user
whitelistMapping[_to] -= _count;

// presale minting logic here
}