Token.sol

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

import "erc721a/contracts/ERC721A.sol";
import "erc721a/contracts/extensions/ERC721AQueryable.sol";

contract Token is ERC721A, ERC721AQueryable {
  enum TokenTypes {
    None,
    Fist,
    Second,
    Third
  }

  uint16 firstCount = 600;
  uint16 secondCount = 300;
  uint16 thirdCount = 100;

  uint16 constant MAX_SUPPLY = 1000;

  mapping(uint256 => TokenTypes) public tokenType;

  constructor() ERC721A("Token", "T") {}

  function mint(uint256 _quantity) external payable {
    uint256 _totalSupply = _currentIndex;
    uint256 _supplyCount = _totalSupply + _quantity;

    require(_supplyCount <= MAX_SUPPLY, "Exceeds supply");

    unchecked {
      for (uint256 i = _totalSupply; i < _supplyCount; ++i) {
        uint256 _rand = random();

        if (_rand <= thirdCount) {
          tokenType[i] = TokenTypes.Third;
          thirdCount--;
        } else if (_rand <= secondCount) {
          tokenType[i] = TokenTypes.Second;
          secondCount--;
        } else if (_rand <= firstCount) {
          tokenType[i] = TokenTypes.First;
          firstCount--;
        }
      }
    }

    _safeMint(msg.sender, _quantity);
  }

  function random() internal view returns (uint256) {
    uint256 _totalSupply = getLargestSupply();

    return
      (uint256(
        keccak256(
          abi.encodePacked(
            msg.sender,
            block.difficulty,
            block.timestamp,
            _totalSupply
          )
        )
      ) % _totalSupply) + 1;
  }

  function getLargestSupply() internal view returns (uint16) {
    if (firstCount >= secondCount && firstCount >= thirdCount) {
      return firstCount;
    } else if (studioCount >= firstCount && secondCount >= thirdCount) {
      return secondCount;
    } else {
      return thirdCount;
    }
  }
}