tiny baby dinos

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9 <0.9.0;

import "https://github.com/FrankNFT-labs/ERC721F/blob/v1.0.2/ERC721F.sol";


/**
 * @title tiny baby dinos contract
 * @dev Extends ERC721F Non-Fungible Token Standard basic implementation.
 * Optimized to no longer use ERC721Enumarable , but still provide a totalSupply() implementation.
 * @author @FrankNFT.eth
 */

contract TinyBabyDinos is ERC721F {
    
    uint256 public constant MAX_TOKENS=5000;
    uint public constant MAX_PURCHASE = 21; // set 1 to high to avoid some gas
    uint public constant MAX_RESERVE = 26; // set 1 to high to avoid some gas
    
    bool public saleIsActive;

    address private constant FRANK = 0xF40Fd88ac59A206D009A07F8c09828a01e2ACC0d;
    
    constructor() ERC721F("tiny baby dinos", "TBD") {
        setBaseTokenURI("ipfs://Qmad7WxHtjEacWMEDnNhRkVa5b5zPH41nEqKMap36PtPwx/"); 
        _safeMint( FRANK, 0);
    }

    /**
     * Mint Tokens to a wallet.
     */
    function mint(address to,uint numberOfTokens) public onlyOwner {    
        uint supply = totalSupply();
        require(supply + numberOfTokens <= MAX_TOKENS, "Reserve would exceed max supply of Tokens");
        require(numberOfTokens < MAX_RESERVE, "Can only mint 25 tokens at a time");
        for (uint i = 0; i < numberOfTokens; i++) {
            _safeMint(to, supply + i);
        }
    }
     /**
     * Mint Tokens to the owners reserve.
     */   
    function reserveTokens() external onlyOwner {    
        mint(owner(),MAX_RESERVE-1);
    }

    /**
     * Pause sale if active, make active if paused
     */
    function flipSaleState() external onlyOwner {
        saleIsActive = !saleIsActive;
    }
    
    /**
     * FREE mint.
     */
    function mint(uint256 numberOfTokens) external {
        require(saleIsActive,"Sale NOT active yet");
        require(numberOfTokens > 0, "numberOfNfts cannot be 0");
        require(numberOfTokens < MAX_PURCHASE, "Can only mint 20 tokens at a time");
        uint256 supply = totalSupply();
        require(supply + numberOfTokens <= MAX_TOKENS, "Purchase would exceed max supply of Tokens");
        for(uint256 i; i < numberOfTokens; i++){
            _safeMint( msg.sender, supply + i );
        }
    }
    
    function withdraw() public onlyOwner {
        uint256 balance = address(this).balance;
        require(balance > 0, "Insufficent balance");
        _withdraw(owner(), address(this).balance);
    }
}

{
  "compilationTarget": {
    "contracts/TinyDinos.sol": "TinyBabyDinos"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 1000
  },
  "remappings": []
}