pragma solidity 0.8.14;

import "@openzeppelin/contracts@4.6.0/token/ERC20/ERC20.sol";

contract Crowdfund is ERC20 {
    event LogReceive(address _from, uint256 amount);
    event LogWithdraw(address _to, uint256 amount);

    address public founder;
    uint256 public constant rate = 100;
    
    constructor() ERC20("DeFi For Dummies", "DEFIFD"){
        founder = msg.sender;
        _mint(founder, 1000*1000000000000000000);
    }
    
    receive() external payable {
        emit LogReceive(msg.sender, msg.value);
        _mint(msg.sender, msg.value * rate);
    }

    function withdraw(address payable _to, uint256 amount) public {
        require(msg.sender == founder, "not the founder");
        require(address(this).balance >= amount, "insufficient funds");
        _to.transfer(amount);
        emit LogWithdraw(_to, amount);
    }
}