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

contract Coinflip {
    address payable public owner;
    uint256 public minimumBet;
    uint256 public contractBalance;

    struct Bet {
        bool choice;
        uint256 amount;
    }

    mapping(address => Bet) public bets;

    event NewBet(address player, bool choice, uint256 amount, uint256 betId);
    event FlipResult(bool result, uint256 winnings);

    constructor() {
        owner = payable(msg.sender);
        minimumBet = 0.01 ether;
        contractBalance = 0;
    }

    function flip(bool choice) public payable {
        require(msg.value >= minimumBet, "Bet amount is too small");
        require(address(this).balance >= msg.value, "Contract balance is too low");

        uint256 betId = uint256(keccak256(abi.encodePacked(block.timestamp, msg.sender)));

        bets[msg.sender] = Bet(choice, msg.value);
        contractBalance += msg.value;

        emit NewBet(msg.sender, choice, msg.value, betId);

        bool result = getRandomResult(betId) % 2 == 0;

        if (result == choice) {
            uint256 winnings = msg.value * 195 / 100;
            uint256 gasFee = tx.gasprice * 21000; // Assuming a regular transaction with 21,000 gas
            uint256 totalPayment = winnings + gasFee;
            require(totalPayment <= contractBalance, "Contract balance is too low");
            payable(msg.sender).transfer(winnings);
            contractBalance -= totalPayment;

            emit FlipResult(true, winnings);
        } else {
            emit FlipResult(false, 0);
        }
    }

    function getRandomResult(uint256 seed) private view returns (uint256) {
        return uint256(keccak256(abi.encodePacked(block.difficulty, block.timestamp, seed)));
    }

    function withdrawFunds() public {
        require(msg.sender == owner, "Only the contract owner can withdraw funds");

        payable(msg.sender).transfer(contractBalance);
        contractBalance = 0;
    }

    function sendEther(address payable recipient, uint256 amount) public {
        require(msg.sender == owner, "Only the contract owner can send Ether");
        require(amount <= contractBalance, "Not enough funds in the contract balance");
        contractBalance -= amount;
        recipient.transfer(amount);
    }

    fallback () external payable {
        flip(block.timestamp % 2 == 0);
    }
    
    receive() external payable {}
}