// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

/// @title TipJar - Multi-currency digital tip jar (ETH + simulated USD/EUR)
/// @author Saurav
/// @notice Accepts ETH tips and simulated foreign currency tips
/// @dev Owner manages conversion rates; all contributions stored in wei-equivalent
contract TipJar {
    address public owner;

    enum Currency { USD, EUR }

    // Conversion: wei-per-cent (1 cent of USD/EUR = X wei)
    mapping(Currency => uint256) public weiPerCent;

    // Track real ETH and simulated (converted) contributions
    mapping(address => uint256) public ethContributed;
    mapping(address => uint256) public simulatedWeiContributed;

    uint256 public totalEthReceived;
    uint256 public totalSimulatedWei;

    // Events
    event EtherTipped(address indexed from, uint256 amountWei, string message);
    event CurrencyTipped(address indexed from, Currency currency, uint256 amountCents, uint256 weiEquivalent, string message);
    event RateUpdated(Currency currency, uint256 weiPerCent);
    event Withdraw(address indexed to, uint256 amountWei);

    modifier onlyOwner() {
        require(msg.sender == owner, "Not owner");
        _;
    }

    constructor(uint256 usdWeiPerCent, uint256 eurWeiPerCent) {
        owner = msg.sender;
        weiPerCent[Currency.USD] = usdWeiPerCent;
        weiPerCent[Currency.EUR] = eurWeiPerCent;
    }

    /// @notice Tip with Ether
    function tipEther(string calldata message) external payable {
        require(msg.value > 0, "Send some ETH");
        ethContributed[msg.sender] += msg.value;
        totalEthReceived += msg.value;
        emit EtherTipped(msg.sender, msg.value, message);
    }

    /// @notice Simulate USD/EUR tip
    function tipCurrency(Currency currency, uint256 amountCents, string calldata message) external {
        require(amountCents > 0, "Amount must be > 0");
        uint256 rate = weiPerCent[currency];
        require(rate > 0, "Rate not set");

        uint256 weiEquivalent = amountCents * rate;
        simulatedWeiContributed[msg.sender] += weiEquivalent;
        totalSimulatedWei += weiEquivalent;

        emit CurrencyTipped(msg.sender, currency, amountCents, weiEquivalent, message);
    }

    /// @notice Update conversion rate (owner only)
    function setRate(Currency currency, uint256 newWeiPerCent) external onlyOwner {
        require(newWeiPerCent > 0, "Rate must be > 0");
        weiPerCent[currency] = newWeiPerCent;
        emit RateUpdated(currency, newWeiPerCent);
    }

    /// @notice Withdraw ETH (owner only)
    function withdraw(address payable to, uint256 amountWei) external onlyOwner {
        require(amountWei <= address(this).balance, "Not enough balance");
        (bool ok, ) = to.call{value: amountWei}("");
        require(ok, "Transfer failed");
        emit Withdraw(to, amountWei);
    }

    /// @notice Get total (ETH + simulated) wei contributed by user
    function totalWeiBy(address user) external view returns (uint256) {
        return ethContributed[user] + simulatedWeiContributed[user];
    }

    receive() external payable {
        ethContributed[msg.sender] += msg.value;
        totalEthReceived += msg.value;
        emit EtherTipped(msg.sender, msg.value, "");
    }
}