// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IERC20 {
    function transfer(address to, uint256 amount) external returns (bool);
    function balanceOf(address a) external view returns (uint256);
}

/// @title Squatchi 1-Month Play-to-Earn Victory Pool
/// @notice Pays 1 $SQUATCHI once per wallet to champions who beat all 10 levels, for 30 days.
contract SquatchiVictoryRewards {
    IERC20 public immutable SQUATCHI;
    uint256 public constant REWARD_AMOUNT = 1e18;
    uint256 public constant ALL_LEVELS_MASK = 0x3FF;
    uint256 public immutable campaignEndTime;
    bytes32 private immutable depositorHash;

    mapping(address => bool) public hasClaimed;
    uint256 public totalWinners;
    bool private locked;

    event VictoryRewarded(address indexed champion, uint256 amount, uint256 timestamp);
    event RemainingRecovered(address indexed to, uint256 amount);

    constructor(address tokenAddress) {
        require(tokenAddress != address(0), "invalid token");
        SQUATCHI = IERC20(tokenAddress);
        campaignEndTime = block.timestamp + 30 days;
        depositorHash = keccak256(abi.encodePacked(msg.sender));
    }

    function expectedProof(address champion) public view returns (bytes32) {
        return keccak256(abi.encodePacked("SQUATCHI_CHAMPION_10_LEVELS", champion, ALL_LEVELS_MASK, address(this)));
    }

    function claimVictoryReward(uint256 starsMask, bytes32 completionProof) external {
        require(!locked, "reentrant");
        require(block.timestamp <= campaignEndTime, "campaign ended");
        require(msg.sender == tx.origin, "EOA only");
        require(!hasClaimed[msg.sender], "already claimed");
        require(starsMask == ALL_LEVELS_MASK, "beat all 10 levels");
        require(completionProof == expectedProof(msg.sender), "bad proof");
        locked = true;
        hasClaimed[msg.sender] = true;
        totalWinners += 1;
        require(SQUATCHI.transfer(msg.sender, REWARD_AMOUNT), "transfer failed");
        locked = false;
        emit VictoryRewarded(msg.sender, REWARD_AMOUNT, block.timestamp);
    }

    function poolBalance() external view returns (uint256) { return SQUATCHI.balanceOf(address(this)); }

    function withdrawTokens(address to, uint256 amount) external {
        require(keccak256(abi.encodePacked(msg.sender)) == depositorHash, "not depositor");
        require(SQUATCHI.transfer(to, amount), "transfer failed");
        emit RemainingRecovered(to, amount);
    }

    function recoverRemainingAfterExpiry(address to) external {
        require(block.timestamp > campaignEndTime, "campaign active");
        require(keccak256(abi.encodePacked(msg.sender)) == depositorHash, "not depositor");
        uint256 bal = SQUATCHI.balanceOf(address(this));
        require(SQUATCHI.transfer(to, bal), "transfer failed");
        emit RemainingRecovered(to, bal);
    }
}