theFairLoto.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract theFairLoto {

    struct Commitment {
        uint256 deposit;
        uint256 timestamp;
        bool claimed;
    }

    bytes32[] public commitments; // Store all commitments
    uint256 public totalDeposits;
    uint256 public randomResult;
    bool public randomNumberGenerated;
    address public owner;
    
    uint256 public constant TTL = 30 days;

    event CommitmentSubmitted(address indexed user, bytes32 commitment);

    constructor() {
        owner = msg.sender;
    }

    // Function to submit a commitment
    function submitCommitment(bytes32 _commitment) public payable {
        require(msg.value == 1 ether, "You must deposit exactly 1 ETH");

        commitments.push(_commitment);  // Store commitment in array
        totalDeposits += msg.value;
        emit CommitmentSubmitted(msg.sender, _commitment);
    }

    // Function to get the number of commitments
    function getCommitmentCount() public view returns (uint256) {
        return commitments.length;
    }

        // Random number generation after TTL has expired
    function generateRandomNumber() public {
        require(block.timestamp > block.timestamp + TTL, "Too early to generate random number");
        require(!randomNumberGenerated, "Random number already generated");

        uint256 commitmentCount = commitments.length;
        require(commitmentCount > 0, "No commitments made");

        // Generate a random index based on the number of participants
        randomResult = uint256(keccak256(abi.encodePacked(block.timestamp, block.difficulty))) % 10000; // Range 1-10000
        randomNumberGenerated = true;
    }

    // Function to get the winning number
    function getWinningNumber() public view returns (uint256) {
        require(randomNumberGenerated, "Random number has not been generated yet");
        return randomResult;
    }


    // Verify zk-SNARK proof and allow winner to claim the prize
    function submitProof(
        uint256[8] calldata proof,  // zk-SNARK proof elements
        uint256[1] calldata input   // zk-SNARK input (the commitment hash)
    ) public {
        require(randomNumberGenerated, "Random number has not been generated yet");

        // Verify zk-SNARK proof
        bool valid = verifyProof(proof, input);
        require(valid, "Invalid proof");

        require(WinnerClaimedFlag, "Time of claimed winner isn't finish yet");
        // If the proof is valid, the participant's commitment was based on the winning number
        // This participant can claim their portion of the prize

        Commitment storage commitment = commitments[bytes32(input[0])];
        require(commitment.deposit > 0, "No commitment found");
        require(!commitment.claimed, "Commitment already claimed");

        // Transfer the prize (split among valid winners)
        uint256 numberOfWinners = getNumberOfValidWinners(); 
        uint256 share = totalDeposits / numberOfWinners;

        commitment.claimed = true;
        payable(msg.sender).transfer(share);
    }   

    bool WinnerClaimedFlag = false;

    // Function to calculate the number of valid winners
    function getNumberOfValidWinners() internal view returns (uint256) onlyOwner {
        // we limit this function to- 1 day afte the TTL- meaning
        uint256 winnerCount = 0;
        
        // Loop through all commitments and count the ones related to the winning number
        for (uint256 i = 0; i < commitments.length; i++) {
            if (isValidCommitment(commitments[i])) { // This function would check if the commitment is related to the winning number
                winnerCount++;
            }
    }   

        // only going to be true once the prizepool(submission to the commitments is over and the winner was declared
        if (timeOfPrizePool + block.timestamp) { 
            WinnerClaimedFlag = true
        }
        
        return winnerCount;
    }

    // zk-SNARKs or a different off-chain verification mechanism to ensure only valid commitments are considered
    function isValidCommitment(bytes32 commitment) internal view returns (bool) {
        // Logic to determine if the commitment corresponds to the winning number
        // This can involve comparing with zk-SNARK proofs or other cryptographic methods
    }

}