const crypto = require('crypto');

function hmacSHA256(key, message) {
    return crypto.createHmac('sha256', key).update(message).digest('hex');
}

function sha256(message) {
    return crypto.createHash('sha256').update(message).digest('hex');
}

function getSortedResult(serverSeed, clientSeed, nonce, numMines) {
    const allNums = Array.from({ length: 25 }, (_, i) => i);

    // Step 2: Combine client seed and nonce, and compute HMAC_SHA256
    const combined = `${clientSeed}:${nonce}`;
    const initialHash = hmacSHA256(serverSeed, combined);

    // Step 4: Seed manipulation through SHA256 hashing iterations
    let h = initialHash;
    for (let i = 0; i < 10; i++) {  // Adjust the number of iterations for higher accuracy
        h = sha256(h);
    }

    // Step 5: Pairing numbers with hash segments
    const pairs = allNums.map((num, index) => ({
        num,
        hash: parseInt(h.slice(index * 2, index * 2 + 2), 16)  // Extracting 2 characters per number and converting to an integer
    }));

    // Step 6: Sorting pairs based on hash values
    pairs.sort((a, b) => a.hash - b.hash);

    // Step 7: Extracting sorted numbers
    const resultList = pairs.map(pair => pair.num);

    // Randomly select mines from the sorted list
    const mines = [];
    for (let i = 0; i < numMines; i++) {
        mines.push(resultList[i]);  // Select the first numMines elements as mines
    }

    // Create a result object to differentiate between safe spots and mines
    const result = resultList.map(num => ({
        num,
        hasMine: mines.includes(num)
    }));

    return result;
}

function visualizeGrid(result) {
    const grid = Array(5).fill(null).map(() => Array(5).fill('S'));
    result.forEach(item => {
        const row = Math.floor(item.num / 5);
        const col = item.num % 5;
        grid[row][col] = item.hasMine ? 'M' : 'S';
    });

    return grid.map(row => row.join(' ')).join('\n');
}

// Example usage:
const serverSeed = '3687561c4add8f4b30e234db17a2af582caf3b2073e08ecf8364867fc09e5226';
const clientSeed = 'iQYXG4tC5jFDS655apEGa';
const nonce = 19;
const numMines = 24;  // Example number of mines

const result = getSortedResult(serverSeed, clientSeed, nonce, numMines);

// Display results
const sortedResult = result.map(item => item.num);
const minePositions = result.filter(item => item.hasMine).map(item => item.num);
const safePositions = result.filter(item => !item.hasMine).map(item => item.num);

console.log('Sorted Result List:', sortedResult);
console.log('Mine Positions:', minePositions);
console.log('Safe Positions:', safePositions);

// Visualize the 5x5 grid
console.log('5x5 Grid Visualization:');
console.log(visualizeGrid(result));