const cells = document.querySelectorAll('.cell');
const resetButton = document.querySelector('#reset');
const aiButton = document.querySelector('#toggle-ai');

let board = Array.from({ length: 9 }, () => 0);
let currentPlayer = 1;
let aiEnabled = true;
let gameMode = 'ai';
let running = true;

function handleClick(e) {
    const cell = e.target;
    const index = cells.findIndex(c => c === cell);

    if (board[index] !== 0 || !running) {
        return;
    }

    makeMove(index);

    if (checkWinner(board) !== 0 || board.every(cell => cell !== 0)) {
        running = false;
    }

    if (running && gameMode === 'ai' && currentPlayer === 2) {
        const { move } = minimax(board, false);
        makeMove(move);

        if (checkWinner(board) !== 0 || board.every(cell => cell !== 0)) {
            running = false;
        }
    }
}

function makeMove(index) {
    board[index] = currentPlayer;
    cells[index].textContent = currentPlayer === 1 ? 'X' : 'O';
    currentPlayer = 3 - currentPlayer;
}

function isRunning() {
    return !checkWinner(board) && board.some(cell => cell === 0);
}

function checkWinner(tempBoard) {
    const winningCombinations = [
        [0, 1, 2],
        [3, 4, 5],
        [6, 7, 8],
        [0, 3, 6],
        [1, 4, 7],
        [2, 5, 8],
        [0, 4, 8],
        [2, 4, 6],
    ];

    for (const combination of winningCombinations) {
        const [a, b, c] = combination;
        if (tempBoard[a] !== 0 && tempBoard[a] === tempBoard[b] && tempBoard[a] === tempBoard[c]) {
            return tempBoard[a];
        }
    }

    return 0;
}

function checkGameOver() {
    const winner = checkWinner(board);
    if (winner !== 0) {
        alert(`Le joueur ${winner} a gagné !`);
    } else if (!isRunning()) {
        alert('Match nul !');
    }
}

function resetBoard() {
    board = Array.from({ length: 9 }, () => 0);
    currentPlayer = 1;
    running = true;
    cells.forEach(cell => (cell.textContent = ''));
}

function toggleAi() {
    aiEnabled = !aiEnabled;
    gameMode = aiEnabled ? 'ai' : '1v1';
}

function minimax(tempBoard, maximizing) {
    const winner = checkWinner(tempBoard);

    if (winner !== 0) {
        return { eval: winner === 1 ? 1 : -1, move: null };
    } else if (!tempBoard.some(cell => cell === 0)) {
        return { eval: 0, move: null };
    }

    let bestEval, bestMove;

    if (maximizing) {
        bestEval = -Infinity;

        for (let i = 0; i < tempBoard.length; i++) {
            if (tempBoard[i] === 0) {
                const newBoard = [...tempBoard];
                newBoard[i] = 1;

                const eval = minimax(newBoard, false).eval;
                if (eval > bestEval) {
                    bestEval = eval;
                    bestMove = i;
                }
            }
        }
    } else {
        bestEval = Infinity;

        for (let i = 0; i < tempBoard.length; i++) {
            if (tempBoard[i] === 0) {
                const newBoard = [...tempBoard];
                newBoard[i] = 2;

                const eval = minimax(newBoard, true).eval;
                if (eval < bestEval) {
                    bestEval = eval;
                    bestMove = i;
                }
            }
        }
    }

    return { eval: bestEval, move: bestMove };
}

cells.forEach(cell => cell.addEventListener('click', handleClick));
resetButton.addEventListener('click', resetBoard);
aiButton.addEventListener('click', toggleAi);