document.addEventListener('DOMContentLoaded', () => {
    // Game state
    let board = ['', '', '', '', '', '', '', '', ''];
    let currentPlayer = 'X';
    let gameActive = true;
    let gameMode = 'pvp'; // pvp, pvc, cvc
    let scores = { x: 0, o: 0, d: 0 };
    let theme = 'default';
    
    // DOM elements
    const cells = document.querySelectorAll('#game-board .cell');
    const gameOverlay = document.getElementById('game-overlay');
    const gameResult = document.getElementById('game-result');
    const playAgainBtn = document.getElementById('play-again-btn');
    const xWinsEl = document.getElementById('x-wins');
    const oWinsEl = document.getElementById('o-wins');
    const drawsEl = document.getElementById('draws');
    const gameBoard = document.getElementById('game-board');
    
    // Initialize the game board
    function initializeBoard() {
        gameBoard.innerHTML = '';
        for (let i = 0; i < 9; i++) {
            const cell = document.createElement('div');
            cell.classList.add('cell', 'flex', 'items-center', 'justify-center', 'text-6xl', 'font-bold', 'bg-white', 'dark:bg-gray-800', 'rounded-lg', 'shadow-md');
            cell.dataset.index = i;
            cell.addEventListener('click', () => handleCellClick(i));
            gameBoard.appendChild(cell);
        }
    }
    
    // Handle cell click
    function handleCellClick(index) {
        if (!gameActive || board[index] !== '') return;
        
        makeMove(index, currentPlayer);
        
        if (gameMode === 'pvc' && currentPlayer === 'O' && gameActive) {
            setTimeout(() => {
                const bestMove = findBestMove();
                makeMove(bestMove, 'O');
            }, 500);
        } else if (gameMode === 'cvc' && gameActive) {
            setTimeout(() => {
                const bestMove = findBestMove();
                makeMove(bestMove, currentPlayer);
            }, 500);
        }
    }
    
    // Make a move
    function makeMove(index, player) {
        board[index] = player;
        const cell = gameBoard.children[index];
        cell.textContent = player;
        cell.classList.add(player.toLowerCase());
        
        if (checkWin(player)) {
            endGame(`${player} Wins!`);
            scores[player.toLowerCase()]++;
            updateScoreboard();
            highlightWinningCells();
            return;
        }
        
        if (checkDraw()) {
            endGame("It's a Draw!");
            scores.d++;
            updateScoreboard();
            return;
        }
        
        currentPlayer = currentPlayer === 'X' ? 'O' : 'X';
        
        // If it's computer's turn in pvc mode and player is O
        if (gameMode === 'pvc' && currentPlayer === 'O' && gameActive) {
            setTimeout(() => {
                const bestMove = findBestMove();
                makeMove(bestMove, 'O');
            }, 500);
        }
    }
    
    // Check for win
    function checkWin(player) {
        const winPatterns = [
            [0, 1, 2], [3, 4, 5], [6, 7, 8], // rows
            [0, 3, 6], [1, 4, 7], [2, 5, 8], // columns
            [0, 4, 8], [2, 4, 6]             // diagonals
        ];
        
        return winPatterns.some(pattern => {
            return pattern.every(index => board[index] === player);
        });
    }
    
    // Check for draw
    function checkDraw() {
        return board.every(cell => cell !== '');
    }
    
    // End the game
    function endGame(message) {
        gameActive = false;
        gameResult.textContent = message;
        gameOverlay.classList.remove('hidden');
    }
    
    // Reset the game
    function resetGame() {
        board = ['', '', '', '', '', '', '', '', ''];
        currentPlayer = 'X';
        gameActive = true;
        gameOverlay.classList.add('hidden');
        
        Array.from(gameBoard.children).forEach(cell => {
            cell.textContent = '';
            cell.classList.remove('x', 'o', 'winning-cell');
        });
        
        if (gameMode === 'cvc') {
            setTimeout(() => {
                const bestMove = findBestMove();
                makeMove(bestMove, 'X');
            }, 500);
        } else if (gameMode === 'pvc' && currentPlayer === 'O') {
            setTimeout(() => {
                const bestMove = findBestMove();
                makeMove(bestMove, 'O');
            }, 500);
        }
    }
    
    // Update scoreboard
    function updateScoreboard() {
        xWinsEl.textContent = scores.x;
        oWinsEl.textContent = scores.o;
        drawsEl.textContent = scores.d;
    }
    
    // Highlight winning cells
    function highlightWinningCells() {
        const winPatterns = [
            [0, 1, 2], [3, 4, 5], [6, 7, 8], // rows
            [0, 3, 6], [1, 4, 7], [2, 5, 8], // columns
            [0, 4, 8], [2, 4, 6]             // diagonals
        ];
        
        for (const pattern of winPatterns) {
            const [a, b, c] = pattern;
            if (board[a] !== '' && board[a] === board[b] && board[a] === board[c]) {
                gameBoard.children[a].classList.add('winning-cell');
                gameBoard.children[b].classList.add('winning-cell');
                gameBoard.children[c].classList.add('winning-cell');
                break;
            }
        }
    }
    
    // Computer AI - Minimax algorithm
    function findBestMove() {
        if (gameMode === 'cvc') {
            // For computer vs computer, just pick a random empty spot for demo
            const emptyCells = board.map((cell, index) => cell === '' ? index : null).filter(val => val !== null);
            return emptyCells[Math.floor(Math.random() * emptyCells.length)];
        }
        
        // Minimax algorithm for optimal play
        let bestScore = -Infinity;
        let bestMove = null;
        
        for (let i = 0; i < 9; i++) {
            if (board[i] === '') {
                board[i] = 'O';
                const score = minimax(board, 0, false);
                board[i] = '';
                
                if (score > bestScore) {
                    bestScore = score;
                    bestMove = i;
                }
            }
        }
        
        return bestMove;
    }
    
    function minimax(board, depth, isMaximizing) {
        const scores = {
            'X': -10,
            'O': 10,
            'draw': 0
        };
        
        if (checkWin('O')) return scores['O'] - depth;
        if (checkWin('X')) return scores['X'] + depth;
        if (checkDraw()) return scores['draw'];
        
        if (isMaximizing) {
            let bestScore = -Infinity;
            for (let i = 0; i < 9; i++) {
                if (board[i] === '') {
                    board[i] = 'O';
                    const score = minimax(board, depth + 1, false);
                    board[i] = '';
                    bestScore = Math.max(score, bestScore);
                }
            }
            return bestScore;
        } else {
            let bestScore = Infinity;
            for (let i = 0; i < 9; i++) {
                if (board[i] === '') {
                    board[i] = 'X';
                    const score = minimax(board, depth + 1, true);
                    board[i] = '';
                    bestScore = Math.min(score, bestScore);
                }
            }
            return bestScore;
        }
    }
    
    // Event listeners
    playAgainBtn.addEventListener('click', resetGame);
    
    // Theme change handler
    document.addEventListener('theme-change', (e) => {
        theme = e.detail.theme;
        applyTheme();
    });
    
    // Game mode change handler
    document.addEventListener('game-mode-change', (e) => {
        gameMode = e.detail.mode;
        resetGame();
    });
    // Apply theme
    function applyTheme() {
        // Remove all theme classes first
        const themeClasses = Array.from(document.body.classList).filter(cls => cls.startsWith('theme-'));
        themeClasses.forEach(cls => document.body.classList.remove(cls));
        
        // Add the current theme class
        document.body.classList.add(`theme-${theme}`);
        
        // Update CSS variables
        document.documentElement.style.setProperty('--primary-color', getComputedStyle(document.body).getPropertyValue('--primary-color'));
        document.documentElement.style.setProperty('--secondary-color', getComputedStyle(document.body).getPropertyValue('--secondary-color'));
        
        // Update cell colors
        document.querySelectorAll('.cell.x').forEach(cell => {
            cell.style.color = `var(--primary-color)`;
        });
        document.querySelectorAll('.cell.o').forEach(cell => {
            cell.style.color = `var(--secondary-color)`;
        });
    }
// Initialize
    initializeBoard();
    applyTheme();
});