// 游戏常量
const COLS = 10;
const ROWS = 20;
const BLOCK_SIZE = 30;

// 方块形状定义
const SHAPES = [
    [[1, 1, 1, 1]], // I
    [[1, 1], [1, 1]], // O
    [[0, 1, 0], [1, 1, 1]], // T
    [[1, 0, 0], [1, 1, 1]], // L
    [[0, 0, 1], [1, 1, 1]], // J
    [[0, 1, 1], [1, 1, 0]], // S
    [[1, 1, 0], [0, 1, 1]]  // Z
];

// 方块颜色
const COLORS = [
    '#00f0f0', // I - 青色
    '#f0f000', // O - 黄色
    '#a000f0', // T - 紫色
    '#f0a000', // L - 橙色
    '#0000f0', // J - 蓝色
    '#00f000', // S - 绿色
    '#f00000'  // Z - 红色
];

// 游戏状态
let canvas, ctx, nextCanvas, nextCtx;
let board = [];
let currentPiece = null;
let nextPiece = null;
let score = 0;
let level = 1;
let lines = 0;
let gameLoop = null;
let isPaused = false;
let isGameOver = false;
let dropInterval = 1000;

// 初始化
function init() {
    canvas = document.getElementById('game-canvas');
    ctx = canvas.getContext('2d');
    nextCanvas = document.getElementById('next-canvas');
    nextCtx = nextCanvas.getContext('2d');

    // 初始化游戏板
    for (let r = 0; r < ROWS; r++) {
        board[r] = [];
        for (let c = 0; c < COLS; c++) {
            board[r][c] = 0;
        }
    }

    // 绑定事件
    document.addEventListener('keydown', handleKeyPress);
    document.getElementById('start-btn').addEventListener('click', startGame);
    document.getElementById('restart-btn').addEventListener('click', startGame);

    // 绘制初始游戏板
    drawBoard();
}

// 创建新方块
function createPiece() {
    const shapeIndex = Math.floor(Math.random() * SHAPES.length);
    return {
        shape: SHAPES[shapeIndex],
        color: COLORS[shapeIndex],
        x: Math.floor(COLS / 2) - Math.floor(SHAPES[shapeIndex][0].length / 2),
        y: 0
    };
}

// 绘制方块
function drawBlock(ctx, x, y, color, size = BLOCK_SIZE) {
    ctx.fillStyle = color;
    ctx.fillRect(x * size, y * size, size, size);

    // 添加3D效果
    ctx.fillStyle = 'rgba(255, 255, 255, 0.3)';
    ctx.fillRect(x * size, y * size, size, 2);
    ctx.fillRect(x * size, y * size, 2, size);

    ctx.fillStyle = 'rgba(0, 0, 0, 0.3)';
    ctx.fillRect(x * size + size - 2, y * size, 2, size);
    ctx.fillRect(x * size, y * size + size - 2, size, 2);
}

// 绘制游戏板
function drawBoard() {
    // 清空画布
    ctx.fillStyle = '#1a1a2e';
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    // 绘制网格
    ctx.strokeStyle = 'rgba(255, 255, 255, 0.1)';
    for (let r = 0; r < ROWS; r++) {
        for (let c = 0; c < COLS; c++) {
            ctx.strokeRect(c * BLOCK_SIZE, r * BLOCK_SIZE, BLOCK_SIZE, BLOCK_SIZE);
        }
    }

    // 绘制已放置的方块
    for (let r = 0; r < ROWS; r++) {
        for (let c = 0; c < COLS; c++) {
            if (board[r][c]) {
                drawBlock(ctx, c, r, board[r][c]);
            }
        }
    }
}

// 绘制当前方块
function drawPiece() {
    if (!currentPiece) return;

    for (let r = 0; r < currentPiece.shape.length; r++) {
        for (let c = 0; c < currentPiece.shape[r].length; c++) {
            if (currentPiece.shape[r][c]) {
                drawBlock(ctx, currentPiece.x + c, currentPiece.y + r, currentPiece.color);
            }
        }
    }
}

// 绘制下一个方块
function drawNextPiece() {
    if (!nextPiece) return;

    nextCtx.fillStyle = '#fff';
    nextCtx.fillRect(0, 0, nextCanvas.width, nextCanvas.height);

    const size = 20;
    const offsetX = (nextCanvas.width - nextPiece.shape[0].length * size) / 2;
    const offsetY = (nextCanvas.height - nextPiece.shape.length * size) / 2;

    for (let r = 0; r < nextPiece.shape.length; r++) {
        for (let c = 0; c < nextPiece.shape[r].length; c++) {
            if (nextPiece.shape[r][c]) {
                nextCtx.fillStyle = nextPiece.color;
                nextCtx.fillRect(offsetX + c * size, offsetY + r * size, size, size);
                nextCtx.strokeStyle = 'rgba(0, 0, 0, 0.3)';
                nextCtx.strokeRect(offsetX + c * size, offsetY + r * size, size, size);
            }
        }
    }
}

// 检测碰撞
function collide(piece, offsetX = 0, offsetY = 0) {
    for (let r = 0; r < piece.shape.length; r++) {
        for (let c = 0; c < piece.shape[r].length; c++) {
            if (piece.shape[r][c]) {
                const newX = piece.x + c + offsetX;
                const newY = piece.y + r + offsetY;

                if (newX < 0 || newX >= COLS || newY >= ROWS) {
                    return true;
                }

                if (newY >= 0 && board[newY][newX]) {
                    return true;
                }
            }
        }
    }
    return false;
}

// 锁定方块
function lockPiece() {
    for (let r = 0; r < currentPiece.shape.length; r++) {
        for (let c = 0; c < currentPiece.shape[r].length; c++) {
            if (currentPiece.shape[r][c]) {
                if (currentPiece.y + r < 0) {
                    gameOver();
                    return;
                }
                board[currentPiece.y + r][currentPiece.x + c] = currentPiece.color;
            }
        }
    }

    clearLines();
    currentPiece = nextPiece;
    nextPiece = createPiece();
    drawNextPiece();

    if (collide(currentPiece)) {
        gameOver();
    }
}

// 消除行
function clearLines() {
    let linesCleared = 0;

    for (let r = ROWS - 1; r >= 0; r--) {
        if (board[r].every(cell => cell !== 0)) {
            board.splice(r, 1);
            board.unshift(new Array(COLS).fill(0));
            linesCleared++;
            r++;
        }
    }

    if (linesCleared > 0) {
        updateScore(linesCleared);
    }
}

// 更新分数
function updateScore(linesCleared) {
    const points = [0, 100, 300, 500, 800];
    score += points[linesCleared] * level;
    lines += linesCleared;

    // 升级
    if (lines >= level * 10) {
        level++;
        dropInterval = Math.max(100, 1000 - (level - 1) * 100);
        resetGameLoop();
    }

    updateDisplay();
}

// 更新显示
function updateDisplay() {
    document.getElementById('score').textContent = score;
    document.getElementById('level').textContent = level;
    document.getElementById('lines').textContent = lines;
}

// 移动方块
function movePiece(offsetX, offsetY) {
    if (!currentPiece || isPaused || isGameOver) return;

    if (!collide(currentPiece, offsetX, offsetY)) {
        currentPiece.x += offsetX;
        currentPiece.y += offsetY;
        draw();
    }
}

// 旋转方块
function rotatePiece() {
    if (!currentPiece || isPaused || isGameOver) return;

    const rotated = currentPiece.shape[0].map((_, index) =>
        currentPiece.shape.map(row => row[index]).reverse()
    );

    const originalShape = currentPiece.shape;
    currentPiece.shape = rotated;

    // 墙踢 - 尝试调整位置
    const kicks = [0, -1, 1, -2, 2];
    for (let kick of kicks) {
        if (!collide(currentPiece, kick, 0)) {
            currentPiece.x += kick;
            draw();
            return;
        }
    }

    // 无法旋转，恢复原状
    currentPiece.shape = originalShape;
}

// 硬降落
function hardDrop() {
    if (!currentPiece || isPaused || isGameOver) return;

    while (!collide(currentPiece, 0, 1)) {
        currentPiece.y++;
        score += 2;
    }
    lockPiece();
    updateDisplay();
    draw();
}

// 绘制
function draw() {
    drawBoard();
    drawPiece();
}

// 游戏循环
function gameStep() {
    if (!isPaused && !isGameOver) {
        if (!collide(currentPiece, 0, 1)) {
            currentPiece.y++;
            draw();
        } else {
            lockPiece();
        }
    }
}

// 开始游戏循环
function startGameLoop() {
    gameLoop = setInterval(gameStep, dropInterval);
}

// 重置游戏循环
function resetGameLoop() {
    clearInterval(gameLoop);
    startGameLoop();
}

// 开始游戏
function startGame() {
    // 重置状态
    for (let r = 0; r < ROWS; r++) {
        for (let c = 0; c < COLS; c++) {
            board[r][c] = 0;
        }
    }
    score = 0;
    level = 1;
    lines = 0;
    dropInterval = 1000;
    isPaused = false;
    isGameOver = false;

    // 隐藏游戏结束界面
    document.getElementById('game-over').classList.add('hidden');

    // 创建方块
    currentPiece = createPiece();
    nextPiece = createPiece();

    updateDisplay();
    drawNextPiece();
    draw();
    startGameLoop();
}

// 游戏结束
function gameOver() {
    isGameOver = true;
    clearInterval(gameLoop);
    document.getElementById('final-score').textContent = score;
    document.getElementById('game-over').classList.remove('hidden');
}

// 键盘事件处理
function handleKeyPress(e) {
    if (isGameOver) return;

    switch (e.key) {
        case 'ArrowLeft':
            e.preventDefault();
            movePiece(-1, 0);
            break;
        case 'ArrowRight':
            e.preventDefault();
            movePiece(1, 0);
            break;
        case 'ArrowDown':
            e.preventDefault();
            movePiece(0, 1);
            score += 1;
            updateDisplay();
            break;
        case 'ArrowUp':
            e.preventDefault();
            rotatePiece();
            break;
        case ' ':
            e.preventDefault();
            hardDrop();
            break;
        case 'p':
        case 'P':
            isPaused = !isPaused;
            break;
    }
}

// 启动
window.onload = init;