const DIFFICULTY = {
    easy: { cols: 9, rows: 9, mines: 10 },      // 简单
    normal: { cols: 16, rows: 16, mines: 40 },   // 普通
    hard: { cols: 30, rows: 16, mines: 99 }     // 困难
};

let board = [];           // 存储地雷和数字
let revealed = [];        // 记录格子是否已揭开
let flagged = [];         // 记录格子是否已插旗
let minePos = [];         // 存储所有地雷位置
let firstClick = true;   // 是否第一次点击
let gameOver = false;    // 游戏是否结束
let win = false;         // 是否胜利
let mineCount = MINES;   // 剩余地雷数
let revealCount = 0;     // 已揭开格子数

function initBoard() {
    for (let y = 0; y < ROWS; y++) {
        board[y] = [];
        revealed[y] = [];
        flagged[y] = [];
        for (let x = 0; x < COLS; x++) {
            board[y][x] = 0;
            revealed[y][x] = false;
            flagged[y][x] = false;
        }
    }
}

const SHAPES = {
    I: { matrix: [[1,1,1,1]], color: '#00f5ff' },  // 青色长条
    O: { matrix: [[1,1],[1,1]], color: '#ffeb3b' }, // 黄色方块
    T: { matrix: [[0,1,0],[1,1,1]], color: '#bf5af2' }, // 紫色T形
    S: { matrix: [[0,1,1],[1,1,0]], color: '#30d158' }, // 绿色S形
    Z: { matrix: [[1,1,0],[0,1,1]], color: '#ff375f' }, // 红色Z形
    J: { matrix: [[1,0,0],[1,1,1]], color: '#0a84ff' }, // 蓝色J形
    L: { matrix: [[0,0,1],[1,1,1]], color: '#ff9f0a' }  // 橙色L形
};
const SHAPE_KEYS = ['I', 'O', 'T', 'S', 'Z', 'J', 'L'];

let board = [];           // 12×20 游戏板，存储已落方块颜色
let currentPiece = null; // 当前下落的方块
let currentX = 0;         // 当前方块X坐标
let currentY = 0;        // 当前方块Y坐标
let score = 0;            // 得分
let dropInterval = 800;   // 下落间隔（毫秒）

function randomPiece() {
    const key = SHAPE_KEYS[Math.floor(Math.random() * SHAPE_KEYS.length)];
    const shape = SHAPES[key];
    return {
        matrix: shape.matrix.map(row => [...row]),  // 深拷贝矩阵
        color: shape.color
    };
}

function checkCollision(matrix, x, y) {
    for (let r = 0; r < matrix.length; r++) {
        for (let c = 0; c < matrix[r].length; c++) {
            if (matrix[r][c]) {
                const newX = x + c;
                const newY = y + r;
                // 边界检测
                if (newX < 0 || newX >= COLS || newY >= ROWS) return true;
                // 与已落方块碰撞检测
                if (newY >= 0 && board[newY][newX]) return true;
            }
        }
    }
    return false;
}

window.initSnakeGame = function() {
    // 获取 DOM 元素
    const canvas = document.getElementById('game-canvas');
    const ctx = canvas.getContext('2d');
    // ... 初始化逻辑
};

const gridSize = 20;      // 20x20 网格
const cellSize = 20;      // 每个格子 20px
let snake = [
    {x: 10, y: 10},
    {x: 9, y: 10},
    {x: 8, y: 10}
];
let direction = 'RIGHT';
let nextDirection = 'RIGHT';

function move() {
    // 应用下次方向（防止掉头）
    const opposite = { 'UP': 'DOWN', 'DOWN': 'UP', 'LEFT': 'RIGHT', 'RIGHT': 'LEFT' };
    if (nextDirection && opposite[nextDirection] !== direction) {
        direction = nextDirection;
    }

    const head = snake[0];
    let newHead = { ...head };
    switch (direction) {
        case 'RIGHT': newHead.x++; break;
        case 'LEFT':  newHead.x--; break;
        case 'UP':    newHead.y--; break;
        case 'DOWN':  newHead.y++; break;
    }

    // 判断是否吃到食物
    const isEating = food && newHead.x === food.x && newHead.y === food.y;
    let newSnake = [newHead, ...snake];
    if (!isEating) newSnake.pop();  // 没吃到则移除尾部

    snake = newSnake;
}

// 边界碰撞
if (newHead.x < 0 || newHead.x >= gridSize || 
    newHead.y < 0 || newHead.y >= gridSize) {
    gameOver = true;
    return;
}

// 自身碰撞
if (newSnake.slice(1).some(seg => seg.x === newHead.x && seg.y === newHead.y)) {
    gameOver = true;
    return;
}

function randomFood() {
    for (let i = 0; i < 1000; i++) {
        const x = Math.floor(Math.random() * gridSize);
        const y = Math.floor(Math.random() * gridSize);
        // 避开蛇身
        if (!snake.some(seg => seg.x === x && seg.y === y)) {
            return {x, y};
        }
    }
    return null;
}

function draw() {
    ctx.clearRect(0, 0, canvas.width, canvas.height);

    // 绘制网格线
    for (let i = 0; i <= gridSize; i++) {
        // ... 绘制横竖线
    }

    // 绘制蛇身
    snake.forEach((seg, idx) => {
        ctx.fillStyle = idx === 0 ? '#8bc34a' : '#4CAF50';
        ctx.fillRect(seg.x * cellSize + 1, seg.y * cellSize + 1, 
                     cellSize - 2, cellSize - 2);
        // 蛇眼睛
        if (idx === 0) {
            // ... 绘制眼睛
        }
    });

    // 绘制食物
    if (food) {
        ctx.fillStyle = '#f44336';
        ctx.beginPath();
        ctx.arc(food.x * cellSize + cellSize / 2, 
                food.y * cellSize + cellSize / 2, 8, 0, 2 * Math.PI);
        ctx.fill();
    }
}