class Game {
  constructor() {
    this.canvas = document.getElementById('game-canvas');
    this.ctx = this.canvas.getContext('2d');
    this.audio = {
      bgMusic: document.getElementById('bg-music'),
      eat: new Audio('assets/sounds/eat.wav'),
      die: new Audio('assets/sounds/die.wav'),
      win: new Audio('assets/sounds/win.wav')
    };
    
    this.resizeCanvas();
    this.setupEventListeners();
    
    // Настройки игры
    this.gameState = 'menu';
    this.score = 0;
    this.highScore = localStorage.getItem('highScore') || 0;
    this.volume = 0.5;
    this.pixelSize = 4;
    this.showGrid = true;
    this.currentSkin = 'classic';
    
    // Параметры червяка
    this.worm = {
      x: 100,
      y: 100,
      size: 16,
      speed: 2,
      direction: 'right',
      body: [],
      maxLength: 3
    };
    
    // Еда
    this.food = {
      x: 0,
      y: 0,
      size: 16,
      type: 'normal'
    };
    
    // Достижения
    this.achievements = {
      novice: false,
      experienced: false
    };
    
    this.spawnFood();
    this.updateVolume();
  }
  
  setupEventListeners() {
    // Главное меню
    document.getElementById('start-game').addEventListener('click', () => this.startGame());
    document.getElementById('skins-btn').addEventListener('click', () => this.showMenu('skins'));
    document.getElementById('achievements-btn').addEventListener('click', () => this.showMenu('achievements'));
    document.getElementById('settings-btn').addEventListener('click', () => this.showMenu('settings'));
    
    // Меню скинов
    document.querySelectorAll('.skin-option').forEach(option => {
      option.addEventListener('click', () => this.selectSkin(option.dataset.skin));
    });
    document.getElementById('back-from-skins').addEventListener('click', () => this.showMenu('main'));
    
    // Меню достижений
    document.getElementById('back-from-achievements').addEventListener('click', () => this.showMenu('main'));
    
    // Меню настроек
    document.getElementById('volume-slider').addEventListener('input', (e) => {
      document.getElementById('volume-value').textContent = `${Math.round(e.target.value * 100)}%`;
    });
    document.getElementById('save-settings').addEventListener('click', () => this.saveSettings());
    document.getElementById('exit-game').addEventListener('click', () => window.close());
    document.getElementById('back-from-settings').addEventListener('click', () => this.showMenu('main'));
    
    // Игровые события
    document.addEventListener('keydown', (e) => this.handleKeyInput(e));
    document.getElementById('pause-btn').addEventListener('click', () => this.togglePause());
    document.getElementById('resume-btn').addEventListener('click', () => this.togglePause());
    document.getElementById('quit-to-menu').addEventListener('click', () => this.quitToMenu());
    document.getElementById('restart-btn').addEventListener('click', () => this.startGame());
    document.getElementById('main-menu-btn').addEventListener('click', () => this.quitToMenu());
    
    // Обработка изменения размера окна
    window.addEventListener('resize', () => this.resizeCanvas());
  }
  
  showMenu(menu) {
    const menus = ['main', 'skins', 'achievements', 'settings'];
    menus.forEach(m => {
      document.getElementById(`${m}-menu`).style.display = m === menu ? 'flex' : 'none';
    });
    
    if (menu === 'settings') {
      document.getElementById('volume-slider').value = this.volume;
      document.getElementById('volume-value').textContent = `${Math.round(this.volume * 100)}%`;
      document.getElementById('pixel-size').value = this.pixelSize;
    }
  }
  
  selectSkin(skin) {
    this.currentSkin = skin;
    document.querySelectorAll('.skin-option').forEach(option => {
      option.classList.toggle('selected', option.dataset.skin === skin);
    });
  }
  
  startGame() {
    this.showMenu(null);
    document.getElementById('game-container').style.display = 'block';
    document.getElementById('game-over-menu').style.display = 'none';
    
    this.gameState = 'playing';
    this.score = 0;
    this.worm = {
      x: 100,
      y: 100,
      size: 16,
      speed: 2,
      direction: 'right',
      body: [],
      maxLength: 3
    };
    
    document.getElementById('score').textContent = `ОЧКИ: ${this.score}`;
    document.getElementById('high-score').textContent = `РЕКОРД: ${this.highScore}`;
    
    this.audio.bgMusic.currentTime = 0;
    this.audio.bgMusic.play();
    
    this.spawnFood();
    this.gameLoop();
  }
  
  togglePause() {
    if (this.gameState === 'playing') {
      this.gameState = 'paused';
      document.getElementById('pause-menu').style.display = 'block';
      this.audio.bgMusic.pause();
    } else if (this.gameState === 'paused') {
      this.gameState = 'playing';
      document.getElementById('pause-menu').style.display = 'none';
      this.audio.bgMusic.play();
      this.gameLoop();
    }
  }
  
  quitToMenu() {
    this.gameState = 'menu';
    document.getElementById('game-container').style.display = 'none';
    document.getElementById('pause-menu').style.display = 'none';
    document.getElementById('game-over-menu').style.display = 'none';
    this.showMenu('main');
    this.audio.bgMusic.pause();
  }
  
  gameOver() {
    this.gameState = 'gameover';
    document.getElementById('game-over-menu').style.display = 'block';
    document.getElementById('final-score').textContent = this.score;
    
    if (this.score > this.highScore) {
      this.highScore = this.score;
      localStorage.setItem('highScore', this.highScore);
    }
    
    this.audio.bgMusic.pause();
    this.audio.die.play();
  }
  
  spawnFood() {
    this.food = {
      x: Math.floor(Math.random() * (this.canvas.width - 32) / 16) * 16 + 8,
      y: Math.floor(Math.random() * (this.canvas.height - 32) / 16) * 16 + 8,
      size: 16,
      type: Math.random() > 0.9 ? 'special' : 'normal'
    };
  }
  
  checkCollision() {
    // Проверка столкновения с границами
    if (this.worm.x < 0 || this.worm.x >= this.canvas.width || 
        this.worm.y < 0 || this.worm.y >= this.canvas.height) {
      this.gameOver();
      return;
    }
    
    // Проверка столкновения с телом
    for (let i = 0; i < this.worm.body.length; i++) {
      if (this.worm.x === this.worm.body[i].x && this.worm.y === this.worm.body[i].y) {
        this.gameOver();
        return;
      }
    }
    
    // Проверка столкновения с едой
    const distance = Math.sqrt(
      Math.pow(this.worm.x - this.food.x, 2) + 
      Math.pow(this.worm.y - this.food.y, 2)
    );
    
    if (distance < this.worm.size / 2 + this.food.size / 2) {
      this.eatFood();
    }
  }
  
  eatFood() {
    this.score += this.food.type === 'special' ? 50 : 10;
    document.getElementById('score').textContent = `ОЧКИ: ${this.score}`;
    
    this.worm.maxLength += 3;
    this.audio.eat.play();
    
    // Проверка достижений
    if (this.score >= 100 && !this.achievements.novice) {
      this.achievements.novice = true;
      this.audio.win.play();
    }
    if (this.score >= 500 && !this.achievements.experienced) {
      this.achievements.experienced = true;
      this.audio.win.play();
    }
    
    this.spawnFood();
  }
  
  updateWorm() {
    // Добавляем новую голову
    this.worm.body.unshift({ x: this.worm.x, y: this.worm.y });
    
    // Удаляем лишние сегменты
    if (this.worm.body.length > this.worm.maxLength) {
      this.worm.body.pop();
    }
    
    // Двигаем голову
    switch (this.worm.direction) {
      case 'up': this.worm.y -= this.worm.speed; break;
      case 'down': this.worm.y += this.worm.speed; break;
      case 'left': this.worm.x -= this.worm.speed; break;
      case 'right': this.worm.x += this.worm.speed; break;
    }
  }
  
  handleKeyInput(e) {
    if (this.gameState !== 'playing') return;
    
    switch (e.key) {
      case 'ArrowUp':
        if (this.worm.direction !== 'down') this.worm.direction = 'up';
        break;
      case 'ArrowDown':
        if (this.worm.direction !== 'up') this.worm.direction = 'down';
        break;
      case 'ArrowLeft':
        if (this.worm.direction !== 'right') this.worm.direction = 'left';
        break;
      case 'ArrowRight':
        if (this.worm.direction !== 'left') this.worm.direction = 'right';
        break;
    }
  }
  
  drawPixel(x, y, size, color) {
    this.ctx.fillStyle = color;
    this.ctx.fillRect(
      Math.floor(x / this.pixelSize) * this.pixelSize,
      Math.floor(y / this.pixelSize) * this.pixelSize,
      Math.floor(size / this.pixelSize) * this.pixelSize,
      Math.floor(size / this.pixelSize) * this.pixelSize
    );
  }
  
  drawWorm() {
    // Рисуем тело
    for (let i = 0; i < this.worm.body.length; i++) {
      const segment = this.worm.body[i];
      let color;
      
      switch (this.currentSkin) {
        case 'fire':
          color = i === 0 ? '#ff5e5e' : `hsl(${20 + i * 2}, 100%, ${50 + i}%)`;
          break;
        case 'ice':
          color = i === 0 ? '#5ebdff' : `hsl(${180 + i * 2}, 100%, ${50 + i}%)`;
          break;
        default: // classic
          color = i === 0 ? '#5eff5e' : `hsl(${120 + i * 2}, 100%, ${50 + i}%)`;
      }
      
      this.drawPixel(segment.x, segment.y, this.worm.size, color);
    }
  }
  
  drawFood() {
    const color = this.food.type === 'special' ? '#ff55ff' : '#ff5555';
    this.drawPixel(this.food.x, this.food.y, this.food.size, color);
    
    // Анимация специальной еды
    if (this.food.type === 'special') {
      this.ctx.strokeStyle = '#ffffff';
      this.ctx.lineWidth = 2;
      const size = this.food.size + Math.sin(Date.now() / 200) * 4;
      this.ctx.strokeRect(
        Math.floor((this.food.x - size/2) / this.pixelSize) * this.pixelSize,
        Math.floor((this.food.y - size/2) / this.pixelSize) * this.pixelSize,
        Math.floor(size / this.pixelSize) * this.pixelSize,
        Math.floor(size / this.pixelSize) * this.pixelSize
      );
    }
  }
  
  drawGrid() {
    if (!this.showGrid) return;
    
    this.ctx.strokeStyle = 'rgba(106, 58, 199, 0.2)';
    this.ctx.lineWidth = 1;
    
    for (let x = 0; x < this.canvas.width; x += this.pixelSize * 8) {
      this.ctx.beginPath();
      this.ctx.moveTo(x, 0);
      this.ctx.lineTo(x, this.canvas.height);
      this.ctx.stroke();
    }
    
    for (let y = 0; y < this.canvas.height; y += this.pixelSize * 8) {
      this.ctx.beginPath();
      this.ctx.moveTo(0, y);
      this.ctx.lineTo(this.canvas.width, y);
      this.ctx.stroke();
    }
  }
  
  saveSettings() {
    this.volume = parseFloat(document.getElementById('volume-slider').value);
    this.pixelSize = parseInt(document.getElementById('pixel-size').value);
    this.updateVolume();
    this.resizeCanvas();
    this.showMenu('main');
  }
  
  updateVolume() {
    Object.values(this.audio).forEach(sound => {
      if (sound) sound.volume = this.volume;
    });
  }
  
  resizeCanvas() {
    this.canvas.width = Math.floor(window.innerWidth / this.pixelSize) * this.pixelSize;
    this.canvas.height = Math.floor(window.innerHeight / this.pixelSize) * this.pixelSize;
  }
  
  gameLoop() {
    if (this.gameState !== 'playing') return;
    
    // Очистка экрана
    this.ctx.fillStyle = '#0a0a1a';
    this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
    
    // Рисование
    this.drawGrid();
    this.drawFood();
    this.drawWorm();
    
    // Обновление
    this.updateWorm();
    this.checkCollision();
    
    // Следующий кадр
    requestAnimationFrame(() => this.gameLoop());
  }
}

// Инициализация игры при загрузке страницы
window.addEventListener('load', () => {
  const game = new Game();
});