import * as Notifications from 'expo-notifications';
import { Platform } from 'react-native';

// 配置通知处理方式
Notifications.setNotificationHandler({
  handleNotification: async () => ({
    shouldShowAlert: true,
    shouldPlaySound: true,
    shouldSetBadge: true,
    shouldShowBanner: true,
    shouldShowList: true,
  }),
});

export interface NotificationData {
  title: string;
  body: string;
  data?: Record<string, any>;
  sound?: boolean;
  priority?: 'default' | 'normal' | 'high';
  vibrate?: number[];
}

export class NotificationService {
  private static instance: NotificationService;
  private isInitialized = false;

  private constructor() {}

  public static getInstance(): NotificationService {
    if (!NotificationService.instance) {
      NotificationService.instance = new NotificationService();
    }
    return NotificationService.instance;
  }

  /**
   * 初始化推送通知服务
   */
  async initialize(): Promise<void> {
    if (this.isInitialized) return;

    try {
      // 请求通知权限
      const { status: existingStatus } = await Notifications.getPermissionsAsync();
      let finalStatus = existingStatus;
      
      if (existingStatus !== 'granted') {
        const { status } = await Notifications.requestPermissionsAsync();
        finalStatus = status;
      }
      
      if (finalStatus !== 'granted') {
        console.warn('推送通知权限未授予');
        return;
      }

      // 获取推送令牌（用于远程推送，本地推送不需要）
      if (Platform.OS !== 'web') {
        const token = await Notifications.getExpoPushTokenAsync({
          projectId: 'your-project-id', // 需要替换为实际的Expo项目ID
        });
        console.log('推送令牌:', token.data);
      }

      // 设置通知监听器
      this.setupNotificationListeners();
      
      this.isInitialized = true;
      console.log('推送通知服务初始化成功');
    } catch (error) {
      console.error('推送通知服务初始化失败:', error);
    }
  }

  /**
   * 设置通知监听器
   */
  private setupNotificationListeners(): void {
    // 监听通知接收
    Notifications.addNotificationReceivedListener((notification) => {
      console.log('收到通知:', notification);
    });

    // 监听通知点击
    Notifications.addNotificationResponseReceivedListener((response) => {
      console.log('用户点击了通知:', response);
      // 这里可以处理通知点击后的逻辑
      this.handleNotificationResponse(response);
    });
  }

  /**
   * 处理通知响应
   */
  private handleNotificationResponse(response: Notifications.NotificationResponse): void {
    const { notification } = response;
    const data = notification.request.content.data;
    
    // 根据通知类型处理不同的逻辑
    if (data?.type === 'workout_reminder') {
      // 处理运动提醒
      console.log('用户点击了运动提醒通知');
    } else if (data?.type === 'goal_achievement') {
      // 处理目标达成通知
      console.log('用户点击了目标达成通知');
    } else if (data?.type === 'mood_checkin') {
      // 处理心情打卡提醒
      console.log('用户点击了心情打卡提醒');
    }
  }

  /**
   * 发送本地推送通知
   */
  async scheduleLocalNotification(
    notification: NotificationData,
    trigger?: Notifications.NotificationTriggerInput
  ): Promise<string> {
    try {
      const notificationId = await Notifications.scheduleNotificationAsync({
        content: {
          title: notification.title,
          body: notification.body,
          data: notification.data || {},
          sound: notification.sound ? 'default' : undefined,
          priority: notification.priority || 'default',
          vibrate: notification.vibrate,
        },
        trigger: trigger || null, // null表示立即发送
      });
      
      console.log('本地通知已安排，ID:', notificationId);
      return notificationId;
    } catch (error) {
      console.error('安排本地通知失败:', error);
      throw error;
    }
  }

  /**
   * 发送立即通知
   */
  async sendImmediateNotification(notification: NotificationData): Promise<string> {
    return this.scheduleLocalNotification(notification);
  }

  /**
   * 安排定时通知
   */
  async scheduleNotificationAtDate(
    notification: NotificationData,
    date: Date
  ): Promise<string> {
    try {
      const notificationId = await Notifications.scheduleNotificationAsync({
        content: {
          title: notification.title,
          body: notification.body,
          data: notification.data || {},
          sound: notification.sound ? 'default' : undefined,
          priority: notification.priority || 'default',
          vibrate: notification.vibrate,
        },
        trigger: {
          date: date.getTime(),
        } as any,
      });
      
      console.log('定时通知已安排，ID:', notificationId);
      return notificationId;
    } catch (error) {
      console.error('安排定时通知失败:', error);
      throw error;
    }
  }

  /**
   * 安排重复通知（仅支持秒级别）
   */
  async scheduleRepeatingNotification(
    notification: NotificationData,
    interval: {
      seconds?: number;
      minutes?: number;
      hours?: number;
      days?: number;
      weeks?: number;
      months?: number;
      years?: number;
    }
  ): Promise<string> {
    try {
      // 计算总秒数
      const totalSeconds = 
        (interval.seconds || 0) +
        (interval.minutes || 0) * 60 +
        (interval.hours || 0) * 3600 +
        (interval.days || 0) * 86400 +
        (interval.weeks || 0) * 604800 +
        (interval.months || 0) * 2592000 +
        (interval.years || 0) * 31536000;

      if (totalSeconds <= 0) {
        throw new Error('重复间隔必须大于0');
      }

      const notificationId = await Notifications.scheduleNotificationAsync({
        content: {
          title: notification.title,
          body: notification.body,
          data: notification.data || {},
          sound: notification.sound ? 'default' : undefined,
          priority: notification.priority || 'default',
          vibrate: notification.vibrate,
        },
        trigger: {
          seconds: totalSeconds,
          repeats: true,
        } as any,
      });
      
      console.log('重复通知已安排，ID:', notificationId);
      return notificationId;
    } catch (error) {
      console.error('安排重复通知失败:', error);
      throw error;
    }
  }

  /**
   * 取消特定通知
   */
  async cancelNotification(notificationId: string): Promise<void> {
    try {
      await Notifications.cancelScheduledNotificationAsync(notificationId);
      console.log('通知已取消:', notificationId);
    } catch (error) {
      console.error('取消通知失败:', error);
      throw error;
    }
  }

  /**
   * 取消所有通知
   */
  async cancelAllNotifications(): Promise<void> {
    try {
      await Notifications.cancelAllScheduledNotificationsAsync();
      console.log('所有通知已取消');
    } catch (error) {
      console.error('取消所有通知失败:', error);
      throw error;
    }
  }

  /**
   * 获取所有已安排的通知
   */
  async getAllScheduledNotifications(): Promise<Notifications.NotificationRequest[]> {
    try {
      const notifications = await Notifications.getAllScheduledNotificationsAsync();
      return notifications;
    } catch (error) {
      console.error('获取已安排通知失败:', error);
      throw error;
    }
  }

  /**
   * 获取通知权限状态
   */
  async getPermissionStatus(): Promise<Notifications.PermissionStatus> {
    try {
      const { status } = await Notifications.getPermissionsAsync();
      return status;
    } catch (error) {
      console.error('获取通知权限状态失败:', error);
      throw error;
    }
  }

  /**
   * 请求通知权限
   */
  async requestPermission(): Promise<Notifications.PermissionStatus> {
    try {
      const { status } = await Notifications.requestPermissionsAsync();
      return status;
    } catch (error) {
      console.error('请求通知权限失败:', error);
      throw error;
    }
  }
}

// 导出单例实例
export const notificationService = NotificationService.getInstance();

// 预定义的推送通知类型
export const NotificationTypes = {
  WORKOUT_REMINDER: 'workout_reminder',
  GOAL_ACHIEVEMENT: 'goal_achievement',
  MOOD_CHECKIN: 'mood_checkin',
  NUTRITION_REMINDER: 'nutrition_reminder',
  PROGRESS_UPDATE: 'progress_update',
} as const;

// 便捷方法
export const sendWorkoutReminder = (title: string, body: string, date?: Date) => {
  const notification: NotificationData = {
    title,
    body,
    data: { type: NotificationTypes.WORKOUT_REMINDER },
    sound: true,
    priority: 'high',
  };
  
  if (date) {
    return notificationService.scheduleNotificationAtDate(notification, date);
  } else {
    return notificationService.sendImmediateNotification(notification);
  }
};

export const sendGoalAchievement = (title: string, body: string) => {
  const notification: NotificationData = {
    title,
    body,
    data: { type: NotificationTypes.GOAL_ACHIEVEMENT },
    sound: true,
    priority: 'high',
  };
  
  return notificationService.sendImmediateNotification(notification);
};

export const sendMoodCheckinReminder = (title: string, body: string, date?: Date) => {
  const notification: NotificationData = {
    title,
    body,
    data: { type: NotificationTypes.MOOD_CHECKIN },
    sound: true,
    priority: 'normal',
  };
  
  if (date) {
    return notificationService.scheduleNotificationAtDate(notification, date);
  } else {
    return notificationService.sendImmediateNotification(notification);
  }
};