import 'dart:async';
import 'dart:typed_data';

import 'package:flutter/services.dart';

/// BLE连接状态常量
class BleConnectionState {
  static const int disconnected = 0;
  static const int connecting = 1;
  static const int connected = 2;
  static const int disconnecting = 3;
  static const int error = 4;
}

/// BLE服务插件
class BleService {
  static final BleService _instance = BleService._internal();
  
  /// 获取单例
  factory BleService() => _instance;
  
  // 方法通道
  final MethodChannel _methodChannel = const MethodChannel('com.yunqiinnovation.ble_service');
  
  // 事件通道 - 简化为只使用数据和状态通道
  late final EventChannel _dataEventChannel;
  late final EventChannel _statusEventChannel;
  
  // 事件流
  late final Stream<dynamic> _dataStream;
  late final Stream<dynamic> _statusStream;
  
  // 获取事件流
  Stream<dynamic> get onDataReceived => _dataStream;
  
  // 状态流直接传递原始数据
  Stream<dynamic> get onStatusUpdated => _statusStream;
  
  // 内部构造函数
  BleService._internal() {
    _dataEventChannel = const EventChannel('com.yunqiinnovation.ble_service/data_events');
    _statusEventChannel = const EventChannel('com.yunqiinnovation.ble_service/status_events');
    
    // 初始化事件流
    _dataStream = _dataEventChannel.receiveBroadcastStream();
    _statusStream = _statusEventChannel.receiveBroadcastStream();
  }

  /// 检查是否已连接
  Future<bool> isConnected() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('isConnected');
      return result ?? false;
    } catch (e) {
      print('检查连接状态失败: $e');
      return false;
    }
  }
  
  /// 获取电池电量
  Future<int> getBatteryLevel() async {
    try {
      final result = await _methodChannel.invokeMethod<int>('getBatteryLevel');
      return result ?? 0;
    } catch (e) {
      print('获取电池电量失败: $e');
      return 0;
    }
  }
  
  /// 获取设备版本信息
  Future<bool> getDeviceVersion() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('getDeviceVersion');
      return result ?? false;
    } catch (e) {
      print('获取设备版本失败: $e');
      return false;
    }
  }
  
  /// 获取电池信息
  Future<bool> getBatteryInfo() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('getBatteryInfo');
      return result ?? false;
    } catch (e) {
      print('获取电池信息失败: $e');
      return false;
    }
  }
  
  /// 打开编码器
  Future<bool> openEncoder() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('openEncoder');
      return result ?? false;
    } catch (e) {
      print('打开编码器失败: $e');
      return false;
    }
  }
  
  /// 打开解码器
  Future<bool> openDecoder() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('openDecoder');
      return result ?? false;
    } catch (e) {
      print('打开解码器失败: $e');
      return false;
    }
  }
  
  /// 关闭编解码器
  Future<bool> closeCodec() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('closeCodec');
      return result ?? false;
    } catch (e) {
      print('关闭编解码器失败: $e');
      return false;
    }
  }
  
  /// 播放A2DP
  Future<bool> playA2DP() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('playA2DP');
      return result ?? false;
    } catch (e) {
      print('播放A2DP失败: $e');
      return false;
    }
  }
  
  /// 启动BLE后台服务
  /// [config] 配置参数，可包含：
  /// - scan_interval: 扫描间隔时间(毫秒)
  /// - scan_duration: 扫描持续时间(毫秒)
  /// - notification_title: 通知标题
  /// - notification_content: 通知内容
  /// - mac: 设备地址
  /// - device_name: 设备名称
  Future<bool> startBleService(Map<String, dynamic> config) async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('startBleService', config);
      return result ?? false;
    } catch (e) {
      print('启动BLE后台服务失败: $e');
      return false;
    }
  }
  
  /// 停止BLE后台服务
  Future<bool> stopBleService() async {
    try {
      final result = await _methodChannel.invokeMethod<bool>('stopBleService');
      return result ?? false;
    } catch (e) {
      print('停止BLE后台服务失败: $e');
      return false;
    }
  }
  
  /// 获取已连接设备地址 - 使用其他方式获取设备地址，不再直接调用此方法
  Future<String?> getConnectedDeviceAddress() async {
    // 简化版处理，返回空值
    return null;
  }
}