import 'dart:async';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:permission_handler/permission_handler.dart';
import '../../core/utils/logger.dart';

/// 蓝牙设备信息
class BluetoothDevice {
  final String name;
  final String address;
  final String type;

  BluetoothDevice({
    required this.name, 
    required this.address, 
    required this.type
  });

  @override
  String toString() => 'BluetoothDevice(name: $name, address: $address, type: $type)';
}

/// 经典蓝牙服务
class ClassicBluetoothService extends GetxService {
  static ClassicBluetoothService get to => Get.find<ClassicBluetoothService>();

  // 通道名称
  final MethodChannel _channel = const MethodChannel('com.deep_voice.classic_bluetooth');
  final EventChannel _eventChannel = const EventChannel('com.deep_voice.classic_bluetooth_events');
  
  /// 当前连接的设备
  final currentDevice = Rx<BluetoothDevice?>(null);
  
  /// 已连接耳机设备列表
  final connectedDevices = <BluetoothDevice>[].obs;
  
  /// 蓝牙设备状态监听
  StreamSubscription? _bluetoothStateListener;
  
  /// 蓝牙开关状态
  final bluetoothState = 'unknown'.obs;
  
  /// 蓝牙是否可用
  bool get isBluetoothOn => bluetoothState.value == 'on';
  
  /// 服务是否已初始化
  bool _isInitialized = false;

  /// 初始化蓝牙服务 - 单一入口点
  Future<bool> initialize() async {
    if (_isInitialized) {
      Logger.info('蓝牙服务已经初始化，跳过');
      return true;
    }
    
    try {
      Logger.info('正在初始化蓝牙服务...');
      
      // 获取当前蓝牙状态
      final bool isEnabled = await _channel.invokeMethod<bool>('isBluetoothEnabled') ?? false;
      bluetoothState.value = isEnabled ? 'on' : 'off';
      Logger.info('初始蓝牙状态: ${bluetoothState.value}');
      
      // 启动蓝牙设备监控 - 这将调用原生代码中的initBluetooth
      await _channel.invokeMethod('startBluetoothDeviceMonitoring');
      
      // 设置事件监听
      _setupBluetoothStateListener();
      
      _isInitialized = true;
      Logger.info('蓝牙服务初始化成功');
      return true;
    } catch (e) {
      Logger.error('初始化蓝牙服务失败: $e');
      return false;
    }
  }
  
  /// 检查蓝牙权限
  Future<bool> checkPermissions() async {
    // 检查蓝牙相关权限
    Map<Permission, PermissionStatus> statuses = await [
      Permission.bluetooth,
      Permission.bluetoothConnect,
      Permission.bluetoothScan,
    ].request();
    
    return statuses[Permission.bluetoothConnect] == PermissionStatus.granted;
  }
  
  /// 刷新已连接的蓝牙耳机设备
  Future<bool> refreshConnectedDevices() async {
    // 确保服务已初始化
    if (!_isInitialized && !(await initialize())) {
      return false;
    }
    
    // 如果蓝牙未开启，无法获取设备
    if (!isBluetoothOn) {
      Logger.info('蓝牙未开启，无法获取设备');
      return false;
    }
    
    try {
      // 只获取耳机设备
      final devices = await getConnectedHeadsetDevices();
      
      // 更新设备列表
      connectedDevices.value = devices;
      
      // 更新当前设备
      if (connectedDevices.isNotEmpty && currentDevice.value == null) {
        currentDevice.value = connectedDevices.first;
      }
      
      return connectedDevices.isNotEmpty;
    } catch (e) {
      Logger.error('刷新已连接设备失败: $e');
      return false;
    }
  }
  
  /// 获取已连接的耳机设备
  Future<List<BluetoothDevice>> getConnectedHeadsetDevices() async {
    try {
      // 确保服务已初始化
      if (!_isInitialized && !(await initialize())) {
        return [];
      }
      
      final result = await _channel.invokeMethod('getConnectedHeadsetDevices');
      
      if (result is List) {
        return result.map((device) => BluetoothDevice(
          name: device['name'] ?? '未知设备',
          address: device['address'] ?? '',
          type: 'headset'
        )).toList();
      }
      
      return [];
    } catch (e) {
      Logger.error('获取已连接的耳机设备失败: $e');
      return [];
    }
  }
  
  /// 设置蓝牙状态监听
  void _setupBluetoothStateListener() {
    _bluetoothStateListener?.cancel();
    
    _bluetoothStateListener = _eventChannel
      .receiveBroadcastStream()
      .listen((event) {
        if (event is Map) {
          Logger.info('蓝牙状态监听: $event');
          final type = event['type'] as String?;
          
          if (type == 'bluetoothStateChanged') {
            final state = event['state'] as String?;
            if (state != null) {
              _handleBluetoothStateChange(state);
            }
          } else if (type == 'deviceConnected') {
            _handleDeviceConnected(event);
          } else if (type == 'deviceDisconnected') {
            _handleDeviceDisconnected(event);
          }
        }
      }, onError: (error) {
        Logger.error('蓝牙状态监听错误: $error');
      });
  }
  
  /// 处理设备连接事件
  void _handleDeviceConnected(Map event) {
    final deviceMap = event['device'] as Map?;
    if (deviceMap != null) {
      final device = BluetoothDevice(
        name: deviceMap['name'] ?? '未知设备',
        address: deviceMap['address'] ?? '',
        type: deviceMap['type'] ?? 'unknown'
      );
      
      // 更新设备列表
      if (!connectedDevices.any((d) => d.address == device.address)) {
        connectedDevices.add(device);
      }
      
      // 更新当前设备
      currentDevice.value = device;
      
      Logger.info('设备已连接: ${device.name}');
    }
  }
  
  /// 处理设备断开事件
  void _handleDeviceDisconnected(Map event) {
    final deviceMap = event['device'] as Map?;
    if (deviceMap != null) {
      final address = deviceMap['address'] as String?;
      
      if (address != null) {
        // 更新设备列表
        connectedDevices.removeWhere((d) => d.address == address);
        
        // 如果是当前设备，清除当前设备
        if (currentDevice.value?.address == address) {
          currentDevice.value = connectedDevices.isEmpty ? null : connectedDevices.first;
          Logger.info('当前设备已断开连接');
        }
      }
    }
  }
  
  /// 处理蓝牙状态变化
  void _handleBluetoothStateChange(String state) {
    Logger.info('蓝牙状态变化: $state');
    
    // 更新蓝牙状态
    bluetoothState.value = state;
    
    if (state == 'off') {
      // 蓝牙关闭，清空设备信息
      connectedDevices.clear();
      currentDevice.value = null;
    } else if (state == 'on') {
      // 蓝牙重新打开，延迟一小段时间后刷新设备
      Future.delayed(const Duration(milliseconds: 1000), () {
        refreshConnectedDevices();
      });
    }
  }
  
  @override
  void onClose() {
    // 取消蓝牙状态监听
    _bluetoothStateListener?.cancel();
    super.onClose();
  }
}