import 'dart:async';
import 'package:flutter/services.dart';

/// 经典蓝牙插件
class ClassicBluetooth {
  static const MethodChannel _methodChannel =
      MethodChannel('com.yunqiinnovation.classic_bluetooth/methods');

  static const EventChannel _eventChannel =
      EventChannel('com.yunqiinnovation.classic_bluetooth/events');

  static Stream<BluetoothEvent>? _eventStream;

  /// 获取已连接的蓝牙设备
  static Future<List<BluetoothDevice>> getConnectedDevices() async {
    final List<dynamic> devices =
        await _methodChannel.invokeMethod('getConnectedDevices');
    return devices.map((device) => BluetoothDevice.fromJson(device)).toList();
  }

  /// 检查蓝牙是否已启用
  static Future<bool> isBluetoothEnabled() async {
    return await _methodChannel.invokeMethod('isBluetoothEnabled');
  }

  /// 发起经典蓝牙配对（A2DP 出声的前置动作）。**2026-09-11 为车载香薰新增。**
  ///
  /// 返回原生层的状态串：
  /// - Android：`already_bonded` / `bonding_in_progress` / `bonding_started`
  ///   （Android 没有"直接连某个 profile"的公开 API，配对成功后系统自己接 A2DP）
  /// - iOS：恒为 `unsupported_ios` —— Apple 不提供发起经典蓝牙配对的接口，
  ///   只能引导用户去「设置 → 蓝牙」手动配一次
  ///
  /// 失败抛 [PlatformException]（`INVALID_MAC` / `PERMISSION_DENIED` /
  /// `BT_DISABLED` / `NO_ADAPTER` / `BOND_FAILED`）。
  static Future<String?> connectDevice(String macAddress) async {
    return await _methodChannel.invokeMethod<String>(
      'connectDevice',
      {'macAddress': macAddress},
    );
  }

  /// 这台 MAC 当前是不是已经接上音频通路（A2DP）。**2026-09-11 新增。**
  ///
  /// Android 查 `BluetoothProfile.A2DP` 的已连接列表；
  /// iOS 查 `AVAudioSession` 的当前输出（`uid` 去掉后缀就是经典蓝牙 MAC）。
  /// 拿不到一律 false，不抛。
  static Future<bool> isA2dpConnected(String macAddress) async {
    try {
      return await _methodChannel.invokeMethod<bool>(
            'isA2dpConnected',
            {'macAddress': macAddress},
          ) ??
          false;
    } catch (_) {
      return false;
    }
  }

  /// 监听蓝牙事件（状态变化、设备连接/断开）
  static Stream<BluetoothEvent> get events {
    _eventStream ??= _eventChannel
        .receiveBroadcastStream()
        .map((dynamic event) => BluetoothEvent.fromJson(event))
        .handleError((error) {
      print('[ClassicBluetooth] 事件流错误: $error');
    });

    return _eventStream!;
  }
}

/// 蓝牙设备模型
class BluetoothDevice {
  final String name;
  final String address;
  final bool isActive;

  BluetoothDevice({
    required this.name,
    required this.address,
    this.isActive = false,
  });

  factory BluetoothDevice.fromJson(Map<dynamic, dynamic> json) {
    return BluetoothDevice(
      name: json['name'] as String,
      address: json['address'] as String,
      isActive: json['isActive'] == 'true',
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'name': name,
      'address': address,
      'isActive': isActive,
    };
  }

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

/// 简化的蓝牙事件类
class BluetoothEvent {
  /// 事件类型：stateChanged, deviceConnected, deviceDisconnected
  final String type;

  /// 蓝牙状态: on, off, turningOn, turningOff, unknown
  final String? state;

  /// 相关的蓝牙设备
  final BluetoothDevice? device;

  /// 事件发生时间
  final DateTime timestamp;

  BluetoothEvent({
    required this.type,
    this.state,
    this.device,
    required this.timestamp,
  });

  factory BluetoothEvent.fromJson(Map<dynamic, dynamic> json) {
    final String type = json['type'] as String;
    final timestamp =
        DateTime.fromMillisecondsSinceEpoch(json['timestamp'] as int);

    // 处理设备相关事件
    BluetoothDevice? device;
    if (json.containsKey('device')) {
      device = BluetoothDevice.fromJson(json['device']);
    }

    return BluetoothEvent(
      type: type,
      state: json['state'] as String?,
      device: device,
      timestamp: timestamp,
    );
  }

  @override
  String toString() {
    if (type == 'stateChanged') {
      return 'BluetoothEvent(type: $type, state: $state)';
    } else if (type == 'deviceConnected' || type == 'deviceDisconnected') {
      return 'BluetoothEvent(type: $type, device: $device)';
    } else {
      return 'BluetoothEvent(type: $type)';
    }
  }
}