import 'package:get/get.dart';
import '../../../routes/app_routes.dart';
import '../../../data/services/bluetooth_service.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart' hide BluetoothService;
import '../../../core/utils/logger.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:flutter/material.dart';

/// 简化的配对控制器，仅用于显示已连接或配对的蓝牙耳机信息
class PairingController extends GetxController {
  // 蓝牙服务
  late BluetoothService _bluetoothService;
  
  // 设备信息
  final _deviceInfo = Rx<Map<String, dynamic>>({});
  Map<String, dynamic> get deviceInfo => _deviceInfo.value;
  
  // 蓝牙状态
  final _isBluetoothAvailable = false.obs;
  final _isBluetoothOn = false.obs;
  bool get isBluetoothAvailable => _isBluetoothAvailable.value;
  bool get isBluetoothOn => _isBluetoothOn.value;
  
  // 错误消息
  final _errorMessage = ''.obs;
  String get errorMessage => _errorMessage.value;
  
  // 已连接的设备列表
  final _connectedDevices = <BluetoothDevice>[].obs;
  List<BluetoothDevice> get connectedDevices => _connectedDevices;
  
  // 已配对的设备列表
  final _pairedDevices = <BluetoothDevice>[].obs;
  List<BluetoothDevice> get pairedDevices => _pairedDevices;
  
  // 状态描述（用于UI显示）
  final _statusDescription = ''.obs;
  String get statusDescription => _statusDescription.value;
  
  // 防止重复刷新的标志
  bool _isRefreshing = false;
  
  // 上次刷新时间
  DateTime? _lastRefreshTime;
  
  @override
  void onInit() {
    super.onInit();
    _initializeProcess();
  }
  
  // 初始化流程
  Future<void> _initializeProcess() async {
    _updateStatus('正在初始化...');
    
    try {
      // 获取或初始化蓝牙服务
      await _getBluetoothService();
      
      // 检查权限并获取设备信息
      await _checkAndRequestPermissions();
    } catch (e) {
      Logger.error('初始化过程失败: $e');
      _updateStatus('初始化失败');
      _setError('初始化蓝牙服务失败，请重试');
    }
  }
  
  // 获取蓝牙服务
  Future<void> _getBluetoothService() async {
    try {
      // 检查是否已注册
      if (Get.isRegistered<BluetoothService>()) {
        _bluetoothService = Get.find<BluetoothService>();
      } else {
        // 初始化并注册服务
        _bluetoothService = await Get.put(BluetoothService()).init();
      }
      
      // 设置蓝牙状态监听
      _setupBluetoothListeners();
      
      // 获取设备信息
      _refreshDeviceInfo();
    } catch (e) {
      Logger.error('获取蓝牙服务失败: $e');
      throw Exception('获取蓝牙服务失败: $e');
    }
  }
  
  // 设置蓝牙状态监听
  void _setupBluetoothListeners() {
    // 监听蓝牙可用性
    _isBluetoothAvailable.value = _bluetoothService.isAvailable;
    ever(_bluetoothService.isAvailableObs, (bool available) {
      _isBluetoothAvailable.value = available;
      
      if (!available) {
        _updateStatus('蓝牙不可用');
        _setError('蓝牙不可用，请检查设备是否支持蓝牙功能');
      }
    });
    
    // 监听蓝牙开关状态
    _isBluetoothOn.value = _bluetoothService.isOn;
    ever(_bluetoothService.isOnObs, (bool on) {
      _isBluetoothOn.value = on;
      
      if (on) {
        // 蓝牙开启时，延迟一下再刷新设备信息，避免频繁刷新
        Future.delayed(const Duration(milliseconds: 500), () {
          _refreshDeviceInfo();
        });
      } else {
        _updateStatus('蓝牙已关闭');
        _setError('蓝牙已关闭，请开启蓝牙后再试');
      }
    });
    
    // 监听已连接设备变化
    _connectedDevices.value = _bluetoothService.connectedDevices;
    ever(_bluetoothService.connectedDevicesObs, (List<BluetoothDevice> devices) {
      _connectedDevices.value = devices;
      
      // 只有当设备列表不为空时才刷新设备信息
      if (devices.isNotEmpty) {
        // 延迟一下再刷新，避免频繁刷新
        Future.delayed(const Duration(milliseconds: 500), () {
          _refreshDeviceInfo();
        });
      }
    });
    
    // 监听已配对设备变化
    _pairedDevices.value = _bluetoothService.systemPairedDevices;
  }
  
  // 检查并请求权限
  Future<void> _checkAndRequestPermissions() async {
    _updateStatus('正在请求权限...');
    
    try {
      bool hasPermissions = await _bluetoothService.requestPermissions();
      
      if (!hasPermissions) {
        // 权限被拒绝
        _handlePermissionDenied();
        return;
      }
      
      // 权限已授予，检查蓝牙状态
      if (!_bluetoothService.isOn) {
        _updateStatus('蓝牙已关闭');
        _setError('蓝牙已关闭，请开启蓝牙后再试');
        return;
      }
      
      // 刷新设备信息
      _refreshDeviceInfo();
    } catch (e) {
      Logger.error('权限请求失败: $e');
      _updateStatus('权限请求失败');
      _setError('权限请求失败，请手动授予蓝牙和位置权限');
    }
  }
  
  // 处理权限被拒绝的情况
  void _handlePermissionDenied() async {
    // 检查是否永久拒绝
    bool isPermanentlyDenied = false;
    
    if (GetPlatform.isAndroid) {
      PermissionStatus bluetoothScan = await Permission.bluetoothScan.status;
      PermissionStatus bluetoothConnect = await Permission.bluetoothConnect.status;
      PermissionStatus location = await Permission.location.status;
      
      // 如果任一权限被永久拒绝
      isPermanentlyDenied = 
          bluetoothScan.isPermanentlyDenied || 
          bluetoothConnect.isPermanentlyDenied || 
          location.isPermanentlyDenied;
    }
    
    _updateStatus('缺少必要权限');
    
    if (isPermanentlyDenied) {
      _setError('缺少必要权限，您已永久拒绝权限，请前往系统设置中手动开启');
      // 显示前往设置的提示
      _showGoToSettingsDialog();
    } else {
      _setError('缺少必要权限，请授予蓝牙和位置权限以继续');
    }
  }
  
  // 显示前往设置的对话框
  void _showGoToSettingsDialog() {
    Get.dialog(
      AlertDialog(
        title: const Text('需要权限'),
        content: const Text('蓝牙搜索需要特定权限，请前往系统设置开启'),
        actions: [
          TextButton(
            onPressed: () => Get.back(),
            child: const Text('稍后'),
          ),
          TextButton(
            onPressed: () {
              Get.back();
              openAppSettings();
            },
            child: const Text('前往设置'),
          ),
        ],
      ),
      barrierDismissible: false,
    );
  }
  
  // 刷新设备信息
  Future<void> _refreshDeviceInfo() async {
    // 防止重复刷新
    if (_isRefreshing) return;
    
    _isRefreshing = true;
    
    if (!_isBluetoothOn.value) {
      _updateStatus('蓝牙已关闭');
      _deviceInfo.value = {};
      _isRefreshing = false;
      return;
    }
    
    try {
      // 更新已配对设备列表
      _pairedDevices.value = _bluetoothService.systemPairedDevices;
      
      // 查找系统已连接设备
      BluetoothDevice? device = await _bluetoothService.findConnectedSystemDevice();
      
      if (device != null) {
        // 已连接设备
        _deviceInfo.value = _bluetoothService.getConnectedDeviceInfo();
        _updateStatus('已连接到蓝牙设备');
        _goToHomePage();
      } else if (_bluetoothService.lastConnectedDeviceInfo.isNotEmpty) {
        // 使用上次连接的设备信息
        _deviceInfo.value = _bluetoothService.lastConnectedDeviceInfo;
        _updateStatus('使用上次连接的设备信息');
        _goToHomePage();
      } else if (_pairedDevices.isNotEmpty) {
        // 使用已配对设备
        BluetoothDevice pairedDevice = _pairedDevices.first;
        _deviceInfo.value = _bluetoothService.getPairedDeviceInfo(pairedDevice);
        _bluetoothService.setSelectedDevice(pairedDevice);
        _updateStatus('已找到配对设备');
        _goToHomePage();
      } else {
        // 没有找到任何设备
        _deviceInfo.value = {};
        _updateStatus('未找到已连接或配对的蓝牙设备');
      }
    } catch (e) {
      Logger.error('刷新设备信息失败: $e');
      _updateStatus('获取设备信息失败');
    } finally {
      _isRefreshing = false;
    }
  }
  
  // 更新状态描述
  void _updateStatus(String description) {
    _statusDescription.value = description;
    Logger.info('状态更新: $description');
  }
  
  // 设置错误信息
  void _setError(String message) {
    _errorMessage.value = message;
    Logger.warning('错误: $message');
  }
  
  // 跳转到主页
  void _goToHomePage() {
    Get.offAllNamed(Routes.home, arguments: _deviceInfo.value);
  }
  
  // 刷新搜索
  void refreshSearch() {
    // 防止频繁刷新，限制最小刷新间隔为2秒
    final now = DateTime.now();
    if (_lastRefreshTime != null && 
        now.difference(_lastRefreshTime!).inSeconds < 2) {
      return;
    }
    
    _lastRefreshTime = now;
    _refreshDeviceInfo();
  }
  
  // 跳过连接
  void skipConnecting() {
    Get.offAllNamed(Routes.home);
  }
}