import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart' as fbp;
import 'package:permission_handler/permission_handler.dart';
import 'package:app_settings/app_settings.dart';

class BleController extends GetxController {
  // 扫描状态
  final RxBool isScanning = false.obs;
  final RxBool isBluetoothOn = false.obs;
  final RxBool hasPermissions = false.obs;

  // 发现的设备列表
  final RxList<fbp.ScanResult> scanResults = <fbp.ScanResult>[].obs;

  // 连接的设备
  final Rx<fbp.BluetoothDevice?> connectedDevice =
      Rx<fbp.BluetoothDevice?>(null);

  // 错误信息
  final RxString errorMessage = ''.obs;

  @override
  void onInit() {
    super.onInit();
    _initBluetooth();
  }

  @override
  void onClose() {
    stopScan();
    super.onClose();
  }

  // 初始化蓝牙
  Future<void> _initBluetooth() async {
    try {
      // 先检查权限
      await _checkPermissions();

      // 检查蓝牙适配器状态
      fbp.FlutterBluePlus.adapterState.listen((state) {
        isBluetoothOn.value = state == fbp.BluetoothAdapterState.on;
        if (state == fbp.BluetoothAdapterState.on) {
          errorMessage.value = '';
        } else {
          errorMessage.value = '请开启蓝牙';
          stopScan();
        }
      });

      // 监听扫描结果
      fbp.FlutterBluePlus.scanResults.listen((results) {
        scanResults.value = results;
      });

      // 监听扫描状态
      fbp.FlutterBluePlus.isScanning.listen((scanning) {
        isScanning.value = scanning;
      });
    } catch (e) {
      errorMessage.value = '蓝牙初始化失败: $e';
    }
  }

  // 检查权限（不请求）
  Future<void> _checkPermissions() async {
    try {
      Map<Permission, PermissionStatus> statuses = await [
        Permission.bluetoothScan,
        Permission.bluetoothConnect,
        Permission.location,
      ].request();

      hasPermissions.value =
          statuses.values.every((status) => status == PermissionStatus.granted);

      if (!hasPermissions.value) {
        errorMessage.value = '需要蓝牙和位置权限才能扫描设备';
      }
    } catch (e) {
      print('检查权限失败: $e');
      hasPermissions.value = false;
    }
  }

  // 请求权限
  Future<bool> _requestPermissions() async {
    try {
      Map<Permission, PermissionStatus> statuses = await [
        Permission.bluetoothScan,
        Permission.bluetoothConnect,
        Permission.location,
      ].request();

      bool allGranted =
          statuses.values.every((status) => status == PermissionStatus.granted);
      hasPermissions.value = allGranted;

      if (!allGranted) {
        // 检查是否有权限被永久拒绝
        bool hasPermanentlyDenied = statuses.values
            .any((status) => status == PermissionStatus.permanentlyDenied);

        if (hasPermanentlyDenied) {
          _showPermissionDialog();
        } else {
          errorMessage.value = '需要蓝牙和位置权限才能扫描设备';
        }
      }

      return allGranted;
    } catch (e) {
      print('请求权限失败: $e');
      errorMessage.value = '权限请求失败: $e';
      return false;
    }
  }

  // 显示权限对话框
  void _showPermissionDialog() {
    Get.dialog(
      AlertDialog(
        title: Text('需要权限'),
        content: Text('应用需要蓝牙和位置权限才能扫描设备。请在设置中手动开启权限。'),
        actions: [
          TextButton(
            onPressed: () => Get.back(),
            child: Text('取消'),
          ),
          TextButton(
            onPressed: () {
              Get.back();
              AppSettings.openAppSettings();
            },
            child: Text('去设置'),
          ),
        ],
      ),
    );
  }

  // 显示蓝牙开启对话框
  void _showBluetoothDialog() {
    Get.dialog(
      AlertDialog(
        title: Text('需要开启蓝牙'),
        content: Text('请开启蓝牙以扫描和连接设备。'),
        actions: [
          TextButton(
            onPressed: () => Get.back(),
            child: Text('取消'),
          ),
          TextButton(
            onPressed: () {
              Get.back();
              // 尝试开启蓝牙
              fbp.FlutterBluePlus.turnOn();
            },
            child: Text('开启蓝牙'),
          ),
        ],
      ),
    );
  }

  // 开始扫描
  Future<void> startScan() async {
    try {
      errorMessage.value = '';

      // 检查权限
      if (!hasPermissions.value) {
        if (!await _requestPermissions()) {
          return;
        }
      }

      // 检查蓝牙状态
      if (!isBluetoothOn.value) {
        _showBluetoothDialog();
        return;
      }

      // 清空之前的结果
      scanResults.clear();

      // 开始扫描
      await fbp.FlutterBluePlus.startScan(
        timeout: const Duration(seconds: 30),
        androidUsesFineLocation: true,
      );
    } catch (e) {
      errorMessage.value = '扫描失败: $e';
    }
  }

  // 停止扫描
  Future<void> stopScan() async {
    try {
      await fbp.FlutterBluePlus.stopScan();
    } catch (e) {
      print('停止扫描失败: $e');
    }
  }

  // 连接设备
  Future<void> connectToDevice(fbp.BluetoothDevice device) async {
    try {
      errorMessage.value = '';

      // 停止扫描
      await stopScan();

      // 连接设备
      await device.connect(timeout: const Duration(seconds: 15));
      connectedDevice.value = device;

      Get.snackbar(
        '连接成功',
        '已连接到 ${device.platformName.isNotEmpty ? device.platformName : '未知设备'}',
        backgroundColor: Colors.green,
        colorText: Colors.white,
      );
    } catch (e) {
      errorMessage.value = '连接失败: $e';
      Get.snackbar(
        '连接失败',
        e.toString(),
        backgroundColor: Colors.red,
        colorText: Colors.white,
      );
    }
  }

  // 断开连接
  Future<void> disconnectDevice() async {
    try {
      if (connectedDevice.value != null) {
        await connectedDevice.value!.disconnect();
        connectedDevice.value = null;

        Get.snackbar(
          '已断开连接',
          '设备已断开连接',
          backgroundColor: Colors.orange,
          colorText: Colors.white,
        );
      }
    } catch (e) {
      errorMessage.value = '断开连接失败: $e';
    }
  }

  // 获取设备名称
  String getDeviceName(fbp.ScanResult result) {
    if (result.device.platformName.isNotEmpty) {
      return result.device.platformName;
    }
    if (result.advertisementData.localName.isNotEmpty) {
      return result.advertisementData.localName;
    }
    return '未知设备';
  }

  // 获取信号强度描述
  String getSignalStrengthText(int rssi) {
    if (rssi >= -50) return '信号强';
    if (rssi >= -70) return '信号中等';
    if (rssi >= -90) return '信号弱';
    return '信号很弱';
  }

  // 获取信号强度图标
  IconData getSignalStrengthIcon(int rssi) {
    if (rssi >= -50) return Icons.signal_wifi_4_bar;
    if (rssi >= -70) return Icons.signal_wifi_4_bar;
    if (rssi >= -90) return Icons.signal_wifi_4_bar;
    return Icons.signal_wifi_4_bar;
  }
}