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 '../../../core/utils/permission_util.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 = 'pleaseEnableBluetooth'.tr;
          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 = 'bleInitFailedWithError'.trParams({'error': e.toString()});
    }
  }

  // 检查权限（只查状态，绝不发起申请）
  //
  // 合规（场景 1/2）：进页面就自动弹权限框是明确禁止的。这里原来虽然叫
  // "不请求"，实际却调了 .request()，用户一进 BLE 页就被弹蓝牙+定位框，
  // 拒绝之后每次重进页面还会再弹。现在只读状态，申请交给用户点"扫描"时触发。
  Future<void> _checkPermissions() async {
    try {
      bool allGranted = true;
      for (final p in _blePermissions) {
        if (!await p.status.isGranted) {
          allGranted = false;
          break;
        }
      }
      hasPermissions.value = allGranted;

      if (!allGranted) {
        errorMessage.value = 'needBluetoothAndLocationPermission'.tr;
      }
    } catch (e) {
      print('检查权限失败: $e');
      hasPermissions.value = false;
    }
  }

  // 扫描需要的权限（成套，缺一个都扫不出设备）
  static const List<Permission> _blePermissions = [
    Permission.bluetoothScan,
    Permission.bluetoothConnect,
    Permission.location,
  ];

  // 请求权限（仅由用户点击"扫描"触发）
  //
  // 合规（场景 1）：拒绝之后不再弹任何框、不跳设置页——原来这里在检测到
  // permanentlyDenied 时会立刻弹一个带"前往设置"的自定义框，正是要禁掉的行为。
  // 现在统一走 PermissionUtil，拒绝即进入 48h 冷却，返回 false 后由 UI 置灰扫描按钮。
  Future<bool> _requestPermissions() async {
    try {
      final allGranted = await PermissionUtil.instance.requestPermissions(
        permissions: _blePermissions,
        permissionName: 'bluetooth'.tr,
        explanationText: 'needBluetoothAndLocationPermission'.tr,
      );
      hasPermissions.value = allGranted;

      if (!allGranted) {
        // 只做静态提示，不引导、不跳转
        errorMessage.value = 'needBluetoothAndLocationPermission'.tr;
      }

      return allGranted;
    } catch (e) {
      print('请求权限失败: $e');
      errorMessage.value = 'permissionRequestFailedWithError'.trParams({'error': e.toString()});
      return false;
    }
  }

  /// 权限被拒且仍在冷却期 —— 视图据此把扫描入口置灰
  bool get isPermissionCoolingDown => _blePermissions
      .any((p) => PermissionUtil.instance.isDenialCoolingDown(p));

  // 显示蓝牙开启对话框
  void _showBluetoothDialog() {
    Get.dialog(
      AlertDialog(
        title: Text('needEnableBluetooth'.tr),
        content: Text('enableBluetoothDialogContent'.tr),
        actions: [
          TextButton(
            onPressed: () => Get.back(),
            child: Text('cancel'.tr),
          ),
          TextButton(
            onPressed: () {
              Get.back();
              // 尝试开启蓝牙
              fbp.FlutterBluePlus.turnOn();
            },
            child: Text('enableBluetooth'.tr),
          ),
        ],
      ),
    );
  }

  // 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 = 'bleScanFailedWithError'.trParams({'error': e.toString()});
    }
  }

  // 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(
        'bleConnectionSuccess'.tr,
        'bleConnectedToDevice'.trParams({'device': device.platformName.isNotEmpty ? device.platformName : 'unknownEquipment'.tr}),
        backgroundColor: Colors.green,
        colorText: Colors.white,
      );
    } catch (e) {
      errorMessage.value = 'bleConnectionFailedWithError'.trParams({'error': e.toString()});
      Get.snackbar(
        'connectionFailed'.tr,
        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(
          'bleDisconnected'.tr,
          'bleDeviceDisconnected'.tr,
          backgroundColor: Colors.orange,
          colorText: Colors.white,
        );
      }
    } catch (e) {
      errorMessage.value = 'bleDisconnectFailedWithError'.trParams({'error': e.toString()});
    }
  }

  // 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 'unknownEquipment'.tr;
  }

  // 获取信号强度描述
  String getSignalStrengthText(int rssi) {
    if (rssi >= -50) return 'signalStrong'.tr;
    if (rssi >= -70) return 'signalMedium'.tr;
    if (rssi >= -90) return 'signalWeak'.tr;
    return 'signalVeryWeak'.tr;
  }

  // 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;
  }
}