import 'dart:async';

import 'package:flutter_blue_plus/flutter_blue_plus.dart';
import 'package:starwork_flutter/base/app_logger.dart';
import 'package:starwork_flutter/ble/model/scan_device_info.dart';
import 'package:starwork_flutter/common/constant/device_type.dart';

class BleService {
  // 私有构造函数
  BleService._() {
    // ✅ 这里就是单例初始化的地方
    // 只会执行一次（第一次获取实例时）
    _initialize();
  }

  // 静态实例
  static final BleService _instance = BleService._();

  // 工厂构造函数，提供全局访问点
  factory BleService() => _instance;

  /// 用来存储搜索到的设备，并用于去重和过滤
  final Map<String, ScanResult> _discoveredDevices = {};

  /// 用来监听蓝牙适配器状态的订阅流
  StreamSubscription<BluetoothAdapterState>? _adapterStateSubscription;

  /// 用来监听搜索到的设备的订阅流
  StreamSubscription<List<ScanResult>>? _scanResultSubscription;

  // 内部维护的蓝牙状态
  BluetoothAdapterState _bluetoothAdapterState = BluetoothAdapterState.unknown;

  /// 提供外部获取蓝牙适配器方法
  BluetoothAdapterState get bluetoothAdapterState => _bluetoothAdapterState;

  /// 搜索状态
  bool get isScanningNow => FlutterBluePlus.isScanningNow;

  /// 初始化服务时执行的
  Future<void> _initialize() async {
    AppLogger.highlight('🚀 BleService 正在初始化...');

    /// 监听蓝牙适配器状态
    _adapterStateSubscription = FlutterBluePlus.adapterState.listen((BluetoothAdapterState state) {
      _bluetoothAdapterState = state;
      AppLogger.highlight('蓝牙适配器状态发送变化:${state}');
    });

    AppLogger.highlight('✅ BleService 初始化完成');
  }

  /// 开启蓝牙搜索
  void enableBluetoothSearch({
    DeviceType deviceType = DeviceType.all,
    Duration searchTime = const Duration(seconds: 30),
    required void Function(ScanDeviceInfo device) onDeviceFound,
  }) async {
    // 如果正在搜索中，直接返回
    var isScanningNow = FlutterBluePlus.isScanningNow;
    if (isScanningNow) {
      AppLogger.warn('正处于搜索状态，请勿重复搜索');
      return;
    }
    if (_bluetoothAdapterState == BluetoothAdapterState.on) {
      FlutterBluePlus.startScan(timeout: searchTime);

      /// 取消旧的订阅，防止重复
      _scanResultSubscription?.cancel();
      _discoveredDevices.clear();

      /// 监听搜索到的设备
      _scanResultSubscription = FlutterBluePlus.onScanResults.listen(
        (List<ScanResult> results) {
          for (var result in results) {
            var device = result.device;
            final deviceId = device.remoteId.toString();
            final platformName = device.platformName;
            var serviceUuids = result.advertisementData.serviceUuids;

            // ✅ 只有新设备才回调
            if (!_discoveredDevices.containsKey(deviceId) && platformName.isNotEmpty) {
              _discoveredDevices[deviceId] = result;
              bool pairStatus = false;
              bool hasNewEvent = false;
              for (var uuid in serviceUuids) {
                String uuidStr = uuid.toString().replaceAll('-', '');
                if (uuidStr.length == 8) {
                  var pairStatusStr = uuidStr.substring(4, 6);
                  var hasNewEventStr = uuidStr.substring(6, 8);
                  pairStatus = pairStatusStr == '01';
                  hasNewEvent = hasNewEventStr == '01';
                  var scanDeviceInfo = ScanDeviceInfo(
                    isBinding: pairStatus,
                    advName: device.advName,
                    rawDeviceInfo: result,
                    hasNewEvent: hasNewEvent,
                  );
                  onDeviceFound.call(scanDeviceInfo);
                } else if (uuidStr.length == 32) {
                  var pairStatusStr = uuidStr.substring(26, 28);
                  pairStatus = pairStatusStr == '00'; // 第4、5位（索引3和4）
                  int statusValue = int.parse(pairStatusStr, radix: 16);
                  // 提取 byte0（配对状态：第1位）
                  int byte0 = (statusValue >> 0) & 0x01; // 取最低位
                  // 提取 byte1（事件状态：第2位）
                  int byte1 = (statusValue >> 1) & 0x01; // 取次低位
                  // 判断是否未配对
                  pairStatus = (byte0 == 1);
                  // 判断是否有新事件
                  hasNewEvent = (byte1 == 1);
                  var scanDeviceInfo = ScanDeviceInfo(
                    isBinding: pairStatus,
                    advName: device.advName,
                    rawDeviceInfo: result,
                    hasNewEvent: hasNewEvent,
                  );
                  onDeviceFound.call(scanDeviceInfo);
                }
              }
            } else {
              // 可选：更新 RSSI
              _discoveredDevices[deviceId] = result;
            }
          }
        },
        onError: (e) => AppLogger.error('搜索设备时遇到错误：' + e),
      );
    }
  }

  /// 停止扫描
  void stopBluetoothSearch() async {
    var isScanningNow = FlutterBluePlus.isScanningNow;
    if (isScanningNow) {
      FlutterBluePlus.stopScan();

      /// 清空搜索到的设备
      _discoveredDevices.clear();
    }
  }

  void cancel() {
    /// 销毁蓝牙适配器监听
    _adapterStateSubscription?.cancel();
    _scanResultSubscription?.cancel();
    _bluetoothAdapterState = BluetoothAdapterState.unknown;
  }
}