import 'dart:async';
import 'package:common_utils/common_utils.dart';
import 'package:event_bus/event_bus.dart';
import 'package:permission_handler/permission_handler.dart';

import 'package:get/get.dart';

import 'package:pj_supermarket_cloud/common/index.dart';

enum AppStartupStepStatus {
  /// 尚未开始执行当前启动步骤。
  waiting,

  /// 当前启动步骤正在执行。
  running,

  /// 当前启动步骤已完整完成。
  success,

  /// 当前能力受限，但不阻断应用进入业务页面。
  warning,

  /// 核心启动依赖失败，应用不能继续进入业务页面。
  failure,
}

/// Load 页展示的单个启动步骤状态。
class AppStartupStepState {
  /// 创建一条不可变的启动步骤展示数据。
  const AppStartupStepState({
    required this.title,
    required this.detail,
    this.status = AppStartupStepStatus.waiting,
  });

  /// 启动步骤标题。
  final String title;

  /// 当前进度或处理结果说明。
  final String detail;

  /// 当前步骤状态。
  final AppStartupStepStatus status;

  /// 复制当前步骤并替换可变的状态和说明。
  AppStartupStepState copyWith({
    String? detail,
    AppStartupStepStatus? status,
  }) {
    return AppStartupStepState(
      title: title,
      detail: detail ?? this.detail,
      status: status ?? this.status,
    );
  }
}

/// 应用启动、数据库和终端硬件生命周期的统一控制器。
class AppControl extends GetxController {
  /// 启动流程日志标签。
  static const String _tag = "AppControl";

  /// Load 页按执行顺序展示的启动步骤集合。
  final startupSteps = <AppStartupStepState>[
    const AppStartupStepState(
      title: '加载终端配置',
      detail: '等待读取设备模式与本地设置',
    ),
    const AppStartupStepState(
      title: '打开业务数据库',
      detail: '等待准备订单、商品与用户数据',
    ),
    const AppStartupStepState(
      title: '初始化设备服务',
      detail: '等待准备打印、读卡与电子秤服务',
    ),
    const AppStartupStepState(
      title: '准备人脸识别',
      detail: '等待检查激活参数与本地人脸库',
    ),
  ].obs;

  /// 核心启动失败时面向用户展示的统一说明。
  final startupFailureMessage = ''.obs;

  /// 所有阻塞启动步骤完成后为 true。
  final startupFinished = false.obs;

  final startupEnvironmentDescription = '正在识别终端运行环境'.obs;

  final startupEnvironmentDetail = '双屏、虚拟机与硬件输入模式将按设备能力自动适配'.obs;

  final startupStatusLabel = '正在启动'.obs;

  /// 最近一次启动阶段的人脸准备结果；尚未执行时为空。
  final faceStartupPreparationResult = Rxn<FaceStartupPreparationResult>();

  bool _initializing = false;
  bool _databaseInitialized = false;

  /// 当前账号是否允许启动需要鉴权或设备身份的 MQTT、心跳和后台同步任务。
  bool _authenticatedServicesEnabled = false;

  /// 网络监听和消息连接在执行前读取的会话开关；退出动作会先关闭它再释放资源。
  bool get authenticatedServicesEnabled => _authenticatedServicesEnabled;

  int get startupCompletedCount => startupSteps
      .where((item) =>
          item.status == AppStartupStepStatus.success ||
          item.status == AppStartupStepStatus.warning)
      .length;

  double get startupProgress =>
      startupSteps.isEmpty ? 0 : startupCompletedCount / startupSteps.length;

  /// 打印机
  late PrintManage printManage;

  /// 读卡器串口
  late SerialCardManage serialCardManage;

  /// 称串口
  late SerialSteelyardManage srialSteelyardManage;

  /// mq
  StreamSubscription? mqListen;

  EventBus mqUpdateEventBus = EventBus();

  /// 数据库
  late final AppDatabase dataBase;

  // 是否有网络
  RxBool isNetwork = RxBool(false);

  @override
  void onClose() {
    super.onClose();
    _authenticatedServicesEnabled = false;
    if (printManageInitialized) printManage.close();
    if (serialCardManageInitialized) serialCardManage.close();
    if (steelyardManageInitialized) srialSteelyardManage.close();
    AppNetworkTool.closeListenNetwork();
    TtsManage.dispose();
    SyncCheckTool.instance.dispose();
    TerminalHeartbeatTool.stop();
  }

  bool get printManageInitialized {
    try {
      printManage;
      return true;
    } catch (_) {
      return false;
    }
  }

  bool get serialCardManageInitialized {
    try {
      serialCardManage;
      return true;
    } catch (_) {
      return false;
    }
  }

  bool get steelyardManageInitialized {
    try {
      srialSteelyardManage;
      return true;
    } catch (_) {
      return false;
    }
  }

  Future<void> initAsync({
    String destination = RouteNames.login,
    bool force = false,
  }) async {
    if (_initializing || (startupFinished.value && !force)) return;
    _initializing = true;
    startupFinished.value = false;
    startupFailureMessage.value = '';
    faceStartupPreparationResult.value = null;
    startupStatusLabel.value = '正在启动';
    _resetStartupSteps();

    try {
      _setStartupStep(
        0,
        status: AppStartupStepStatus.running,
        detail: '正在读取运行环境与本地终端配置',
      );
      await AppRuntimeTool.initializePlatform();
      await AppSettingTool.removeSettingCache();

      _setStartupStep(
        1,
        status: AppStartupStepStatus.running,
        detail: '正在打开本地业务数据库',
      );
      if (!_databaseInitialized) {
        dataBase = await AppDatabase.getDataBase();
        _databaseInitialized = true;
      }

      final setting = await AppSettingTool.getSysSetting();
      // 插件会在 Android 注册阶段自动创建副屏；这里统一确认可用状态并记录常驻标记，
      // 即使无副屏或权限不足也只影响设备状态，不阻塞后续启动流程。
      unawaited(AppSubScreenTool.show());
      var storageGranted =
          await Permission.manageExternalStorage.request().isGranted;
      if (!storageGranted) {
        storageGranted = await Permission.storage.request().isGranted;
      }
      AppRuntimeTool.applyManualHardwareInput(setting.manualHardwareInput);
      final environment = _resolveEnvironment(setting);
      startupEnvironmentDescription.value = environment.title;
      startupEnvironmentDetail.value = environment.detail;
      _setStartupStep(
        0,
        status: AppStartupStepStatus.success,
        detail: environment.stepDetail,
      );
      _setStartupStep(
        1,
        status: storageGranted
            ? AppStartupStepStatus.success
            : AppStartupStepStatus.warning,
        detail:
            storageGranted ? '数据库已打开，本地备份目录权限可用' : '数据库已打开；未获存储权限，本地备份可能不可用',
      );

      _setStartupStep(
        2,
        status: AppStartupStepStatus.running,
        detail: '正在创建打印、读卡与电子秤管理服务',
      );
      if (!printManageInitialized) printManage = PrintManage();
      await AppDeviceStatusTool.loadCachedStatus();
      if (!serialCardManageInitialized) serialCardManage = SerialCardManage();
      if (!steelyardManageInitialized) {
        srialSteelyardManage = SerialSteelyardManage();
      }
      // 硬件检查失败只能影响状态展示，不能阻塞收银终端进入业务页面。
      unawaited(
        AppDeviceStatusTool.refreshAll()
            .catchError((Object error, StackTrace stack) {
          logger.w('|$_tag|首次检查设备状态失败error:|$error|stack:|$stack|');
          return AppDeviceStatusTool.status.value;
        }),
      );
      await TtsManage.initialize();
      _setStartupStep(
        2,
        status: environment.manualHardwareInput
            ? AppStartupStepStatus.warning
            : AppStartupStepStatus.success,
        detail: environment.manualHardwareInput
            ? '当前为手动硬件输入模式，实体设备将在业务使用时按需连接'
            : '设备管理服务已就绪，实体设备将在业务使用时按需连接',
      );

      _setStartupStep(
        3,
        status: AppStartupStepStatus.running,
        detail: '正在检查激活参数并装载本地人脸库',
      );
      final facePreparation = await AppFaceTool.prepareForStartup();
      faceStartupPreparationResult.value = facePreparation;
      _setStartupStep(
        3,
        status: facePreparation.status == FaceStartupPreparationStatus.success
            ? AppStartupStepStatus.success
            : AppStartupStepStatus.warning,
        detail: _facePreparationDetail(facePreparation),
      );

      final backupSucceeded =
          storageGranted ? await AppFileTool.backupSqlFile() : false;
      if (storageGranted && !backupSucceeded) {
        _setStartupStep(
          1,
          status: AppStartupStepStatus.warning,
          detail: '数据库已打开；本次自动备份未完成，可稍后在设置中重试',
        );
      }

      // 网络、MQTT 与后台同步属于运行期能力，不参与加载页检查或阻塞进入系统。
      if (AppNetworkTool.subscription == null) {
        AppNetworkTool.listenNetwork();
      }
      // 突然关机密码策略必须在读取用户凭据前执行，否则自动登录会抢先使用旧密码。
      final clearedSavedPassword =
          await AppSettingTool.applyStartupPowerLossPasswordPolicy();
      var resolvedDestination = destination;
      if (clearedSavedPassword && destination == RouteNames.terminal) {
        // 凭据已按策略清除，跳过更新恢复直达终端的预留路径，回到登录页。
        resolvedDestination = RouteNames.login;
      }
      final userSetting = await AppSettingTool.getUserSetting();
      _authenticatedServicesEnabled =
          ObjectUtil.isNotEmpty(userSetting.accessToken);
      if (_authenticatedServicesEnabled) {
        await SyncCheckTool.instance.startAll();
        TerminalHeartbeatTool.start();
      }
      await TerminalAutoUpdateTool.recoverPendingUpdate();

      startupFinished.value = true;
      startupStatusLabel.value = startupSteps
              .any((item) => item.status == AppStartupStepStatus.warning)
          ? '受限启动完成'
          : '启动完成';
      await Future.delayed(const Duration(milliseconds: 650));
      if (Get.currentRoute == RouteNames.load) {
        Get.offAllNamed(resolvedDestination);
      }
    } catch (e, stack) {
      final currentIndex = startupSteps.indexWhere(
        (item) => item.status == AppStartupStepStatus.running,
      );
      if (currentIndex >= 0) {
        _setStartupStep(
          currentIndex,
          status: AppStartupStepStatus.failure,
          detail: '启动失败，请检查终端配置或本地设备后重试',
        );
      }
      startupStatusLabel.value = '启动失败';
      startupFailureMessage.value = '终端初始化未完成，请检查设备状态后重试。';
      _closePartiallyInitializedResources();
      logger.e('|$_tag|初始化失败error:|$e|stack:|$stack|');
    } finally {
      _initializing = false;
    }
  }

  Future<void> retryStartup({String destination = RouteNames.login}) async {
    if (_initializing) return;
    await initAsync(destination: destination, force: true);
  }

  /// 登录成功后恢复业务终端的后台任务与在线心跳。
  Future<void> resumeAuthenticatedServices() async {
    _authenticatedServicesEnabled = true;
    await SyncCheckTool.instance.startAll();
    TerminalHeartbeatTool.start();
  }

  /// 退出登录时停止所有需要账号或设备身份的后台任务，并断开消息订阅。
  Future<void> suspendAuthenticatedServices() async {
    _authenticatedServicesEnabled = false;
    await SyncCheckTool.instance.dispose();
    TerminalHeartbeatTool.stop();
    AppMqTool.mqListenClose();
    await MqManager.closeMqtt();
  }

  /// 关闭已创建的设备和后台资源，供核心启动异常后的重试流程重新初始化。
  void _closePartiallyInitializedResources() {
    _authenticatedServicesEnabled = false;
    if (printManageInitialized) printManage.close();
    if (serialCardManageInitialized) serialCardManage.close();
    if (steelyardManageInitialized) srialSteelyardManage.close();
    AppNetworkTool.closeListenNetwork();
    SyncCheckTool.instance.dispose();
    TerminalHeartbeatTool.stop();
  }

  /// 将全部启动步骤恢复到初始文案，供首次启动和人工重试共用。
  void _resetStartupSteps() {
    for (var index = 0; index < startupSteps.length; index++) {
      final item = startupSteps[index];
      startupSteps[index] = item.copyWith(
        status: AppStartupStepStatus.waiting,
        detail: switch (index) {
          0 => '等待读取设备模式与本地设置',
          1 => '等待准备订单、商品与用户数据',
          2 => '等待准备打印、读卡与电子秤服务',
          _ => '等待检查激活参数与本地人脸库',
        },
      );
    }
  }

  /// 更新指定启动步骤的状态和结果文案。
  void _setStartupStep(
    int index, {
    required AppStartupStepStatus status,
    required String detail,
  }) {
    startupSteps[index] = startupSteps[index].copyWith(
      status: status,
      detail: detail,
    );
  }

  /// 将结构化人脸准备结果转换为不暴露密钥的 Load 页简短说明。
  String _facePreparationDetail(FaceStartupPreparationResult result) {
    if (result.total <= 0) return result.message;
    if (result.failedCount <= 0) {
      return '${result.message}，已装载 ${result.successCount} 个人脸样本';
    }
    return '${result.message}，成功 ${result.successCount}，失败 ${result.failedCount}';
  }

  ({
    String title,
    String detail,
    String stepDetail,
    bool manualHardwareInput,
  }) _resolveEnvironment(SysSetting setting) {
    final manualHardwareInput =
        AppRuntimeTool.isEmulator || setting.manualHardwareInput;
    if (AppRuntimeTool.isEmulator) {
      return (
        title: '虚拟机调试模式',
        detail: '已切换为手动硬件输入，不启动真实副屏和实体串口设备。',
        stepDetail: '已识别虚拟机，终端配置读取完成',
        manualHardwareInput: true,
      );
    }
    if (manualHardwareInput) {
      return (
        title: '手动硬件输入模式',
        detail: '终端配置为手动录入硬件结果，真实副屏仍按设备能力启用。',
        stepDetail: '终端配置读取完成，已启用手动硬件输入',
        manualHardwareInput: true,
      );
    }
    if (AppRuntimeTool.hasMultipleDisplays) {
      return (
        title: '双屏终端模式',
        detail: '已检测到 ${AppRuntimeTool.displayCount} 个显示设备，副屏将在业务页面按需启动。',
        stepDetail: '终端配置读取完成，已检测到可用双屏环境',
        manualHardwareInput: false,
      );
    }
    return (
      title: '单屏终端模式',
      detail: '当前仅检测到主屏，收银核心流程可继续使用，副屏功能不会启动。',
      stepDetail: '终端配置读取完成，当前为单屏环境',
      manualHardwareInput: false,
    );
  }
}