import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:geolocator/geolocator.dart';

import '../../../app/load_state.dart';
import '../../../models/home_config.dart';
import '../geofence_logic.dart';
import '../models/geofence_diagnostics.dart';
import '../models/geofence_runtime_state.dart';
import '../services/geofence_notifications_service.dart';
import '../services/geofence_runtime_store.dart';
import 'homes_providers.dart';

final geofenceRuntimeStoreProvider = Provider((ref) => GeofenceRuntimeStore());

final geofenceNotificationsServiceProvider = Provider(
  (ref) => GeofenceNotificationsService(),
);

final geofenceDiagnosticsProvider =
    NotifierProvider<
      GeofenceDiagnosticsNotifier,
      LoadState<GeofenceDiagnostics>
    >(GeofenceDiagnosticsNotifier.new);

class GeofenceDiagnosticsNotifier
    extends Notifier<LoadState<GeofenceDiagnostics>> {
  bool _refreshing = false;

  @override
  LoadState<GeofenceDiagnostics> build() {
    return const LoadState.idle(GeofenceDiagnostics.initial());
  }

  Future<void> refresh() async {
    if (_refreshing) return;
    _refreshing = true;

    final previous = state.data;
    state = LoadState.loading(previous);

    try {
      final currentHome = ref.read(currentHomeProvider);
      final runtime = await ref.read(geofenceRuntimeStoreProvider).load();

      if (currentHome == null) {
        state = LoadState.data(
          GeofenceDiagnostics(
            activeHome: null,
            status: GeofenceStatusKind.noActiveHome,
            runtime: runtime,
            locationServicesEnabled: true,
            locationPermission: LocationPermission.denied,
            notificationsEnabled: true,
          ),
        );
        return;
      }

      if (!currentHome.geofenceEnabled) {
        state = LoadState.data(
          GeofenceDiagnostics(
            activeHome: currentHome,
            status: GeofenceStatusKind.disabled,
            runtime: runtime,
            locationServicesEnabled: true,
            locationPermission: LocationPermission.denied,
            notificationsEnabled: true,
          ),
        );
        return;
      }

      if (!currentHome.hasCoordinates) {
        state = LoadState.data(
          GeofenceDiagnostics(
            activeHome: currentHome,
            status: GeofenceStatusKind.missingCoordinates,
            runtime: runtime,
            locationServicesEnabled: true,
            locationPermission: LocationPermission.denied,
            notificationsEnabled: true,
          ),
        );
        return;
      }

      final locationServicesEnabled =
          await Geolocator.isLocationServiceEnabled();
      final locationPermission = await Geolocator.checkPermission();
      final notificationsEnabled = await ref
          .read(geofenceNotificationsServiceProvider)
          .areNotificationsEnabled();

      final diagnostics = _buildDiagnostics(
        currentHome: currentHome,
        runtime: runtime,
        locationServicesEnabled: locationServicesEnabled,
        locationPermission: locationPermission,
        notificationsEnabled: notificationsEnabled,
      );
      state = LoadState.data(diagnostics);
    } catch (error) {
      state = LoadState.error(
        previous,
        'Не удалось обновить состояние geofence: $error',
      );
    } finally {
      _refreshing = false;
    }
  }

  Future<void> requestLocationPermission() async {
    await Geolocator.requestPermission();
    await refresh();
  }

  Future<void> requestBackgroundLocationPermission() async {
    final result = await Geolocator.requestPermission();
    if (!hasBackgroundLocationAccess(result)) {
      await Geolocator.openAppSettings();
    }
    await refresh();
  }

  Future<void> requestNotificationPermission() async {
    await ref
        .read(geofenceNotificationsServiceProvider)
        .requestNotificationsPermission();
    await refresh();
  }

  Future<void> openAppSettings() async {
    await Geolocator.openAppSettings();
  }

  Future<void> openLocationSettings() async {
    await Geolocator.openLocationSettings();
  }

  GeofenceDiagnostics _buildDiagnostics({
    required HomeConfig currentHome,
    required GeofenceRuntimeState runtime,
    required bool locationServicesEnabled,
    required LocationPermission locationPermission,
    required bool notificationsEnabled,
  }) {
    if (!locationServicesEnabled) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.locationServicesDisabled,
        runtime: runtime,
        locationServicesEnabled: false,
        locationPermission: locationPermission,
        notificationsEnabled: notificationsEnabled,
      );
    }

    if (!hasForegroundLocationAccess(locationPermission)) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.locationPermissionDenied,
        runtime: runtime,
        locationServicesEnabled: true,
        locationPermission: locationPermission,
        notificationsEnabled: notificationsEnabled,
      );
    }

    if (!hasBackgroundLocationAccess(locationPermission)) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.backgroundPermissionDenied,
        runtime: runtime,
        locationServicesEnabled: true,
        locationPermission: locationPermission,
        notificationsEnabled: notificationsEnabled,
      );
    }

    if (!notificationsEnabled) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.notificationsPermissionDenied,
        runtime: runtime,
        locationServicesEnabled: true,
        locationPermission: locationPermission,
        notificationsEnabled: false,
      );
    }

    final failureAt = runtime.failureAtFor(currentHome.id);
    final retryRemaining = geofenceRetryRemaining(failureAt);
    if (retryRemaining != null) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.cooldown,
        runtime: runtime,
        locationServicesEnabled: true,
        locationPermission: locationPermission,
        notificationsEnabled: true,
        retryRemaining: retryRemaining,
        detail: runtime.failureMessageFor(currentHome.id),
      );
    }

    if (runtime.isTriggeredFor(currentHome.id)) {
      return GeofenceDiagnostics(
        activeHome: currentHome,
        status: GeofenceStatusKind.triggered,
        runtime: runtime,
        locationServicesEnabled: true,
        locationPermission: locationPermission,
        notificationsEnabled: true,
      );
    }

    return GeofenceDiagnostics(
      activeHome: currentHome,
      status: GeofenceStatusKind.ready,
      runtime: runtime,
      locationServicesEnabled: true,
      locationPermission: locationPermission,
      notificationsEnabled: true,
    );
  }
}