import 'dart:async';

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

import '../models/live_position.dart';
import '../services/background_location_service.dart';
import 'profile_provider.dart';
import 'supabase_provider.dart';
import 'stream_recovery.dart';
import 'realtime_controller.dart';

/// All live positions of tracked users.
final livePositionsProvider = StreamProvider<List<LivePosition>>((ref) {
  final client = ref.watch(supabaseClientProvider);

  final wrapper = StreamRecoveryWrapper<LivePosition>(
    stream: client.from('live_positions').stream(primaryKey: ['user_id']),
    onPollData: () async {
      final data = await client.from('live_positions').select();
      return data.map(LivePosition.fromMap).toList();
    },
    fromMap: LivePosition.fromMap,
    channelName: 'live_positions',
    onStatusChanged: ref.read(realtimeControllerProvider).handleChannelStatus,
  );

  ref.onDispose(wrapper.dispose);
  return wrapper.stream.map((result) => result.data);
});

final whereaboutsControllerProvider = Provider<WhereaboutsController>((ref) {
  final client = ref.watch(supabaseClientProvider);
  return WhereaboutsController(client);
});

class WhereaboutsController {
  WhereaboutsController(this._client);

  final SupabaseClient _client;

  /// Upsert current position. Returns `in_premise` status.
  Future<bool> updatePosition(double lat, double lng) async {
    final data = await _client.rpc(
      'update_live_position',
      params: {'p_lat': lat, 'p_lng': lng},
    );
    return data as bool? ?? false;
  }

  /// Toggle allow_tracking preference.
  Future<void> setTracking(bool allow) async {
    final userId = _client.auth.currentUser?.id;
    if (userId == null) throw Exception('Not authenticated');
    await _client
        .from('profiles')
        .update({'allow_tracking': allow})
        .eq('id', userId);

    // Start or stop background location updates
    if (allow) {
      await startBackgroundLocationUpdates();
    } else {
      await stopBackgroundLocationUpdates();
      // Remove the live position entry
      await _client.from('live_positions').delete().eq('user_id', userId);
    }
  }
}

/// Background location reporting service.
/// Starts a 1-minute periodic timer that reports position to the server.
final locationReportingProvider =
    Provider.autoDispose<LocationReportingService>((ref) {
      final client = ref.watch(supabaseClientProvider);
      final profileAsync = ref.watch(currentProfileProvider);
      final profile = profileAsync.valueOrNull;

      final service = LocationReportingService(client);

      // Auto-start if user has tracking enabled
      if (profile != null && profile.allowTracking) {
        service.start();
        // Also ensure background task is registered
        startBackgroundLocationUpdates();
      }

      ref.onDispose(service.stop);
      return service;
    });

class LocationReportingService {
  LocationReportingService(this._client);

  final SupabaseClient _client;
  Timer? _timer;
  bool _isRunning = false;

  bool get isRunning => _isRunning;

  void start() {
    if (_isRunning) return;
    _isRunning = true;
    // Report immediately, then every 60 seconds
    _reportPosition();
    _timer = Timer.periodic(const Duration(seconds: 60), (_) {
      _reportPosition();
    });
  }

  void stop() {
    _isRunning = false;
    _timer?.cancel();
    _timer = null;
  }

  Future<void> _reportPosition() async {
    try {
      final serviceEnabled = await Geolocator.isLocationServiceEnabled();
      if (!serviceEnabled) return;

      var permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.denied ||
          permission == LocationPermission.deniedForever) {
        return;
      }

      final position = await Geolocator.getCurrentPosition(
        locationSettings: const LocationSettings(
          accuracy: LocationAccuracy.high,
        ),
      );

      await _client.rpc(
        'update_live_position',
        params: {'p_lat': position.latitude, 'p_lng': position.longitude},
      );
    } catch (_) {
      // Silently ignore errors in background reporting
    }
  }
}