import 'dart:async';
import 'package:flutter/foundation.dart';
import '../models/route_model.dart';
import '../models/models.dart';
import '../data/routes_data.dart';
import '../database/db_helper.dart';

enum NotifEvent { routeStart, truckProximity, routeCompleted, gpsLost, truckStopped, routeCancelled, none }

class AppNotification {
  final NotifEvent event;
  final String title;
  final String body;
  final String routeId; // Para filtrar por usuario
  final DateTime timestamp;
  AppNotification({required this.event, required this.title,
      required this.body, required this.routeId})
      : timestamp = DateTime.now();
}

class SimulatorState {
  final String routeId;
  int positionIndex;
  bool gpsActive;
  DateTime lastMoved;
  bool stoppedAlertSent;
  SimulatorState({required this.routeId, this.positionIndex = 0,
      this.gpsActive = true, required this.lastMoved, this.stoppedAlertSent = false});
}

class RouteSimulatorService extends ChangeNotifier {
  final Map<String, SimulatorState> _states = {};
  Timer? _globalTimer;
  Timer? _gpsMonitorTimer;

  AppNotification? _lastNotification; // Admin ve todas
  final List<AppNotification> _history = [];

  // ── Getters ─────────────────────────────────────────────────────────────
  // Admin: ve la última notificación global
  AppNotification? get lastNotification => _lastNotification;

  // Ciudadano/Conductor: solo ve notificaciones de SU ruta
  AppNotification? getNotificationForRoute(String routeId) {
    if (_lastNotification?.routeId == routeId) return _lastNotification;
    return null;
  }

  List<AppNotification> get history => List.unmodifiable(_history);

  // Historial filtrado por ruta
  List<AppNotification> historyForRoute(String routeId) =>
      _history.where((n) => n.routeId == routeId).toList();

  // ── Inicio ───────────────────────────────────────────────────────────────
  void startAllRoutes() {
    for (final r in routesData) {
      _states[r.routeId] = SimulatorState(routeId: r.routeId, lastMoved: DateTime.now());
    }
    _globalTimer?.cancel();
    _globalTimer = Timer.periodic(const Duration(seconds: 30), (_) => _tick());
    _gpsMonitorTimer?.cancel();
    _gpsMonitorTimer = Timer.periodic(const Duration(minutes: 5), (_) => _monitorGps());
    notifyListeners();
  }

  void startRoute(String routeId) {
    _states[routeId] = SimulatorState(routeId: routeId, lastMoved: DateTime.now());
    _globalTimer ??= Timer.periodic(const Duration(seconds: 30), (_) => _tick());
    notifyListeners();
  }

  void _tick() {
    bool changed = false;
    for (final entry in _states.entries) {
      final state = entry.value;
      final route = getRouteById(state.routeId);
      if (route == null || !state.gpsActive) continue;
      if (state.positionIndex < route.positions.length - 1) {
        state.positionIndex++;
        state.lastMoved = DateTime.now();
        _checkNotification(state, route);
        changed = true;
      }
    }
    if (changed) notifyListeners();
  }

  void _monitorGps() {
    for (final state in _states.values) {
      if (!state.gpsActive) continue;
      final diff = DateTime.now().difference(state.lastMoved);
      if (diff.inMinutes >= 30 && !state.stoppedAlertSent) {
        state.stoppedAlertSent = true;
        _fireAndSaveAlert(
          event: NotifEvent.truckStopped, routeId: state.routeId,
          title: '⚠️ Camión detenido',
          body: 'El camión ${state.routeId} lleva +30 min sin moverse.',
          tipo: 'CAMION_DETENIDO',
        );
      }
    }
  }

  void _checkNotification(SimulatorState state, RouteModel route) {
    if (state.positionIndex == 1) {
      _fireNotif(NotifEvent.routeStart, '¡Ruta Iniciada! 🚛',
          'El camión ha salido del Relleno Sanitario rumbo a tu sector.', state.routeId);
    } else if (state.positionIndex == 3) {
      _fireNotif(NotifEvent.truckProximity, 'Camión Cercano ⚠️',
          'El camión está a menos de 15 minutos. ¡Saca tus bolsas!', state.routeId);
    } else if (state.positionIndex == route.positions.length - 1) {
      _fireNotif(NotifEvent.routeCompleted, 'Servicio Finalizado 🏁',
          'El camión de ${state.routeId} concluyó su jornada.', state.routeId);
    }
  }

  void _fireNotif(NotifEvent event, String title, String body, String routeId) {
    final n = AppNotification(event: event, title: title, body: body, routeId: routeId);
    _lastNotification = n;
    _history.insert(0, n);
    notifyListeners();
  }

  Future<void> _fireAndSaveAlert({required NotifEvent event, required String routeId,
      required String title, required String body, required String tipo}) async {
    _fireNotif(event, title, body, routeId);
    await DbHelper.insertAlerta(AlertaModel(
        tipo: tipo, routeId: routeId, mensaje: body,
        fecha: DateTime.now().toIso8601String()));
  }

  // Notificación manual (admin cancela, retrasa ruta, etc.)
  void fireCustomNotification(String title, String body, String routeId, NotifEvent event) {
    _fireNotif(event, title, body, routeId);
  }

  // ── GPS ──────────────────────────────────────────────────────────────────
  Future<void> simulateGpsLost(String routeId) async {
    final state = _states[routeId];
    if (state == null) return;
    state.gpsActive = false;
    await _fireAndSaveAlert(
      event: NotifEvent.gpsLost, routeId: routeId,
      title: '📡 GPS Desactivado',
      body: 'Se perdió la señal GPS del camión $routeId.',
      tipo: 'GPS_PERDIDO',
    );
    notifyListeners();
  }

  void restoreGps(String routeId) {
    final state = _states[routeId];
    if (state == null) return;
    state.gpsActive = true;
    state.stoppedAlertSent = false;
    notifyListeners();
  }

  // ── Getters de estado ────────────────────────────────────────────────────
  SimulatorState? getState(String routeId) => _states[routeId];
  int getPositionIndex(String routeId) => _states[routeId]?.positionIndex ?? 0;
  bool isTruckClose(String routeId) => getPositionIndex(routeId) >= 3;
  bool isGpsActive(String routeId) => _states[routeId]?.gpsActive ?? true;

  String getEtaText(String routeId) {
    final state = _states[routeId];
    if (state == null) return 'Sin información';
    if (!state.gpsActive) return '📡 Señal GPS perdida';
    final route = getRouteById(routeId);
    if (route == null) return 'Ruta no encontrada';
    final idx = state.positionIndex;
    if (idx >= route.positions.length) return '✅ Servicio finalizado';
    switch (idx) {
      case 0: return '🕐 Ruta por iniciar';
      case 1: return '🚛 Camión en camino';
      case 2: return '🚛 Aprox. 30 min para llegar';
      case 3: return '⚠️ Menos de 15 min — ¡Saca tus bolsas!';
      case 4: return '🔔 El camión está en tu zona';
      case 5: return '✅ Pasando por tu colonia';
      case 6: return '↩️ Regresando al relleno';
      default: return '🏁 Servicio del día finalizado';
    }
  }

  void dismissNotification() {
    _lastNotification = null;
    notifyListeners();
  }

  void dismissRouteNotification(String routeId) {
    if (_lastNotification?.routeId == routeId) {
      _lastNotification = null;
      notifyListeners();
    }
  }

  @override
  void dispose() {
    _globalTimer?.cancel();
    _gpsMonitorTimer?.cancel();
    super.dispose();
  }
}