import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:em2rp/models/event_model.dart';
import 'package:em2rp/services/data_service.dart';
import 'package:em2rp/services/api_service.dart';
import 'package:em2rp/utils/performance_monitor.dart';

class EventProvider with ChangeNotifier {
  final DataService _dataService = DataService(FirebaseFunctionsApiService());
  List<EventModel> _events = [];
  bool _isLoading = false;

  List<EventModel> get events => _events;
  bool get isLoading => _isLoading;

  // Cache des utilisateurs chargés depuis getEvents
  Map<String, Map<String, dynamic>> _usersCache = {};

  // Cache pour éviter les rechargements inutiles
  DateTime? _lastLoadTime;
  String? _lastUserId;
  bool _lastCanViewAll = false;

  /// Vérifie si les données doivent être rechargées (cache de 30 secondes)
  bool _shouldReload(String userId, bool canViewAllEvents) {
    if (_lastLoadTime == null) return true;
    if (_lastUserId != userId || _lastCanViewAll != canViewAllEvents) return true;

    final now = DateTime.now();
    final difference = now.difference(_lastLoadTime!);
    return difference.inSeconds > 30;
  }

  /// Charger les événements d'un utilisateur via l'API
  Future<void> loadUserEvents(String userId, {bool canViewAllEvents = false, bool forceReload = false}) async {
    PerformanceMonitor.start('EventProvider.loadUserEvents');

    // Éviter les rechargements inutiles
    if (!forceReload && !_shouldReload(userId, canViewAllEvents)) {
      print('Using cached events (loaded ${DateTime.now().difference(_lastLoadTime!).inSeconds}s ago)');
      PerformanceMonitor.end('EventProvider.loadUserEvents');
      return;
    }

    _isLoading = true;
    notifyListeners();

    try {
      print('Loading events for user: $userId (canViewAllEvents: $canViewAllEvents)');

      PerformanceMonitor.start('EventProvider.getEvents_API');
      // Charger via l'API - les permissions sont vérifiées côté serveur
      final result = await _dataService.getEvents(userId: userId);
      PerformanceMonitor.end('EventProvider.getEvents_API');

      final eventsData = result['events'] as List<Map<String, dynamic>>;
      final usersData = result['users'] as Map<String, dynamic>;

      // Stocker les utilisateurs dans le cache
      _usersCache = usersData.map((key, value) =>
        MapEntry(key, value as Map<String, dynamic>)
      );

      print('Found ${eventsData.length} events from API');

      PerformanceMonitor.start('EventProvider.parseEvents');
      List<EventModel> allEvents = [];
      int failedCount = 0;

      // Parser chaque événement
      for (var eventData in eventsData) {
        try {
          final event = EventModel.fromMap(eventData, eventData['id'] as String);
          allEvents.add(event);
        } catch (e) {
          print('Failed to parse event ${eventData['id']}: $e');
          failedCount++;
        }
      }
      PerformanceMonitor.end('EventProvider.parseEvents');

      _events = allEvents;
      _lastLoadTime = DateTime.now();
      _lastUserId = userId;
      _lastCanViewAll = canViewAllEvents;

      print('Successfully loaded ${_events.length} events (${failedCount} failed)');

      _isLoading = false;
      notifyListeners();
      PerformanceMonitor.end('EventProvider.loadUserEvents');
    } catch (e) {
      print('Error loading events: $e');
      _isLoading = false;
      notifyListeners();
      PerformanceMonitor.end('EventProvider.loadUserEvents');
      rethrow;
    }
  }

  /// Recharger les événements (utilise le dernier userId)
  Future<void> refreshEvents(String userId, {bool canViewAllEvents = false}) async {
    await loadUserEvents(userId, canViewAllEvents: canViewAllEvents, forceReload: true);
  }

  /// Récupérer un événement spécifique par ID
  EventModel? getEventById(String eventId) {
    try {
      return _events.firstWhere((event) => event.id == eventId);
    } catch (e) {
      return null;
    }
  }

  /// Ajouter un nouvel événement
  Future<void> addEvent(EventModel event) async {
    try {
      // L'événement est créé via l'API dans le service
      await refreshEvents(_lastUserId ?? '', canViewAllEvents: _lastCanViewAll);
    } catch (e) {
      print('Error adding event: $e');
      rethrow;
    }
  }

  /// Mettre à jour un événement
  Future<void> updateEvent(EventModel event) async {
    try {
      // Mise à jour locale immédiate
      final index = _events.indexWhere((e) => e.id == event.id);
      if (index != -1) {
        _events[index] = event;
        notifyListeners();
      }
    } catch (e) {
      print('Error updating event: $e');
      rethrow;
    }
  }

  /// Supprimer un événement
  Future<void> deleteEvent(String eventId) async {
    try {
      await _dataService.deleteEvent(eventId);
      _events.removeWhere((event) => event.id == eventId);
      notifyListeners();
    } catch (e) {
      print('Error deleting event: $e');
      rethrow;
    }
  }

  /// Récupérer les données d'un utilisateur depuis le cache
  Map<String, dynamic>? getUserFromCache(String uid) {
    return _usersCache[uid];
  }

  /// Récupérer les utilisateurs de la workforce d'un événement
  List<Map<String, dynamic>> getWorkforceUsers(EventModel event) {
    final users = <Map<String, dynamic>>[];

    for (final dynamic userRef in event.workforce) {
      try {
        String? uid;

        // Tenter d'extraire l'UID
        if (userRef is String) {
          uid = userRef;
        } else {
          // Essayer d'extraire l'ID si c'est une DocumentReference
          final ref = userRef as DocumentReference?;
          uid = ref?.id;
        }

        if (uid != null) {
          final userData = getUserFromCache(uid);
          if (userData != null) {
            users.add(userData);
          }
        }
      } catch (e) {
        // Ignorer les références invalides
        print('Skipping invalid workforce reference: $userRef');
      }
    }

    return users;
  }

  /// Vider la liste des événements
  void clearEvents() {
    _events = [];
    _lastLoadTime = null;
    _lastUserId = null;
    _lastCanViewAll = false;
    notifyListeners();
  }
}