import 'dart:async';
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import '../models/supplement.dart';
import '../models/supplement_intake.dart';
import '../services/database_helper.dart';
import '../services/notification_service.dart';

class SupplementProvider with ChangeNotifier, WidgetsBindingObserver {
  final DatabaseHelper _databaseHelper = DatabaseHelper.instance;
  final NotificationService _notificationService = NotificationService();

  List<Supplement> _supplements = [];
  List<Map<String, dynamic>> _todayIntakes = [];
  List<Map<String, dynamic>> _monthlyIntakes = [];
  bool _isLoading = false;
  Timer? _persistentReminderTimer;
  Timer? _dateChangeTimer;
  DateTime _lastDateCheck = DateTime.now();

  List<Supplement> get supplements => _supplements;
  List<Map<String, dynamic>> get todayIntakes => _todayIntakes;
  List<Map<String, dynamic>> get monthlyIntakes => _monthlyIntakes;
  bool get isLoading => _isLoading;

  Future<void> initialize() async {
    // Add this provider as an observer for app lifecycle changes
    WidgetsBinding.instance.addObserver(this);
    
    await _notificationService.initialize();
    
    // Set up the callback for handling supplement intake from notifications
    print('📱 Setting up notification callback...');
    _notificationService.setTakeSupplementCallback((supplementId, supplementName, units, unitType) {
      print('📱 === NOTIFICATION CALLBACK TRIGGERED ===');
      print('📱 Supplement ID: $supplementId');
      print('📱 Supplement Name: $supplementName');
      print('📱 Units: $units');
      print('📱 Unit Type: $unitType');
      
      // Record the intake when user taps "Take" on notification
      recordIntake(supplementId, 0.0, unitsTaken: units);
      print('📱 Intake recorded successfully');
      print('📱 === CALLBACK COMPLETE ===');
      
      if (kDebugMode) {
        print('📱 Recorded intake from notification: $supplementName ($units $unitType)');
      }
    });
    print('📱 Notification callback setup complete');
    
    // Request permissions with error handling
    try {
      await _notificationService.requestPermissions();
    } catch (e) {
      if (kDebugMode) {
        print('Error requesting notification permissions: $e');
      }
      // Continue without notifications rather than crashing
    }
    
    await loadSupplements();
    await loadTodayIntakes();
    
    // Reschedule notifications for all active supplements to ensure persistence
    await _rescheduleAllNotifications();
    
    // Start periodic checking for persistent reminders (every 5 minutes)
    _startPersistentReminderCheck();
    
    // Start date change monitoring to reset daily intake status
    _startDateChangeMonitoring();
  }

  void _startPersistentReminderCheck() {
    // Cancel any existing timer
    _persistentReminderTimer?.cancel();
    
    // Check every 5 minutes for persistent reminders
    _persistentReminderTimer = Timer.periodic(const Duration(minutes: 5), (timer) async {
      try {
        // This will be called from settings provider context, so we need to import it
        await _checkPersistentReminders();
      } catch (e) {
        if (kDebugMode) {
          print('Error checking persistent reminders: $e');
        }
      }
    });
    
    // Also check immediately
    _checkPersistentReminders();
  }

  void _startDateChangeMonitoring() {
    // Cancel any existing timer
    _dateChangeTimer?.cancel();
    
    // Check every minute if the date has changed
    _dateChangeTimer = Timer.periodic(const Duration(minutes: 1), (timer) async {
      final now = DateTime.now();
      final currentDate = DateTime(now.year, now.month, now.day);
      final lastCheckDate = DateTime(_lastDateCheck.year, _lastDateCheck.month, _lastDateCheck.day);
      
      if (currentDate != lastCheckDate) {
        if (kDebugMode) {
          print('Date changed detected: ${lastCheckDate} -> ${currentDate}');
          print('Refreshing today\'s intakes for new day...');
        }
        
        // Date has changed, refresh today's intakes
        _lastDateCheck = now;
        await loadTodayIntakes();
        
        if (kDebugMode) {
          print('Today\'s intakes refreshed for new day');
        }
      }
    });
  }

  Future<void> _checkPersistentReminders() async {
    // This method will be enhanced to accept settings from the UI layer
    // For now, we'll check with default settings
    // In practice, the UI should call checkPersistentRemindersWithSettings
    if (kDebugMode) {
      print('📱 Checking persistent reminders with default settings');
    }
  }

  // Method to be called from UI with actual settings
  Future<void> checkPersistentRemindersWithSettings({
    required bool persistentReminders,
    required int reminderRetryInterval,
    required int maxRetryAttempts,
  }) async {
    print('📱 🔄 MANUAL CHECK: Persistent reminders called from UI');
    await _notificationService.checkPersistentReminders(
      persistentReminders,
      reminderRetryInterval,
      maxRetryAttempts,
    );
  }

  // Add a manual trigger method for testing
  Future<void> triggerRetryCheck() async {
    print('📱 🚨 MANUAL TRIGGER: Forcing retry check...');
    await checkPersistentRemindersWithSettings(
      persistentReminders: true,
      reminderRetryInterval: 5, // Force 5 minute interval for testing
      maxRetryAttempts: 3,
    );
  }

    @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _persistentReminderTimer?.cancel();
    _dateChangeTimer?.cancel();
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    
    if (state == AppLifecycleState.resumed) {
      // App came back to foreground, check if date changed
      if (kDebugMode) {
        print('App resumed, checking for date change...');
      }
      forceCheckDateChange();
    }
  }

  Future<void> _rescheduleAllNotifications() async {
    if (kDebugMode) {
      print('📱 Rescheduling notifications for all active supplements...');
    }
    
    for (final supplement in _supplements) {
      if (supplement.reminderTimes.isNotEmpty) {
        try {
          await _notificationService.scheduleSupplementReminders(supplement);
        } catch (e) {
          if (kDebugMode) {
            print('📱 Error rescheduling notifications for ${supplement.name}: $e');
          }
        }
      }
    }
    
    if (kDebugMode) {
      print('📱 Finished rescheduling notifications');
    }
  }

  Future<void> loadSupplements() async {
    _isLoading = true;
    notifyListeners();

    try {
      print('Loading supplements from database...');
      _supplements = await _databaseHelper.getAllSupplements();
      print('Loaded ${_supplements.length} supplements');
      for (var supplement in _supplements) {
        print('Supplement: ${supplement.name}');
      }
    } catch (e) {
      print('Error loading supplements: $e');
      if (kDebugMode) {
        print('Error loading supplements: $e');
      }
    } finally {
      _isLoading = false;
      notifyListeners();
    }
  }

  Future<void> addSupplement(Supplement supplement) async {
    try {
      print('Adding supplement: ${supplement.name}');
      final id = await _databaseHelper.insertSupplement(supplement);
      print('Supplement inserted with ID: $id');
      final newSupplement = supplement.copyWith(id: id);
      
      // Schedule notifications (skip if there's an error)
      try {
        await _notificationService.scheduleSupplementReminders(newSupplement);
        print('Notifications scheduled');
      } catch (notificationError) {
        print('Warning: Could not schedule notifications: $notificationError');
      }
      
      await loadSupplements();
      print('Supplements reloaded, count: ${_supplements.length}');
    } catch (e) {
      print('Error adding supplement: $e');
      if (kDebugMode) {
        print('Error adding supplement: $e');
      }
      rethrow;
    }
  }

  Future<void> updateSupplement(Supplement supplement) async {
    try {
      await _databaseHelper.updateSupplement(supplement);
      
      // Reschedule notifications
      await _notificationService.scheduleSupplementReminders(supplement);
      
      await loadSupplements();
    } catch (e) {
      if (kDebugMode) {
        print('Error updating supplement: $e');
      }
    }
  }

  Future<void> deleteSupplement(int id) async {
    try {
      await _databaseHelper.deleteSupplement(id);
      
      // Cancel notifications
      await _notificationService.cancelSupplementReminders(id);
      
      await loadSupplements();
    } catch (e) {
      if (kDebugMode) {
        print('Error deleting supplement: $e');
      }
    }
  }

  Future<void> recordIntake(int supplementId, double dosage, {double? unitsTaken, String? notes, DateTime? takenAt}) async {
    try {
      final intake = SupplementIntake(
        supplementId: supplementId,
        takenAt: takenAt ?? DateTime.now(),
        dosageTaken: dosage,
        unitsTaken: unitsTaken ?? 1.0,
        notes: notes,
      );

      await _databaseHelper.insertIntake(intake);
      await loadTodayIntakes();
      
      // Show confirmation notification
      final supplement = _supplements.firstWhere((s) => s.id == supplementId);
      final unitsText = unitsTaken != null && unitsTaken != 1 ? '${unitsTaken.toStringAsFixed(unitsTaken % 1 == 0 ? 0 : 1)} ${supplement.unitType}' : '';
      await _notificationService.showInstantNotification(
        'Supplement Taken',
        'Recorded ${supplement.name}${unitsText.isNotEmpty ? ' - $unitsText' : ''} (${supplement.ingredientsDisplay})',
      );
    } catch (e) {
      if (kDebugMode) {
        print('Error recording intake: $e');
      }
    }
  }

  Future<void> loadTodayIntakes() async {
    try {
      final today = DateTime.now();
      if (kDebugMode) {
        print('Loading intakes for date: ${today.year}-${today.month}-${today.day}');
      }
      
      _todayIntakes = await _databaseHelper.getIntakesWithSupplementsForDate(today);
      
      if (kDebugMode) {
        print('Loaded ${_todayIntakes.length} intakes for today');
        for (var intake in _todayIntakes) {
          print('  - Supplement ID: ${intake['supplement_id']}, taken at: ${intake['takenAt']}');
        }
      }
      
      notifyListeners();
    } catch (e) {
      if (kDebugMode) {
        print('Error loading today\'s intakes: $e');
      }
    }
  }

  Future<void> loadMonthlyIntakes(int year, int month) async {
    try {
      _monthlyIntakes = await _databaseHelper.getIntakesWithSupplementsForMonth(year, month);
      notifyListeners();
    } catch (e) {
      if (kDebugMode) {
        print('Error loading monthly intakes: $e');
      }
    }
  }

  Future<List<Map<String, dynamic>>> getIntakesForDate(DateTime date) async {
    try {
      return await _databaseHelper.getIntakesWithSupplementsForDate(date);
    } catch (e) {
      if (kDebugMode) {
        print('Error loading intakes for date: $e');
      }
      return [];
    }
  }

  Future<void> deleteIntake(int intakeId) async {
    try {
      await _databaseHelper.deleteIntake(intakeId);
      await loadTodayIntakes();
      // Also refresh monthly intakes if they're loaded
      if (_monthlyIntakes.isNotEmpty) {
        await loadMonthlyIntakes(DateTime.now().year, DateTime.now().month);
      }
      notifyListeners();
    } catch (e) {
      if (kDebugMode) {
        print('Error deleting intake: $e');
      }
    }
  }

  bool hasBeenTakenToday(int supplementId) {
    return _todayIntakes.any((intake) => intake['supplement_id'] == supplementId);
  }

  int getTodayIntakeCount(int supplementId) {
    return _todayIntakes.where((intake) => intake['supplement_id'] == supplementId).length;
  }

  // Method to manually refresh daily status (useful for testing or manual refresh)
  Future<void> refreshDailyStatus() async {
    if (kDebugMode) {
      print('Manually refreshing daily status...');
    }
    _lastDateCheck = DateTime.now();
    await loadTodayIntakes();
  }

  // Method to force check for date change (useful for testing)
  Future<void> forceCheckDateChange() async {
    final now = DateTime.now();
    final currentDate = DateTime(now.year, now.month, now.day);
    final lastCheckDate = DateTime(_lastDateCheck.year, _lastDateCheck.month, _lastDateCheck.day);
    
    if (kDebugMode) {
      print('Force checking date change...');
      print('Current date: $currentDate');
      print('Last check date: $lastCheckDate');
    }
    
    if (currentDate != lastCheckDate) {
      if (kDebugMode) {
        print('Date change detected, refreshing intakes...');
      }
      _lastDateCheck = now;
      await loadTodayIntakes();
    } else {
      if (kDebugMode) {
        print('No date change detected');
      }
    }
  }

  // Archive functionality
  List<Supplement> _archivedSupplements = [];
  List<Supplement> get archivedSupplements => _archivedSupplements;

  Future<void> loadArchivedSupplements() async {
    try {
      _archivedSupplements = await _databaseHelper.getArchivedSupplements();
      notifyListeners();
    } catch (e) {
      if (kDebugMode) {
        print('Error loading archived supplements: $e');
      }
    }
  }

  Future<void> archiveSupplement(int supplementId) async {
    try {
      await _databaseHelper.archiveSupplement(supplementId);
      await loadSupplements(); // Refresh active supplements
      await loadArchivedSupplements(); // Refresh archived supplements
    } catch (e) {
      if (kDebugMode) {
        print('Error archiving supplement: $e');
      }
    }
  }

  Future<void> unarchiveSupplement(int supplementId) async {
    try {
      await _databaseHelper.unarchiveSupplement(supplementId);
      await loadSupplements(); // Refresh active supplements
      await loadArchivedSupplements(); // Refresh archived supplements
    } catch (e) {
      if (kDebugMode) {
        print('Error unarchiving supplement: $e');
      }
    }
  }

  Future<void> deleteArchivedSupplement(int supplementId) async {
    try {
      await _databaseHelper.deleteSupplement(supplementId);
      await loadArchivedSupplements(); // Refresh archived supplements
    } catch (e) {
      if (kDebugMode) {
        print('Error deleting archived supplement: $e');
      }
    }
  }

  // Debug methods for notification testing
  Future<void> testNotifications() async {
    await _notificationService.testNotification();
  }

  Future<void> testScheduledNotification() async {
    await _notificationService.testScheduledNotification();
  }

  Future<void> testNotificationActions() async {
    await _notificationService.testNotificationWithActions();
  }

  Future<List<PendingNotificationRequest>> getPendingNotifications() async {
    return await _notificationService.getPendingNotifications();
  }

  // Get pending notifications with retry information from database
  Future<List<Map<String, dynamic>>> getTrackedNotifications() async {
    return await DatabaseHelper.instance.getPendingNotifications();
  }

  // Debug method to test notification persistence
  Future<void> rescheduleAllNotifications() async {
    await _rescheduleAllNotifications();
  }

  // Debug method to cancel all notifications
  Future<void> cancelAllNotifications() async {
    await _notificationService.cancelAllReminders();
  }
}