import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:provider/provider.dart';
import 'package:supplements/logging.dart';

import '../models/supplement.dart';
import '../models/supplement_intake.dart';
import '../providers/settings_provider.dart';
import '../services/database_helper.dart';
import '../services/database_sync_service.dart';
import '../services/simple_notification_service.dart';

class SupplementProvider with ChangeNotifier, WidgetsBindingObserver {
  final DatabaseHelper _databaseHelper = DatabaseHelper.instance;
  final SimpleNotificationService _notificationService = SimpleNotificationService.instance;
  bool _initialized = false;

  List<Supplement> _supplements = [];
  List<Map<String, dynamic>> _todayIntakes = [];
  List<Map<String, dynamic>> _monthlyIntakes = [];
  bool _isLoading = false;

  Timer? _dateChangeTimer;
  DateTime _lastDateCheck = DateTime.now();

  // Callback for triggering sync when data changes
  VoidCallback? _onDataChanged;

  // Context for accessing other providers
  BuildContext? _context;

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

  /// Set callback for triggering sync when data changes
  void setOnDataChangedCallback(VoidCallback? callback) {
    _onDataChanged = callback;
  }

  /// Trigger sync if callback is set
  void _triggerSyncIfEnabled() {
    _onDataChanged?.call();
  }

  Future<void> initialize([BuildContext? context]) async {
    if (_initialized) {
      return;
    }
    _initialized = true;
    _context = context;

    // Add this provider as an observer for app lifecycle changes
    WidgetsBinding.instance.addObserver(this);

    await _notificationService.initialize();

    // Request permissions with error handling
    try {
      await _notificationService.requestPermissions();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error requesting notification permissions: $e');
      }
      // Continue without notifications rather than crashing
    }

    await loadSupplements();
    await loadTodayIntakes();

    // Schedule notifications for all active supplements
    await _rescheduleAllNotifications();

    // Start date change monitoring to reset daily intake status
    _startDateChangeMonitoring();
  }



  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) {
          printLog('Date changed detected: $lastCheckDate -> $currentDate');
          printLog('Refreshing today\'s intakes for new day...');
        }

        // Date has changed, refresh today's intakes
        _lastDateCheck = now;
        await loadTodayIntakes();

        if (kDebugMode) {
          printLog('Today\'s intakes refreshed for new day');
        }
      }
    });
  }







    @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);

    _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) {
        printLog('App resumed, checking for date change...');
      }
      forceCheckDateChange();
    }
  }

  Future<void> _rescheduleAllNotifications() async {
    if (kDebugMode) {
      printLog('📱 Rescheduling notifications for all active supplements...');
    }

    try {
      SettingsProvider? settingsProvider;
      if (_context != null && _context!.mounted) {
        try {
          settingsProvider = Provider.of<SettingsProvider>(_context!, listen: false);
        } catch (e) {
          if (kDebugMode) {
            printLog('📱 Could not access SettingsProvider: $e');
          }
        }
      }

      await _notificationService.scheduleDailyGroupedRemindersSafe(
        _supplements,
        settingsProvider: settingsProvider,
      );
      await _notificationService.getPendingNotifications();
    } catch (e) {
      if (kDebugMode) {
        printLog('📱 Error scheduling grouped notifications: $e');
      }
    }

    if (kDebugMode) {
      printLog('📱 Finished rescheduling notifications');
    }
  }

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

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

  Future<void> addSupplement(Supplement supplement) async {
    try {
      printLog('Adding supplement: ${supplement.name}');
      final id = await _databaseHelper.insertSupplement(supplement);
      printLog('Supplement inserted with ID: $id');

      await loadSupplements();
      printLog('Supplements reloaded, count: ${_supplements.length}');
      await _rescheduleAllNotifications();

      // Trigger sync after adding supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      printLog('Error adding supplement: $e');
      if (kDebugMode) {
        printLog('Error adding supplement: $e');
      }
      rethrow;
    }
  }

  Future<void> updateSupplement(Supplement supplement) async {
    try {
      await _databaseHelper.updateSupplement(supplement);

      await loadSupplements();
      await _rescheduleAllNotifications();

      // Trigger sync after updating supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error updating supplement: $e');
      }
    }
  }

  Future<void> duplicateSupplement(int supplementId) async {
    try {
      final originalSupplement = await _databaseHelper.getSupplement(supplementId);
      if (originalSupplement != null) {
        final newSupplement = originalSupplement.copyWith(
          setNullId: true, // This will be a new entry
          newSyncId: true, // Generate a new syncId
          name: '${originalSupplement.name} (Copy)',
          createdAt: DateTime.now(),
          lastModified: DateTime.now(),
          syncStatus: RecordSyncStatus.pending,
          isDeleted: false,
        );
        await addSupplement(newSupplement);
      }
    } catch (e) {
      if (kDebugMode) {
        printLog('Error duplicating supplement: $e');
      }
    }
  }

  Future<void> deleteSupplement(int id) async {
    try {
      await _databaseHelper.deleteSupplement(id);

      await loadSupplements();
      await _rescheduleAllNotifications();

      // Trigger sync after deleting supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('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();

      // Trigger sync after recording intake
      _triggerSyncIfEnabled();

      // 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.showInstant(
        title: 'Supplement Taken',
        body: 'Recorded ${supplement.name}${unitsText.isNotEmpty ? ' - $unitsText' : ''} (${supplement.ingredientsDisplay})',
      );
    } catch (e) {
      if (kDebugMode) {
        printLog('Error recording intake: $e');
      }
    }
  }

  Future<void> loadTodayIntakes() async {
    try {
      final today = DateTime.now();
      if (kDebugMode) {
        printLog('Loading intakes for date: ${today.year}-${today.month}-${today.day}');
      }

      _todayIntakes = await _databaseHelper.getIntakesWithSupplementsForDate(today);

      if (kDebugMode) {
        printLog('Loaded ${_todayIntakes.length} intakes for today');
        for (var intake in _todayIntakes) {
          printLog('  - Supplement ID: ${intake['supplement_id']}, taken at: ${intake['takenAt']}');
        }
      }

      notifyListeners();
    } catch (e) {
      if (kDebugMode) {
        printLog('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) {
        printLog('Error loading monthly intakes: $e');
      }
    }
  }

  Future<List<Map<String, dynamic>>> getIntakesForDate(DateTime date) async {
    try {
      return await _databaseHelper.getIntakesWithSupplementsForDate(date);
    } catch (e) {
      if (kDebugMode) {
        printLog('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();

      // Trigger sync after deleting intake
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error deleting intake: $e');
      }
    }
  }

  Future<void> permanentlyDeleteIntake(int intakeId) async {
    try {
      await _databaseHelper.permanentlyDeleteIntake(intakeId);
      await loadTodayIntakes();
      // Also refresh monthly intakes if they're loaded
      if (_monthlyIntakes.isNotEmpty) {
        await loadMonthlyIntakes(DateTime.now().year, DateTime.now().month);
      }
      notifyListeners();

      // Trigger sync after permanently deleting intake
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error permanently 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;
  }

  /// Get the most recent intake for a supplement today
  Map<String, dynamic>? getMostRecentIntake(int supplementId) {
    final supplementIntakes = _todayIntakes
        .where((intake) => intake['supplement_id'] == supplementId)
        .toList();

    if (supplementIntakes.isEmpty) return null;

    // Sort by takenAt time (most recent first)
    supplementIntakes.sort((a, b) {
      final aTime = DateTime.parse(a['takenAt']);
      final bTime = DateTime.parse(b['takenAt']);
      return bTime.compareTo(aTime); // Descending order
    });

    return supplementIntakes.first;
  }

  Map<String, double> get dailyIngredientIntake {
    final Map<String, double> ingredientIntake = {};

    for (final intake in _todayIntakes) {
      final supplement = _supplements.firstWhere((s) => s.id == intake['supplement_id']);
      final unitsTaken = intake['unitsTaken'] as double;

      for (final ingredient in supplement.ingredients) {
        final currentAmount = ingredientIntake[ingredient.name] ?? 0;
        ingredientIntake[ingredient.name] = currentAmount + (ingredient.amount * unitsTaken);
      }
    }

    return ingredientIntake;
  }

  // Method to manually refresh daily status (useful for testing or manual refresh)
  Future<void> refreshDailyStatus() async {
    if (kDebugMode) {
      printLog('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) {
      printLog('Force checking date change...');
      printLog('Current date: $currentDate');
      printLog('Last check date: $lastCheckDate');
    }

    if (currentDate != lastCheckDate) {
      if (kDebugMode) {
        printLog('Date change detected, refreshing intakes...');
      }
      _lastDateCheck = now;
      await loadTodayIntakes();
    } else {
      if (kDebugMode) {
        printLog('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) {
        printLog('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

      // Trigger sync after archiving supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('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

      // Trigger sync after unarchiving supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error unarchiving supplement: $e');
      }
    }
  }

  Future<void> deleteArchivedSupplement(int supplementId) async {
    try {
      await _databaseHelper.permanentlyDeleteSupplement(supplementId);
      await loadArchivedSupplements(); // Refresh archived supplements

      // Trigger sync after permanently deleting archived supplement
      _triggerSyncIfEnabled();
    } catch (e) {
      if (kDebugMode) {
        printLog('Error permanently deleting archived supplement: $e');
      }
    }
  }

  // Debug methods for notification testing
  Future<void> testNotifications() async {
    await _notificationService.showInstant(
      title: 'Test Notification',
      body: 'This is a test notification to verify the system is working.',
    );
  }

  Future<void> testScheduledNotification() async {
    await _notificationService.showInstant(
      title: 'Test Scheduled Notification',
      body: 'This is a simple test notification.',
    );
  }

  Future<void> testNotificationActions() async {
    await _notificationService.showInstant(
      title: 'Test Action Notification',
      body: 'Actions are not available in the simple notification service.',
    );
  }

  Future<List<PendingNotificationRequest>> getPendingNotifications() async {
    // Not supported in simple service; return empty list for compatibility.
    return [];
  }



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

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