import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:firebase_core/firebase_core.dart';
import '../config/config_loader.dart';
import '../data/local/local_storage_service.dart';
import '../data/nostr/nostr_service.dart';
import '../data/sync/sync_engine.dart';
import '../data/firebase/firebase_service.dart';
import '../data/session/session_service.dart';
import '../data/immich/immich_service.dart';
import '../data/blossom/blossom_service.dart';
import '../data/media/media_service_interface.dart';
import '../data/media/multi_media_service.dart';
import '../data/media/models/media_server_config.dart';
import '../data/nostr/models/nostr_keypair.dart';
import '../data/recipes/recipe_service.dart';
import 'app_services.dart';
import 'service_locator.dart';
import 'logger.dart';
import 'theme_notifier.dart';
import 'package:flutter/material.dart';

/// Initializes all application services.
/// 
/// Handles the complete initialization sequence:
/// 1. Load environment configuration
/// 2. Initialize Firebase (if enabled)
/// 3. Initialize local storage
/// 4. Initialize Nostr service and sync engine
/// 5. Initialize Immich service
/// 6. Initialize Firebase service (if enabled)
/// 7. Initialize session service
/// 8. Register all services with ServiceLocator
class AppInitializer {
  /// Initializes all application services.
  /// 
  /// [environment] - The environment to use ('dev' or 'prod').
  /// 
  /// Returns an [AppServices] instance with all initialized services.
  /// 
  /// Throws if initialization fails.
  static Future<AppServices> initialize({
    String environment = 'dev',
  }) async {
    Logger.info('Starting application initialization...');

    // Load .env file (optional - falls back to defaults if not found)
    try {
      await dotenv.load(fileName: '.env');
      Logger.debug('.env file loaded successfully');
    } catch (e) {
      Logger.warning('.env file not found, using default values: $e');
    }

    // Load configuration based on environment
    final config = ConfigLoader.load(environment);
    Logger.setEnabled(config.enableLogging);
    Logger.info('Configuration loaded for environment: $environment');

    // Initialize Firebase if enabled
    if (config.firebaseConfig.enabled) {
      try {
        await Firebase.initializeApp();
        Logger.info('Firebase initialized successfully');
      } catch (e) {
        Logger.error(
          'Firebase initialization failed: $e',
          e,
        );
        Logger.warning(
          'Note: Firebase requires google-services.json (Android) and GoogleService-Info.plist (iOS)',
        );
      }
    }

    // Initialize local storage service
    Logger.debug('Initializing local storage service...');
    final storageService = LocalStorageService();
    try {
      await storageService.initialize();
      Logger.info('Local storage service initialized');
    } catch (e) {
      Logger.error('Failed to initialize storage: $e', e);
      rethrow;
    }

    // Initialize Nostr service and sync engine
    Logger.debug('Initializing Nostr service...');
    final nostrService = NostrService();
    final nostrKeyPair = nostrService.generateKeyPair();
    
    final syncEngine = SyncEngine(
      localStorage: storageService,
      nostrService: nostrService,
      nostrKeyPair: nostrKeyPair,
    );
    Logger.info('Nostr service and sync engine initialized');

    // Load relays from config
    for (final relayUrl in config.nostrRelays) {
      nostrService.addRelay(relayUrl);
    }
    Logger.debug('Loaded ${config.nostrRelays.length} relay(s) from config');

    // Initialize MultiMediaService for managing multiple media servers with fallback
    Logger.debug('Initializing MultiMediaService...');
    final multiMediaService = MultiMediaService(localStorage: storageService);
    await multiMediaService.loadServers();
    
    // Migrate old single server config if no servers exist
    if (multiMediaService.getServers().isEmpty) {
      final settingsItem = await storageService.getItem('app_settings');
      final immichEnabled = config.immichEnabled;
      final defaultBlossomServer = config.blossomServer;
      
      final mediaServerType = settingsItem?.data['media_server_type'] as String? ??
          (immichEnabled ? 'immich' : 'blossom');
      final immichBaseUrl = settingsItem?.data['immich_base_url'] as String? ?? config.immichBaseUrl;
      final immichApiKey = settingsItem?.data['immich_api_key'] as String? ?? config.immichApiKey;
      final blossomBaseUrl = settingsItem?.data['blossom_base_url'] as String? ?? defaultBlossomServer;
      
      // Migrate Immich config
      if (immichEnabled && mediaServerType == 'immich' && immichBaseUrl.isNotEmpty && immichApiKey.isNotEmpty) {
        final config = MediaServerConfig(
          id: 'immich-${DateTime.now().millisecondsSinceEpoch}',
          type: 'immich',
          baseUrl: immichBaseUrl,
          apiKey: immichApiKey,
          isDefault: true,
          name: 'Immich Server',
        );
        await multiMediaService.addServer(config);
        Logger.info('Migrated Immich server config to MultiMediaService');
      }
      
      // Migrate Blossom config
      if ((mediaServerType == 'blossom' || !immichEnabled) && blossomBaseUrl.isNotEmpty) {
        final config = MediaServerConfig(
          id: 'blossom-${DateTime.now().millisecondsSinceEpoch}',
          type: 'blossom',
          baseUrl: blossomBaseUrl,
          isDefault: true,
          name: 'Blossom Server',
    );
        await multiMediaService.addServer(config);
        Logger.info('Migrated Blossom server config to MultiMediaService');
      }
      
      await multiMediaService.saveServers();
    }
    
    MediaServiceInterface? mediaService = multiMediaService;
    if (multiMediaService.getServers().isEmpty) {
      Logger.warning('No media servers configured');
      mediaService = null;
    } else {
      Logger.info('MultiMediaService initialized with ${multiMediaService.getServers().length} server(s)');
    }

    // Initialize Firebase service if enabled
    FirebaseService? firebaseService;
    if (config.firebaseConfig.enabled) {
      try {
        Logger.debug('Initializing Firebase service...');
        firebaseService = FirebaseService(
          config: config.firebaseConfig,
          localStorage: storageService,
        );
        await firebaseService.initialize();
        Logger.info(
            'Firebase service initialized: ${firebaseService.isEnabled}');
      } catch (e) {
        Logger.error('Firebase service initialization failed: $e', e);
        firebaseService = null;
      }
    }

    // Initialize SessionService with Firebase and Nostr integration
    Logger.debug('Initializing session service...');
    final sessionService = SessionService(
      localStorage: storageService,
      syncEngine: syncEngine,
      firebaseService: firebaseService,
      nostrService: nostrService,
    );
    Logger.info('Session service initialized');

    // Initialize RecipeService
    Logger.debug('Initializing recipe service...');
    final recipeService = RecipeService(
      localStorage: storageService,
      nostrService: nostrService,
    );
    try {
      await recipeService.initialize();
      Logger.info('Recipe service initialized');
    } catch (e) {
      Logger.error('Failed to initialize recipe service: $e', e);
      // Continue without recipe service - it will be initialized later when user logs in
    }

    // Initialize ThemeNotifier and load theme preference
    Logger.debug('Initializing theme notifier...');
    final themeNotifier = ThemeNotifier();
    try {
      final settingsItem = await storageService.getItem('app_settings');
      if (settingsItem != null && settingsItem.data.containsKey('dark_mode')) {
        final isDark = settingsItem.data['dark_mode'] == true;
        themeNotifier.setThemeMode(isDark ? ThemeMode.dark : ThemeMode.light);
        Logger.info('Theme preference loaded: ${isDark ? "dark" : "light"}');
      } else {
        Logger.info('No theme preference found, using light mode');
      }
    } catch (e) {
      Logger.warning('Failed to load theme preference: $e');
    }

    // Create AppServices container
    final appServices = AppServices(
      localStorageService: storageService,
      nostrService: nostrService,
      syncEngine: syncEngine,
      firebaseService: firebaseService,
      sessionService: sessionService,
      mediaService: mediaService,
      recipeService: recipeService,
    );

    // Register all services with ServiceLocator
    ServiceLocator.instance.registerServices(
      localStorageService: storageService,
      nostrService: nostrService,
      syncEngine: syncEngine,
      firebaseService: firebaseService,
      sessionService: sessionService,
      mediaService: mediaService,
      recipeService: recipeService,
      themeNotifier: themeNotifier,
    );

    Logger.info('Application initialization completed successfully');
    return appServices;
  }

  /// Reinitializes the media service based on current settings.
  ///
  /// This should be called when media server settings are changed.
  /// Preserves the Nostr keypair if Blossom is selected.
  static Future<void> reinitializeMediaService() async {
    Logger.info('Reinitializing media service...');

    final localStorage = ServiceLocator.instance.localStorageService;

    if (localStorage == null) {
      Logger.warning(
          'Cannot reinitialize media service: LocalStorageService not available');
      return;
    }

    // Create new MultiMediaService instance and load servers
    final multiMediaService = MultiMediaService(localStorage: localStorage);
    await multiMediaService.loadServers();
    
    MediaServiceInterface? newMediaService = multiMediaService;
    if (multiMediaService.getServers().isEmpty) {
      Logger.warning('No media servers configured');
      newMediaService = null;
    } else {
      Logger.info('MultiMediaService reinitialized with ${multiMediaService.getServers().length} server(s)');
    }

    // Register the new media service with ServiceLocator
    ServiceLocator.instance.registerServices(
      mediaService: newMediaService,
    );

    Logger.info('Media service reinitialized and registered successfully');
  }
}