mudular code ready to fork

lib/config/config_loader.dart

@@ -1,22 +1,8 @@
 import 'package:flutter_dotenv/flutter_dotenv.dart';
+import '../core/exceptions/invalid_environment_exception.dart';
 import 'app_config.dart';
 import '../data/firebase/models/firebase_config.dart';
 
-/// Exception thrown when an invalid environment is provided to [ConfigLoader].
-class InvalidEnvironmentException implements Exception {
-  /// The invalid environment that was provided.
-  final String environment;
-
-  /// Creates an [InvalidEnvironmentException] with the provided environment.
-  InvalidEnvironmentException(this.environment);
-
-  @override
-  String toString() {
-    return 'InvalidEnvironmentException: Invalid environment "$environment". '
-        'Valid environments are: dev, prod';
-  }
-}
-
 /// Loads application configuration based on the specified environment.
 /// 
 /// This class provides a factory method to load configuration for either

lib/data/firebase/firebase_service.dart

@@ -5,22 +5,11 @@ import 'package:firebase_storage/firebase_storage.dart';
 import 'package:firebase_auth/firebase_auth.dart' as firebase_auth;
 import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:firebase_analytics/firebase_analytics.dart';
+import '../../core/exceptions/firebase_exception.dart' show FirebaseServiceException;
 import '../local/local_storage_service.dart';
 import '../local/models/item.dart';
 import 'models/firebase_config.dart';
 
-/// Exception thrown when Firebase operations fail.
-class FirebaseException implements Exception {
-  /// Error message.
-  final String message;
-
-  /// Creates a [FirebaseException] with the provided message.
-  FirebaseException(this.message);
-
-  @override
-  String toString() => 'FirebaseException: $message';
-}
-
 /// Service for Firebase integration (optional cloud sync, storage, auth, notifications, analytics).
 ///
 /// This service provides:
@@ -86,7 +75,7 @@ class FirebaseService {
   /// Must be called before using any Firebase services.
   /// If Firebase is disabled, this method does nothing.
   ///
-  /// Throws [FirebaseException] if initialization fails.
+  /// Throws [FirebaseServiceException] if initialization fails.
   Future<void> initialize() async {
     if (!config.enabled) {
       return; // Firebase disabled, nothing to initialize
@@ -135,7 +124,7 @@ class FirebaseService {
 
       _initialized = true;
     } catch (e) {
-      throw FirebaseException('Failed to initialize Firebase: $e');
+      throw FirebaseServiceException('Failed to initialize Firebase: $e');
     }
   }
 
@@ -146,17 +135,17 @@ class FirebaseService {
   ///
   /// Returns the Firebase Auth user.
   ///
-  /// Throws [FirebaseException] if auth is disabled or login fails.
+  /// Throws [FirebaseServiceException] if auth is disabled or login fails.
   Future<firebase_auth.User> loginWithEmailPassword({
     required String email,
     required String password,
   }) async {
     if (!config.enabled || !config.authEnabled) {
-      throw FirebaseException('Firebase Auth is not enabled');
+      throw FirebaseServiceException('Firebase Auth is not enabled');
     }
 
     if (!_initialized || _auth == null) {
-      throw FirebaseException(
+      throw FirebaseServiceException(
           'Firebase not initialized. Call initialize() first.');
     }
 
@@ -168,20 +157,20 @@ class FirebaseService {
       _firebaseUser = credential.user;
       return _firebaseUser!;
     } catch (e) {
-      throw FirebaseException('Failed to login: $e');
+      throw FirebaseServiceException('Failed to login: $e');
     }
   }
 
   /// Logs out the current user.
   ///
-  /// Throws [FirebaseException] if auth is disabled or logout fails.
+  /// Throws [FirebaseServiceException] if auth is disabled or logout fails.
   Future<void> logout() async {
     if (!config.enabled || !config.authEnabled) {
-      throw FirebaseException('Firebase Auth is not enabled');
+      throw FirebaseServiceException('Firebase Auth is not enabled');
     }
 
     if (!_initialized || _auth == null) {
-      throw FirebaseException(
+      throw FirebaseServiceException(
           'Firebase not initialized. Call initialize() first.');
     }
 
@@ -189,7 +178,7 @@ class FirebaseService {
       await _auth!.signOut();
       _firebaseUser = null;
     } catch (e) {
-      throw FirebaseException('Failed to logout: $e');
+      throw FirebaseServiceException('Failed to logout: $e');
     }
   }
 
@@ -197,14 +186,14 @@ class FirebaseService {
   ///
   /// [userId] - User ID to associate items with (for multi-user support).
   ///
-  /// Throws [FirebaseException] if Firestore is disabled or sync fails.
+  /// Throws [FirebaseServiceException] if Firestore is disabled or sync fails.
   Future<void> syncItemsToFirestore(String userId) async {
     if (!config.enabled || !config.firestoreEnabled) {
-      throw FirebaseException('Firestore is not enabled');
+      throw FirebaseServiceException('Firestore is not enabled');
     }
 
     if (!_initialized || _firestore == null) {
-      throw FirebaseException(
+      throw FirebaseServiceException(
           'Firestore not initialized. Call initialize() first.');
     }
 
@@ -229,7 +218,7 @@ class FirebaseService {
 
       await batch.commit();
     } catch (e) {
-      throw FirebaseException('Failed to sync items to Firestore: $e');
+      throw FirebaseServiceException('Failed to sync items to Firestore: $e');
     }
   }
 
@@ -237,14 +226,14 @@ class FirebaseService {
   ///
   /// [userId] - User ID to fetch items for.
   ///
-  /// Throws [FirebaseException] if Firestore is disabled or sync fails.
+  /// Throws [FirebaseServiceException] if Firestore is disabled or sync fails.
   Future<void> syncItemsFromFirestore(String userId) async {
     if (!config.enabled || !config.firestoreEnabled) {
-      throw FirebaseException('Firestore is not enabled');
+      throw FirebaseServiceException('Firestore is not enabled');
     }
 
     if (!_initialized || _firestore == null) {
-      throw FirebaseException(
+      throw FirebaseServiceException(
           'Firestore not initialized. Call initialize() first.');
     }
 
@@ -271,7 +260,7 @@ class FirebaseService {
         }
       }
     } catch (e) {
-      throw FirebaseException('Failed to sync items from Firestore: $e');
+      throw FirebaseServiceException('Failed to sync items from Firestore: $e');
     }
   }
 
@@ -282,14 +271,14 @@ class FirebaseService {
   ///
   /// Returns the download URL.
   ///
-  /// Throws [FirebaseException] if Storage is disabled or upload fails.
+  /// Throws [FirebaseServiceException] if Storage is disabled or upload fails.
   Future<String> uploadFile(File file, String path) async {
     if (!config.enabled || !config.storageEnabled) {
-      throw FirebaseException('Firebase Storage is not enabled');
+      throw FirebaseServiceException('Firebase Storage is not enabled');
     }
 
     if (!_initialized || _storage == null) {
-      throw FirebaseException(
+      throw FirebaseServiceException(
           'Firebase Storage not initialized. Call initialize() first.');
     }
 
@@ -298,7 +287,7 @@ class FirebaseService {
       await ref.putFile(file);
       return await ref.getDownloadURL();
     } catch (e) {
-      throw FirebaseException('Failed to upload file: $e');
+      throw FirebaseServiceException('Failed to upload file: $e');
     }
   }
 

lib/data/immich/immich_service.dart

@@ -1,32 +1,14 @@
 import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 import 'package:dio/dio.dart';
-import 'package:flutter/foundation.dart';
+import '../../core/logger.dart';
+import '../../core/exceptions/immich_exception.dart';
 import '../local/local_storage_service.dart';
 import '../local/models/item.dart';
 import 'models/immich_asset.dart';
 import 'models/upload_response.dart';
 
-/// Exception thrown when Immich API operations fail.
-class ImmichException implements Exception {
-  /// Error message.
-  final String message;
-
-  /// HTTP status code if available.
-  final int? statusCode;
-
-  /// Creates an [ImmichException] with the provided message.
-  ImmichException(this.message, [this.statusCode]);
-
-  @override
-  String toString() {
-    if (statusCode != null) {
-      return 'ImmichException: $message (Status: $statusCode)';
-    }
-    return 'ImmichException: $message';
-  }
-}
-
 /// Service for interacting with Immich API.
 ///
 /// This service provides:
@@ -175,15 +157,15 @@ class ImmichService {
       }
 
       final uploadUrl = '$_baseUrl$endpointPath';
-      debugPrint('=== Immich Upload Request ===');
+      Logger.debug('=== Immich Upload Request ===');
-      debugPrint('URL: $uploadUrl');
+      Logger.debug('URL: $uploadUrl');
-      debugPrint('Base URL: $_baseUrl');
+      Logger.debug('Base URL: $_baseUrl');
-      debugPrint('File: $fileName, Size: ${await imageFile.length()} bytes');
+      Logger.debug('File: $fileName, Size: ${await imageFile.length()} bytes');
-      debugPrint('Device ID: $deviceId');
+      Logger.debug('Device ID: $deviceId');
-      debugPrint('Device Asset ID: $deviceAssetId');
+      Logger.debug('Device Asset ID: $deviceAssetId');
-      debugPrint('File Created At: $fileCreatedAtIso');
+      Logger.debug('File Created At: $fileCreatedAtIso');
-      debugPrint('File Modified At: $fileModifiedAtIso');
+      Logger.debug('File Modified At: $fileModifiedAtIso');
-      debugPrint('Metadata: $metadataJson');
+      Logger.debug('Metadata: $metadataJson');
 
       final response = await _dio.post(
         endpointPath,
@@ -196,17 +178,17 @@ class ImmichService {
         ),
       );
 
-      debugPrint('=== Immich Upload Response ===');
+      Logger.debug('=== Immich Upload Response ===');
-      debugPrint('Status Code: ${response.statusCode}');
+      Logger.debug('Status Code: ${response.statusCode}');
-      debugPrint('Response Data: ${response.data}');
+      Logger.debug('Response Data: ${response.data}');
-      debugPrint('Response Headers: ${response.headers}');
+      Logger.debug('Response Headers: ${response.headers}');
 
       if (response.statusCode != 200 && response.statusCode != 201) {
         final errorMessage = response.data is Map
             ? (response.data as Map)['message']?.toString() ??
                 response.statusMessage
             : response.statusMessage;
-        debugPrint(
+        Logger.error(
             'Upload failed with status ${response.statusCode}: $errorMessage');
         throw ImmichException(
           'Upload failed: $errorMessage',
@@ -216,15 +198,15 @@ class ImmichService {
 
       // Log the response data structure
       if (response.data is Map) {
-        debugPrint('Response is Map with keys: ${(response.data as Map).keys}');
+        Logger.debug('Response is Map with keys: ${(response.data as Map).keys}');
-        debugPrint('Full response map: ${response.data}');
+        Logger.debug('Full response map: ${response.data}');
       } else if (response.data is List) {
-        debugPrint(
+        Logger.debug(
             'Response is List with ${(response.data as List).length} items');
-        debugPrint('First item: ${(response.data as List).first}');
+        Logger.debug('First item: ${(response.data as List).first}');
       } else {
-        debugPrint('Response type: ${response.data.runtimeType}');
+        Logger.debug('Response type: ${response.data.runtimeType}');
-        debugPrint('Response value: ${response.data}');
+        Logger.debug('Response value: ${response.data}');
       }
 
       // Handle response - it might be a single object or an array
@@ -232,7 +214,7 @@ class ImmichService {
       if (response.data is List && (response.data as List).isNotEmpty) {
         // If response is an array, take the first item
         responseData = (response.data as List).first as Map<String, dynamic>;
-        debugPrint('Using first item from array response');
+        Logger.debug('Using first item from array response');
       } else if (response.data is Map) {
         responseData = response.data as Map<String, dynamic>;
       } else {
@@ -243,24 +225,24 @@ class ImmichService {
       }
 
       final uploadResponse = UploadResponse.fromJson(responseData);
-      debugPrint('Parsed Upload Response:');
+      Logger.debug('Parsed Upload Response:');
-      debugPrint('  ID: ${uploadResponse.id}');
+      Logger.debug('  ID: ${uploadResponse.id}');
-      debugPrint('  Duplicate: ${uploadResponse.duplicate}');
+      Logger.debug('  Duplicate: ${uploadResponse.duplicate}');
 
       // Fetch full asset details to store complete metadata
-      debugPrint('Fetching full asset details for ID: ${uploadResponse.id}');
+      Logger.debug('Fetching full asset details for ID: ${uploadResponse.id}');
       try {
         final asset = await _getAssetById(uploadResponse.id);
-        debugPrint('Fetched asset: ${asset.id}, ${asset.fileName}');
+        Logger.debug('Fetched asset: ${asset.id}, ${asset.fileName}');
 
         // Store metadata in local storage
-        debugPrint('Storing asset metadata in local storage');
+        Logger.debug('Storing asset metadata in local storage');
         await _storeAssetMetadata(asset);
-        debugPrint('Asset metadata stored successfully');
+        Logger.debug('Asset metadata stored successfully');
       } catch (e) {
         // Log error but don't fail the upload - asset was uploaded successfully
-        debugPrint('Warning: Failed to fetch/store asset metadata: $e');
+        Logger.warning('Failed to fetch/store asset metadata: $e');
-        debugPrint('Upload was successful, but metadata caching failed');
+        Logger.warning('Upload was successful, but metadata caching failed');
       }
 
       return uploadResponse;
@@ -558,9 +540,9 @@ class ImmichService {
     }
 
     try {
-      debugPrint('=== Immich Delete Assets ===');
+      Logger.debug('=== Immich Delete Assets ===');
-      debugPrint('Asset IDs to delete: $assetIds');
+      Logger.debug('Asset IDs to delete: $assetIds');
-      debugPrint('Count: ${assetIds.length}');
+      Logger.debug('Count: ${assetIds.length}');
 
       // DELETE /api/assets with ids in request body
       // According to Immich API: DELETE /api/assets with body: {"ids": ["uuid1", "uuid2", ...]}
@@ -568,7 +550,7 @@ class ImmichService {
         'ids': assetIds,
       };
 
-      debugPrint('Request body: $requestBody');
+      Logger.debug('Request body: $requestBody');
 
       final response = await _dio.delete(
         '/api/assets',
@@ -581,9 +563,9 @@ class ImmichService {
         ),
       );
 
-      debugPrint('=== Immich Delete Response ===');
+      Logger.debug('=== Immich Delete Response ===');
-      debugPrint('Status Code: ${response.statusCode}');
+      Logger.debug('Status Code: ${response.statusCode}');
-      debugPrint('Response Data: ${response.data}');
+      Logger.debug('Response Data: ${response.data}');
 
       if (response.statusCode != 200 && response.statusCode != 204) {
         final errorMessage = response.data is Map
@@ -601,11 +583,11 @@ class ImmichService {
         try {
           await _localStorage.deleteItem('immich_$assetId');
         } catch (e) {
-          debugPrint('Warning: Failed to remove asset $assetId from cache: $e');
+          Logger.warning('Failed to remove asset $assetId from cache: $e');
         }
       }
 
-      debugPrint('Successfully deleted ${assetIds.length} asset(s)');
+      Logger.info('Successfully deleted ${assetIds.length} asset(s)');
     } on DioException catch (e) {
       final statusCode = e.response?.statusCode;
       final errorData = e.response?.data;

lib/data/nostr/nostr_service.dart

@@ -1,26 +1,15 @@
 import 'dart:async';
 import 'dart:convert';
-import 'package:flutter/foundation.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';
 import 'package:nostr_tools/nostr_tools.dart';
 import 'package:http/http.dart' as http;
+import '../../core/logger.dart';
+import '../../core/exceptions/nostr_exception.dart';
 import 'models/nostr_keypair.dart';
 import 'models/nostr_event.dart';
 import 'models/nostr_relay.dart';
 import 'models/nostr_profile.dart';
 
-/// Exception thrown when Nostr operations fail.
-class NostrException implements Exception {
-  /// Error message.
-  final String message;
-
-  /// Creates a [NostrException] with the provided message.
-  NostrException(this.message);
-
-  @override
-  String toString() => 'NostrException: $message';
-}
-
 /// Service for interacting with Nostr protocol.
 ///
 /// This service provides:
@@ -492,7 +481,7 @@ class NostrService {
             }
           } catch (e) {
             // Ignore parsing errors
-            debugPrint('Error parsing profile event: $e');
+            Logger.warning('Error parsing profile event: $e');
           }
         } else if (message['type'] == 'EOSE' &&
             message['subscription_id'] == reqId) {
@@ -634,7 +623,7 @@ class NostrService {
           addedCount++;
         } catch (e) {
           // Skip invalid relay URLs
-          debugPrint('Warning: Invalid relay URL from NIP-05: $relayUrl');
+          Logger.warning('Invalid relay URL from NIP-05: $relayUrl');
         }
       }
 

lib/data/session/session_service.dart

@@ -1,7 +1,8 @@
 import 'dart:io';
-import 'package:flutter/foundation.dart';
 import 'package:path/path.dart' as path;
 import 'package:path_provider/path_provider.dart';
+import '../../core/logger.dart';
+import '../../core/exceptions/session_exception.dart';
 import '../local/local_storage_service.dart';
 import '../sync/sync_engine.dart';
 import '../firebase/firebase_service.dart';
@@ -10,18 +11,6 @@ import '../nostr/models/nostr_keypair.dart';
 import '../nostr/models/nostr_profile.dart';
 import 'models/user.dart';
 
-/// Exception thrown when session operations fail.
-class SessionException implements Exception {
-  /// Error message.
-  final String message;
-
-  /// Creates a [SessionException] with the provided message.
-  SessionException(this.message);
-
-  @override
-  String toString() => 'SessionException: $message';
-}
-
 /// Service for managing user sessions, login, logout, and session isolation.
 /// 
 /// This service provides:
@@ -124,7 +113,7 @@ class SessionService {
           await _firebaseService!.syncItemsFromFirestore(user.id);
         } catch (e) {
           // Log error but don't fail login - offline-first behavior
-          debugPrint('Warning: Failed to sync from Firebase on login: $e');
+          Logger.warning('Failed to sync from Firebase on login: $e');
         }
       }
 
@@ -174,7 +163,7 @@ class SessionService {
       try {
         profile = await _nostrService!.fetchProfile(keyPair.publicKey);
       } catch (e) {
-        debugPrint('Warning: Failed to fetch Nostr profile: $e');
+        Logger.warning('Failed to fetch Nostr profile: $e');
         // Continue without profile - offline-first behavior
       }
 
@@ -195,7 +184,7 @@ class SessionService {
           await _firebaseService!.syncItemsFromFirestore(user.id);
         } catch (e) {
           // Log error but don't fail login - offline-first behavior
-          debugPrint('Warning: Failed to sync from Firebase on login: $e');
+          Logger.warning('Failed to sync from Firebase on login: $e');
         }
       }
 
@@ -230,7 +219,7 @@ class SessionService {
           await _firebaseService!.syncItemsToFirestore(userId);
         } catch (e) {
           // Log error but don't fail logout - offline-first behavior
-          debugPrint('Warning: Failed to sync to Firebase on logout: $e');
+          Logger.warning('Failed to sync to Firebase on logout: $e');
         }
       }
 
@@ -407,7 +396,7 @@ class SessionService {
       try {
         profile = await _nostrService!.fetchProfile(_currentUser!.id);
       } catch (e) {
-        debugPrint('Warning: Failed to refresh Nostr profile: $e');
+        Logger.warning('Failed to refresh Nostr profile: $e');
         // Continue without profile update - offline-first behavior
       }
 
@@ -447,11 +436,11 @@ class SessionService {
       );
 
       if (addedCount > 0) {
-        debugPrint('Loaded $addedCount preferred relay(s) from NIP-05: $nip05');
+        Logger.info('Loaded $addedCount preferred relay(s) from NIP-05: $nip05');
       }
     } catch (e) {
       // Log error but don't fail - offline-first behavior
-      debugPrint('Warning: Failed to load preferred relays from NIP-05: $e');
+      Logger.warning('Failed to load preferred relays from NIP-05: $e');
     }
   }
 }

lib/data/sync/sync_engine.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import '../../core/exceptions/sync_exception.dart';
 import '../local/local_storage_service.dart';
 import '../immich/immich_service.dart';
 import '../nostr/nostr_service.dart';
@@ -6,18 +7,6 @@ import '../nostr/models/nostr_keypair.dart';
 import 'models/sync_status.dart';
 import 'models/sync_operation.dart';
 
-/// Exception thrown when sync operations fail.
-class SyncException implements Exception {
-  /// Error message.
-  final String message;
-
-  /// Creates a [SyncException] with the provided message.
-  SyncException(this.message);
-
-  @override
-  String toString() => 'SyncException: $message';
-}
-
 /// Engine for coordinating data synchronization between local storage, Immich, and Nostr.
 ///
 /// This service provides:

lib/main.dart

@@ -1,182 +1,70 @@
 import 'package:flutter/material.dart';
-import 'package:flutter_dotenv/flutter_dotenv.dart';
+import 'core/app_initializer.dart';
-import 'package:firebase_core/firebase_core.dart';
+import 'core/app_services.dart';
-import 'config/config_loader.dart';
+import 'core/logger.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 'ui/navigation/main_navigation_scaffold.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
-  
-  // Load .env file (optional - falls back to defaults if not found)
-  try {
-    await dotenv.load(fileName: '.env');
-  } catch (e) {
-    debugPrint('Note: .env file not found, using default values: $e');
-  }
 
-  // Load configuration based on environment
+  // Determine environment
   const String environment = String.fromEnvironment(
     'ENV',
     defaultValue: 'dev',
   );
 
-  final config = ConfigLoader.load(environment);
+  // Initialize all services
-
+  AppServices? appServices;
-  // Initialize Firebase if enabled
+  try {
-  if (config.firebaseConfig.enabled) {
+    appServices = await AppInitializer.initialize(environment: environment);
-    try {
+  } catch (e, stackTrace) {
-      await Firebase.initializeApp();
+    Logger.error('Failed to initialize application', e, stackTrace);
-      if (config.enableLogging) {
+    // App will show error state
-        debugPrint('Firebase initialized successfully');
-      }
-    } catch (e) {
-      debugPrint('Firebase initialization failed: $e');
-      debugPrint('Note: Firebase requires google-services.json (Android) and GoogleService-Info.plist (iOS)');
-    }
   }
 
-  if (config.enableLogging) {
+  runApp(MyApp(appServices: appServices));
-    debugPrint('App initialized with config: $config');
-  }
-
-  runApp(const MyApp());
 }
 
 /// The root widget of the application.
 class MyApp extends StatefulWidget {
-  const MyApp({super.key});
+  final AppServices? appServices;
+
+  const MyApp({super.key, this.appServices});
 
   @override
   State<MyApp> createState() => _MyAppState();
 }
 
 class _MyAppState extends State<MyApp> {
-  LocalStorageService? _storageService;
-  NostrService? _nostrService;
-  SyncEngine? _syncEngine;
-  FirebaseService? _firebaseService;
-  SessionService? _sessionService;
-  ImmichService? _immichService;
-  bool _isInitialized = false;
-
-  @override
-  void initState() {
-    super.initState();
-    _initializeStorage();
-  }
-
-  Future<void> _initializeStorage() async {
-    try {
-      _storageService = LocalStorageService();
-      await _storageService!.initialize();
-      
-      // Initialize Nostr service and sync engine
-      _nostrService = NostrService();
-      final nostrKeyPair = _nostrService!.generateKeyPair();
-      _syncEngine = SyncEngine(
-        localStorage: _storageService!,
-        nostrService: _nostrService!,
-        nostrKeyPair: nostrKeyPair,
-      );
-      
-      // Load relays from config
-      final config = ConfigLoader.load(
-        const String.fromEnvironment('ENV', defaultValue: 'dev'),
-      );
-      for (final relayUrl in config.nostrRelays) {
-        _nostrService!.addRelay(relayUrl);
-      }
-      
-      // Initialize Immich service
-      _immichService = ImmichService(
-        baseUrl: config.immichBaseUrl,
-        apiKey: config.immichApiKey,
-        localStorage: _storageService!,
-      );
-      
-      // Initialize Firebase service if enabled
-      if (config.firebaseConfig.enabled) {
-        try {
-          _firebaseService = FirebaseService(
-            config: config.firebaseConfig,
-            localStorage: _storageService!,
-          );
-          await _firebaseService!.initialize();
-          if (config.enableLogging) {
-            debugPrint('Firebase service initialized: ${_firebaseService!.isEnabled}');
-          }
-        } catch (e) {
-          debugPrint('Firebase service initialization failed: $e');
-          _firebaseService = null;
-        }
-      }
-      
-      // Initialize SessionService with Firebase and Nostr integration
-      _sessionService = SessionService(
-        localStorage: _storageService!,
-        syncEngine: _syncEngine,
-        firebaseService: _firebaseService,
-        nostrService: _nostrService,
-      );
-      
-      setState(() {
-        _isInitialized = true;
-      });
-    } catch (e) {
-      debugPrint('Failed to initialize storage: $e');
-      // Reset to null if initialization failed
-      _storageService = null;
-      _nostrService = null;
-      _syncEngine = null;
-      _firebaseService = null;
-      _sessionService = null;
-      _immichService = null;
-    }
-  }
-
-
   @override
   void dispose() {
-    _syncEngine?.dispose();
+    // Dispose of all services
-    _nostrService?.dispose();
+    widget.appServices?.dispose();
-    _firebaseService?.dispose();
-    // Only close if storage service was initialized
-    if (_storageService != null) {
-      try {
-        _storageService!.close();
-      } catch (e) {
-        debugPrint('Error closing storage service: $e');
-      }
-    }
     super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
+    final appServices = widget.appServices;
+
     return MaterialApp(
       title: 'App Boilerplate',
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
         useMaterial3: true,
       ),
-      home: _isInitialized
+      home: appServices != null
-          ? MainNavigationScaffold(
+          ? const MainNavigationScaffold()
-              sessionService: _sessionService,
-              localStorageService: _storageService,
-              nostrService: _nostrService,
-              syncEngine: _syncEngine,
-              firebaseService: _firebaseService,
-              immichService: _immichService,
-            )
           : const Scaffold(
               body: Center(
-                child: CircularProgressIndicator(),
+                child: Column(
+                  mainAxisAlignment: MainAxisAlignment.center,
+                  children: [
+                    CircularProgressIndicator(),
+                    SizedBox(height: 16),
+                    Text('Initializing application...'),
+                  ],
+                ),
               ),
             ),
     );

lib/ui/home/home_screen.dart

@@ -1,15 +1,11 @@
 import 'package:flutter/material.dart';
+import '../../core/service_locator.dart';
 import '../../data/local/local_storage_service.dart';
 import '../../data/local/models/item.dart';
 
 /// Home screen showing local storage and cached content.
 class HomeScreen extends StatefulWidget {
-  final LocalStorageService? localStorageService;
+  const HomeScreen({super.key});
-
-  const HomeScreen({
-    super.key,
-    this.localStorageService,
-  });
 
   @override
   State<HomeScreen> createState() => _HomeScreenState();
@@ -26,15 +22,16 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   Future<void> _loadItems() async {
-    if (widget.localStorageService == null) {
-      setState(() {
-        _isLoading = false;
-      });
-      return;
-    }
-
     try {
-      final items = await widget.localStorageService!.getAllItems();
+      final localStorageService = ServiceLocator.instance.localStorageService;
+      if (localStorageService == null) {
+        setState(() {
+          _isLoading = false;
+        });
+        return;
+      }
+
+      final items = await localStorageService.getAllItems();
       setState(() {
         _items = items;
         _isLoading = false;
@@ -90,7 +87,8 @@ class _HomeScreenState extends State<HomeScreen> {
                           trailing: IconButton(
                             icon: const Icon(Icons.delete_outline),
                             onPressed: () async {
-                              await widget.localStorageService?.deleteItem(item.id);
+                              final localStorageService = ServiceLocator.instance.localStorageService;
+                              await localStorageService?.deleteItem(item.id);
                               _loadItems();
                             },
                           ),
@@ -98,9 +96,10 @@ class _HomeScreenState extends State<HomeScreen> {
                       },
                     ),
             ),
-      floatingActionButton: widget.localStorageService != null
+      floatingActionButton: ServiceLocator.instance.localStorageService != null
           ? FloatingActionButton(
               onPressed: () async {
+                final localStorageService = ServiceLocator.instance.localStorageService;
                 final item = Item(
                   id: 'item-${DateTime.now().millisecondsSinceEpoch}',
                   data: {
@@ -108,7 +107,7 @@ class _HomeScreenState extends State<HomeScreen> {
                     'timestamp': DateTime.now().toIso8601String(),
                   },
                 );
-                await widget.localStorageService!.insertItem(item);
+                await localStorageService!.insertItem(item);
                 _loadItems();
               },
               child: const Icon(Icons.add),

lib/ui/immich/immich_screen.dart

@@ -2,6 +2,8 @@ import 'dart:io';
 import 'dart:typed_data';
 import 'package:flutter/material.dart';
 import 'package:image_picker/image_picker.dart';
+import '../../core/logger.dart';
+import '../../core/service_locator.dart';
 import '../../data/local/local_storage_service.dart';
 import '../../data/immich/immich_service.dart';
 import '../../data/immich/models/immich_asset.dart';
@@ -11,14 +13,7 @@ import '../../data/immich/models/immich_asset.dart';
 /// Displays images from Immich in a grid layout with pull-to-refresh.
 /// Shows cached images first, then fetches from API.
 class ImmichScreen extends StatefulWidget {
-  final LocalStorageService? localStorageService;
+  const ImmichScreen({super.key});
-  final ImmichService? immichService;
-
-  const ImmichScreen({
-    super.key,
-    this.localStorageService,
-    this.immichService,
-  });
 
   @override
   State<ImmichScreen> createState() => _ImmichScreenState();
@@ -41,7 +36,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
   /// Loads assets from cache first, then fetches from API.
   Future<void> _loadAssets({bool forceRefresh = false}) async {
-    if (widget.immichService == null) {
+    if (ServiceLocator.instance.immichService == null) {
       setState(() {
         _errorMessage = 'Immich service not available';
         _isLoading = false;
@@ -57,7 +52,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
     try {
       // First, try to load cached assets
       if (!forceRefresh) {
-        final cachedAssets = await widget.immichService!.getCachedAssets();
+        final cachedAssets = await ServiceLocator.instance.immichService!.getCachedAssets();
         if (cachedAssets.isNotEmpty) {
           setState(() {
             _assets = cachedAssets;
@@ -82,7 +77,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
   /// Fetches assets from Immich API.
   Future<void> _fetchFromApi() async {
     try {
-      final assets = await widget.immichService!.fetchAssets(limit: 100);
+      final assets = await ServiceLocator.instance.immichService!.fetchAssets(limit: 100);
       setState(() {
         _assets = assets;
         _isLoading = false;
@@ -97,7 +92,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
   /// Gets the thumbnail URL for an asset with proper headers.
   String _getThumbnailUrl(ImmichAsset asset) {
-    return widget.immichService!.getThumbnailUrl(asset.id);
+    return ServiceLocator.instance.immichService!.getThumbnailUrl(asset.id);
   }
 
   @override
@@ -305,7 +300,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
     // Use FutureBuilder to fetch image bytes via ImmichService with proper auth
     return FutureBuilder<Uint8List?>(
       future:
-          widget.immichService?.fetchImageBytes(asset.id, isThumbnail: true),
+          ServiceLocator.instance.immichService?.fetchImageBytes(asset.id, isThumbnail: true),
       builder: (context, snapshot) {
         if (snapshot.connectionState == ConnectionState.waiting) {
           return const Center(
@@ -350,7 +345,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
             ),
             Expanded(
               child: FutureBuilder<Uint8List?>(
-                future: widget.immichService
+                future: ServiceLocator.instance.immichService
                     ?.fetchImageBytes(asset.id, isThumbnail: false),
                 builder: (context, snapshot) {
                   if (snapshot.connectionState == ConnectionState.waiting) {
@@ -405,7 +400,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
   /// Tests the connection to Immich server by calling /api/server/about.
   Future<void> _testServerConnection() async {
-    if (widget.immichService == null) {
+    if (ServiceLocator.instance.immichService == null) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
           const SnackBar(
@@ -426,7 +421,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
     );
 
     try {
-      final serverInfo = await widget.immichService!.getServerInfo();
+      final serverInfo = await ServiceLocator.instance.immichService!.getServerInfo();
 
       if (!mounted) return;
 
@@ -493,7 +488,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
   }
 
   Future<void> _deleteSelectedAssets() async {
-    if (_selectedAssetIds.isEmpty || widget.immichService == null) {
+    if (_selectedAssetIds.isEmpty || ServiceLocator.instance.immichService == null) {
       return;
     }
 
@@ -527,7 +522,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
     try {
       final assetIdsToDelete = _selectedAssetIds.toList();
-      await widget.immichService!.deleteAssets(assetIdsToDelete);
+      await ServiceLocator.instance.immichService!.deleteAssets(assetIdsToDelete);
 
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
@@ -585,7 +580,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
   /// Opens image picker and uploads selected images to Immich.
   Future<void> _pickAndUploadImages() async {
-    if (widget.immichService == null) {
+    if (ServiceLocator.instance.immichService == null) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
           const SnackBar(
@@ -644,8 +639,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
         }
       } catch (pickError, stackTrace) {
         // Handle image picker specific errors
-        debugPrint('Image picker error: $pickError');
+        Logger.error('Image picker error: $pickError', pickError, stackTrace);
-        debugPrint('Stack trace: $stackTrace');
 
         if (mounted) {
           String errorMessage = 'Failed to open gallery';
@@ -732,13 +726,12 @@ class _ImmichScreenState extends State<ImmichScreen> {
       for (final pickedFile in pickedFiles) {
         try {
           final file = File(pickedFile.path);
-          debugPrint('Uploading file: ${pickedFile.name}');
+          Logger.debug('Uploading file: ${pickedFile.name}');
-          final uploadResponse = await widget.immichService!.uploadImage(file);
+          final uploadResponse = await ServiceLocator.instance.immichService!.uploadImage(file);
-          debugPrint('Upload successful for ${pickedFile.name}: ${uploadResponse.id}');
+          Logger.info('Upload successful for ${pickedFile.name}: ${uploadResponse.id}');
           successCount++;
         } catch (e, stackTrace) {
-          debugPrint('Upload failed for ${pickedFile.name}: $e');
+          Logger.error('Upload failed for ${pickedFile.name}: $e', e, stackTrace);
-          debugPrint('Stack trace: $stackTrace');
           failureCount++;
           errors.add('${pickedFile.name}: ${e.toString()}');
         }
@@ -788,9 +781,9 @@ class _ImmichScreenState extends State<ImmichScreen> {
         }
 
         // Refresh the asset list
-        debugPrint('Refreshing asset list after upload');
+        Logger.debug('Refreshing asset list after upload');
         await _loadAssets(forceRefresh: true);
-        debugPrint('Asset list refreshed, current count: ${_assets.length}');
+        Logger.debug('Asset list refreshed, current count: ${_assets.length}');
       }
     } catch (e, stackTrace) {
       setState(() {
@@ -799,8 +792,7 @@ class _ImmichScreenState extends State<ImmichScreen> {
 
       if (mounted) {
         // Log the full error for debugging
-        debugPrint('Image picker error: $e');
+        Logger.error('Image picker error: $e', e, stackTrace);
-        debugPrint('Stack trace: $stackTrace');
 
         String errorMessage = 'Failed to pick images';
         if (e.toString().contains('Permission')) {

lib/ui/navigation/app_router.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import '../../core/service_locator.dart';
 import '../home/home_screen.dart';
 import '../immich/immich_screen.dart';
 import '../nostr_events/nostr_events_screen.dart';
@@ -6,11 +7,6 @@ import '../relay_management/relay_management_screen.dart';
 import '../relay_management/relay_management_controller.dart';
 import '../session/session_screen.dart';
 import '../settings/settings_screen.dart';
-import '../../data/nostr/nostr_service.dart';
-import '../../data/sync/sync_engine.dart';
-import '../../data/session/session_service.dart';
-import '../../data/local/local_storage_service.dart';
-import '../../data/firebase/firebase_service.dart';
 
 /// Route names for the app navigation.
 class AppRoutes {
@@ -86,31 +82,25 @@ class AppRouter {
     switch (settings.name) {
       case AppRoutes.home:
         return MaterialPageRoute(
-          builder: (_) => HomeScreen(
+          builder: (_) => const HomeScreen(),
-            localStorageService: localStorageService,
-          ),
           settings: settings,
         );
 
       case AppRoutes.immich:
         return MaterialPageRoute(
-          builder: (_) => ImmichScreen(
+          builder: (_) => const ImmichScreen(),
-            localStorageService: localStorageService,
-          ),
           settings: settings,
         );
 
       case AppRoutes.nostrEvents:
         return MaterialPageRoute(
-          builder: (_) => NostrEventsScreen(
+          builder: (_) => const NostrEventsScreen(),
-            nostrService: nostrService,
-            syncEngine: syncEngine,
-            sessionService: sessionService,
-          ),
           settings: settings,
         );
 
       case AppRoutes.relayManagement:
+        final nostrService = ServiceLocator.instance.nostrService;
+        final syncEngine = ServiceLocator.instance.syncEngine;
         if (nostrService == null || syncEngine == null) {
           return MaterialPageRoute(
             builder: (_) => _buildErrorScreen('Nostr service not available'),
@@ -120,8 +110,8 @@ class AppRouter {
         return MaterialPageRoute(
           builder: (_) => RelayManagementScreen(
             controller: RelayManagementController(
-              nostrService: nostrService!,
+              nostrService: nostrService,
-              syncEngine: syncEngine!,
+              syncEngine: syncEngine,
             ),
           ),
           settings: settings,
@@ -129,19 +119,13 @@ class AppRouter {
 
       case AppRoutes.session:
         return MaterialPageRoute(
-          builder: (_) => SessionScreen(
+          builder: (_) => const SessionScreen(),
-            sessionService: sessionService,
-            firebaseService: firebaseService,
-            nostrService: nostrService,
-          ),
           settings: settings,
         );
 
       case AppRoutes.settings:
         return MaterialPageRoute(
-          builder: (_) => SettingsScreen(
+          builder: (_) => const SettingsScreen(),
-            firebaseService: firebaseService,
-          ),
           settings: settings,
         );
 

lib/ui/navigation/main_navigation_scaffold.dart

@@ -4,31 +4,11 @@ import '../immich/immich_screen.dart';
 import '../nostr_events/nostr_events_screen.dart';
 import '../session/session_screen.dart';
 import '../settings/settings_screen.dart';
-import '../../data/session/session_service.dart';
+import '../../core/service_locator.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/immich/immich_service.dart';
 
 /// Main navigation scaffold with bottom navigation bar.
 class MainNavigationScaffold extends StatefulWidget {
-  final SessionService? sessionService;
+  const MainNavigationScaffold({super.key});
-  final LocalStorageService? localStorageService;
-  final NostrService? nostrService;
-  final SyncEngine? syncEngine;
-  final FirebaseService? firebaseService;
-  final ImmichService? immichService;
-
-  const MainNavigationScaffold({
-    super.key,
-    this.sessionService,
-    this.localStorageService,
-    this.nostrService,
-    this.syncEngine,
-    this.firebaseService,
-    this.immichService,
-  });
 
   @override
   State<MainNavigationScaffold> createState() => _MainNavigationScaffoldState();
@@ -43,7 +23,8 @@ class _MainNavigationScaffoldState extends State<MainNavigationScaffold> {
     setState(() {
       _currentIndex = index;
       // If accessing a protected route (Immich=1, Nostr=2) while not logged in, remember it
-      if ((index == 1 || index == 2) && !(widget.sessionService?.isLoggedIn ?? false)) {
+      final sessionService = ServiceLocator.instance.sessionService;
+      if ((index == 1 || index == 2) && !(sessionService?.isLoggedIn ?? false)) {
         _pendingProtectedRoute = index;
       } else {
         _pendingProtectedRoute = null;
@@ -57,7 +38,8 @@ class _MainNavigationScaffoldState extends State<MainNavigationScaffold> {
       _loginStateVersion++; // Force rebuild when login state changes
       
       // If user just logged in and was trying to access a protected route, navigate there
-      if (widget.sessionService?.isLoggedIn == true && _pendingProtectedRoute != null) {
+      final sessionService = ServiceLocator.instance.sessionService;
+      if (sessionService?.isLoggedIn == true && _pendingProtectedRoute != null) {
         _currentIndex = _pendingProtectedRoute!;
         _pendingProtectedRoute = null;
       }
@@ -65,43 +47,30 @@ class _MainNavigationScaffoldState extends State<MainNavigationScaffold> {
   }
 
   Widget _buildScreen(int index) {
+    final locator = ServiceLocator.instance;
+    final sessionService = locator.sessionService;
+    
     switch (index) {
       case 0:
-        return HomeScreen(
+        return const HomeScreen();
-          localStorageService: widget.localStorageService,
-        );
       case 1:
         // Check auth guard for Immich
-        if (!(widget.sessionService?.isLoggedIn ?? false)) {
+        if (!(sessionService?.isLoggedIn ?? false)) {
           return _buildLoginRequiredScreen();
         }
-        return ImmichScreen(
+        return const ImmichScreen();
-          localStorageService: widget.localStorageService,
-          immichService: widget.immichService,
-        );
       case 2:
         // Check auth guard for Nostr Events
-        if (!(widget.sessionService?.isLoggedIn ?? false)) {
+        if (!(sessionService?.isLoggedIn ?? false)) {
           return _buildLoginRequiredScreen();
         }
-        return NostrEventsScreen(
+        return const NostrEventsScreen();
-          nostrService: widget.nostrService,
-          syncEngine: widget.syncEngine,
-          sessionService: widget.sessionService,
-        );
       case 3:
         return SessionScreen(
-          sessionService: widget.sessionService,
-          firebaseService: widget.firebaseService,
-          nostrService: widget.nostrService,
           onSessionChanged: _onSessionStateChanged,
         );
       case 4:
-        return SettingsScreen(
+        return const SettingsScreen();
-          firebaseService: widget.firebaseService,
-          nostrService: widget.nostrService,
-          syncEngine: widget.syncEngine,
-        );
       default:
         return const SizedBox();
     }

lib/ui/nostr_events/nostr_events_screen.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import '../../core/service_locator.dart';
 import '../../data/nostr/nostr_service.dart';
 import '../../data/sync/sync_engine.dart';
 import '../../data/session/session_service.dart';
@@ -9,16 +10,7 @@ import '../relay_management/relay_management_controller.dart';
 
 /// Screen for displaying and testing Nostr events.
 class NostrEventsScreen extends StatefulWidget {
-  final NostrService? nostrService;
+  const NostrEventsScreen({super.key});
-  final SyncEngine? syncEngine;
-  final SessionService? sessionService;
-
-  const NostrEventsScreen({
-    super.key,
-    this.nostrService,
-    this.syncEngine,
-    this.sessionService,
-  });
 
   @override
   State<NostrEventsScreen> createState() => _NostrEventsScreenState();
@@ -29,7 +21,7 @@ class _NostrEventsScreenState extends State<NostrEventsScreen> {
   bool _isLoading = false;
 
   Future<void> _publishTestEvent() async {
-    if (widget.nostrService == null) {
+    if (ServiceLocator.instance.nostrService == null) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
           const SnackBar(
@@ -42,7 +34,7 @@ class _NostrEventsScreenState extends State<NostrEventsScreen> {
     }
 
     // Check if user is logged in with Nostr
-    final currentUser = widget.sessionService?.currentUser;
+    final currentUser = ServiceLocator.instance.sessionService?.currentUser;
     if (currentUser == null || currentUser.nostrPrivateKey == null) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
@@ -56,7 +48,7 @@ class _NostrEventsScreenState extends State<NostrEventsScreen> {
     }
 
     // Get relays
-    final relays = widget.nostrService!.getRelays();
+    final relays = ServiceLocator.instance.nostrService!.getRelays();
     if (relays.isEmpty) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
@@ -85,7 +77,7 @@ class _NostrEventsScreenState extends State<NostrEventsScreen> {
       );
 
       // Publish to all enabled relays
-      final results = await widget.nostrService!.publishEventToAllRelays(event);
+      final results = await ServiceLocator.instance.nostrService!.publishEventToAllRelays(event);
 
       setState(() {
         _isLoading = false;
@@ -169,13 +161,13 @@ class _NostrEventsScreenState extends State<NostrEventsScreen> {
             const SizedBox(height: 8),
             TextButton.icon(
               onPressed: () {
-                if (widget.nostrService != null && widget.syncEngine != null) {
+                if (ServiceLocator.instance.nostrService != null && ServiceLocator.instance.syncEngine != null) {
                   Navigator.of(context).push(
                     MaterialPageRoute(
                       builder: (_) => RelayManagementScreen(
                         controller: RelayManagementController(
-                          nostrService: widget.nostrService!,
+                          nostrService: ServiceLocator.instance.nostrService!,
-                          syncEngine: widget.syncEngine!,
+                          syncEngine: ServiceLocator.instance.syncEngine!,
                         ),
                       ),
                     ),

lib/ui/session/session_screen.dart

@@ -1,4 +1,6 @@
 import 'package:flutter/material.dart';
+import '../../core/logger.dart';
+import '../../core/service_locator.dart';
 import '../../data/session/session_service.dart';
 import '../../data/firebase/firebase_service.dart';
 import '../../data/nostr/nostr_service.dart';
@@ -6,16 +8,10 @@ import '../../data/nostr/models/nostr_keypair.dart';
 
 /// Screen for user session management (login/logout).
 class SessionScreen extends StatefulWidget {
-  final SessionService? sessionService;
-  final FirebaseService? firebaseService;
-  final NostrService? nostrService;
   final VoidCallback? onSessionChanged;
 
   const SessionScreen({
     super.key,
-    this.sessionService,
-    this.firebaseService,
-    this.nostrService,
     this.onSessionChanged,
   });
 
@@ -38,8 +34,8 @@ class _SessionScreenState extends State<SessionScreen> {
   void initState() {
     super.initState();
     // Check if Firebase Auth is available
-    _useFirebaseAuth = widget.firebaseService?.isEnabled == true &&
+    _useFirebaseAuth = ServiceLocator.instance.firebaseService?.isEnabled == true &&
-        widget.firebaseService?.config.authEnabled == true;
+        ServiceLocator.instance.firebaseService?.config.authEnabled == true;
   }
 
   @override
@@ -53,7 +49,7 @@ class _SessionScreenState extends State<SessionScreen> {
   }
 
   Future<void> _handleLogin() async {
-    if (widget.sessionService == null) return;
+    if (ServiceLocator.instance.sessionService == null) return;
 
     setState(() {
       _isLoading = true;
@@ -89,7 +85,7 @@ class _SessionScreenState extends State<SessionScreen> {
         }
 
         // Login with Nostr
-        await widget.sessionService!.loginWithNostr(nostrKey);
+        await ServiceLocator.instance.sessionService!.loginWithNostr(nostrKey);
 
         if (mounted) {
           ScaffoldMessenger.of(context).showSnackBar(
@@ -104,7 +100,7 @@ class _SessionScreenState extends State<SessionScreen> {
       }
 
       // Handle Firebase or regular login
-      if (_useFirebaseAuth && widget.firebaseService != null) {
+      if (_useFirebaseAuth && ServiceLocator.instance.firebaseService != null) {
         // Use Firebase Auth for authentication
         final email = _emailController.text.trim();
         final password = _passwordController.text.trim();
@@ -121,13 +117,13 @@ class _SessionScreenState extends State<SessionScreen> {
         }
 
         // Authenticate with Firebase
-        final firebaseUser = await widget.firebaseService!.loginWithEmailPassword(
+        final firebaseUser = await ServiceLocator.instance.firebaseService!.loginWithEmailPassword(
           email: email,
           password: password,
         );
 
         // Create session with Firebase user info
-        await widget.sessionService!.login(
+        await ServiceLocator.instance.sessionService!.login(
           id: firebaseUser.uid,
           username: firebaseUser.email?.split('@').first ?? firebaseUser.uid,
           token: await firebaseUser.getIdToken(),
@@ -183,7 +179,7 @@ class _SessionScreenState extends State<SessionScreen> {
         }
 
         // Create session (demo mode - no real authentication)
-        await widget.sessionService!.login(
+        await ServiceLocator.instance.sessionService!.login(
           id: userId,
           username: username,
         );
@@ -204,7 +200,7 @@ class _SessionScreenState extends State<SessionScreen> {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Text('Login failed: ${e.toString().replaceAll('FirebaseException: ', '').replaceAll('SessionException: ', '')}'),
+            content: Text('Login failed: ${e.toString().replaceAll('FirebaseServiceException: ', '').replaceAll('SessionException: ', '')}'),
             backgroundColor: Colors.red,
           ),
         );
@@ -219,7 +215,7 @@ class _SessionScreenState extends State<SessionScreen> {
   }
 
   Future<void> _handleLogout() async {
-    if (widget.sessionService == null) return;
+    if (ServiceLocator.instance.sessionService == null) return;
 
     setState(() {
       _isLoading = true;
@@ -227,15 +223,15 @@ class _SessionScreenState extends State<SessionScreen> {
 
     try {
       // Logout from session service first
-      await widget.sessionService!.logout();
+      await ServiceLocator.instance.sessionService!.logout();
 
       // Also logout from Firebase Auth if enabled
-      if (_useFirebaseAuth && widget.firebaseService != null) {
+      if (_useFirebaseAuth && ServiceLocator.instance.firebaseService != null) {
         try {
-          await widget.firebaseService!.logout();
+          await ServiceLocator.instance.firebaseService!.logout();
         } catch (e) {
           // Log error but don't fail logout - session is already cleared
-          debugPrint('Warning: Firebase logout failed: $e');
+          Logger.warning('Firebase logout failed: $e');
         }
       }
 
@@ -268,10 +264,10 @@ class _SessionScreenState extends State<SessionScreen> {
   }
 
   Future<void> _handleRefresh() async {
-    if (widget.sessionService == null) return;
+    if (ServiceLocator.instance.sessionService == null) return;
 
     try {
-      await widget.sessionService!.refreshNostrProfile();
+      await ServiceLocator.instance.sessionService!.refreshNostrProfile();
       if (mounted) {
         setState(() {});
         ScaffoldMessenger.of(context).showSnackBar(
@@ -296,8 +292,8 @@ class _SessionScreenState extends State<SessionScreen> {
 
   @override
   Widget build(BuildContext context) {
-    final isLoggedIn = widget.sessionService?.isLoggedIn ?? false;
+    final isLoggedIn = ServiceLocator.instance.sessionService?.isLoggedIn ?? false;
-    final currentUser = widget.sessionService?.currentUser;
+    final currentUser = ServiceLocator.instance.sessionService?.currentUser;
 
     return Scaffold(
       appBar: AppBar(
@@ -389,7 +385,7 @@ class _SessionScreenState extends State<SessionScreen> {
                               _Nip05Section(
                                 nip05: currentUser.nostrProfile!.nip05!,
                                 publicKey: currentUser.id,
-                                nostrService: widget.nostrService,
+                                nostrService: ServiceLocator.instance.nostrService,
                               ),
                             if (currentUser.nostrProfile?.nip05 != null &&
                                 currentUser.nostrProfile!.nip05!.isNotEmpty)
@@ -476,7 +472,7 @@ class _SessionScreenState extends State<SessionScreen> {
                     const SizedBox(height: 24),
                     if (_useNostrLogin) ...[
                       // Key pair generation section
-                      if (widget.nostrService != null) ...[
+                      if (ServiceLocator.instance.nostrService != null) ...[
                         Card(
                           child: Padding(
                             padding: const EdgeInsets.all(16),
@@ -496,7 +492,7 @@ class _SessionScreenState extends State<SessionScreen> {
                                     ElevatedButton.icon(
                                       onPressed: () {
                                         setState(() {
-                                          _generatedKeyPair = widget.nostrService!.generateKeyPair();
+                                          _generatedKeyPair = ServiceLocator.instance.nostrService!.generateKeyPair();
                                         });
                                       },
                                       icon: const Icon(Icons.refresh, size: 18),
@@ -691,7 +687,7 @@ class _Nip05SectionState extends State<_Nip05Section> {
   }
 
   Future<void> _loadPreferredRelays() async {
-    if (widget.nostrService == null) {
+    if (ServiceLocator.instance.nostrService == null) {
       setState(() {
         _error = 'Nostr service not available';
       });
@@ -704,7 +700,7 @@ class _Nip05SectionState extends State<_Nip05Section> {
     });
 
     try {
-      final relays = await widget.nostrService!.fetchPreferredRelaysFromNip05(
+      final relays = await ServiceLocator.instance.nostrService!.fetchPreferredRelaysFromNip05(
         widget.nip05,
         widget.publicKey,
       );

lib/ui/settings/settings_screen.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import '../../core/service_locator.dart';
 import '../../data/firebase/firebase_service.dart';
 import '../../data/nostr/nostr_service.dart';
 import '../../data/sync/sync_engine.dart';
@@ -7,16 +8,7 @@ import '../relay_management/relay_management_controller.dart';
 
 /// Settings screen (placeholder).
 class SettingsScreen extends StatelessWidget {
-  final FirebaseService? firebaseService;
+  const SettingsScreen({super.key});
-  final NostrService? nostrService;
-  final SyncEngine? syncEngine;
-
-  const SettingsScreen({
-    super.key,
-    this.firebaseService,
-    this.nostrService,
-    this.syncEngine,
-  });
 
   @override
   Widget build(BuildContext context) {
@@ -26,38 +18,56 @@ class SettingsScreen extends StatelessWidget {
       ),
       body: ListView(
         children: [
-          if (firebaseService != null)
+          Builder(
-            SwitchListTile(
+            builder: (context) {
-              title: const Text('Firebase Enabled'),
+              final firebaseService = ServiceLocator.instance.firebaseService;
-              subtitle: Text(
+              if (firebaseService != null) {
-                firebaseService!.isEnabled
+                return SwitchListTile(
-                    ? 'Firebase services are active'
+                  title: const Text('Firebase Enabled'),
-                    : 'Firebase services are disabled',
+                  subtitle: Text(
-              ),
+                    firebaseService.isEnabled
-              value: firebaseService!.isEnabled,
+                        ? 'Firebase services are active'
-              onChanged: null, // Read-only for now
+                        : 'Firebase services are disabled',
-            ),
-          if (nostrService != null && syncEngine != null) ...[
-            const Divider(),
-            ListTile(
-              leading: const Icon(Icons.cloud),
-              title: const Text('Relay Management'),
-              subtitle: const Text('Manage Nostr relays'),
-              trailing: const Icon(Icons.chevron_right),
-              onTap: () {
-                Navigator.of(context).push(
-                  MaterialPageRoute(
-                    builder: (_) => RelayManagementScreen(
-                      controller: RelayManagementController(
-                        nostrService: nostrService!,
-                        syncEngine: syncEngine!,
-                      ),
-                    ),
                   ),
+                  value: firebaseService.isEnabled,
+                  onChanged: null, // Read-only for now
                 );
-              },
+              }
-            ),
+              return const SizedBox.shrink();
-          ],
+            },
+          ),
+          Builder(
+            builder: (context) {
+              final nostrService = ServiceLocator.instance.nostrService;
+              final syncEngine = ServiceLocator.instance.syncEngine;
+              if (nostrService != null && syncEngine != null) {
+                return Column(
+                  children: [
+                    const Divider(),
+                    ListTile(
+                      leading: const Icon(Icons.cloud),
+                      title: const Text('Relay Management'),
+                      subtitle: const Text('Manage Nostr relays'),
+                      trailing: const Icon(Icons.chevron_right),
+                      onTap: () {
+                        Navigator.of(context).push(
+                          MaterialPageRoute(
+                            builder: (_) => RelayManagementScreen(
+                              controller: RelayManagementController(
+                                nostrService: nostrService,
+                                syncEngine: syncEngine,
+                              ),
+                            ),
+                          ),
+                        );
+                      },
+                    ),
+                  ],
+                );
+              }
+              return const SizedBox.shrink();
+            },
+          ),
           const Divider(),
           const ListTile(
             leading: Icon(Icons.info_outline),

test/config/config_loader_test.dart

@@ -1,4 +1,5 @@
 import 'package:flutter_test/flutter_test.dart';
+import 'package:app_boilerplate/core/exceptions/invalid_environment_exception.dart';
 import 'package:app_boilerplate/config/config_loader.dart';
 
 void main() {

test/data/firebase/firebase_service_test.dart

@@ -1,6 +1,7 @@
 import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/annotations.dart';
+import 'package:app_boilerplate/core/exceptions/firebase_exception.dart' show FirebaseServiceException;
 import 'package:app_boilerplate/data/firebase/firebase_service.dart';
 import 'package:app_boilerplate/data/firebase/models/firebase_config.dart';
 import 'package:app_boilerplate/data/local/local_storage_service.dart';
@@ -81,7 +82,7 @@ void main() {
       // but that's expected - Firebase requires actual project setup
       expect(
         () => service.initialize(),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
   });
@@ -102,7 +103,7 @@ void main() {
           email: '[email protected]',
           password: 'password123',
         ),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -118,7 +119,7 @@ void main() {
           email: '[email protected]',
           password: 'password123',
         ),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -134,7 +135,7 @@ void main() {
 
       expect(
         () => service.logout(),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
   });
@@ -152,7 +153,7 @@ void main() {
 
       expect(
         () => service.syncItemsToFirestore('user1'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -165,7 +166,7 @@ void main() {
 
       expect(
         () => service.syncItemsToFirestore('user1'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -181,7 +182,7 @@ void main() {
 
       expect(
         () => service.syncItemsFromFirestore('user1'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -194,7 +195,7 @@ void main() {
 
       expect(
         () => service.syncItemsFromFirestore('user1'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
   });
@@ -215,7 +216,7 @@ void main() {
 
       expect(
         () => service.uploadFile(testFile, 'test/path.txt'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
 
@@ -231,7 +232,7 @@ void main() {
 
       expect(
         () => service.uploadFile(testFile, 'test/path.txt'),
-        throwsA(isA<FirebaseException>()),
+        throwsA(isA<FirebaseServiceException>()),
       );
     });
   });

test/data/immich/immich_service_test.dart

@@ -1,6 +1,7 @@
 import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:dio/dio.dart';
+import 'package:app_boilerplate/core/exceptions/immich_exception.dart';
 import 'package:app_boilerplate/data/immich/immich_service.dart';
 import 'package:app_boilerplate/data/immich/models/immich_asset.dart';
 import 'package:app_boilerplate/data/local/local_storage_service.dart';

test/data/nostr/nostr_service_test.dart

@@ -1,4 +1,5 @@
 import 'package:flutter_test/flutter_test.dart';
+import 'package:app_boilerplate/core/exceptions/nostr_exception.dart';
 import 'package:app_boilerplate/data/nostr/nostr_service.dart';
 import 'package:app_boilerplate/data/nostr/models/nostr_keypair.dart';
 import 'package:app_boilerplate/data/nostr/models/nostr_event.dart';

test/data/session/session_service_test.dart

@@ -2,6 +2,7 @@ import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:path/path.dart' as path;
 import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import 'package:app_boilerplate/core/exceptions/session_exception.dart';
 import 'package:app_boilerplate/data/session/session_service.dart';
 import 'package:app_boilerplate/data/local/local_storage_service.dart';
 import 'package:app_boilerplate/data/local/models/item.dart';

test/data/sync/sync_engine_test.dart

@@ -1,5 +1,6 @@
 import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:app_boilerplate/core/exceptions/sync_exception.dart';
 import 'package:app_boilerplate/data/sync/sync_engine.dart';
 import 'package:app_boilerplate/data/sync/models/sync_status.dart';
 import 'package:app_boilerplate/data/sync/models/sync_operation.dart';

test/ui/navigation/main_navigation_scaffold_test.dart

@@ -9,6 +9,7 @@ import 'package:app_boilerplate/data/nostr/models/nostr_keypair.dart';
 import 'package:app_boilerplate/data/sync/sync_engine.dart';
 import 'package:app_boilerplate/data/session/session_service.dart';
 import 'package:app_boilerplate/data/firebase/firebase_service.dart';
+import 'package:app_boilerplate/core/service_locator.dart';
 
 import 'main_navigation_scaffold_test.mocks.dart';
 
@@ -42,17 +43,25 @@ void main() {
     // Stub NostrService methods that might be called by UI
     final mockKeyPair = NostrKeyPair.generate();
     when(mockNostrService.generateKeyPair()).thenReturn(mockKeyPair);
+    
+    // Register services with ServiceLocator
+    ServiceLocator.instance.registerServices(
+      localStorageService: mockLocalStorageService,
+      nostrService: mockNostrService,
+      syncEngine: mockSyncEngine,
+      sessionService: mockSessionService,
+      firebaseService: mockFirebaseService,
+    );
+  });
+
+  tearDown(() {
+    // Reset ServiceLocator after each test
+    ServiceLocator.instance.reset();
   });
 
   Widget createTestWidget() {
     return MaterialApp(
-      home: MainNavigationScaffold(
+      home: const MainNavigationScaffold(),
-        sessionService: mockSessionService,
-        localStorageService: mockLocalStorageService,
-        nostrService: mockNostrService,
-        syncEngine: mockSyncEngine,
-        firebaseService: mockFirebaseService,
-      ),
     );
   }