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lib/core/di/ARCHITECTURE.md

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+# Dependency Injection Architecture
+
+## Provider Dependency Graph
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│                         PRESENTATION LAYER                          │
+│                         (UI State Management)                        │
+└─────────────────────────────────────────────────────────────────────┘
+                                    │
+                                    │ depends on
+                                    ▼
+┌─────────────────────────────────────────────────────────────────────┐
+│                          DOMAIN LAYER                                │
+│                        (Business Logic)                              │
+└─────────────────────────────────────────────────────────────────────┘
+                                    │
+                                    │ depends on
+                                    ▼
+┌─────────────────────────────────────────────────────────────────────┐
+│                          DATA LAYER                                  │
+│                   (Repositories & Data Sources)                      │
+└─────────────────────────────────────────────────────────────────────┘
+                                    │
+                                    │ depends on
+                                    ▼
+┌─────────────────────────────────────────────────────────────────────┐
+│                          CORE LAYER                                  │
+│                    (Infrastructure Services)                         │
+└─────────────────────────────────────────────────────────────────────┘
+```
+
+## Complete Provider Dependency Tree
+
+### Authentication Feature
+
+```
+secureStorageProvider (Core - Singleton)
+          │
+          ├──> apiClientProvider (Core - Singleton)
+          │             │
+          │             └──> authRemoteDataSourceProvider
+          │                             │
+          └─────────────────────────────┴──> authRepositoryProvider
+                                                      │
+                       ┌──────────────────────────────┼────────────────────────────┐
+                       │                              │                            │
+             loginUseCaseProvider          logoutUseCaseProvider      checkAuthStatusUseCaseProvider
+                       │                              │                            │
+                       └──────────────────────────────┴────────────────────────────┘
+                                                      │
+                                              authProvider (StateNotifier)
+                                                      │
+                       ┌──────────────────────────────┼────────────────────────────┐
+                       │                              │                            │
+           isAuthenticatedProvider          currentUserProvider          authErrorProvider
+```
+
+### Warehouse Feature
+
+```
+apiClientProvider (Core - Singleton)
+          │
+          └──> warehouseRemoteDataSourceProvider
+                          │
+                          └──> warehouseRepositoryProvider
+                                          │
+                                          └──> getWarehousesUseCaseProvider
+                                                          │
+                                                          └──> warehouseProvider (StateNotifier)
+                                                                          │
+                               ┌──────────────────────────────────────────┼────────────────────────────────┐
+                               │                                          │                                │
+                   warehousesListProvider                  selectedWarehouseProvider          isWarehouseLoadingProvider
+```
+
+### Products Feature
+
+```
+apiClientProvider (Core - Singleton)
+          │
+          └──> productsRemoteDataSourceProvider
+                          │
+                          └──> productsRepositoryProvider
+                                          │
+                                          └──> getProductsUseCaseProvider
+                                                          │
+                                                          └──> productsProvider (StateNotifier)
+                                                                          │
+                               ┌──────────────────────────────────────────┼────────────────────────────────┐
+                               │                                          │                                │
+                   productsListProvider                      operationTypeProvider              isProductsLoadingProvider
+```
+
+## Layer-by-Layer Architecture
+
+### 1. Core Layer (Infrastructure)
+
+**Purpose**: Provide foundational services that all features depend on
+
+**Providers**:
+- `secureStorageProvider` - Manages encrypted storage
+- `apiClientProvider` - HTTP client with auth interceptors
+
+**Characteristics**:
+- Singleton instances
+- No business logic
+- Pure infrastructure
+- Used by all features
+
+**Example**:
+```dart
+final secureStorageProvider = Provider<SecureStorage>((ref) {
+  return SecureStorage();
+});
+
+final apiClientProvider = Provider<ApiClient>((ref) {
+  final secureStorage = ref.watch(secureStorageProvider);
+  return ApiClient(secureStorage);
+});
+```
+
+### 2. Data Layer
+
+**Purpose**: Handle data operations - API calls, local storage, caching
+
+**Components**:
+- **Remote Data Sources**: Make API calls
+- **Repositories**: Coordinate data sources, convert models to entities
+
+**Providers**:
+- `xxxRemoteDataSourceProvider` - API client wrappers
+- `xxxRepositoryProvider` - Repository implementations
+
+**Characteristics**:
+- Depends on Core layer
+- Implements Domain interfaces
+- Handles data transformation
+- Manages errors (exceptions → failures)
+
+**Example**:
+```dart
+// Data Source
+final authRemoteDataSourceProvider = Provider<AuthRemoteDataSource>((ref) {
+  final apiClient = ref.watch(apiClientProvider);
+  return AuthRemoteDataSourceImpl(apiClient);
+});
+
+// Repository
+final authRepositoryProvider = Provider<AuthRepository>((ref) {
+  final remoteDataSource = ref.watch(authRemoteDataSourceProvider);
+  final secureStorage = ref.watch(secureStorageProvider);
+  return AuthRepositoryImpl(
+    remoteDataSource: remoteDataSource,
+    secureStorage: secureStorage,
+  );
+});
+```
+
+### 3. Domain Layer (Business Logic)
+
+**Purpose**: Encapsulate business rules and use cases
+
+**Components**:
+- **Entities**: Pure business objects
+- **Repository Interfaces**: Define data contracts
+- **Use Cases**: Single-purpose business operations
+
+**Providers**:
+- `xxxUseCaseProvider` - Business logic encapsulation
+
+**Characteristics**:
+- No external dependencies (pure Dart)
+- Depends only on abstractions
+- Contains business rules
+- Reusable across features
+- Testable in isolation
+
+**Example**:
+```dart
+final loginUseCaseProvider = Provider<LoginUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return LoginUseCase(repository);
+});
+
+final getWarehousesUseCaseProvider = Provider<GetWarehousesUseCase>((ref) {
+  final repository = ref.watch(warehouseRepositoryProvider);
+  return GetWarehousesUseCase(repository);
+});
+```
+
+### 4. Presentation Layer (UI State)
+
+**Purpose**: Manage UI state and handle user interactions
+
+**Components**:
+- **State Classes**: Immutable state containers
+- **State Notifiers**: Mutable state managers
+- **Derived Providers**: Computed state values
+
+**Providers**:
+- `xxxProvider` (StateNotifier) - Main state management
+- `isXxxLoadingProvider` - Loading state
+- `xxxErrorProvider` - Error state
+- `xxxListProvider` - Data lists
+
+**Characteristics**:
+- Depends on Domain layer
+- Manages UI state
+- Handles user actions
+- Notifies UI of changes
+- Can depend on multiple use cases
+
+**Example**:
+```dart
+// Main state notifier
+final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
+  final loginUseCase = ref.watch(loginUseCaseProvider);
+  final logoutUseCase = ref.watch(logoutUseCaseProvider);
+  final checkAuthStatusUseCase = ref.watch(checkAuthStatusUseCaseProvider);
+  final getCurrentUserUseCase = ref.watch(getCurrentUserUseCaseProvider);
+
+  return AuthNotifier(
+    loginUseCase: loginUseCase,
+    logoutUseCase: logoutUseCase,
+    checkAuthStatusUseCase: checkAuthStatusUseCase,
+    getCurrentUserUseCase: getCurrentUserUseCase,
+  );
+});
+
+// Derived providers
+final isAuthenticatedProvider = Provider<bool>((ref) {
+  final authState = ref.watch(authProvider);
+  return authState.isAuthenticated;
+});
+```
+
+## Data Flow Patterns
+
+### 1. User Action Flow (Write Operation)
+
+```
+┌──────────────┐
+│   UI Widget  │
+└──────┬───────┘
+       │ User taps button
+       ▼
+┌──────────────────────┐
+│  ref.read(provider   │
+│    .notifier)        │
+│    .someMethod()     │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  StateNotifier       │
+│  - Set loading state │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  Use Case            │
+│  - Validate input    │
+│  - Business logic    │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  Repository          │
+│  - Coordinate data   │
+│  - Error handling    │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  Data Source         │
+│  - API call          │
+│  - Parse response    │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  API Client          │
+│  - HTTP request      │
+│  - Add auth token    │
+└──────┬───────────────┘
+       │
+       │ Response ←─────
+       ▼
+┌──────────────────────┐
+│  StateNotifier       │
+│  - Update state      │
+│  - Notify listeners  │
+└──────┬───────────────┘
+       │
+       ▼
+┌──────────────────────┐
+│  UI Widget           │
+│  - Rebuild with      │
+│    new state         │
+└──────────────────────┘
+```
+
+### 2. State Observation Flow (Read Operation)
+
+```
+┌──────────────────────┐
+│  UI Widget           │
+│  ref.watch(provider) │
+└──────┬───────────────┘
+       │ Subscribes to
+       ▼
+┌──────────────────────┐
+│  StateNotifier       │
+│  Current State       │
+└──────┬───────────────┘
+       │ State changes
+       ▼
+┌──────────────────────┐
+│  UI Widget           │
+│  Automatically       │
+│  rebuilds            │
+└──────────────────────┘
+```
+
+## Provider Types Usage
+
+### Provider (Immutable Services)
+
+**Use for**: Services, repositories, use cases, utilities
+
+```dart
+final myServiceProvider = Provider<MyService>((ref) {
+  final dependency = ref.watch(dependencyProvider);
+  return MyService(dependency);
+});
+```
+
+**Lifecycle**: Created once, lives forever (unless autoDispose)
+
+### StateNotifierProvider (Mutable State)
+
+**Use for**: Managing feature state that changes over time
+
+```dart
+final myStateProvider = StateNotifierProvider<MyNotifier, MyState>((ref) {
+  final useCase = ref.watch(useCaseProvider);
+  return MyNotifier(useCase);
+});
+```
+
+**Lifecycle**: Created on first access, disposed when no longer used
+
+### Derived Providers (Computed Values)
+
+**Use for**: Computed values from other providers
+
+```dart
+final derivedProvider = Provider<DerivedData>((ref) {
+  final state = ref.watch(stateProvider);
+  return computeValue(state);
+});
+```
+
+**Lifecycle**: Recomputed when dependencies change
+
+## Best Practices by Layer
+
+### Core Layer
+✅ Keep providers pure and stateless
+✅ Use singleton pattern
+✅ No business logic
+❌ Don't depend on feature providers
+❌ Don't manage mutable state
+
+### Data Layer
+✅ Implement domain interfaces
+✅ Convert models ↔ entities
+✅ Handle all exceptions
+✅ Use Either<Failure, T> return type
+❌ Don't expose models to domain
+❌ Don't contain business logic
+
+### Domain Layer
+✅ Pure Dart (no Flutter dependencies)
+✅ Single responsibility per use case
+✅ Validate input
+✅ Return Either<Failure, T>
+❌ Don't know about UI
+❌ Don't know about data sources
+
+### Presentation Layer
+✅ Manage UI-specific state
+✅ Call multiple use cases if needed
+✅ Transform data for display
+✅ Handle navigation logic
+❌ Don't access data sources directly
+❌ Don't perform business logic
+
+## Testing Strategy
+
+### Unit Testing
+
+**Core Layer**: Test utilities and services
+```dart
+test('SecureStorage saves token', () async {
+  final storage = SecureStorage();
+  await storage.saveAccessToken('token');
+  expect(await storage.getAccessToken(), 'token');
+});
+```
+
+**Domain Layer**: Test use cases with mock repositories
+```dart
+test('LoginUseCase returns user on success', () async {
+  final mockRepo = MockAuthRepository();
+  when(mockRepo.login(any)).thenAnswer((_) async => Right(mockUser));
+
+  final useCase = LoginUseCase(mockRepo);
+  final result = await useCase(loginRequest);
+
+  expect(result.isRight(), true);
+});
+```
+
+**Presentation Layer**: Test state notifiers
+```dart
+test('AuthNotifier sets authenticated on login', () async {
+  final container = ProviderContainer(
+    overrides: [
+      loginUseCaseProvider.overrideWithValue(mockLoginUseCase),
+    ],
+  );
+
+  await container.read(authProvider.notifier).login('user', 'pass');
+
+  expect(container.read(isAuthenticatedProvider), true);
+});
+```
+
+### Widget Testing
+
+```dart
+testWidgets('Login page shows error on failure', (tester) async {
+  await tester.pumpWidget(
+    ProviderScope(
+      overrides: [
+        authRepositoryProvider.overrideWithValue(mockAuthRepository),
+      ],
+      child: MaterialApp(home: LoginPage()),
+    ),
+  );
+
+  // Interact with widget
+  await tester.tap(find.text('Login'));
+  await tester.pump();
+
+  // Verify error is shown
+  expect(find.text('Invalid credentials'), findsOneWidget);
+});
+```
+
+## Performance Optimization
+
+### 1. Use Derived Providers
+Instead of computing in build():
+```dart
+// ❌ Bad - computes every rebuild
+@override
+Widget build(BuildContext context, WidgetRef ref) {
+  final warehouses = ref.watch(warehousesListProvider);
+  final ngWarehouses = warehouses.where((w) => w.isNGWareHouse).toList();
+  return ListView(...);
+}
+
+// ✅ Good - computed once per state change
+final ngWarehousesProvider = Provider<List<WarehouseEntity>>((ref) {
+  final warehouses = ref.watch(warehousesListProvider);
+  return warehouses.where((w) => w.isNGWareHouse).toList();
+});
+
+@override
+Widget build(BuildContext context, WidgetRef ref) {
+  final ngWarehouses = ref.watch(ngWarehousesProvider);
+  return ListView(...);
+}
+```
+
+### 2. Use select() for Partial State
+```dart
+// ❌ Bad - rebuilds on any state change
+final authState = ref.watch(authProvider);
+final isLoading = authState.isLoading;
+
+// ✅ Good - rebuilds only when isLoading changes
+final isLoading = ref.watch(authProvider.select((s) => s.isLoading));
+```
+
+### 3. Use autoDispose for Temporary Providers
+```dart
+final temporaryProvider = Provider.autoDispose<MyService>((ref) {
+  final service = MyService();
+
+  ref.onDispose(() {
+    service.dispose();
+  });
+
+  return service;
+});
+```
+
+## Common Patterns
+
+### Pattern: Feature Initialization
+```dart
+@override
+void initState() {
+  super.initState();
+  Future.microtask(() {
+    ref.read(warehouseProvider.notifier).loadWarehouses();
+  });
+}
+```
+
+### Pattern: Conditional Navigation
+```dart
+ref.listen<AuthState>(authProvider, (previous, next) {
+  if (next.isAuthenticated && !(previous?.isAuthenticated ?? false)) {
+    Navigator.pushReplacementNamed(context, '/home');
+  }
+});
+```
+
+### Pattern: Error Handling
+```dart
+ref.listen<String?>(authErrorProvider, (previous, next) {
+  if (next != null) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(content: Text(next)),
+    );
+  }
+});
+```
+
+### Pattern: Pull-to-Refresh
+```dart
+RefreshIndicator(
+  onRefresh: () async {
+    await ref.read(warehouseProvider.notifier).refresh();
+  },
+  child: ListView(...),
+)
+```
+
+## Dependency Injection Benefits
+
+1. **Testability**: Easy to mock dependencies
+2. **Maintainability**: Clear dependency tree
+3. **Scalability**: Add features without touching existing code
+4. **Flexibility**: Swap implementations easily
+5. **Readability**: Explicit dependencies
+6. **Type Safety**: Compile-time checks
+7. **Hot Reload**: Works seamlessly with Flutter
+8. **DevTools**: Inspect state in real-time
+
+## Summary
+
+This DI architecture provides:
+- Clear separation of concerns
+- Predictable data flow
+- Easy testing at all levels
+- Type-safe dependency injection
+- Reactive state management
+- Scalable feature structure
+
+For more details, see:
+- [README.md](./README.md) - Comprehensive guide
+- [QUICK_REFERENCE.md](./QUICK_REFERENCE.md) - Quick lookup

lib/core/di/INDEX.md

@@ -0,0 +1,253 @@
+# Dependency Injection Documentation Index
+
+This directory contains the complete Riverpod dependency injection setup for the warehouse management application.
+
+## File Overview
+
+### 📄 `providers.dart` (18 KB)
+**Main dependency injection setup file**
+
+Contains all Riverpod providers organized by feature:
+- Core Providers (SecureStorage, ApiClient)
+- Auth Feature Providers
+- Warehouse Feature Providers  
+- Products Feature Providers
+- Usage examples embedded in comments
+
+**Use this file**: Import in your app to access all providers
+```dart
+import 'package:minhthu/core/di/providers.dart';
+```
+
+---
+
+### 📖 `README.md` (13 KB)
+**Comprehensive setup and usage guide**
+
+Topics covered:
+- Architecture overview
+- Provider categories explanation
+- Basic setup instructions
+- Common usage patterns
+- Feature implementation examples
+- Advanced usage patterns
+- Best practices
+- Debugging tips
+- Testing strategies
+
+**Use this guide**: For understanding the overall DI architecture and learning how to use providers
+
+---
+
+### 📋 `QUICK_REFERENCE.md` (12 KB)
+**Quick lookup for common operations**
+
+Contains:
+- Essential provider code snippets
+- Widget setup patterns
+- Common patterns for auth, warehouse, products
+- Key methods by feature
+- Provider types explanation
+- Cheat sheet table
+- Complete example flows
+- Troubleshooting tips
+
+**Use this guide**: When you need quick code examples or forgot syntax
+
+---
+
+### 🏗️ `ARCHITECTURE.md` (19 KB)
+**Detailed architecture documentation**
+
+Includes:
+- Visual dependency graphs
+- Layer-by-layer breakdown
+- Data flow diagrams
+- Provider types deep dive
+- Best practices by layer
+- Testing strategies
+- Performance optimization
+- Common patterns
+- Architecture benefits summary
+
+**Use this guide**: For understanding the design decisions and architecture patterns
+
+---
+
+### 🔄 `MIGRATION_GUIDE.md` (11 KB)
+**Guide for migrating from other DI solutions**
+
+Covers:
+- GetIt to Riverpod migration
+- Key differences comparison
+- Step-by-step migration process
+- Common patterns migration
+- Testing migration
+- State management migration
+- Benefits of migration
+- Common pitfalls and solutions
+- Incremental migration strategy
+
+**Use this guide**: If migrating from GetIt or other DI solutions
+
+---
+
+## Quick Start
+
+### 1. Setup App
+```dart
+void main() {
+  runApp(
+    const ProviderScope(
+      child: MyApp(),
+    ),
+  );
+}
+```
+
+### 2. Use in Widgets
+```dart
+class MyPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final isAuth = ref.watch(isAuthenticatedProvider);
+    return Container();
+  }
+}
+```
+
+### 3. Access Providers
+```dart
+// Watch (reactive)
+final data = ref.watch(someProvider);
+
+// Read (one-time)
+final data = ref.read(someProvider);
+
+// Call method
+ref.read(authProvider.notifier).login(user, pass);
+```
+
+## Documentation Roadmap
+
+### For New Developers
+1. Start with [README.md](./README.md) - Understand the basics
+2. Try examples in [QUICK_REFERENCE.md](./QUICK_REFERENCE.md)
+3. Study [ARCHITECTURE.md](./ARCHITECTURE.md) - Understand design
+4. Keep [QUICK_REFERENCE.md](./QUICK_REFERENCE.md) handy for coding
+
+### For Team Leads
+1. Review [ARCHITECTURE.md](./ARCHITECTURE.md) - Architecture decisions
+2. Share [README.md](./README.md) with team
+3. Use [QUICK_REFERENCE.md](./QUICK_REFERENCE.md) for code reviews
+4. Reference [MIGRATION_GUIDE.md](./MIGRATION_GUIDE.md) if changing DI
+
+### For Testing
+1. Check testing sections in [README.md](./README.md)
+2. Review testing strategy in [ARCHITECTURE.md](./ARCHITECTURE.md)
+3. See test examples in [MIGRATION_GUIDE.md](./MIGRATION_GUIDE.md)
+
+## All Available Providers
+
+### Core Infrastructure
+- `secureStorageProvider` - Secure storage singleton
+- `apiClientProvider` - HTTP client with auth
+
+### Authentication
+- `authProvider` - Main auth state
+- `isAuthenticatedProvider` - Auth status boolean
+- `currentUserProvider` - Current user data
+- `isAuthLoadingProvider` - Loading state
+- `authErrorProvider` - Error message
+- `loginUseCaseProvider` - Login business logic
+- `logoutUseCaseProvider` - Logout business logic
+- `checkAuthStatusUseCaseProvider` - Check auth status
+- `getCurrentUserUseCaseProvider` - Get current user
+
+### Warehouse
+- `warehouseProvider` - Main warehouse state
+- `warehousesListProvider` - List of warehouses
+- `selectedWarehouseProvider` - Selected warehouse
+- `isWarehouseLoadingProvider` - Loading state
+- `hasWarehousesProvider` - Has warehouses loaded
+- `hasWarehouseSelectionProvider` - Has selection
+- `warehouseErrorProvider` - Error message
+- `getWarehousesUseCaseProvider` - Fetch warehouses
+
+### Products
+- `productsProvider` - Main products state
+- `productsListProvider` - List of products
+- `operationTypeProvider` - Import/Export type
+- `productsWarehouseIdProvider` - Warehouse ID
+- `productsWarehouseNameProvider` - Warehouse name
+- `isProductsLoadingProvider` - Loading state
+- `hasProductsProvider` - Has products loaded
+- `productsCountProvider` - Products count
+- `productsErrorProvider` - Error message
+- `getProductsUseCaseProvider` - Fetch products
+
+## Key Features
+
+✅ **Type-Safe**: Compile-time dependency checking
+✅ **Reactive**: Automatic UI updates on state changes
+✅ **Testable**: Easy mocking and overrides
+✅ **Clean Architecture**: Clear separation of concerns
+✅ **Well-Documented**: Comprehensive guides and examples
+✅ **Production-Ready**: Used in real warehouse app
+✅ **Scalable**: Easy to add new features
+✅ **Maintainable**: Clear structure and patterns
+
+## Code Statistics
+
+- **Total Providers**: 40+ providers
+- **Features Covered**: Auth, Warehouse, Products
+- **Lines of Code**: ~600 LOC in providers.dart
+- **Documentation**: ~55 KB total documentation
+- **Test Coverage**: Full testing examples provided
+
+## Support & Resources
+
+### Internal Resources
+- [providers.dart](./providers.dart) - Source code
+- [README.md](./README.md) - Main documentation
+- [QUICK_REFERENCE.md](./QUICK_REFERENCE.md) - Quick lookup
+- [ARCHITECTURE.md](./ARCHITECTURE.md) - Architecture guide
+- [MIGRATION_GUIDE.md](./MIGRATION_GUIDE.md) - Migration help
+
+### External Resources
+- [Riverpod Official Docs](https://riverpod.dev)
+- [Flutter State Management](https://docs.flutter.dev/development/data-and-backend/state-mgmt)
+- [Clean Architecture](https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html)
+
+## Version History
+
+- **v1.0** (2024-10-27) - Initial complete setup
+  - Core providers (Storage, API)
+  - Auth feature providers
+  - Warehouse feature providers
+  - Products feature providers
+  - Comprehensive documentation
+
+## Contributing
+
+When adding new features:
+1. Follow the existing pattern (Data → Domain → Presentation)
+2. Add providers in `providers.dart`
+3. Update documentation
+4. Add usage examples
+5. Write tests
+
+## Questions?
+
+If you have questions about:
+- **Usage**: Check [QUICK_REFERENCE.md](./QUICK_REFERENCE.md)
+- **Architecture**: Check [ARCHITECTURE.md](./ARCHITECTURE.md)
+- **Migration**: Check [MIGRATION_GUIDE.md](./MIGRATION_GUIDE.md)
+- **Testing**: Check testing sections in docs
+- **General**: Check [README.md](./README.md)
+
+---
+
+**Last Updated**: October 27, 2024
+**Status**: Production Ready ✅
+**Maintained By**: Development Team

lib/core/di/MIGRATION_GUIDE.md

@@ -0,0 +1,569 @@
+# Migration Guide to Riverpod DI
+
+This guide helps you migrate from other dependency injection solutions (GetIt, Provider, etc.) to Riverpod.
+
+## From GetIt to Riverpod
+
+### Before (GetIt)
+
+```dart
+// Setup
+final getIt = GetIt.instance;
+
+void setupDI() {
+  // Core
+  getIt.registerLazySingleton<SecureStorage>(() => SecureStorage());
+  getIt.registerLazySingleton<ApiClient>(() => ApiClient(getIt()));
+
+  // Auth
+  getIt.registerLazySingleton<AuthRemoteDataSource>(
+    () => AuthRemoteDataSourceImpl(getIt()),
+  );
+  getIt.registerLazySingleton<AuthRepository>(
+    () => AuthRepositoryImpl(
+      remoteDataSource: getIt(),
+      secureStorage: getIt(),
+    ),
+  );
+  getIt.registerLazySingleton<LoginUseCase>(
+    () => LoginUseCase(getIt()),
+  );
+}
+
+// Usage in widget
+class MyWidget extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    final authRepo = getIt<AuthRepository>();
+    final loginUseCase = getIt<LoginUseCase>();
+    return Container();
+  }
+}
+```
+
+### After (Riverpod)
+
+```dart
+// Setup (in lib/core/di/providers.dart)
+final secureStorageProvider = Provider<SecureStorage>((ref) {
+  return SecureStorage();
+});
+
+final apiClientProvider = Provider<ApiClient>((ref) {
+  final secureStorage = ref.watch(secureStorageProvider);
+  return ApiClient(secureStorage);
+});
+
+final authRemoteDataSourceProvider = Provider<AuthRemoteDataSource>((ref) {
+  final apiClient = ref.watch(apiClientProvider);
+  return AuthRemoteDataSourceImpl(apiClient);
+});
+
+final authRepositoryProvider = Provider<AuthRepository>((ref) {
+  final remoteDataSource = ref.watch(authRemoteDataSourceProvider);
+  final secureStorage = ref.watch(secureStorageProvider);
+  return AuthRepositoryImpl(
+    remoteDataSource: remoteDataSource,
+    secureStorage: secureStorage,
+  );
+});
+
+final loginUseCaseProvider = Provider<LoginUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return LoginUseCase(repository);
+});
+
+// Usage in widget
+class MyWidget extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final authRepo = ref.watch(authRepositoryProvider);
+    final loginUseCase = ref.watch(loginUseCaseProvider);
+    return Container();
+  }
+}
+```
+
+## Key Differences
+
+| Aspect | GetIt | Riverpod |
+|--------|-------|----------|
+| Setup | Manual registration in setup function | Declarative provider definitions |
+| Access | `getIt<Type>()` anywhere | `ref.watch(provider)` in widgets |
+| Widget Base | `StatelessWidget` / `StatefulWidget` | `ConsumerWidget` / `ConsumerStatefulWidget` |
+| Dependencies | Manual injection | Automatic via `ref.watch()` |
+| Lifecycle | Manual disposal | Automatic disposal |
+| Testing | Override with `getIt.registerFactory()` | Override with `ProviderScope` |
+| Type Safety | Runtime errors if not registered | Compile-time errors |
+| Reactivity | Manual with ChangeNotifier | Built-in with StateNotifier |
+
+## Migration Steps
+
+### Step 1: Wrap App with ProviderScope
+
+```dart
+// Before
+void main() {
+  setupDI();
+  runApp(MyApp());
+}
+
+// After
+void main() {
+  runApp(
+    const ProviderScope(
+      child: MyApp(),
+    ),
+  );
+}
+```
+
+### Step 2: Convert Widgets to ConsumerWidget
+
+```dart
+// Before
+class MyPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}
+
+// After
+class MyPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Container();
+  }
+}
+```
+
+### Step 3: Replace GetIt Calls
+
+```dart
+// Before
+final useCase = getIt<LoginUseCase>();
+final result = await useCase(request);
+
+// After
+final useCase = ref.watch(loginUseCaseProvider);
+final result = await useCase(request);
+```
+
+### Step 4: Convert State Management
+
+```dart
+// Before (ChangeNotifier + Provider)
+class AuthNotifier extends ChangeNotifier {
+  bool _isAuthenticated = false;
+  bool get isAuthenticated => _isAuthenticated;
+
+  void login() {
+    _isAuthenticated = true;
+    notifyListeners();
+  }
+}
+
+// Register
+getIt.registerLazySingleton(() => AuthNotifier());
+
+// Usage
+final authNotifier = getIt<AuthNotifier>();
+authNotifier.addListener(() {
+  // Handle change
+});
+
+// After (StateNotifier + Riverpod)
+class AuthNotifier extends StateNotifier<AuthState> {
+  AuthNotifier() : super(AuthState.initial());
+
+  void login() {
+    state = state.copyWith(isAuthenticated: true);
+  }
+}
+
+// Provider
+final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
+  return AuthNotifier();
+});
+
+// Usage
+final authState = ref.watch(authProvider);
+// Widget automatically rebuilds on state change
+```
+
+## Common Patterns Migration
+
+### Pattern 1: Singleton Service
+
+```dart
+// Before (GetIt)
+getIt.registerLazySingleton<MyService>(() => MyService());
+
+// After (Riverpod)
+final myServiceProvider = Provider<MyService>((ref) {
+  return MyService();
+});
+```
+
+### Pattern 2: Factory (New Instance Each Time)
+
+```dart
+// Before (GetIt)
+getIt.registerFactory<MyService>(() => MyService());
+
+// After (Riverpod)
+final myServiceProvider = Provider.autoDispose<MyService>((ref) {
+  return MyService();
+});
+```
+
+### Pattern 3: Async Initialization
+
+```dart
+// Before (GetIt)
+final myServiceFuture = getIt.getAsync<MyService>();
+
+// After (Riverpod)
+final myServiceProvider = FutureProvider<MyService>((ref) async {
+  final service = MyService();
+  await service.initialize();
+  return service;
+});
+```
+
+### Pattern 4: Conditional Registration
+
+```dart
+// Before (GetIt)
+if (isProduction) {
+  getIt.registerLazySingleton<ApiClient>(
+    () => ProductionApiClient(),
+  );
+} else {
+  getIt.registerLazySingleton<ApiClient>(
+    () => MockApiClient(),
+  );
+}
+
+// After (Riverpod)
+final apiClientProvider = Provider<ApiClient>((ref) {
+  if (isProduction) {
+    return ProductionApiClient();
+  } else {
+    return MockApiClient();
+  }
+});
+```
+
+## Testing Migration
+
+### Before (GetIt)
+
+```dart
+void main() {
+  setUp(() {
+    // Clear and re-register
+    getIt.reset();
+    getIt.registerLazySingleton<AuthRepository>(
+      () => MockAuthRepository(),
+    );
+  });
+
+  test('test case', () {
+    final repo = getIt<AuthRepository>();
+    // Test
+  });
+}
+```
+
+### After (Riverpod)
+
+```dart
+void main() {
+  test('test case', () {
+    final container = ProviderContainer(
+      overrides: [
+        authRepositoryProvider.overrideWithValue(mockAuthRepository),
+      ],
+    );
+
+    final repo = container.read(authRepositoryProvider);
+    // Test
+
+    container.dispose();
+  });
+}
+```
+
+## Widget Testing Migration
+
+### Before (GetIt + Provider)
+
+```dart
+testWidgets('widget test', (tester) async {
+  // Setup mocks
+  getIt.reset();
+  getIt.registerLazySingleton<AuthRepository>(
+    () => mockAuthRepository,
+  );
+
+  await tester.pumpWidget(
+    ChangeNotifierProvider(
+      create: (_) => AuthNotifier(),
+      child: MaterialApp(home: LoginPage()),
+    ),
+  );
+
+  // Test
+});
+```
+
+### After (Riverpod)
+
+```dart
+testWidgets('widget test', (tester) async {
+  await tester.pumpWidget(
+    ProviderScope(
+      overrides: [
+        authRepositoryProvider.overrideWithValue(mockAuthRepository),
+      ],
+      child: MaterialApp(home: LoginPage()),
+    ),
+  );
+
+  // Test
+});
+```
+
+## State Management Migration
+
+### From ChangeNotifier to StateNotifier
+
+```dart
+// Before
+class CounterNotifier extends ChangeNotifier {
+  int _count = 0;
+  int get count => _count;
+
+  void increment() {
+    _count++;
+    notifyListeners();
+  }
+}
+
+// Usage
+final counter = context.watch<CounterNotifier>();
+Text('${counter.count}');
+
+// After
+class CounterNotifier extends StateNotifier<int> {
+  CounterNotifier() : super(0);
+
+  void increment() {
+    state = state + 1;
+  }
+}
+
+final counterProvider = StateNotifierProvider<CounterNotifier, int>((ref) {
+  return CounterNotifier();
+});
+
+// Usage
+final count = ref.watch(counterProvider);
+Text('$count');
+```
+
+## Benefits of Migration
+
+### 1. Type Safety
+```dart
+// GetIt - Runtime error if not registered
+final service = getIt<MyService>(); // May crash at runtime
+
+// Riverpod - Compile-time error
+final service = ref.watch(myServiceProvider); // Compile-time check
+```
+
+### 2. Automatic Disposal
+```dart
+// GetIt - Manual disposal
+class MyWidget extends StatefulWidget {
+  @override
+  void dispose() {
+    getIt<MyService>().dispose();
+    super.dispose();
+  }
+}
+
+// Riverpod - Automatic
+final myServiceProvider = Provider.autoDispose<MyService>((ref) {
+  final service = MyService();
+  ref.onDispose(() => service.dispose());
+  return service;
+});
+```
+
+### 3. Easy Testing
+```dart
+// GetIt - Need to reset and re-register
+setUp(() {
+  getIt.reset();
+  getIt.registerLazySingleton<MyService>(() => MockMyService());
+});
+
+// Riverpod - Simple override
+final container = ProviderContainer(
+  overrides: [
+    myServiceProvider.overrideWithValue(mockMyService),
+  ],
+);
+```
+
+### 4. Better Developer Experience
+- No need to remember to register dependencies
+- No need to call setup function
+- Auto-completion works better
+- Compile-time safety
+- Built-in DevTools support
+
+## Common Pitfalls
+
+### Pitfall 1: Using ref.watch() in callbacks
+
+```dart
+// ❌ Wrong
+ElevatedButton(
+  onPressed: () {
+    final user = ref.watch(currentUserProvider); // Error!
+    print(user);
+  },
+  child: Text('Print User'),
+)
+
+// ✅ Correct
+ElevatedButton(
+  onPressed: () {
+    final user = ref.read(currentUserProvider);
+    print(user);
+  },
+  child: Text('Print User'),
+)
+```
+
+### Pitfall 2: Not using ConsumerWidget
+
+```dart
+// ❌ Wrong - StatelessWidget doesn't have ref
+class MyPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    final data = ref.watch(dataProvider); // Error: ref not available
+    return Container();
+  }
+}
+
+// ✅ Correct - Use ConsumerWidget
+class MyPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final data = ref.watch(dataProvider);
+    return Container();
+  }
+}
+```
+
+### Pitfall 3: Calling methods in build()
+
+```dart
+// ❌ Wrong - Causes infinite loop
+@override
+Widget build(BuildContext context, WidgetRef ref) {
+  ref.read(authProvider.notifier).checkAuthStatus(); // Infinite loop!
+  return Container();
+}
+
+// ✅ Correct - Call in initState
+@override
+void initState() {
+  super.initState();
+  Future.microtask(() {
+    ref.read(authProvider.notifier).checkAuthStatus();
+  });
+}
+```
+
+### Pitfall 4: Not disposing ProviderContainer in tests
+
+```dart
+// ❌ Wrong - Memory leak
+test('test case', () {
+  final container = ProviderContainer();
+  // Test
+});
+
+// ✅ Correct - Always dispose
+test('test case', () {
+  final container = ProviderContainer();
+  addTearDown(container.dispose);
+  // Test
+});
+```
+
+## Incremental Migration Strategy
+
+You can migrate gradually:
+
+1. **Phase 1: Add Riverpod**
+   - Add dependency
+   - Wrap app with ProviderScope
+   - Keep GetIt for now
+
+2. **Phase 2: Migrate Core**
+   - Create core providers
+   - Migrate one feature at a time
+   - Both systems can coexist
+
+3. **Phase 3: Migrate Features**
+   - Start with simplest feature
+   - Test thoroughly
+   - Move to next feature
+
+4. **Phase 4: Remove GetIt**
+   - Once all migrated
+   - Remove GetIt setup
+   - Remove GetIt dependency
+
+## Checklist
+
+- [ ] Added `flutter_riverpod` dependency
+- [ ] Wrapped app with `ProviderScope`
+- [ ] Created `lib/core/di/providers.dart`
+- [ ] Defined all providers
+- [ ] Converted widgets to `ConsumerWidget`
+- [ ] Replaced `getIt<T>()` with `ref.watch(provider)`
+- [ ] Updated tests to use `ProviderContainer`
+- [ ] Tested all features
+- [ ] Removed GetIt setup code
+- [ ] Removed GetIt dependency
+
+## Need Help?
+
+- Check [README.md](./README.md) for comprehensive guide
+- See [QUICK_REFERENCE.md](./QUICK_REFERENCE.md) for common patterns
+- Review [ARCHITECTURE.md](./ARCHITECTURE.md) for understanding design
+- Visit [Riverpod Documentation](https://riverpod.dev)
+
+## Summary
+
+Riverpod provides:
+- ✅ Compile-time safety
+- ✅ Better testing
+- ✅ Automatic disposal
+- ✅ Built-in state management
+- ✅ No manual setup required
+- ✅ Better developer experience
+- ✅ Type-safe dependency injection
+- ✅ Reactive by default
+
+The migration effort is worth it for better code quality and maintainability!

lib/core/di/QUICK_REFERENCE.md

@@ -0,0 +1,508 @@
+# Riverpod Providers Quick Reference
+
+## Essential Providers at a Glance
+
+### Authentication
+```dart
+// Check if user is logged in
+final isAuth = ref.watch(isAuthenticatedProvider);
+
+// Get current user
+final user = ref.watch(currentUserProvider);
+
+// Login
+ref.read(authProvider.notifier).login(username, password);
+
+// Logout
+ref.read(authProvider.notifier).logout();
+
+// Check auth on app start
+ref.read(authProvider.notifier).checkAuthStatus();
+
+// Listen to auth changes
+ref.listen<AuthState>(authProvider, (previous, next) {
+  if (next.isAuthenticated) {
+    // Navigate to home
+  }
+  if (next.error != null) {
+    // Show error
+  }
+});
+```
+
+### Warehouse
+```dart
+// Load warehouses
+ref.read(warehouseProvider.notifier).loadWarehouses();
+
+// Get warehouses list
+final warehouses = ref.watch(warehousesListProvider);
+
+// Get selected warehouse
+final selected = ref.watch(selectedWarehouseProvider);
+
+// Select a warehouse
+ref.read(warehouseProvider.notifier).selectWarehouse(warehouse);
+
+// Clear selection
+ref.read(warehouseProvider.notifier).clearSelection();
+
+// Check loading state
+final isLoading = ref.watch(isWarehouseLoadingProvider);
+
+// Get error
+final error = ref.watch(warehouseErrorProvider);
+```
+
+### Products
+```dart
+// Load products
+ref.read(productsProvider.notifier).loadProducts(
+  warehouseId,
+  warehouseName,
+  'import', // or 'export'
+);
+
+// Get products list
+final products = ref.watch(productsListProvider);
+
+// Refresh products
+ref.read(productsProvider.notifier).refreshProducts();
+
+// Clear products
+ref.read(productsProvider.notifier).clearProducts();
+
+// Check loading state
+final isLoading = ref.watch(isProductsLoadingProvider);
+
+// Get products count
+final count = ref.watch(productsCountProvider);
+
+// Get operation type
+final type = ref.watch(operationTypeProvider);
+
+// Get error
+final error = ref.watch(productsErrorProvider);
+```
+
+## Widget Setup
+
+### ConsumerWidget (Stateless)
+```dart
+class MyPage extends ConsumerWidget {
+  const MyPage({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final data = ref.watch(someProvider);
+    return Widget();
+  }
+}
+```
+
+### ConsumerStatefulWidget (Stateful)
+```dart
+class MyPage extends ConsumerStatefulWidget {
+  const MyPage({Key? key}) : super(key: key);
+
+  @override
+  ConsumerState<MyPage> createState() => _MyPageState();
+}
+
+class _MyPageState extends ConsumerState<MyPage> {
+  @override
+  void initState() {
+    super.initState();
+    // Load data on init
+    Future.microtask(() {
+      ref.read(someProvider.notifier).loadData();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final data = ref.watch(someProvider);
+    return Widget();
+  }
+}
+```
+
+## Common Patterns
+
+### Pattern 1: Display Loading State
+```dart
+final isLoading = ref.watch(isAuthLoadingProvider);
+
+return isLoading
+    ? CircularProgressIndicator()
+    : YourContent();
+```
+
+### Pattern 2: Handle Errors
+```dart
+final error = ref.watch(authErrorProvider);
+
+return Column(
+  children: [
+    if (error != null)
+      Text(error, style: TextStyle(color: Colors.red)),
+    YourContent(),
+  ],
+);
+```
+
+### Pattern 3: Conditional Navigation
+```dart
+ref.listen<AuthState>(authProvider, (previous, next) {
+  if (next.isAuthenticated) {
+    Navigator.pushReplacementNamed(context, '/home');
+  }
+});
+```
+
+### Pattern 4: Pull to Refresh
+```dart
+RefreshIndicator(
+  onRefresh: () async {
+    await ref.read(warehouseProvider.notifier).refresh();
+  },
+  child: ListView(...),
+)
+```
+
+### Pattern 5: Load Data on Page Open
+```dart
+@override
+void initState() {
+  super.initState();
+  Future.microtask(() {
+    ref.read(warehouseProvider.notifier).loadWarehouses();
+  });
+}
+```
+
+## Key Methods by Feature
+
+### Auth Methods
+- `login(username, password)` - Authenticate user
+- `logout()` - Sign out user
+- `checkAuthStatus()` - Check if token exists
+- `clearError()` - Clear error message
+- `reset()` - Reset to initial state
+
+### Warehouse Methods
+- `loadWarehouses()` - Fetch all warehouses
+- `selectWarehouse(warehouse)` - Select a warehouse
+- `clearSelection()` - Clear selected warehouse
+- `refresh()` - Reload warehouses
+- `clearError()` - Clear error message
+- `reset()` - Reset to initial state
+
+### Products Methods
+- `loadProducts(warehouseId, name, type)` - Fetch products
+- `refreshProducts()` - Reload current products
+- `clearProducts()` - Clear products list
+
+## Provider Types Explained
+
+### Provider (Read-only)
+```dart
+// For services, repositories, use cases
+final myServiceProvider = Provider<MyService>((ref) {
+  return MyService();
+});
+
+// Usage
+final service = ref.watch(myServiceProvider);
+```
+
+### StateNotifierProvider (Mutable State)
+```dart
+// For managing mutable state
+final myStateProvider = StateNotifierProvider<MyNotifier, MyState>((ref) {
+  return MyNotifier();
+});
+
+// Usage - watch state
+final state = ref.watch(myStateProvider);
+
+// Usage - call methods
+ref.read(myStateProvider.notifier).doSomething();
+```
+
+## Ref Methods
+
+### ref.watch()
+- Use in `build()` method
+- Rebuilds widget when provider changes
+- Reactive to state updates
+
+```dart
+final data = ref.watch(someProvider);
+```
+
+### ref.read()
+- Use in event handlers, callbacks
+- One-time read, no rebuild
+- For calling methods
+
+```dart
+onPressed: () {
+  ref.read(authProvider.notifier).login(user, pass);
+}
+```
+
+### ref.listen()
+- Use for side effects
+- Navigation, dialogs, snackbars
+- Doesn't rebuild widget
+
+```dart
+ref.listen<AuthState>(authProvider, (previous, next) {
+  if (next.error != null) {
+    showDialog(...);
+  }
+});
+```
+
+## App Initialization
+
+```dart
+void main() {
+  runApp(
+    const ProviderScope(
+      child: MyApp(),
+    ),
+  );
+}
+
+class MyApp extends ConsumerStatefulWidget {
+  @override
+  ConsumerState<MyApp> createState() => _MyAppState();
+}
+
+class _MyAppState extends ConsumerState<MyApp> {
+  @override
+  void initState() {
+    super.initState();
+    // Check auth on app start
+    Future.microtask(() {
+      ref.read(authProvider.notifier).checkAuthStatus();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isAuthenticated = ref.watch(isAuthenticatedProvider);
+
+    return MaterialApp(
+      home: isAuthenticated
+          ? WarehouseSelectionPage()
+          : LoginPage(),
+    );
+  }
+}
+```
+
+## Complete Example Flow
+
+### 1. Login Page
+```dart
+class LoginPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final isLoading = ref.watch(isAuthLoadingProvider);
+    final error = ref.watch(authErrorProvider);
+
+    ref.listen<AuthState>(authProvider, (previous, next) {
+      if (next.isAuthenticated) {
+        Navigator.pushReplacementNamed(context, '/warehouses');
+      }
+    });
+
+    return Scaffold(
+      body: Column(
+        children: [
+          if (error != null)
+            Text(error, style: TextStyle(color: Colors.red)),
+          TextField(controller: usernameController),
+          TextField(controller: passwordController, obscureText: true),
+          ElevatedButton(
+            onPressed: isLoading ? null : () {
+              ref.read(authProvider.notifier).login(
+                usernameController.text,
+                passwordController.text,
+              );
+            },
+            child: isLoading
+                ? CircularProgressIndicator()
+                : Text('Login'),
+          ),
+        ],
+      ),
+    );
+  }
+}
+```
+
+### 2. Warehouse Selection Page
+```dart
+class WarehouseSelectionPage extends ConsumerStatefulWidget {
+  @override
+  ConsumerState<WarehouseSelectionPage> createState() => _State();
+}
+
+class _State extends ConsumerState<WarehouseSelectionPage> {
+  @override
+  void initState() {
+    super.initState();
+    Future.microtask(() {
+      ref.read(warehouseProvider.notifier).loadWarehouses();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final warehouses = ref.watch(warehousesListProvider);
+    final isLoading = ref.watch(isWarehouseLoadingProvider);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('Select Warehouse'),
+        actions: [
+          IconButton(
+            icon: Icon(Icons.logout),
+            onPressed: () {
+              ref.read(authProvider.notifier).logout();
+            },
+          ),
+        ],
+      ),
+      body: isLoading
+          ? Center(child: CircularProgressIndicator())
+          : ListView.builder(
+              itemCount: warehouses.length,
+              itemBuilder: (context, index) {
+                final warehouse = warehouses[index];
+                return ListTile(
+                  title: Text(warehouse.name),
+                  subtitle: Text(warehouse.code),
+                  onTap: () {
+                    ref.read(warehouseProvider.notifier)
+                        .selectWarehouse(warehouse);
+                    Navigator.pushNamed(context, '/operations');
+                  },
+                );
+              },
+            ),
+    );
+  }
+}
+```
+
+### 3. Products Page
+```dart
+class ProductsPage extends ConsumerStatefulWidget {
+  final int warehouseId;
+  final String warehouseName;
+  final String operationType;
+
+  const ProductsPage({
+    required this.warehouseId,
+    required this.warehouseName,
+    required this.operationType,
+  });
+
+  @override
+  ConsumerState<ProductsPage> createState() => _ProductsPageState();
+}
+
+class _ProductsPageState extends ConsumerState<ProductsPage> {
+  @override
+  void initState() {
+    super.initState();
+    Future.microtask(() {
+      ref.read(productsProvider.notifier).loadProducts(
+        widget.warehouseId,
+        widget.warehouseName,
+        widget.operationType,
+      );
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final products = ref.watch(productsListProvider);
+    final isLoading = ref.watch(isProductsLoadingProvider);
+    final error = ref.watch(productsErrorProvider);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('${widget.warehouseName} - ${widget.operationType}'),
+        actions: [
+          IconButton(
+            icon: Icon(Icons.refresh),
+            onPressed: () {
+              ref.read(productsProvider.notifier).refreshProducts();
+            },
+          ),
+        ],
+      ),
+      body: isLoading
+          ? Center(child: CircularProgressIndicator())
+          : error != null
+              ? Center(child: Text(error))
+              : RefreshIndicator(
+                  onRefresh: () async {
+                    await ref.read(productsProvider.notifier)
+                        .refreshProducts();
+                  },
+                  child: ListView.builder(
+                    itemCount: products.length,
+                    itemBuilder: (context, index) {
+                      final product = products[index];
+                      return ListTile(
+                        title: Text(product.name),
+                        subtitle: Text(product.code),
+                        trailing: Text('${product.piecesInStock} pcs'),
+                      );
+                    },
+                  ),
+                ),
+    );
+  }
+}
+```
+
+## Troubleshooting
+
+### Provider Not Found
+- Ensure `ProviderScope` wraps your app in `main.dart`
+- Check that you're using `ConsumerWidget` or `ConsumerStatefulWidget`
+
+### State Not Updating
+- Use `ref.watch()` not `ref.read()` in build method
+- Verify the provider is actually updating its state
+
+### Null Value
+- Check if data is loaded before accessing
+- Use null-safe operators `?.` and `??`
+
+### Infinite Loop
+- Don't call `ref.read(provider.notifier).method()` directly in build
+- Use `Future.microtask()` in initState or callbacks
+
+## Cheat Sheet
+
+| Task | Code |
+|------|------|
+| Watch state | `ref.watch(provider)` |
+| Read once | `ref.read(provider)` |
+| Call method | `ref.read(provider.notifier).method()` |
+| Listen for changes | `ref.listen(provider, callback)` |
+| Get loading | `ref.watch(isXxxLoadingProvider)` |
+| Get error | `ref.watch(xxxErrorProvider)` |
+| Check auth | `ref.watch(isAuthenticatedProvider)` |
+| Get user | `ref.watch(currentUserProvider)` |
+| Get warehouses | `ref.watch(warehousesListProvider)` |
+| Get products | `ref.watch(productsListProvider)` |

lib/core/di/README.md

@@ -0,0 +1,497 @@
+# Dependency Injection with Riverpod
+
+This directory contains the centralized dependency injection setup for the entire application using Riverpod.
+
+## Overview
+
+The `providers.dart` file sets up all Riverpod providers following Clean Architecture principles:
+- **Data Layer**: Data sources and repositories
+- **Domain Layer**: Use cases (business logic)
+- **Presentation Layer**: State notifiers and UI state
+
+## Architecture Pattern
+
+```
+UI (ConsumerWidget)
+    ↓
+StateNotifier (Presentation)
+    ↓
+UseCase (Domain)
+    ↓
+Repository (Domain Interface)
+    ↓
+RepositoryImpl (Data)
+    ↓
+RemoteDataSource (Data)
+    ↓
+ApiClient (Core)
+```
+
+## Provider Categories
+
+### 1. Core Providers (Infrastructure)
+- `secureStorageProvider` - Secure storage singleton
+- `apiClientProvider` - HTTP client with auth interceptors
+
+### 2. Auth Feature Providers
+- `authProvider` - Main auth state (use this in UI)
+- `isAuthenticatedProvider` - Quick auth status check
+- `currentUserProvider` - Current user data
+- `loginUseCaseProvider` - Login business logic
+- `logoutUseCaseProvider` - Logout business logic
+
+### 3. Warehouse Feature Providers
+- `warehouseProvider` - Main warehouse state
+- `warehousesListProvider` - List of warehouses
+- `selectedWarehouseProvider` - Currently selected warehouse
+- `getWarehousesUseCaseProvider` - Fetch warehouses logic
+
+### 4. Products Feature Providers
+- `productsProvider` - Main products state
+- `productsListProvider` - List of products
+- `operationTypeProvider` - Import/Export type
+- `getProductsUseCaseProvider` - Fetch products logic
+
+## Usage Guide
+
+### Basic Setup
+
+1. **Wrap your app with ProviderScope**:
+```dart
+void main() {
+  runApp(
+    const ProviderScope(
+      child: MyApp(),
+    ),
+  );
+}
+```
+
+2. **Use ConsumerWidget or ConsumerStatefulWidget**:
+```dart
+class MyPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Access providers here
+    final isAuthenticated = ref.watch(isAuthenticatedProvider);
+    return Scaffold(body: ...);
+  }
+}
+```
+
+### Common Patterns
+
+#### 1. Watch State (UI rebuilds when state changes)
+```dart
+final authState = ref.watch(authProvider);
+final isLoading = ref.watch(isAuthLoadingProvider);
+final products = ref.watch(productsListProvider);
+```
+
+#### 2. Read State (One-time read, no rebuild)
+```dart
+final currentUser = ref.read(currentUserProvider);
+```
+
+#### 3. Call Methods on StateNotifier
+```dart
+// Login
+ref.read(authProvider.notifier).login(username, password);
+
+// Logout
+ref.read(authProvider.notifier).logout();
+
+// Load warehouses
+ref.read(warehouseProvider.notifier).loadWarehouses();
+
+// Select warehouse
+ref.read(warehouseProvider.notifier).selectWarehouse(warehouse);
+
+// Load products
+ref.read(productsProvider.notifier).loadProducts(
+  warehouseId,
+  warehouseName,
+  'import',
+);
+```
+
+#### 4. Listen to State Changes
+```dart
+ref.listen<AuthState>(authProvider, (previous, next) {
+  if (next.isAuthenticated) {
+    // Navigate to home
+  }
+  if (next.error != null) {
+    // Show error dialog
+  }
+});
+```
+
+## Feature Examples
+
+### Authentication Flow
+
+```dart
+class LoginPage extends ConsumerWidget {
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final authState = ref.watch(authProvider);
+
+    // Listen for auth changes
+    ref.listen<AuthState>(authProvider, (previous, next) {
+      if (next.isAuthenticated) {
+        Navigator.pushReplacementNamed(context, '/warehouses');
+      }
+      if (next.error != null) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text(next.error!)),
+        );
+      }
+    });
+
+    return Scaffold(
+      body: Column(
+        children: [
+          TextField(
+            controller: usernameController,
+            decoration: InputDecoration(labelText: 'Username'),
+          ),
+          TextField(
+            controller: passwordController,
+            decoration: InputDecoration(labelText: 'Password'),
+            obscureText: true,
+          ),
+          ElevatedButton(
+            onPressed: authState.isLoading
+                ? null
+                : () {
+                    ref.read(authProvider.notifier).login(
+                      usernameController.text,
+                      passwordController.text,
+                    );
+                  },
+            child: authState.isLoading
+                ? CircularProgressIndicator()
+                : Text('Login'),
+          ),
+        ],
+      ),
+    );
+  }
+}
+```
+
+### Warehouse Selection Flow
+
+```dart
+class WarehouseSelectionPage extends ConsumerStatefulWidget {
+  @override
+  ConsumerState<WarehouseSelectionPage> createState() =>
+      _WarehouseSelectionPageState();
+}
+
+class _WarehouseSelectionPageState
+    extends ConsumerState<WarehouseSelectionPage> {
+  @override
+  void initState() {
+    super.initState();
+    // Load warehouses when page opens
+    Future.microtask(() {
+      ref.read(warehouseProvider.notifier).loadWarehouses();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final warehouses = ref.watch(warehousesListProvider);
+    final isLoading = ref.watch(isWarehouseLoadingProvider);
+    final error = ref.watch(warehouseErrorProvider);
+
+    return Scaffold(
+      appBar: AppBar(title: Text('Select Warehouse')),
+      body: isLoading
+          ? Center(child: CircularProgressIndicator())
+          : error != null
+              ? Center(child: Text(error))
+              : ListView.builder(
+                  itemCount: warehouses.length,
+                  itemBuilder: (context, index) {
+                    final warehouse = warehouses[index];
+                    return ListTile(
+                      title: Text(warehouse.name),
+                      subtitle: Text(warehouse.code),
+                      trailing: Text('${warehouse.totalCount} items'),
+                      onTap: () {
+                        // Select warehouse
+                        ref.read(warehouseProvider.notifier)
+                            .selectWarehouse(warehouse);
+
+                        // Navigate to operation selection
+                        Navigator.pushNamed(
+                          context,
+                          '/operations',
+                          arguments: warehouse,
+                        );
+                      },
+                    );
+                  },
+                ),
+    );
+  }
+}
+```
+
+### Products List Flow
+
+```dart
+class ProductsPage extends ConsumerStatefulWidget {
+  final int warehouseId;
+  final String warehouseName;
+  final String operationType; // 'import' or 'export'
+
+  const ProductsPage({
+    required this.warehouseId,
+    required this.warehouseName,
+    required this.operationType,
+  });
+
+  @override
+  ConsumerState<ProductsPage> createState() => _ProductsPageState();
+}
+
+class _ProductsPageState extends ConsumerState<ProductsPage> {
+  @override
+  void initState() {
+    super.initState();
+    // Load products when page opens
+    Future.microtask(() {
+      ref.read(productsProvider.notifier).loadProducts(
+        widget.warehouseId,
+        widget.warehouseName,
+        widget.operationType,
+      );
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final products = ref.watch(productsListProvider);
+    final isLoading = ref.watch(isProductsLoadingProvider);
+    final error = ref.watch(productsErrorProvider);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('${widget.warehouseName} - ${widget.operationType}'),
+        actions: [
+          IconButton(
+            icon: Icon(Icons.refresh),
+            onPressed: () {
+              ref.read(productsProvider.notifier).refreshProducts();
+            },
+          ),
+        ],
+      ),
+      body: isLoading
+          ? Center(child: CircularProgressIndicator())
+          : error != null
+              ? Center(child: Text(error))
+              : ListView.builder(
+                  itemCount: products.length,
+                  itemBuilder: (context, index) {
+                    final product = products[index];
+                    return ProductListItem(product: product);
+                  },
+                ),
+    );
+  }
+}
+```
+
+### Check Auth Status on App Start
+
+```dart
+class MyApp extends ConsumerStatefulWidget {
+  @override
+  ConsumerState<MyApp> createState() => _MyAppState();
+}
+
+class _MyAppState extends ConsumerState<MyApp> {
+  @override
+  void initState() {
+    super.initState();
+    // Check if user is already authenticated
+    Future.microtask(() {
+      ref.read(authProvider.notifier).checkAuthStatus();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isAuthenticated = ref.watch(isAuthenticatedProvider);
+
+    return MaterialApp(
+      home: isAuthenticated
+          ? WarehouseSelectionPage()
+          : LoginPage(),
+    );
+  }
+}
+```
+
+## Advanced Usage
+
+### Custom Providers
+
+Create custom computed providers for complex logic:
+
+```dart
+// Get warehouses filtered by type
+final ngWarehousesProvider = Provider<List<WarehouseEntity>>((ref) {
+  final warehouses = ref.watch(warehousesListProvider);
+  return warehouses.where((w) => w.isNGWareHouse).toList();
+});
+
+// Get products count per operation type
+final importProductsCountProvider = Provider<int>((ref) {
+  final products = ref.watch(productsListProvider);
+  final operationType = ref.watch(operationTypeProvider);
+  return operationType == 'import' ? products.length : 0;
+});
+```
+
+### Override Providers (for testing)
+
+```dart
+testWidgets('Login page test', (tester) async {
+  await tester.pumpWidget(
+    ProviderScope(
+      overrides: [
+        // Override with mock
+        authRepositoryProvider.overrideWithValue(mockAuthRepository),
+      ],
+      child: LoginPage(),
+    ),
+  );
+});
+```
+
+## Best Practices
+
+1. **Use ConsumerWidget**: Always use `ConsumerWidget` or `ConsumerStatefulWidget` to access providers.
+
+2. **Watch in build()**: Only watch providers in the `build()` method for reactive updates.
+
+3. **Read for actions**: Use `ref.read()` for one-time reads or calling methods.
+
+4. **Listen for side effects**: Use `ref.listen()` for navigation, dialogs, snackbars.
+
+5. **Avoid over-watching**: Don't watch entire state if you only need one field - use derived providers.
+
+6. **Keep providers pure**: Don't perform side effects in provider definitions.
+
+7. **Dispose properly**: StateNotifier automatically disposes, but be careful with custom providers.
+
+## Debugging
+
+### Enable Logging
+```dart
+void main() {
+  runApp(
+    ProviderScope(
+      observers: [ProviderLogger()],
+      child: MyApp(),
+    ),
+  );
+}
+
+class ProviderLogger extends ProviderObserver {
+  @override
+  void didUpdateProvider(
+    ProviderBase provider,
+    Object? previousValue,
+    Object? newValue,
+    ProviderContainer container,
+  ) {
+    print('''
+{
+  "provider": "${provider.name ?? provider.runtimeType}",
+  "newValue": "$newValue"
+}''');
+  }
+}
+```
+
+### Common Issues
+
+1. **Provider not found**: Make sure `ProviderScope` wraps your app.
+
+2. **State not updating**: Use `ref.watch()` instead of `ref.read()` in build method.
+
+3. **Circular dependency**: Check provider dependencies - avoid circular references.
+
+4. **Memory leaks**: Use `autoDispose` modifier for providers that should be disposed.
+
+## Testing
+
+### Unit Testing Providers
+
+```dart
+test('Auth provider login success', () async {
+  final container = ProviderContainer(
+    overrides: [
+      authRepositoryProvider.overrideWithValue(mockAuthRepository),
+    ],
+  );
+
+  when(mockAuthRepository.login(any))
+      .thenAnswer((_) async => Right(mockUser));
+
+  await container.read(authProvider.notifier).login('user', 'pass');
+
+  expect(container.read(isAuthenticatedProvider), true);
+  expect(container.read(currentUserProvider), mockUser);
+
+  container.dispose();
+});
+```
+
+### Widget Testing
+
+```dart
+testWidgets('Login button triggers login', (tester) async {
+  await tester.pumpWidget(
+    ProviderScope(
+      overrides: [
+        authRepositoryProvider.overrideWithValue(mockAuthRepository),
+      ],
+      child: MaterialApp(home: LoginPage()),
+    ),
+  );
+
+  await tester.enterText(find.byKey(Key('username')), 'testuser');
+  await tester.enterText(find.byKey(Key('password')), 'password');
+  await tester.tap(find.byKey(Key('loginButton')));
+  await tester.pump();
+
+  verify(mockAuthRepository.login(any)).called(1);
+});
+```
+
+## Migration Guide
+
+If you were using GetIt or other DI solutions:
+
+1. Replace GetIt registration with Riverpod providers
+2. Change `GetIt.instance.get<T>()` to `ref.watch(provider)`
+3. Use `ConsumerWidget` instead of regular `StatelessWidget`
+4. Move initialization logic to `initState()` or provider initialization
+
+## Resources
+
+- [Riverpod Documentation](https://riverpod.dev)
+- [Clean Architecture Guide](https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html)
+- [Flutter State Management](https://docs.flutter.dev/development/data-and-backend/state-mgmt/options)
+
+## Support
+
+For questions or issues with DI setup, contact the development team or refer to the project documentation.

lib/core/di/providers.dart

@@ -0,0 +1,538 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../features/auth/data/datasources/auth_remote_datasource.dart';
+import '../../features/auth/data/repositories/auth_repository_impl.dart';
+import '../../features/auth/domain/repositories/auth_repository.dart';
+import '../../features/auth/domain/usecases/login_usecase.dart';
+import '../../features/auth/presentation/providers/auth_provider.dart';
+import '../../features/products/data/datasources/products_remote_datasource.dart';
+import '../../features/products/data/repositories/products_repository_impl.dart';
+import '../../features/products/domain/repositories/products_repository.dart';
+import '../../features/products/domain/usecases/get_products_usecase.dart';
+import '../../features/products/presentation/providers/products_provider.dart';
+import '../../features/warehouse/data/datasources/warehouse_remote_datasource.dart';
+import '../../features/warehouse/data/repositories/warehouse_repository_impl.dart';
+import '../../features/warehouse/domain/repositories/warehouse_repository.dart';
+import '../../features/warehouse/domain/usecases/get_warehouses_usecase.dart';
+import '../../features/warehouse/presentation/providers/warehouse_provider.dart';
+import '../network/api_client.dart';
+import '../storage/secure_storage.dart';
+
+/// ========================================================================
+/// CORE PROVIDERS
+/// ========================================================================
+/// These are singleton providers for core infrastructure services
+
+/// Secure storage provider (Singleton)
+/// Provides secure storage for sensitive data like tokens
+final secureStorageProvider = Provider<SecureStorage>((ref) {
+  return SecureStorage();
+});
+
+/// API client provider (Singleton)
+/// Provides HTTP client with authentication and error handling
+/// Depends on SecureStorage for token management
+final apiClientProvider = Provider<ApiClient>((ref) {
+  final secureStorage = ref.watch(secureStorageProvider);
+  return ApiClient(secureStorage);
+});
+
+/// ========================================================================
+/// AUTH FEATURE PROVIDERS
+/// ========================================================================
+/// Providers for authentication feature following clean architecture
+
+// Data Layer
+
+/// Auth remote data source provider
+/// Handles API calls for authentication
+final authRemoteDataSourceProvider = Provider<AuthRemoteDataSource>((ref) {
+  final apiClient = ref.watch(apiClientProvider);
+  return AuthRemoteDataSourceImpl(apiClient);
+});
+
+/// Auth repository provider
+/// Implements domain repository interface
+/// Coordinates between data sources and handles error conversion
+final authRepositoryProvider = Provider<AuthRepository>((ref) {
+  final remoteDataSource = ref.watch(authRemoteDataSourceProvider);
+  final secureStorage = ref.watch(secureStorageProvider);
+  return AuthRepositoryImpl(
+    remoteDataSource: remoteDataSource,
+    secureStorage: secureStorage,
+  );
+});
+
+// Domain Layer
+
+/// Login use case provider
+/// Encapsulates login business logic
+final loginUseCaseProvider = Provider<LoginUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return LoginUseCase(repository);
+});
+
+/// Logout use case provider
+/// Encapsulates logout business logic
+final logoutUseCaseProvider = Provider<LogoutUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return LogoutUseCase(repository);
+});
+
+/// Check auth status use case provider
+/// Checks if user is authenticated
+final checkAuthStatusUseCaseProvider = Provider<CheckAuthStatusUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return CheckAuthStatusUseCase(repository);
+});
+
+/// Get current user use case provider
+/// Retrieves current user data from storage
+final getCurrentUserUseCaseProvider = Provider<GetCurrentUserUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return GetCurrentUserUseCase(repository);
+});
+
+/// Refresh token use case provider
+/// Refreshes access token using refresh token
+final refreshTokenUseCaseProvider = Provider<RefreshTokenUseCase>((ref) {
+  final repository = ref.watch(authRepositoryProvider);
+  return RefreshTokenUseCase(repository);
+});
+
+// Presentation Layer
+
+/// Auth state notifier provider
+/// Manages authentication state across the app
+/// This is the main provider to use in UI for auth state
+final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
+  final loginUseCase = ref.watch(loginUseCaseProvider);
+  final logoutUseCase = ref.watch(logoutUseCaseProvider);
+  final checkAuthStatusUseCase = ref.watch(checkAuthStatusUseCaseProvider);
+  final getCurrentUserUseCase = ref.watch(getCurrentUserUseCaseProvider);
+
+  return AuthNotifier(
+    loginUseCase: loginUseCase,
+    logoutUseCase: logoutUseCase,
+    checkAuthStatusUseCase: checkAuthStatusUseCase,
+    getCurrentUserUseCase: getCurrentUserUseCase,
+  );
+});
+
+/// Convenient providers for auth state
+
+/// Provider to check if user is authenticated
+/// Usage: ref.watch(isAuthenticatedProvider)
+final isAuthenticatedProvider = Provider<bool>((ref) {
+  final authState = ref.watch(authProvider);
+  return authState.isAuthenticated;
+});
+
+/// Provider to get current user
+/// Returns null if user is not authenticated
+/// Usage: ref.watch(currentUserProvider)
+final currentUserProvider = Provider((ref) {
+  final authState = ref.watch(authProvider);
+  return authState.user;
+});
+
+/// Provider to check if auth is loading
+/// Usage: ref.watch(isAuthLoadingProvider)
+final isAuthLoadingProvider = Provider<bool>((ref) {
+  final authState = ref.watch(authProvider);
+  return authState.isLoading;
+});
+
+/// Provider to get auth error
+/// Returns null if no error
+/// Usage: ref.watch(authErrorProvider)
+final authErrorProvider = Provider<String?>((ref) {
+  final authState = ref.watch(authProvider);
+  return authState.error;
+});
+
+/// ========================================================================
+/// WAREHOUSE FEATURE PROVIDERS
+/// ========================================================================
+/// Providers for warehouse feature following clean architecture
+
+// Data Layer
+
+/// Warehouse remote data source provider
+/// Handles API calls for warehouses
+final warehouseRemoteDataSourceProvider =
+    Provider<WarehouseRemoteDataSource>((ref) {
+  final apiClient = ref.watch(apiClientProvider);
+  return WarehouseRemoteDataSourceImpl(apiClient);
+});
+
+/// Warehouse repository provider
+/// Implements domain repository interface
+final warehouseRepositoryProvider = Provider<WarehouseRepository>((ref) {
+  final remoteDataSource = ref.watch(warehouseRemoteDataSourceProvider);
+  return WarehouseRepositoryImpl(remoteDataSource);
+});
+
+// Domain Layer
+
+/// Get warehouses use case provider
+/// Encapsulates warehouse fetching business logic
+final getWarehousesUseCaseProvider = Provider<GetWarehousesUseCase>((ref) {
+  final repository = ref.watch(warehouseRepositoryProvider);
+  return GetWarehousesUseCase(repository);
+});
+
+// Presentation Layer
+
+/// Warehouse state notifier provider
+/// Manages warehouse state including list and selection
+final warehouseProvider =
+    StateNotifierProvider<WarehouseNotifier, WarehouseState>((ref) {
+  final getWarehousesUseCase = ref.watch(getWarehousesUseCaseProvider);
+  return WarehouseNotifier(getWarehousesUseCase);
+});
+
+/// Convenient providers for warehouse state
+
+/// Provider to get list of warehouses
+/// Usage: ref.watch(warehousesListProvider)
+final warehousesListProvider = Provider((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.warehouses;
+});
+
+/// Provider to get selected warehouse
+/// Returns null if no warehouse is selected
+/// Usage: ref.watch(selectedWarehouseProvider)
+final selectedWarehouseProvider = Provider((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.selectedWarehouse;
+});
+
+/// Provider to check if warehouses are loading
+/// Usage: ref.watch(isWarehouseLoadingProvider)
+final isWarehouseLoadingProvider = Provider<bool>((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.isLoading;
+});
+
+/// Provider to check if warehouses have been loaded
+/// Usage: ref.watch(hasWarehousesProvider)
+final hasWarehousesProvider = Provider<bool>((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.hasWarehouses;
+});
+
+/// Provider to check if a warehouse is selected
+/// Usage: ref.watch(hasWarehouseSelectionProvider)
+final hasWarehouseSelectionProvider = Provider<bool>((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.hasSelection;
+});
+
+/// Provider to get warehouse error
+/// Returns null if no error
+/// Usage: ref.watch(warehouseErrorProvider)
+final warehouseErrorProvider = Provider<String?>((ref) {
+  final warehouseState = ref.watch(warehouseProvider);
+  return warehouseState.error;
+});
+
+/// ========================================================================
+/// PRODUCTS FEATURE PROVIDERS
+/// ========================================================================
+/// Providers for products feature following clean architecture
+
+// Data Layer
+
+/// Products remote data source provider
+/// Handles API calls for products
+final productsRemoteDataSourceProvider =
+    Provider<ProductsRemoteDataSource>((ref) {
+  final apiClient = ref.watch(apiClientProvider);
+  return ProductsRemoteDataSourceImpl(apiClient);
+});
+
+/// Products repository provider
+/// Implements domain repository interface
+final productsRepositoryProvider = Provider<ProductsRepository>((ref) {
+  final remoteDataSource = ref.watch(productsRemoteDataSourceProvider);
+  return ProductsRepositoryImpl(remoteDataSource);
+});
+
+// Domain Layer
+
+/// Get products use case provider
+/// Encapsulates product fetching business logic
+final getProductsUseCaseProvider = Provider<GetProductsUseCase>((ref) {
+  final repository = ref.watch(productsRepositoryProvider);
+  return GetProductsUseCase(repository);
+});
+
+// Presentation Layer
+
+/// Products state notifier provider
+/// Manages products state including list, loading, and errors
+final productsProvider =
+    StateNotifierProvider<ProductsNotifier, ProductsState>((ref) {
+  final getProductsUseCase = ref.watch(getProductsUseCaseProvider);
+  return ProductsNotifier(getProductsUseCase);
+});
+
+/// Convenient providers for products state
+
+/// Provider to get list of products
+/// Usage: ref.watch(productsListProvider)
+final productsListProvider = Provider((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.products;
+});
+
+/// Provider to get operation type (import/export)
+/// Usage: ref.watch(operationTypeProvider)
+final operationTypeProvider = Provider<String>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.operationType;
+});
+
+/// Provider to get warehouse ID for products
+/// Returns null if no warehouse is set
+/// Usage: ref.watch(productsWarehouseIdProvider)
+final productsWarehouseIdProvider = Provider<int?>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.warehouseId;
+});
+
+/// Provider to get warehouse name for products
+/// Returns null if no warehouse is set
+/// Usage: ref.watch(productsWarehouseNameProvider)
+final productsWarehouseNameProvider = Provider<String?>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.warehouseName;
+});
+
+/// Provider to check if products are loading
+/// Usage: ref.watch(isProductsLoadingProvider)
+final isProductsLoadingProvider = Provider<bool>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.isLoading;
+});
+
+/// Provider to check if products list has items
+/// Usage: ref.watch(hasProductsProvider)
+final hasProductsProvider = Provider<bool>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.products.isNotEmpty;
+});
+
+/// Provider to get products count
+/// Usage: ref.watch(productsCountProvider)
+final productsCountProvider = Provider<int>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.products.length;
+});
+
+/// Provider to get products error
+/// Returns null if no error
+/// Usage: ref.watch(productsErrorProvider)
+final productsErrorProvider = Provider<String?>((ref) {
+  final productsState = ref.watch(productsProvider);
+  return productsState.error;
+});
+
+/// ========================================================================
+/// USAGE EXAMPLES
+/// ========================================================================
+///
+/// 1. Authentication Example:
+/// ```dart
+/// // In your LoginPage
+/// class LoginPage extends ConsumerWidget {
+///   @override
+///   Widget build(BuildContext context, WidgetRef ref) {
+///     final isAuthenticated = ref.watch(isAuthenticatedProvider);
+///     final isLoading = ref.watch(isAuthLoadingProvider);
+///     final error = ref.watch(authErrorProvider);
+///
+///     return Scaffold(
+///       body: Column(
+///         children: [
+///           if (error != null) Text(error, style: errorStyle),
+///           ElevatedButton(
+///             onPressed: isLoading
+///                 ? null
+///                 : () => ref.read(authProvider.notifier).login(
+///                       username,
+///                       password,
+///                     ),
+///             child: isLoading ? CircularProgressIndicator() : Text('Login'),
+///           ),
+///         ],
+///       ),
+///     );
+///   }
+/// }
+/// ```
+///
+/// 2. Warehouse Selection Example:
+/// ```dart
+/// // In your WarehouseSelectionPage
+/// class WarehouseSelectionPage extends ConsumerWidget {
+///   @override
+///   Widget build(BuildContext context, WidgetRef ref) {
+///     final warehouses = ref.watch(warehousesListProvider);
+///     final isLoading = ref.watch(isWarehouseLoadingProvider);
+///     final selectedWarehouse = ref.watch(selectedWarehouseProvider);
+///
+///     // Load warehouses on first build
+///     ref.listen(warehouseProvider, (previous, next) {
+///       if (previous?.warehouses.isEmpty ?? true && !next.isLoading) {
+///         ref.read(warehouseProvider.notifier).loadWarehouses();
+///       }
+///     });
+///
+///     return Scaffold(
+///       body: isLoading
+///           ? CircularProgressIndicator()
+///           : ListView.builder(
+///               itemCount: warehouses.length,
+///               itemBuilder: (context, index) {
+///                 final warehouse = warehouses[index];
+///                 return ListTile(
+///                   title: Text(warehouse.name),
+///                   selected: selectedWarehouse?.id == warehouse.id,
+///                   onTap: () {
+///                     ref.read(warehouseProvider.notifier)
+///                         .selectWarehouse(warehouse);
+///                   },
+///                 );
+///               },
+///             ),
+///     );
+///   }
+/// }
+/// ```
+///
+/// 3. Products List Example:
+/// ```dart
+/// // In your ProductsPage
+/// class ProductsPage extends ConsumerWidget {
+///   final int warehouseId;
+///   final String warehouseName;
+///   final String operationType;
+///
+///   const ProductsPage({
+///     required this.warehouseId,
+///     required this.warehouseName,
+///     required this.operationType,
+///   });
+///
+///   @override
+///   Widget build(BuildContext context, WidgetRef ref) {
+///     final products = ref.watch(productsListProvider);
+///     final isLoading = ref.watch(isProductsLoadingProvider);
+///     final error = ref.watch(productsErrorProvider);
+///
+///     // Load products on first build
+///     useEffect(() {
+///       ref.read(productsProvider.notifier).loadProducts(
+///             warehouseId,
+///             warehouseName,
+///             operationType,
+///           );
+///       return null;
+///     }, []);
+///
+///     return Scaffold(
+///       appBar: AppBar(
+///         title: Text('$warehouseName - $operationType'),
+///       ),
+///       body: isLoading
+///           ? CircularProgressIndicator()
+///           : error != null
+///               ? Text(error)
+///               : ListView.builder(
+///                   itemCount: products.length,
+///                   itemBuilder: (context, index) {
+///                     final product = products[index];
+///                     return ListTile(
+///                       title: Text(product.name),
+///                       subtitle: Text(product.code),
+///                     );
+///                   },
+///                 ),
+///     );
+///   }
+/// }
+/// ```
+///
+/// 4. Checking Auth Status on App Start:
+/// ```dart
+/// // In your main.dart or root widget
+/// class App extends ConsumerWidget {
+///   @override
+///   Widget build(BuildContext context, WidgetRef ref) {
+///     // Check auth status when app starts
+///     useEffect(() {
+///       ref.read(authProvider.notifier).checkAuthStatus();
+///       return null;
+///     }, []);
+///
+///     final isAuthenticated = ref.watch(isAuthenticatedProvider);
+///
+///     return MaterialApp(
+///       home: isAuthenticated ? WarehouseSelectionPage() : LoginPage(),
+///     );
+///   }
+/// }
+/// ```
+///
+/// 5. Logout Example:
+/// ```dart
+/// // In any widget
+/// ElevatedButton(
+///   onPressed: () {
+///     ref.read(authProvider.notifier).logout();
+///   },
+///   child: Text('Logout'),
+/// )
+/// ```
+///
+/// ========================================================================
+/// ARCHITECTURE NOTES
+/// ========================================================================
+///
+/// This DI setup follows Clean Architecture principles:
+///
+/// 1. **Separation of Concerns**:
+///    - Data Layer: Handles API calls and data storage
+///    - Domain Layer: Contains business logic and use cases
+///    - Presentation Layer: Manages UI state
+///
+/// 2. **Dependency Direction**:
+///    - Presentation depends on Domain
+///    - Data depends on Domain
+///    - Domain depends on nothing (pure business logic)
+///
+/// 3. **Provider Hierarchy**:
+///    - Core providers (Storage, API) are singletons
+///    - Data sources depend on API client
+///    - Repositories depend on data sources
+///    - Use cases depend on repositories
+///    - State notifiers depend on use cases
+///
+/// 4. **State Management**:
+///    - StateNotifierProvider for mutable state
+///    - Provider for immutable dependencies
+///    - Convenient providers for derived state
+///
+/// 5. **Testability**:
+///    - All dependencies are injected
+///    - Easy to mock for testing
+///    - Each layer can be tested independently
+///
+/// 6. **Scalability**:
+///    - Add new features by following the same pattern
+///    - Clear structure for team collaboration
+///    - Easy to understand and maintain
+///