retail/docs/AUTH_TROUBLESHOOTING.md

Authentication Troubleshooting Guide

Date: October 10, 2025

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Issue: Login Successful But No Navigation

Symptoms

• Login API call succeeds
• Token is saved
• But app doesn't navigate to MainScreen
• AuthWrapper doesn't react to state change

Root Causes Fixed

1. GetIt Dependency Injection Error ✅ FIXED

• Problem: AuthRepository was trying to use GetIt but wasn't registered
• Solution: Migrated to pure Riverpod dependency injection
• Files Changed: lib/features/auth/presentation/providers/auth_provider.dart

2. Circular Dependency in Auth Provider ✅ FIXED

• Problem: Auth.build() was calling async _checkAuthStatus() causing circular dependency
• Solution: Moved initialization to separate initialize() method
• Files Changed: lib/features/auth/presentation/providers/auth_provider.dart, lib/app.dart

3. Provider Not Kept Alive ✅ FIXED

• Problem: Auth state provider was being disposed between rebuilds
• Solution: Added @Riverpod(keepAlive: true) to Auth provider
• Files Changed: lib/features/auth/presentation/providers/auth_provider.dart

4. State Not Updating Properly ✅ FIXED

• Problem: copyWith method wasn't properly setting isAuthenticated: true
• Solution: Updated login/register methods to create new AuthState with explicit values
• Files Changed: lib/features/auth/presentation/providers/auth_provider.dart

---

How Auth Flow Should Work

1. App Startup

main()
  → ProviderScope created
  → RetailApp builds
  → initState() schedules auth initialization
  → auth.initialize() checks for saved token
  → If token found: loads user profile, sets isAuthenticated = true
  → If no token: sets isAuthenticated = false

2. Login Flow

User enters credentials
  → Taps Login button
  → _handleLogin() called
  → ref.read(authProvider.notifier).login(email, password)
  → API call to /api/auth/login
  → Success: saves token, sets user, sets isAuthenticated = true
  → AuthWrapper watches authProvider
  → isAuthenticated changes to true
  → AuthWrapper rebuilds
  → Shows MainScreen instead of LoginPage

3. Logout Flow

User taps Logout in Settings
  → Confirmation dialog shown
  → ref.read(authProvider.notifier).logout()
  → Token cleared from secure storage
  → DioClient token cleared
  → State set to isAuthenticated = false
  → AuthWrapper rebuilds
  → Shows LoginPage

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Debug Checklist

If auth flow still not working, check these:

1. Verify Provider State

// Add this to login_page.dart _handleLogin after login success
final authState = ref.read(authProvider);
print('🔐 Auth State after login:');
print('  isAuthenticated: ${authState.isAuthenticated}');
print('  user: ${authState.user?.name}');
print('  isLoading: ${authState.isLoading}');
print('  errorMessage: ${authState.errorMessage}');

2. Verify AuthWrapper Reaction

// Add this to auth_wrapper.dart build method
@override
Widget build(BuildContext context, WidgetRef ref) {
  final authState = ref.watch(authProvider);

  print('🔄 AuthWrapper rebuild:');
  print('  isAuthenticated: ${authState.isAuthenticated}');
  print('  isLoading: ${authState.isLoading}');
  print('  user: ${authState.user?.name}');

  // ... rest of build method
}

3. Verify Token Saved

// Add this to auth_repository_impl.dart login method after saving token
print('💾 Token saved: ${authResponse.accessToken.substring(0, 20)}...');
print('💾 DioClient token set');

4. Verify API Response

// Add this to auth_remote_datasource.dart login method
print('📡 Login API response:');
print('  Status: ${response.statusCode}');
print('  User: ${response.data['user']?['name']}');
print('  Token length: ${response.data['accessToken']?.length}');

---

Common Issues and Solutions

Issue: State Updates But UI Doesn't Rebuild

Cause: Using ref.read() instead of ref.watch() in AuthWrapper

Solution: Ensure AuthWrapper uses ref.watch(authProvider)

final authState = ref.watch(authProvider);  // ✅ Correct - watches for changes
// NOT ref.read(authProvider)  // ❌ Wrong - doesn't rebuild

Issue: Login Success But isAuthenticated = false

Cause: State update not explicitly setting isAuthenticated: true

Solution: Create new AuthState with explicit values

state = AuthState(
  user: authResponse.user,
  isAuthenticated: true,  // ✅ Explicit value
  isLoading: false,
  errorMessage: null,
);

Issue: Provider Disposes Between Rebuilds

Cause: Provider not marked as keepAlive

Solution: Add @Riverpod(keepAlive: true) to Auth provider

@Riverpod(keepAlive: true)  // ✅ Keeps state alive
class Auth extends _$Auth {
  // ...
}

Issue: Circular Dependency Error

Cause: Calling async operations in build() method

Solution: Use separate initialization method

@override
AuthState build() {
  return const AuthState();  // ✅ Sync only
}

Future<void> initialize() async {
  // ✅ Async operations here
}

---

Testing the Fix

Test 1: Fresh App Start (No Token)

1. Clear app data or use fresh install
2. Run app: flutter run
3. Expected: Shows LoginPage immediately
4. Result: ✅ Pass / ❌ Fail

Test 2: Login Flow

1. Start at LoginPage
2. Enter credentials: admin@retailpos.com / Admin123!
3. Tap Login
4. Expected:
   • Loading indicator appears
   • On success: Navigate to MainScreen with bottom tabs
5. Result: ✅ Pass / ❌ Fail

Test 3: Token Persistence

1. Login successfully
2. Close app completely
3. Restart app
4. Expected:
   • Shows loading briefly
   • Automatically goes to MainScreen (no login needed)
5. Result: ✅ Pass / ❌ Fail

Test 4: Logout Flow

1. While logged in, go to Settings tab
2. Tap Logout button
3. Confirm logout
4. Expected: Navigate back to LoginPage
5. Result: ✅ Pass / ❌ Fail

Test 5: Invalid Credentials

1. Enter wrong email/password
2. Tap Login
3. Expected:
   • Shows error SnackBar
   • Stays on LoginPage
   • Error message displayed
4. Result: ✅ Pass / ❌ Fail

---

Architecture Diagram

┌─────────────────────────────────────────────────┐
│              ProviderScope                      │
│  ┌───────────────────────────────────────────┐ │
│  │           RetailApp                       │ │
│  │  (initializes auth on startup)            │ │
│  │  ┌─────────────────────────────────────┐  │ │
│  │  │      MaterialApp                    │  │ │
│  │  │  ┌───────────────────────────────┐  │  │ │
│  │  │  │     AuthWrapper              │  │  │ │
│  │  │  │  (watches authProvider)      │  │  │ │
│  │  │  │                              │  │  │ │
│  │  │  │  if isAuthenticated:         │  │  │ │
│  │  │  │  ┌─────────────────────────┐ │  │  │ │
│  │  │  │  │   MainScreen            │ │  │  │ │
│  │  │  │  │   (with bottom tabs)    │ │  │  │ │
│  │  │  │  └─────────────────────────┘ │  │  │ │
│  │  │  │                              │  │  │ │
│  │  │  │  else:                       │  │  │ │
│  │  │  │  ┌─────────────────────────┐ │  │  │ │
│  │  │  │  │   LoginPage             │ │  │  │ │
│  │  │  │  │   (login form)          │ │  │  │ │
│  │  │  │  └─────────────────────────┘ │  │  │ │
│  │  │  └───────────────────────────────┘  │  │ │
│  │  └─────────────────────────────────────┘  │ │
│  └───────────────────────────────────────────┘ │
└─────────────────────────────────────────────────┘
                      ↕
              ┌───────────────┐
              │  authProvider │
              │  (keepAlive)  │
              └───────────────┘
                      ↕
          ┌───────────────────────┐
          │  authRepository       │
          │  ↓                    │
          │  authRemoteDataSource │
          │  ↓                    │
          │  dioClient            │
          │  ↓                    │
          │  secureStorage        │
          └───────────────────────┘

---

Files Modified

Core Auth Files

• ✅ lib/features/auth/presentation/providers/auth_provider.dart

  • Added @Riverpod(keepAlive: true) to Auth provider
  • Fixed copyWith method with clearUser and clearError flags
  • Updated login/register to explicitly set isAuthenticated: true
  • Moved auth check to initialize() method

• ✅ lib/app.dart

  • Changed from ConsumerWidget to ConsumerStatefulWidget
  • Added initState() to call auth.initialize()

• ✅ lib/main.dart

  • Removed GetIt initialization
  • Using pure Riverpod for DI

• ✅ lib/features/auth/presentation/widgets/auth_wrapper.dart

  • Already correct - uses ref.watch(authProvider)

• ✅ lib/features/auth/presentation/pages/login_page.dart

  • Already correct - login logic properly calls provider

---

Expected Behavior After Fixes

1. ✅ App starts → auth initializes → shows LoginPage (if no token)
2. ✅ Login success → state updates → AuthWrapper rebuilds → shows MainScreen
3. ✅ Token persists → app restart → auto-login works
4. ✅ Logout → state clears → AuthWrapper rebuilds → shows LoginPage
5. ✅ All tabs accessible after login (Home, Products, Categories, Settings)

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Next Steps If Still Not Working

1. Add Debug Logs: Add print statements to trace state changes
2. Check Backend: Ensure API endpoints are working and returning correct data
3. Verify Token Format: Check that JWT token is valid format
4. Check API Response Structure: Ensure response matches model expectations
5. Test with Hot Restart: Try r (hot reload) vs R (hot restart) in Flutter

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Status: All known issues fixed. Auth flow should work correctly now.

If issues persist, add debug logging as described above to trace the exact point of failure.