fix hub stream behaviour, gradually migrate encryption to new format, guard di in ClientHelper

Author: dabblingwithcode

school_data_hub_flutter/lib/app_utils/download_and_decrypt_file.dart

@@ -8,27 +8,28 @@ import 'package:school_data_hub_client/school_data_hub_client.dart';
 import 'package:school_data_hub_flutter/app_utils/custom_encrypter.dart';
 import 'package:school_data_hub_flutter/common/services/notification_service.dart';
 
+DefaultCacheManager get _cacheManager => di<DefaultCacheManager>();
+NotificationService get _notificationService => di<NotificationService>();
+
 Future<File?> downloadAndDecryptFile({
   required String documentId,
   required bool decrypt,
 }) async {
-  final cacheManager = di<DefaultCacheManager>();
-  final notificationService = di<NotificationService>();
-
   // Check cache
-  final fileInfo = await cacheManager.getFileFromCache(documentId);
+  final fileInfo = await _cacheManager.getFileFromCache(documentId);
 
   if (fileInfo != null && await fileInfo.file.exists()) {
     if (!decrypt) {
       return fileInfo.file;
     }
 
     final fileBytes = await fileInfo.file.readAsBytes();
-    final (:bytes, :wasLegacy) =
-        await customEncrypter.decryptFileBytesAsync(fileBytes);
+    final (:bytes, :wasLegacy) = await customEncrypter.decryptFileBytesAsync(
+      fileBytes,
+    );
 
     if (wasLegacy) {
-      _migrateToNewFormat(documentId, bytes, cacheManager);
+      _migrateToNewFormat(documentId, bytes);
     }
 
     final tempDir = await Directory.systemTemp.createTemp();
@@ -41,12 +42,12 @@ Future<File?> downloadAndDecryptFile({
   }
 
   // Download
-  notificationService.apiRunning(true);
+  _notificationService.apiRunning(true);
   final ByteData? byteData = await di<Client>().files.getImage(documentId);
-  notificationService.apiRunning(false);
+  _notificationService.apiRunning(false);
 
   if (byteData == null) {
-    notificationService.showSnackBar(
+    _notificationService.showSnackBar(
       NotificationType.error,
       'Fehler beim Laden der Datei',
     );
@@ -55,7 +56,7 @@ Future<File?> downloadAndDecryptFile({
 
   Uint8List fileBytes = byteData.buffer.asUint8List();
   // Cache it
-  await cacheManager.putFile(documentId, fileBytes);
+  await _cacheManager.putFile(documentId, fileBytes);
 
   if (!decrypt) {
     final tempDir = await Directory.systemTemp.createTemp();
@@ -65,11 +66,12 @@ Future<File?> downloadAndDecryptFile({
     return tempFile;
   }
 
-  final (:bytes, :wasLegacy) =
-      await customEncrypter.decryptFileBytesAsync(fileBytes);
+  final (:bytes, :wasLegacy) = await customEncrypter.decryptFileBytesAsync(
+    fileBytes,
+  );
 
   if (wasLegacy) {
-    _migrateToNewFormat(documentId, bytes, cacheManager);
+    _migrateToNewFormat(documentId, bytes);
   }
 
   final tempDir = await Directory.systemTemp.createTemp();
@@ -83,20 +85,17 @@ Future<File?> downloadAndDecryptFile({
 
 /// Fire-and-forget: re-encrypt [plainBytes] in the new format, update the
 /// server file, and refresh the local cache — all without blocking the caller.
-void _migrateToNewFormat(
-  String documentId,
-  Uint8List plainBytes,
-  DefaultCacheManager cacheManager,
-) {
+void _migrateToNewFormat(String documentId, Uint8List plainBytes) {
   Future(() async {
     try {
       final newEncrypted = customEncrypter.encryptTheseBytes(plainBytes);
       final byteData = ByteData.sublistView(newEncrypted);
-      final ok = await di<Client>()
-          .files
-          .replaceEncryptedFileBytes(documentId, byteData);
+      final ok = await di<Client>().files.replaceEncryptedFileBytes(
+        documentId,
+        byteData,
+      );
       if (ok) {
-        await cacheManager.putFile(documentId, newEncrypted);
+        await _cacheManager.putFile(documentId, newEncrypted);
       }
     } catch (_) {
       // Migration is best-effort; silently ignore failures.

school_data_hub_flutter/lib/common/services/hub_stream_service.dart

@@ -99,6 +99,10 @@ class HubStreamService with WidgetsBindingObserver {
         break;
       case AppLifecycleState.resumed:
         _appInForeground = true;
+        if (isConnected) {
+          _log.info('[HUB] App resumed — already connected, skipping');
+          break;
+        }
         _log.info('[HUB] App resumed — scheduling reconnect');
         _scheduleReconnect(
           isReconnect: true,
@@ -138,8 +142,8 @@ class HubStreamService with WidgetsBindingObserver {
     String reason = 'unknown',
   }) {
     if (!_appInForeground || _disposed) return;
+    if (_connecting) return;
     if (_reconnectTimer != null) return;
-    _cancelReconnectTimer();
     final delayWithJitter = _withJitter(delayMs);
     _log.info(
       '[HUB] reconnect_scheduled reason=$reason delayMs=$delayWithJitter',

school_data_hub_flutter/lib/core/client/client_helper.dart

@@ -4,9 +4,6 @@ import 'package:school_data_hub_flutter/common/services/hub_stream_service.dart'
 import 'package:school_data_hub_flutter/common/services/notification_service.dart';
 import 'package:school_data_hub_flutter/core/session/hub_session_manager.dart';
 
-final _notificationService = di<NotificationService>();
-final _hubSessionManager = di<HubSessionManager>();
-
 class ClientHelper {
   // Make it a singleton
   static final ClientHelper _instance = ClientHelper._internal();
@@ -18,12 +15,12 @@ class ClientHelper {
     String? errorMessage,
   }) async {
     try {
-      _notificationService.apiRunning(true);
+      di<NotificationService>().apiRunning(true);
       final result = await call();
-      _notificationService.apiRunning(false);
+      di<NotificationService>().apiRunning(false);
       return result;
     } on ServerpodClientException catch (e) {
-      _notificationService.apiRunning(false);
+      di<NotificationService>().apiRunning(false);
 
       // 502 / 503 during a server restart are expected transients.
       // Suppress them while the hub stream is not yet connected so the
@@ -39,23 +36,23 @@ class ClientHelper {
         }
       }
 
-      _notificationService.showInformationDialog(
+      di<NotificationService>().showInformationDialog(
         NotificationType.error,
         'API Fehler: ${errorMessage ?? "Unbekannt"}: $e',
       );
 
       if (e.toString().contains('Not authorized') ||
           e.toString().contains('401')) {
-        _notificationService.showInformationDialog(
+        di<NotificationService>().showInformationDialog(
           NotificationType.error,
           'Authentication required. Please log in again.',
         );
-        _hubSessionManager.signOutDevice();
+        di<HubSessionManager>().signOutDevice();
       }
       return null;
     } catch (e) {
-      _notificationService.apiRunning(false);
-      _notificationService.showInformationDialog(
+      di<NotificationService>().apiRunning(false);
+      di<NotificationService>().showInformationDialog(
         NotificationType.error,
         'API Fehler:\n $errorMessage: $e',
       );