refactored chat data fetching to support separate cache and network callbacks

lib/api/marianumcloud/talk/chat/get_chat_cache.dart

@@ -5,7 +5,8 @@ import 'get_chat_response.dart';
 
 class GetChatCache extends SimpleCache<GetChatResponse> {
   GetChatCache({
-    required void Function(GetChatResponse) onUpdate,
+    super.onCacheData,
+    super.onNetworkData,
     super.onError,
     required String chatToken,
   }) : super(
@@ -19,7 +20,6 @@ class GetChatCache extends SimpleCache<GetChatResponse> {
             ),
           ).run(),
           fromJson: GetChatResponse.fromJson,
-          onUpdate: onUpdate,
         ) {
     start('nc-chat-$chatToken');
   }

lib/state/app/modules/chat/bloc/chat_bloc.dart

@@ -1,5 +1,4 @@
 import '../../../../../api/errors/error_mapper.dart';
-import '../../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../infrastructure/loadable_state/loading_error.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc.dart';
 import '../../../infrastructure/utility_widgets/loadable_hydrated_bloc/loadable_hydrated_bloc_event.dart';
@@ -57,23 +56,35 @@ class ChatBloc extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository
     final requestStart = DateTime.now();
     _lastTokenSet = requestStart;
 
+    bool stillCurrent() {
+      if (_lastTokenSet.isAfter(requestStart)) return false;
+      if ((innerState?.currentToken ?? '') != token) return false;
+      return true;
+    }
+
     Object? capturedError;
-    GetChatResponse? response;
     try {
-      response = await repo.data.getChat(
+      await repo.data.getChat(
         token: token,
+        onCacheData: (data) {
+          if (!stillCurrent()) return;
+          // Cache hit: show data immediately but preserve lastFetch — the
+          // cached payload may be stale and we don't want the UI to claim a
+          // fresh fetch just happened.
+          add(Emit((s) => s.copyWith(chatResponse: data)));
+        },
+        onNetworkData: (data) {
+          if (!stillCurrent()) return;
+          add(DataGathered((s) => s.copyWith(chatResponse: data)));
+        },
         onError: (e) => capturedError = e,
       );
     } catch (e) {
       capturedError = e;
     }
 
-    if (_lastTokenSet.isAfter(requestStart)) return;
+    if (!stillCurrent()) return;
-    if ((innerState?.currentToken ?? '') != token) return;
 
-    if (response != null) {
-      add(DataGathered((s) => s.copyWith(chatResponse: response)));
-    }
     if (capturedError != null) {
       add(Error(LoadingError(
         message: errorToUserMessage(capturedError),

lib/state/app/modules/chat/data_provider/chat_data_provider.dart

@@ -2,26 +2,18 @@ import '../../../../../api/marianumcloud/talk/chat/get_chat_cache.dart';
 import '../../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 
 class ChatDataProvider {
-  Future<GetChatResponse> getChat({
+  Future<void> getChat({
     required String token,
-    void Function(GetChatResponse data)? onUpdate,
+    void Function(GetChatResponse data)? onCacheData,
+    void Function(GetChatResponse data)? onNetworkData,
     void Function(Object)? onError,
   }) async {
-    GetChatResponse? latest;
-    Object? capturedError;
     final cache = GetChatCache(
       chatToken: token,
-      onUpdate: (data) {
+      onCacheData: onCacheData,
-        latest = data;
+      onNetworkData: onNetworkData,
-        onUpdate?.call(data);
+      onError: (e) => onError?.call(e),
-      },
-      onError: (e) {
-        capturedError = e;
-        onError?.call(e);
-      },
     );
     await cache.ready;
-    if (latest != null) return latest!;
-    throw capturedError ?? Exception('No data and no error from getChat');
   }
 }