event feed streams

lib/domain_layer/usecases/event_feed.dart

@@ -1,35 +1,35 @@
 import 'dart:async';
 import 'dart:developer';
 
+import 'package:rxdart/rxdart.dart';
+
 import '../entities/nostr_note.dart';
 import '../entities/tree_node.dart';
 import '../repositories/note_repository.dart';
 import 'follow.dart';
 
-///
-/// idea is to combine multiple streams here into the feed stream
-/// the feed stream gets then sorted on the ui in an intervall to prevent huge layout shifts
-///
-/// there could be one update stream and one for scrolling
-///
-///
-
 class EventFeed {
   final NoteRepository _noteRepository;
   final Follow _follow;
 
-  final String rootNoteFetchId = "event-root";
-  final String repliesFetchId = "event-replies";
+  final String repliesFetchId = "replies";
 
-  // root streams
-  final StreamController<NostrNote> _rootNoteController =
-      StreamController<NostrNote>();
-  Stream<NostrNote> get rootNoteStream => _rootNoteController.stream;
+  /// the complete build tree of replies => new updates = new state
+  final StreamController<List<TreeNode<NostrNote>>> _repliesTreeController =
+      StreamController<List<TreeNode<NostrNote>>>();
+  Stream<List<TreeNode<NostrNote>>> get repliesTreeStream =>
+      _repliesTreeController.stream;
 
+  /// raw replies
   final StreamController<NostrNote> _replyNotesController =
       StreamController<NostrNote>();
   Stream<NostrNote> get replyNotesStream => _replyNotesController.stream;
 
+  /// root note
+  final StreamController<NostrNote> _rootNoteController =
+      StreamController<NostrNote>();
+  Stream<NostrNote> get rootNoteStream => _rootNoteController.stream;
+
   EventFeed(this._noteRepository, this._follow);
 
   Future<void> subscribeToReplyNotes({
@@ -41,8 +41,20 @@ class EventFeed {
       rootNoteId: rootNoteId,
     );
 
-    replyNotes.listen((event) {
-      _replyNotesController.add(event);
+    replyNotes
+        .bufferTime(const Duration(milliseconds: 500))
+        .where((events) => events.isNotEmpty)
+        .listen((events) {
+      for (final event in events) {
+        _replyNotesController.add(event);
+      }
+
+      final tree = buildRepliesTree(
+        rootNoteId: rootNoteId,
+        replies: events,
+      );
+
+      _repliesTreeController.add(tree);
     });
   }
 
@@ -61,7 +73,6 @@ class EventFeed {
   /// build a tree from the replies \
   /// [returns] a list of first level replies \
   /// the cildren are replies of replies
-
   static List<TreeNode<NostrNote>> buildRepliesTree({
     required String rootNoteId,
     required List<NostrNote> replies,
@@ -114,6 +125,7 @@ class EventFeed {
     futures.add(_noteRepository.closeSubscription(repliesFetchId));
     futures.add(_rootNoteController.close());
     futures.add(_replyNotesController.close());
+    futures.add(_repliesTreeController.close());
 
     await Future.wait(futures);
   }