android: fix unread ack to use latest visible message

android/CHANGELOG.md

@@ -700,3 +700,9 @@
   - unregister token on logout,
   - handle foreground push payload via existing notification service worker.
 - Added required env keys to `web/.env.example` and backend Firebase env keys to root `.env.example`.
+
+### Step 106 - Unread counter stabilization in Chat screen
+- Fixed read acknowledgement strategy in `ChatViewModel`:
+  - read status is now acknowledged by the latest visible message id in chat (not only latest incoming),
+  - delivery status still uses latest incoming message.
+- This removes cases where unread badge reappears after chat list refresh because the previous read ack used an outdated incoming id.

android/app/src/main/java/ru/daemonlord/messenger/ui/chat/ChatViewModel.kt

@@ -571,7 +571,7 @@ class ChatViewModel @Inject constructor(
                         highlightedMessageId = highlighted,
                     )
                 }
-                acknowledgeLatestIncoming(messages)
+                acknowledgeLatestMessages(messages)
             }
         }
     }
@@ -644,22 +644,20 @@ class ChatViewModel @Inject constructor(
         }
     }
 
-    private fun acknowledgeLatestIncoming(messages: List<MessageItem>) {
-        val latestIncoming = messages
-            .asReversed()
-            .firstOrNull { !it.isOutgoing }
-            ?: return
+    private fun acknowledgeLatestMessages(messages: List<MessageItem>) {
+        val latestVisible = messages.maxByOrNull { it.id } ?: return
+        val latestIncoming = messages.asReversed().firstOrNull { !it.isOutgoing }
 
-        if (lastDeliveredMessageId != latestIncoming.id) {
+        if (latestIncoming != null && lastDeliveredMessageId != latestIncoming.id) {
             lastDeliveredMessageId = latestIncoming.id
             viewModelScope.launch {
                 markMessageDeliveredUseCase(chatId = chatId, messageId = latestIncoming.id)
             }
         }
-        if (lastReadMessageId != latestIncoming.id) {
-            lastReadMessageId = latestIncoming.id
+        if (lastReadMessageId != latestVisible.id) {
+            lastReadMessageId = latestVisible.id
             viewModelScope.launch {
-                markMessageReadUseCase(chatId = chatId, messageId = latestIncoming.id)
+                markMessageReadUseCase(chatId = chatId, messageId = latestVisible.id)
             }
         }
     }