Fix unread divider: update sessionUnreadRef when messages are marked as read

client-web/src/modules/chats/presentation/components/ChatView.tsx

@@ -187,12 +187,31 @@ export default function ChatView({ onStartCall, onStartGroupCall }: { onStartCal
   // Refs and logic for tracking session's first unread message to show the divider exactly once per load
   const sessionUnreadRef = useRef<{ chatId: string, msgId: string | null }>({ chatId: '', msgId: null });
 
-  if (activeChat && activeChat !== sessionUnreadRef.current.chatId && !isLoadingMessages) {
+  // Update sessionUnreadRef when chat changes OR when messages are marked as read
+  useEffect(() => {
+    if (!activeChat || isLoadingMessages) return;
+
+    // Reset on chat change
+    if (activeChat !== sessionUnreadRef.current.chatId) {
       const firstUnreadMsg = chatMessages.find(
         (m) => m.senderId !== user?.id && !m.readBy?.some((r) => r.userId === user?.id)
       );
       sessionUnreadRef.current = { chatId: activeChat, msgId: firstUnreadMsg ? firstUnreadMsg.id : null };
+    } else {
+      // Update if the first unread message was read (msgId no longer exists in unread list)
+      const firstUnreadMsg = chatMessages.find(
+        (m) => m.senderId !== user?.id && !m.readBy?.some((r) => r.userId === user?.id)
+      );
+      if (sessionUnreadRef.current.msgId && !firstUnreadMsg) {
+        // All messages are now read
+        sessionUnreadRef.current.msgId = null;
+      } else if (firstUnreadMsg && sessionUnreadRef.current.msgId !== firstUnreadMsg.id) {
+        // First unread changed (some messages were read)
+        sessionUnreadRef.current.msgId = firstUnreadMsg.id;
       }
+    }
+  }, [activeChat, chatMessages, user?.id, isLoadingMessages]);
+
   const firstUnreadId = activeChat === sessionUnreadRef.current.chatId ? sessionUnreadRef.current.msgId : null;
   const initialScrollChatId = useRef<string | null>(null);
 
@@ -573,6 +592,7 @@ export default function ChatView({ onStartCall, onStartGroupCall }: { onStartCal
       {
         root: scrollContainerRef.current,
         threshold: 0.1,
+        rootMargin: '0px',
       }
     );
 
@@ -584,8 +604,27 @@ export default function ChatView({ onStartCall, onStartGroupCall }: { onStartCal
       unreadElements.forEach((el: Element) => {
         const id = el.getAttribute('data-message-id');
         if (id && !sentReadIdsRef.current.has(id)) {
+          // Check if element is already visible
+          const rect = el.getBoundingClientRect();
+          const containerRect = scrollContainerRef.current!.getBoundingClientRect();
+          const isVisible = rect.top >= containerRect.top && rect.bottom <= containerRect.bottom;
+
+          if (isVisible) {
+            // Mark as read immediately without waiting for intersection
+            const seqId = parseInt(el.getAttribute('data-sequence-id') || '0', 10);
+            if (seqId > 0) {
+              socket.emit('read_messages', {
+                chatId: activeChat,
+                lastReadMessageId: id,
+                lastReadSequenceId: seqId,
+              });
+              useChatStore.getState().markRead(activeChat, user.id, seqId);
+              sentReadIdsRef.current.add(id);
+            }
+          } else {
             observer.observe(el);
           }
+        }
       });
     };