feat(realtime): live online/offline events and unified search

- add websocket events user_online/user_offline
- broadcast presence changes on first connect and final disconnect only
- apply live presence updates in web chat store and realtime hook
- move public discover into unified left search (users + groups/channels)
- remove separate Discover Chats dialog/menu entry

app/realtime/presence.py

@@ -3,26 +3,30 @@ from redis.exceptions import RedisError
 from app.utils.redis_client import get_redis_client
 
 
-async def mark_user_online(user_id: int) -> None:
+async def mark_user_online(user_id: int) -> bool:
     try:
         redis = get_redis_client()
         key = f"presence:user:{user_id}"
         count = await redis.incr(key)
         if count == 1:
             await redis.expire(key, 3600)
+            return True
+        return False
     except RedisError:
-        return
+        return False
 
 
-async def mark_user_offline(user_id: int) -> None:
+async def mark_user_offline(user_id: int) -> bool:
     try:
         redis = get_redis_client()
         key = f"presence:user:{user_id}"
         value = await redis.decr(key)
         if value <= 0:
             await redis.delete(key)
+            return True
+        return False
     except RedisError:
-        return
+        return False
 
 
 async def is_user_online(user_id: int) -> bool:

app/realtime/schemas.py

@@ -15,6 +15,8 @@ RealtimeEventName = Literal[
     "typing_stop",
     "message_read",
     "message_delivered",
+    "user_online",
+    "user_offline",
     "error",
 ]
 

app/realtime/service.py

@@ -54,7 +54,9 @@ class RealtimeGateway:
         )
         for chat_id in user_chat_ids:
             self._chat_subscribers[chat_id].add(user_id)
-        await mark_user_online(user_id)
+        became_online = await mark_user_online(user_id)
+        if became_online:
+            await self._broadcast_presence(user_chat_ids, user_id=user_id, is_online=True, last_seen_at=None)
         await self._send_user_event(
             user_id,
             OutgoingRealtimeEvent(
@@ -77,8 +79,15 @@ class RealtimeGateway:
                 subscribers.discard(user_id)
                 if not subscribers:
                     self._chat_subscribers.pop(chat_id, None)
-            await mark_user_offline(user_id)
+            became_offline = await mark_user_offline(user_id)
             await self._persist_last_seen(user_id)
+            if became_offline:
+                await self._broadcast_presence(
+                    user_chat_ids,
+                    user_id=user_id,
+                    is_online=False,
+                    last_seen_at=datetime.now(timezone.utc),
+                )
 
     async def handle_send_message(self, db: AsyncSession, user_id: int, payload: SendMessagePayload) -> None:
         message = await create_chat_message(
@@ -195,12 +204,22 @@ class RealtimeGateway:
             user_connections.pop(connection_id, None)
         if not user_connections:
             self._connections.pop(user_id, None)
+            affected_chat_ids: list[int] = []
             for chat_id, subscribers in list(self._chat_subscribers.items()):
+                if user_id in subscribers:
+                    affected_chat_ids.append(chat_id)
                 subscribers.discard(user_id)
                 if not subscribers:
                     self._chat_subscribers.pop(chat_id, None)
-            await mark_user_offline(user_id)
+            became_offline = await mark_user_offline(user_id)
             await self._persist_last_seen(user_id)
+            if became_offline:
+                await self._broadcast_presence(
+                    affected_chat_ids,
+                    user_id=user_id,
+                    is_online=False,
+                    last_seen_at=datetime.now(timezone.utc),
+                )
 
     @staticmethod
     def _extract_chat_id(channel: str) -> int | None:
@@ -219,5 +238,24 @@ class RealtimeGateway:
         except Exception:
             return
 
+    async def _broadcast_presence(
+        self,
+        chat_ids: list[int],
+        *,
+        user_id: int,
+        is_online: bool,
+        last_seen_at: datetime | None,
+    ) -> None:
+        event_name = "user_online" if is_online else "user_offline"
+        for chat_id in chat_ids:
+            payload = {
+                "chat_id": chat_id,
+                "user_id": user_id,
+                "is_online": is_online,
+            }
+            if last_seen_at is not None:
+                payload["last_seen_at"] = last_seen_at.isoformat()
+            await self._publish_chat_event(chat_id, event=event_name, payload=payload)
+
 
 realtime_gateway = RealtimeGateway()

web/src/components/ChatList.tsx

@@ -1,6 +1,8 @@
 import { useEffect, useState } from "react";
 import { createPortal } from "react-dom";
-import { clearChat, deleteChat } from "../api/chats";
+import { clearChat, createPrivateChat, discoverChats, deleteChat, getChats, joinChat } from "../api/chats";
+import { searchUsers } from "../api/users";
+import type { DiscoverChat, UserSearchItem } from "../chat/types";
 import { updateMyProfile } from "../api/users";
 import { useAuthStore } from "../store/authStore";
 import { useChatStore } from "../store/chatStore";
@@ -14,6 +16,9 @@ export function ChatList() {
   const loadChats = useChatStore((s) => s.loadChats);
   const me = useAuthStore((s) => s.me);
   const [search, setSearch] = useState("");
+  const [userResults, setUserResults] = useState<UserSearchItem[]>([]);
+  const [discoverResults, setDiscoverResults] = useState<DiscoverChat[]>([]);
+  const [searchLoading, setSearchLoading] = useState(false);
   const [tab, setTab] = useState<"all" | "people" | "groups" | "channels">("all");
   const [ctxChatId, setCtxChatId] = useState<number | null>(null);
   const [ctxPos, setCtxPos] = useState<{ x: number; y: number } | null>(null);
@@ -40,6 +45,40 @@ export function ChatList() {
     return () => clearTimeout(timer);
   }, [search, loadChats]);
 
+  useEffect(() => {
+    const term = search.trim();
+    if (term.replace("@", "").length < 2) {
+      setUserResults([]);
+      setDiscoverResults([]);
+      setSearchLoading(false);
+      return;
+    }
+    let cancelled = false;
+    setSearchLoading(true);
+    void (async () => {
+      try {
+        const [users, publicChats] = await Promise.all([searchUsers(term), discoverChats(term)]);
+        if (cancelled) {
+          return;
+        }
+        setUserResults(users);
+        setDiscoverResults(publicChats);
+      } catch {
+        if (!cancelled) {
+          setUserResults([]);
+          setDiscoverResults([]);
+        }
+      } finally {
+        if (!cancelled) {
+          setSearchLoading(false);
+        }
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [search]);
+
   useEffect(() => {
     const onKeyDown = (event: KeyboardEvent) => {
       if (event.key !== "Escape") {
@@ -112,6 +151,63 @@ export function ChatList() {
             </button>
           ))}
         </div>
+        {search.trim().replace("@", "").length >= 2 ? (
+          <div className="mt-3 rounded-xl border border-slate-700/70 bg-slate-900/70 p-2">
+            {searchLoading ? <p className="px-2 py-1 text-xs text-slate-400">Searching...</p> : null}
+            {!searchLoading && userResults.length === 0 && discoverResults.length === 0 ? (
+              <p className="px-2 py-1 text-xs text-slate-400">Nothing found</p>
+            ) : null}
+            {userResults.length > 0 ? (
+              <div className="mb-1">
+                <p className="px-2 py-1 text-[10px] uppercase tracking-wide text-slate-400">People</p>
+                {userResults.slice(0, 5).map((user) => (
+                  <button
+                    className="block w-full rounded-lg px-2 py-1.5 text-left hover:bg-slate-800"
+                    key={`user-${user.id}`}
+                    onClick={async () => {
+                      const chat = await createPrivateChat(user.id);
+                      const updatedChats = await getChats();
+                      useChatStore.setState({ chats: updatedChats, activeChatId: chat.id });
+                      setSearch("");
+                      setUserResults([]);
+                      setDiscoverResults([]);
+                    }}
+                  >
+                    <p className="truncate text-xs font-semibold">{user.name}</p>
+                    <p className="truncate text-[11px] text-slate-400">@{user.username}</p>
+                  </button>
+                ))}
+              </div>
+            ) : null}
+            {discoverResults.length > 0 ? (
+              <div>
+                <p className="px-2 py-1 text-[10px] uppercase tracking-wide text-slate-400">Groups and Channels</p>
+                {discoverResults.slice(0, 5).map((chat) => (
+                  <button
+                    className="flex w-full items-center justify-between rounded-lg px-2 py-1.5 text-left hover:bg-slate-800"
+                    key={`discover-${chat.id}`}
+                    onClick={async () => {
+                      if (!chat.is_member) {
+                        await joinChat(chat.id);
+                      }
+                      const updatedChats = await getChats();
+                      useChatStore.setState({ chats: updatedChats, activeChatId: chat.id });
+                      setSearch("");
+                      setUserResults([]);
+                      setDiscoverResults([]);
+                    }}
+                  >
+                    <div className="min-w-0">
+                      <p className="truncate text-xs font-semibold">{chat.display_title || chat.title || (chat.type === "group" ? "Group" : "Channel")}</p>
+                      <p className="truncate text-[11px] text-slate-400">{chat.handle ? `@${chat.handle}` : chat.type}</p>
+                    </div>
+                    <span className="ml-2 shrink-0 text-[10px] text-slate-400">{chat.is_member ? "open" : "join"}</span>
+                  </button>
+                ))}
+              </div>
+            ) : null}
+          </div>
+        ) : null}
       </div>
       <div className="tg-scrollbar flex-1 overflow-auto">
         {filteredChats.map((chat) => (

web/src/components/NewChatPanel.tsx

@@ -1,11 +1,11 @@
 import { FormEvent, useMemo, useState } from "react";
-import { createChat, createPrivateChat, createPublicChat, discoverChats, getChats, getSavedMessagesChat, joinChat } from "../api/chats";
+import { createChat, createPrivateChat, createPublicChat, getChats, getSavedMessagesChat } from "../api/chats";
 import { searchUsers } from "../api/users";
-import type { ChatType, DiscoverChat, UserSearchItem } from "../chat/types";
+import type { ChatType, UserSearchItem } from "../chat/types";
 import { useChatStore } from "../store/chatStore";
 
 type CreateMode = "group" | "channel";
-type DialogMode = "none" | "private" | "group" | "channel" | "discover";
+type DialogMode = "none" | "private" | "group" | "channel";
 
 export function NewChatPanel() {
   const [dialog, setDialog] = useState<DialogMode>("none");
@@ -15,7 +15,6 @@ export function NewChatPanel() {
   const [description, setDescription] = useState("");
   const [isPublic, setIsPublic] = useState(false);
   const [results, setResults] = useState<UserSearchItem[]>([]);
-  const [discoverResults, setDiscoverResults] = useState<DiscoverChat[]>([]);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [menuOpen, setMenuOpen] = useState(false);
@@ -38,13 +37,6 @@ export function NewChatPanel() {
     }
   }
 
-  async function handleDiscover(value: string) {
-    setQuery(value);
-    setError(null);
-    const items = await discoverChats(value.trim() ? value : undefined);
-    setDiscoverResults(items);
-  }
-
   async function refreshChatsAndSelect(chatId?: number) {
     const chats = await getChats();
     useChatStore.setState({ chats });
@@ -112,26 +104,11 @@ export function NewChatPanel() {
     }
   }
 
-  async function joinPublicChat(chatId: number) {
-    setLoading(true);
-    setError(null);
-    try {
-      const joined = await joinChat(chatId);
-      await refreshChatsAndSelect(joined.id);
-      setDialog("none");
-    } catch {
-      setError("Failed to join chat");
-    } finally {
-      setLoading(false);
-    }
-  }
-
   function closeDialog() {
     setDialog("none");
     setError(null);
     setQuery("");
     setResults([]);
-    setDiscoverResults([]);
     setIsPublic(false);
   }
 
@@ -143,9 +120,6 @@ export function NewChatPanel() {
             <button className="block w-full rounded-lg px-3 py-2 text-left text-sm hover:bg-slate-800" onClick={() => void openSavedMessages()}>
               Saved Messages
             </button>
-            <button className="block w-full rounded-lg px-3 py-2 text-left text-sm hover:bg-slate-800" onClick={() => { setDialog("discover"); setMenuOpen(false); }}>
-              Discover Chats
-            </button>
             <button className="block w-full rounded-lg px-3 py-2 text-left text-sm hover:bg-slate-800" onClick={() => { setDialog("channel"); setMenuOpen(false); }}>
               New Channel
             </button>
@@ -167,7 +141,7 @@ export function NewChatPanel() {
           <div className="w-full max-w-sm rounded-2xl border border-slate-700/80 bg-slate-900 p-3 shadow-2xl">
             <div className="mb-2 flex items-center justify-between">
               <p className="text-sm font-semibold">
-                {dialog === "private" ? "New Message" : dialog === "group" ? "New Group" : dialog === "channel" ? "New Channel" : "Discover Chats"}
+                {dialog === "private" ? "New Message" : dialog === "group" ? "New Group" : "New Channel"}
               </p>
               <button className="rounded-md bg-slate-700/80 px-2 py-1 text-xs" onClick={closeDialog}>Close</button>
             </div>
@@ -187,31 +161,6 @@ export function NewChatPanel() {
               </div>
             ) : null}
 
-            {dialog === "discover" ? (
-              <div className="space-y-2">
-                <input className="w-full rounded-xl border border-slate-700/80 bg-slate-800/80 px-3 py-2 text-sm outline-none placeholder:text-slate-400 focus:border-sky-500" placeholder="Search groups/channels by title or @handle" value={query} onChange={(e) => void handleDiscover(e.target.value)} />
-                <p className="text-xs text-slate-400">Search works only for public groups/channels.</p>
-                <div className="tg-scrollbar max-h-52 overflow-auto">
-                  {discoverResults.map((chat) => (
-                    <div className="mb-1 flex items-center justify-between rounded-lg bg-slate-800 px-3 py-2" key={chat.id}>
-                      <div className="min-w-0">
-                        <p className="truncate text-sm font-semibold">{chat.display_title || chat.title || (chat.type === "group" ? "Group" : "Channel")}</p>
-                        <p className="truncate text-xs text-slate-400">{chat.handle ? `@${chat.handle}` : chat.type}</p>
-                      </div>
-                      {chat.is_member ? (
-                        <span className="text-xs text-slate-400">joined</span>
-                      ) : (
-                        <button className="rounded bg-sky-500 px-2 py-1 text-xs font-semibold text-slate-950" onClick={() => void joinPublicChat(chat.id)}>
-                          Join
-                        </button>
-                      )}
-                    </div>
-                  ))}
-                  {discoverResults.length === 0 ? <p className="text-xs text-slate-400">No public chats</p> : null}
-                </div>
-              </div>
-            ) : null}
-
             {dialog === "group" || dialog === "channel" ? (
               <form className="space-y-2" onSubmit={(e) => void createByType(e, dialog)}>
                 <input className="w-full rounded-xl border border-slate-700/80 bg-slate-800/80 px-3 py-2 text-sm outline-none placeholder:text-slate-400 focus:border-sky-500" placeholder={dialog === "group" ? "Group title" : "Channel title"} value={title} onChange={(e) => setTitle(e.target.value)} />

web/src/hooks/useRealtime.ts

@@ -127,6 +127,19 @@ export function useRealtime() {
             chatStore.setMessageDeliveryStatusUpTo(chatId, maxId, "read", authStore.me?.id ?? -1);
           }
         }
+        if (event.event === "user_online" || event.event === "user_offline") {
+          const chatId = Number(event.payload.chat_id);
+          const userId = Number(event.payload.user_id);
+          const isOnline = Boolean(event.payload.is_online);
+          const lastSeenAtRaw = event.payload.last_seen_at;
+          const lastSeenAt = typeof lastSeenAtRaw === "string" ? lastSeenAtRaw : undefined;
+          if (!Number.isFinite(chatId) || !Number.isFinite(userId)) {
+            return;
+          }
+          if (userId !== authStore.me?.id) {
+            chatStore.applyPresenceEvent(chatId, userId, isOnline, lastSeenAt);
+          }
+        }
       };
 
       ws.onclose = () => {

web/src/store/chatStore.ts

@@ -37,6 +37,7 @@ interface ChatState {
   setTypingUsers: (chatId: number, userIds: number[]) => void;
   setReplyToMessage: (chatId: number, message: Message | null) => void;
   updateChatPinnedMessage: (chatId: number, pinnedMessageId: number | null) => void;
+  applyPresenceEvent: (chatId: number, userId: number, isOnline: boolean, lastSeenAt?: string) => void;
 }
 
 export const useChatStore = create<ChatState>((set, get) => ({
@@ -244,5 +245,32 @@ export const useChatStore = create<ChatState>((set, get) => ({
   updateChatPinnedMessage: (chatId, pinnedMessageId) =>
     set((state) => ({
       chats: state.chats.map((chat) => (chat.id === chatId ? { ...chat, pinned_message_id: pinnedMessageId } : chat))
+    })),
+  applyPresenceEvent: (chatId, userId, isOnline, lastSeenAt) =>
+    set((state) => ({
+      chats: state.chats.map((chat) => {
+        if (chat.id !== chatId) {
+          return chat;
+        }
+        if (chat.type === "private" && chat.counterpart_user_id === userId) {
+          return {
+            ...chat,
+            counterpart_is_online: isOnline,
+            counterpart_last_seen_at: isOnline ? chat.counterpart_last_seen_at : (lastSeenAt ?? new Date().toISOString())
+          };
+        }
+        if (chat.type === "group") {
+          const currentOnline = chat.online_count ?? 0;
+          const membersCount = chat.members_count ?? currentOnline;
+          const nextOnline = isOnline
+            ? Math.min(membersCount, currentOnline + 1)
+            : Math.max(0, currentOnline - 1);
+          return {
+            ...chat,
+            online_count: nextOnline
+          };
+        }
+        return chat;
+      })
     }))
 }));