Function usePresence

web/hooks/usePresence.ts:26–154

({ socket, sessionId, currentUser }: UsePresenceOptions)

// ─── Hook ─────────────────────────────────────────────────────────────────────

export function usePresence({ socket, sessionId, currentUser }: UsePresenceOptions) {
  const [presence, setPresence] = useState<PresenceState>(createPresenceState);
  const typingTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
  const isTypingRef = useRef(false);

  useEffect(() => {
    if (!socket) return;
    const cleanup: Array<() => void> = [];

    cleanup.push(
      socket.on("presence_sync", (e) => {
        setPresence((s) => presenceSyncUsers(s, e.users));
      })
    );

    cleanup.push(
      socket.on("session_state", (e) => {
        setPresence((s) => presenceSyncUsers(s, e.users));
      })
    );

    cleanup.push(
      socket.on("user_joined", (e) => {
        setPresence((s) => presenceAddUser(s, e.user));
      })
    );

    cleanup.push(
      socket.on("user_left", (e) => {
        setPresence((s) => presenceRemoveUser(s, e.user.id));
      })
    );

    cleanup.push(
      socket.on("cursor_update", (e) => {
        if (e.userId === currentUser.id) return; // skip own cursor
        setPresence((s) =>
          presenceUpdateCursor(s, e.userId, e.position, e.selectionStart, e.selectionEnd)
        );
      })
    );

    cleanup.push(
      socket.on("typing_start", (e) => {
        if (e.userId === currentUser.id) return;
        setPresence((s) => presenceSetTyping(s, e.user.id, true));
      })
    );

    cleanup.push(
      socket.on("typing_stop", (e) => {
        if (e.userId === currentUser.id) return;
        setPresence((s) => presenceSetTyping(s, e.user.id, false));
      })
    );

    return () => cleanup.forEach((off) => off());
  }, [socket, currentUser.id]);