Function ChatApp

demo/chat/App.tsx:87–609

()

}

export function ChatApp() {
  const [session, setSession] = useState<ChatSession>(() => createSession());
  const [sessionList, setSessionList] = useState<
    Awaited<ReturnType<typeof listSessions>>
  >([]);
  const [hydrated, setHydrated] = useState(false);
  const [draft, setDraft] = useState("");
  const [busy, setBusy] = useState(false);
  const [isReplay, setIsReplay] = useState(false);
  const [replaySlice, setReplaySlice] = useState<ChatMessage[] | null>(null);
  const [replayTargetId, setReplayTargetId] = useState<string | null>(null);
  const [replaySettings, setReplaySettings] = useState<ReplaySettings>({
    delayMs: 16,
    chunkSize: 0,
  });
  const [error, setError] = useState<string | null>(null);

  const msgsRef = useRef<HTMLDivElement>(null);
  const btsRef = useRef<HTMLPreElement>(null);
  const rawTextRef = useRef("");
  const rawReasoningRef = useRef("");
  const rawContentRef = useRef("");
  const abortRef = useRef<AbortController | null>(null);
  const msgsScrollFollowRef = useRef(createStreamScrollFollow());
  const btsScrollFollowRef = useRef(createStreamScrollFollow());
  const saveTimerRef = useRef<number | null>(null);

  const [rawStats, setRawStats] = useState({ chars: 0, chunks: 0 });
  const [rawPreviewId, setRawPreviewId] = useState<string | null>(null);

  const streaming = busy || isReplay;

  const refreshSessions = useCallback(async () => {
    setSessionList(await listSessions());
  }, []);

  const paintRawStream = useCallback((reasoning: string, content: string) => {
    rawReasoningRef.current = reasoning;
    rawContentRef.current = content;
    rawTextRef.current = formatRawStream(reasoning, content);
    if (btsRef.current) {
      btsRef.current.textContent = rawTextRef.current;
    }
    setRawStats((prev) => ({
      ...prev,
      chars: rawTextRef.current.length,
    }));
  }, []);

  const appendStreamPart = useCallback((part: StreamPart) => {
    if (!part.delta) {
      return;
    }

    if (part.kind === "reasoning") {
      rawReasoningRef.current += part.delta;
    } else {
      rawContentRef.current += part.delta;