Function useSignalData

src/components/SignalPanel.tsx:53–105

(trades: WhaleTrade[], markets: ProcessedMarket[], leaderboard: SmartWallet[])

/** Hook for page.tsx to get signal data + available categories for the dropdown */
export function useSignalData(trades: WhaleTrade[], markets: ProcessedMarket[], leaderboard: SmartWallet[]) {
  const deferredTrades = useDeferredValue(trades);
  const deferredMarkets = useDeferredValue(markets);
  const [news, setNews] = useState<NewsItem[]>([]);
  const newsRetry = useRef(0);
  const fetchNewsRef = useRef<(() => Promise<void>) | undefined>(undefined);

  const fetchNews = useCallback(async () => {
    try {
      const res = await fetch("/api/news");
      if (!res.ok) return;
      setNews(await res.json());
      newsRetry.current = 0;
    } catch {
      if (newsRetry.current < 2) {
        newsRetry.current++;
        setTimeout(() => fetchNewsRef.current?.(), 3000);
      }
    }
  }, []);

  useEffect(() => {
    fetchNewsRef.current = fetchNews;
    queueMicrotask(() => {
      void fetchNews();
    });
    const iv = setInterval(fetchNews, 120_000);
    return () => clearInterval(iv);
  }, [fetchNews]);

  const signals = useMemo(
    () => generateSignals(deferredTrades, deferredMarkets, leaderboard, news),
    [deferredTrades, deferredMarkets, leaderboard, news]
  );

  // Build slug → category lookup
  const slugToCategory = useMemo(() => {
    const map = new Map<string, string>();
    for (const m of deferredMarkets) map.set(m.slug, m.category);
    return map;
  }, [deferredMarkets]);

  const categories = useMemo(() => {
    const cats = new Set<string>();
    for (const s of signals) {
      const cat = slugToCategory.get(s.market.slug);
      if (cat) cats.add(cat);
    }
    return Array.from(cats).sort();
  }, [signals, slugToCategory]);

  return { signals, categories, slugToCategory };
}

export default function SignalPanel({
  trades,