import { useCallback } from "react";
import { useAsyncResource } from "../../../react/async-resource";
import { type IvStats, loadIvHistory } from "./client";

/** IV30 rank and percentile of the latest stored close; null while loading, uncovered or signed out of Cloud IV. */
export function useIvRank(symbol: string | null | undefined): IvStats | null {
  const normalized = symbol?.trim().toUpperCase() || null;
  const loader = useCallback(async () => (await loadIvHistory(normalized!, { days: 30 })).stats.iv30, [normalized]);
  return useAsyncResource(normalized ? loader : null).data ?? null;
}

/** "35 P18 09-22": rank, percentile and the session they rank. */
export function formatIvRank(stats: IvStats | null): string {
  if (!stats) return "--";
  const whole = (value: number | null) => value == null ? "--" : String(Math.round(value));
  return `${whole(stats.rank)} P${whole(stats.percentile)} ${stats.date.slice(5)}`;
}