import { useCallback, useState, useTransition } from "react";
import type { KisRuntimeCredentials } from "@/features/dashboard/store/use-kis-runtime-store";
import type {
  DashboardMarketPhase,
  DashboardPriceSource,
  DashboardRealtimeTradeTick,
  DashboardStockSearchItem,
  DashboardStockItem,
} from "@/features/dashboard/types/dashboard.types";
import { fetchStockOverview } from "@/features/dashboard/apis/kis-stock.api";

interface OverviewMeta {
  priceSource: DashboardPriceSource;
  marketPhase: DashboardMarketPhase;
  fetchedAt: string;
}

export function useStockOverview() {
  const [selectedStock, setSelectedStock] = useState<DashboardStockItem | null>(
    null,
  );
  const [meta, setMeta] = useState<OverviewMeta | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [isLoading, startTransition] = useTransition();

  const loadOverview = useCallback(
    (
      symbol: string,
      credentials: KisRuntimeCredentials | null,
      marketHint?: DashboardStockSearchItem["market"],
    ) => {
      if (!credentials) return;

      startTransition(async () => {
        try {
          setError(null);
          const data = await fetchStockOverview(symbol, credentials);
          setSelectedStock({
            ...data.stock,
            market: marketHint ?? data.stock.market,
          });
          setMeta({
            priceSource: data.priceSource,
            marketPhase: data.marketPhase,
            fetchedAt: data.fetchedAt,
          });
        } catch (err) {
          const message =
            err instanceof Error
              ? err.message
              : "종목 조회 중 오류가 발생했습니다.";
          setError(message);
          setMeta(null);
        }
      });
    },
    [],
  );

  // 실시간 체결 데이터 수신 시 헤더/차트 기준 가격을 갱신합니다.
  const updateRealtimeTradeTick = useCallback(
    (tick: DashboardRealtimeTradeTick) => {
      setSelectedStock((prev) => {
        if (!prev) return prev;
        const { price, accumulatedVolume, change, changeRate, tickTime } = tick;
        const pointTime =
          tickTime && tickTime.length === 6
            ? `${tickTime.slice(0, 2)}:${tickTime.slice(2, 4)}`
            : "실시간";

        const nextChange = change;
        const nextChangeRate = Number.isFinite(changeRate)
          ? changeRate
          : prev.prevClose > 0
            ? (nextChange / prev.prevClose) * 100
            : prev.changeRate;
        const nextHigh = prev.high > 0 ? Math.max(prev.high, price) : price;
        const nextLow = prev.low > 0 ? Math.min(prev.low, price) : price;
        const nextCandles =
          prev.candles.length > 0 &&
          prev.candles[prev.candles.length - 1]?.time === pointTime
            ? [
                ...prev.candles.slice(0, -1),
                {
                  ...prev.candles[prev.candles.length - 1],
                  time: pointTime,
                  price,
                },
              ]
            : [...prev.candles, { time: pointTime, price }].slice(-80);

        return {
          ...prev,
          currentPrice: price,
          change: nextChange,
          changeRate: nextChangeRate,
          high: nextHigh,
          low: nextLow,
          volume: accumulatedVolume > 0 ? accumulatedVolume : prev.volume,
          candles: nextCandles,
        };
      });
    },
    [],
  );

  return {
    selectedStock,
    setSelectedStock,
    meta,
    setMeta,
    error,
    setError,
    isLoading,
    loadOverview,
    updateRealtimeTradeTick,
  };
}