auto-trade/features/trade/hooks/useOrderBook.ts

import { useEffect, useRef, useState } from "react";
import type { KisRuntimeCredentials } from "@/features/settings/store/use-kis-runtime-store";
import type { DashboardStockOrderBookResponse } from "@/features/trade/types/trade.types";
import { fetchStockOrderBook } from "@/features/trade/apis/kis-stock.api";
import { toast } from "sonner";

/**
 * @description 초기 REST 호가를 한 번 조회하고, 이후에는 웹소켓 호가를 우선 사용합니다.
 * 웹소켓 호가 데이터는 TradeContainer에서 useKisTradeWebSocket을 통해
 * 단일 WebSocket으로 수신되어 externalRealtimeOrderBook으로 주입됩니다.
 * @see features/trade/components/TradeContainer.tsx 호가 데이터 흐름
 * @see features/trade/components/orderbook/OrderBook.tsx 호가창 렌더링 데이터 공급
 */
export function useOrderBook(
  symbol: string | undefined,
  market: "KOSPI" | "KOSDAQ" | undefined,
  credentials: KisRuntimeCredentials | null,
  isVerified: boolean,
  options: {
    enabled?: boolean;
    /** 체결 WS에서 받은 실시간 호가 데이터 (단일 WS 통합) */
    externalRealtimeOrderBook?: DashboardStockOrderBookResponse | null;
  } = {},
) {
  const { enabled = true, externalRealtimeOrderBook = null } = options;
  const isRequestEnabled = enabled && !!symbol && !!credentials;
  const requestSeqRef = useRef(0);
  const lastErrorToastRef = useRef<string>("");

  const [initialData, setInitialData] =
    useState<DashboardStockOrderBookResponse | null>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (!isRequestEnabled || !symbol || !credentials) {
      return;
    }

    const requestSeq = ++requestSeqRef.current;
    let isDisposed = false;

    const loadInitialOrderBook = async () => {
      setInitialData(null);
      setIsLoading(true);
      setError(null);

      try {
        const data = await fetchStockOrderBook(symbol, credentials);
        if (isDisposed || requestSeq !== requestSeqRef.current) return;
        setInitialData(data);
      } catch (err) {
        if (isDisposed || requestSeq !== requestSeqRef.current) return;
        console.error("Failed to fetch initial orderbook:", err);
        const message =
          err instanceof Error
            ? err.message
            : "호가 정보를 불러오지 못했습니다. 잠시 후 다시 시도해주세요.";
        setError(message);

        if (lastErrorToastRef.current !== message) {
          lastErrorToastRef.current = message;
          toast.error(message);
        }
      } finally {
        if (isDisposed || requestSeq !== requestSeqRef.current) return;
        setIsLoading(false);
      }
    };

    void loadInitialOrderBook();

    return () => {
      isDisposed = true;
    };
  }, [isRequestEnabled, symbol, credentials]);

  // 외부 실시간 호가 → 초기 데이터 → null 순 우선
  const orderBook = isRequestEnabled
    ? (externalRealtimeOrderBook ?? initialData)
    : null;
  const mergedError = isRequestEnabled ? error : null;
  const mergedLoading = isRequestEnabled ? isLoading && !orderBook : false;

  return {
    orderBook,
    isLoading: mergedLoading,
    error: mergedError,
    isWsConnected: !!externalRealtimeOrderBook,
  };
}