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

/**
 * @description 선택한 종목의 초기 호가를 조회하고 실시간 호가로 갱신합니다.
 * @see features/dashboard/components/orderbook/OrderBook.tsx 호가창 화면에서 사용합니다.
 */
export function useOrderBook(
  symbol: string | undefined,
  market: "KOSPI" | "KOSDAQ" | undefined,
  credentials: KisRuntimeCredentials | null,
  isVerified: boolean,
  options: { enabled?: boolean } = {},
) {
  const { enabled = true } = 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 시도해 주세요.";
        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]);

  const {
    realtimeOrderBook,
    isConnected: isWsConnected,
    error: wsError,
  } = useKisOrderbookWebSocket(
    symbol,
    market,
    credentials,
    isVerified && enabled,
  );

  // 실시간 패킷이 0값으로 들어오는 경우에는 초기 REST 호가를 유지합니다.
  const safeRealtimeOrderBook = isUsableOrderBook(realtimeOrderBook)
    ? realtimeOrderBook
    : null;
  const orderBook = isRequestEnabled
    ? (safeRealtimeOrderBook ?? initialData)
    : null;
  const mergedError = isRequestEnabled ? error || wsError : null;
  const mergedLoading = isRequestEnabled ? isLoading && !orderBook : false;

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

/**
 * @description 호가 데이터가 실제 유효한지(0만 있는지) 판별합니다.
 * @see features/dashboard/hooks/useOrderBook.ts 실시간/초기 호가 병합 우선순위 결정에 사용합니다.
 */
function isUsableOrderBook(orderBook: DashboardStockOrderBookResponse | null) {
  if (!orderBook) return false;
  if (orderBook.totalAskSize > 0 || orderBook.totalBidSize > 0) return true;

  return orderBook.levels.some(
    (level) =>
      level.askPrice > 0 ||
      level.bidPrice > 0 ||
      level.askSize > 0 ||
      level.bidSize > 0,
  );
}