import { useMemo } from "react";
import type {
  DashboardRealtimeTradeTick,
  DashboardStockItem,
  DashboardStockOrderBookResponse,
} from "@/features/trade/types/trade.types";

interface UseCurrentPriceParams {
  stock?: DashboardStockItem | null;
  latestTick: DashboardRealtimeTradeTick | null;
  orderBook: DashboardStockOrderBookResponse | null;
}

export function useCurrentPrice({
  stock,
  latestTick,
  orderBook,
}: UseCurrentPriceParams) {
  return useMemo(() => {
    let currentPrice = stock?.currentPrice ?? 0;
    let change = stock?.change ?? 0;
    let changeRate = stock?.changeRate ?? 0;
    const prevClose = stock?.prevClose ?? 0;

    // 1. Priority: Realtime Tick (Trade WS)
    if (latestTick?.price && latestTick.price > 0) {
      currentPrice = latestTick.price;
      // 실시간 틱(change/changeRate)은 TR 종류(실체결/예상체결)에 따라 해석 차이가 있을 수 있어
      // 화면 표시는 항상 전일종가(prevClose) 기준으로 재계산해 일관성을 유지합니다.
      if (prevClose > 0) {
        change = currentPrice - prevClose;
        changeRate = (change / prevClose) * 100;
      } else {
        change = latestTick.change;
        changeRate = latestTick.changeRate;
      }
    }
    // 2. Fallback: OrderBook Best Ask (Proxy for current price if no tick)
    else if (
      orderBook?.levels[0]?.askPrice &&
      orderBook.levels[0].askPrice > 0
    ) {
      const askPrice = orderBook.levels[0].askPrice;
      currentPrice = askPrice;

      // Recalculate change/rate based on prevClose
      if (prevClose > 0) {
        change = currentPrice - prevClose;
        changeRate = (change / prevClose) * 100;
      }
    }

    return {
      currentPrice,
      change,
      changeRate,
      prevClose,
    };
  }, [stock, latestTick, orderBook]);
}