import { KOREAN_STOCK_INDEX } from "@/features/trade/data/korean-stocks";
import type { DashboardStockOverviewResponse } from "@/features/trade/types/trade.types";
import type { KisCredentialInput } from "@/lib/kis/config";
import { hasKisConfig, normalizeTradingEnv } from "@/lib/kis/config";
import { hasKisApiSession } from "@/app/api/kis/_session";
import { getDomesticOverview } from "@/lib/kis/domestic";
import { NextRequest, NextResponse } from "next/server";
import {
  DOMESTIC_KIS_SESSION_OVERRIDE_HEADER,
  parseDomesticKisSession,
} from "@/lib/kis/domestic-market-session";

/**
 * @file app/api/kis/domestic/overview/route.ts
 * @description 국내주식 종목 상세(현재가 + 차트) API
 */

/**
 * 국내주식 종목 상세 API
 * @param request query string의 symbol(6자리 종목코드) 사용
 * @returns 대시보드 상세 모델
 */
export async function GET(request: NextRequest) {
  const hasSession = await hasKisApiSession();
  if (!hasSession) {
    return NextResponse.json({ error: "로그인이 필요합니다." }, { status: 401 });
  }

  const { searchParams } = new URL(request.url);
  const symbol = (searchParams.get("symbol") ?? "").trim();

  if (!/^\d{6}$/.test(symbol)) {
    return NextResponse.json({ error: "symbol은 6자리 숫자여야 합니다." }, { status: 400 });
  }

  const credentials = readKisCredentialsFromHeaders(request.headers);

  if (!hasKisConfig(credentials)) {
    return NextResponse.json(
      {
        error:
          "대시보드 상단에서 KIS API 키를 입력하고 검증해 주세요. 키 정보가 없어서 시세를 조회할 수 없습니다.",
      },
      { status: 400 },
    );
  }

  const fallbackMeta = KOREAN_STOCK_INDEX.find((item) => item.symbol === symbol);

  try {
    const sessionOverride = readSessionOverrideFromHeaders(request.headers);
    const overview = await getDomesticOverview(
      symbol,
      fallbackMeta,
      credentials,
      { sessionOverride },
    );

    const response: DashboardStockOverviewResponse = {
      stock: overview.stock,
      source: "kis",
      priceSource: overview.priceSource,
      marketPhase: overview.marketPhase,
      tradingEnv: normalizeTradingEnv(credentials.tradingEnv),
      fetchedAt: new Date().toISOString(),
    };

    return NextResponse.json(response, {
      headers: {
        "cache-control": "no-store",
      },
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : "KIS 조회 중 오류가 발생했습니다.";
    return NextResponse.json({ error: message }, { status: 500 });
  }
}

/**
 * 요청 헤더에서 KIS 키를 읽어옵니다.
 * @param headers 요청 헤더
 * @returns credentials
 */
function readKisCredentialsFromHeaders(headers: Headers): KisCredentialInput {
  const appKey = headers.get("x-kis-app-key")?.trim();
  const appSecret = headers.get("x-kis-app-secret")?.trim();
  const tradingEnv = normalizeTradingEnv(headers.get("x-kis-trading-env") ?? undefined);

  return {
    appKey,
    appSecret,
    tradingEnv,
  };
}

function readSessionOverrideFromHeaders(headers: Headers) {
  if (process.env.NODE_ENV === "production") return null;
  const raw = headers.get(DOMESTIC_KIS_SESSION_OVERRIDE_HEADER);
  return parseDomesticKisSession(raw);
}