import type {
  DashboardChartTimeframe,
  DashboardStockChartResponse,
} from "@/features/trade/types/trade.types";
import type { KisCredentialInput } from "@/lib/kis/config";
import { hasKisConfig, normalizeTradingEnv } from "@/lib/kis/config";
import { getDomesticChart } from "@/lib/kis/domestic";
import { NextRequest, NextResponse } from "next/server";
import { hasKisApiSession } from "@/app/api/kis/_session";

const VALID_TIMEFRAMES: DashboardChartTimeframe[] = [
  "1m",
  "30m",
  "1h",
  "1d",
  "1w",
];

/**
 * @file app/api/kis/domestic/chart/route.ts
 * @description 국내주식 차트(분봉/일봉/주봉) 조회 API
 */
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();
  const timeframe = (
    searchParams.get("timeframe") ?? "1d"
  ).trim() as DashboardChartTimeframe;
  const cursor = (searchParams.get("cursor") ?? "").trim() || undefined;

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

  if (!VALID_TIMEFRAMES.includes(timeframe)) {
    return NextResponse.json(
      { error: "지원하지 않는 timeframe입니다." },
      { 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 차트를 조회할 수 없습니다.",
      },
      { status: 400 },
    );
  }

  try {
    const chart = await getDomesticChart(
      symbol,
      timeframe,
      credentials,
      cursor,
    );

    const response: DashboardStockChartResponse = {
      symbol,
      timeframe,
      candles: chart.candles,
      nextCursor: chart.nextCursor,
      hasMore: chart.hasMore,
      fetchedAt: new Date().toISOString(),
    };

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

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,
  };
}