import {
  ACCESS_TOKEN,
  AUTH_USER_ID,
  CLAIM_NAME,
  REFRESH_TOKEN,
  SERVER_API_URL,
  SITE_ID,
} from "@/shared/config";
import { cookies } from "next/headers";
import { NextResponse } from "next/server";

async function handler(
  request: Request,
  params: { url: string[] },
  method: "GET" | "POST" | "PUT" | "DELETE",
) {
  const cookieStore = await cookies();
  const headers: Record<string, string> = {
    "Content-Type": "application/json",
    "X-Site-Id": SITE_ID,
  };
  let body = {};
  const isRefreshHandler = params.url.includes("refresh");

  console.log(`[Proxy] ${method} ${params.url.join("/")}`);
  console.log(`[Proxy] Server API URL: ${SERVER_API_URL}`);

  // silent refresh
  if (isRefreshHandler) {
    const refreshToken = cookieStore.get(REFRESH_TOKEN);
    headers[CLAIM_NAME] = refreshToken?.value ?? "";

    if (!headers[CLAIM_NAME]) {
      return NextResponse.json({ message: "Can't refresh" }, { status: 401 });
    }
  }

  try {
    if (!isRefreshHandler) {
      body = await request.json();
      console.log(`[Proxy] Request body:`, body);
    }

    const targetUrl = `${SERVER_API_URL}/${params.url.join("/")}`;
    console.log(`[Proxy] Target URL: ${targetUrl}`);

    const result = await fetch(targetUrl, {
      method,
      headers,
      body: JSON.stringify(body),
    });

    console.log(`[Proxy] Response status: ${result.status}`);
    console.log(`[Proxy] Response headers:`, Object.fromEntries(result.headers.entries()));

    // 2FA 관련 엔드포인트인 경우 응답 본문도 확인
    const is2FAEndpoint = params.url.includes("2fa") || params.url.includes("auth");
    let responseData = {};
    
    if (is2FAEndpoint) {
      try {
        responseData = await result.json();
        console.log(`[Proxy] 2FA Response data:`, responseData);
      } catch {
        // JSON 파싱 실패 시 빈 객체 사용
        console.log(`[Proxy] Failed to parse JSON response`);
      }
    }

    const accessToken = result.headers.get(ACCESS_TOKEN) || result.headers.get('ss-token');
    const refreshToken = result.headers.get(REFRESH_TOKEN);
    const userId = result.headers.get(AUTH_USER_ID);

    console.log(`[Proxy] Tokens - accessToken: ${!!accessToken}, userId: ${!!userId}, refreshToken: ${!!refreshToken}`);
    console.log(`[Proxy] Available headers:`, Array.from(result.headers.keys()));

    // 2FA 엔드포인트이고 실패한 경우 실제 오류 메시지 반환
    if (!result.ok && is2FAEndpoint) {
      console.log(`[Proxy] 2FA endpoint failed, returning actual error`);
      return NextResponse.json(responseData, { status: result.status });
    }

    // 2FA 엔드포인트이고 성공한 경우 (토큰이 헤더에 없을 수 있음)
    if (result.ok && is2FAEndpoint) {
      console.log(`[Proxy] 2FA endpoint succeeded, returning response data`);
      return NextResponse.json(responseData, { status: result.status });
    }

    // 일반적인 실패 처리
    if (!result.ok) {
      console.log(`[Proxy] General endpoint failed`);
      return NextResponse.json(
        { message: "Invalid Credentials" },
        { status: 401 },
      );
    }

    if (accessToken && userId) {
      const response = NextResponse.json({
        [ACCESS_TOKEN]: accessToken,
        [AUTH_USER_ID]: userId,
        ...responseData, // 2FA 관련 추가 데이터 포함
      });

      if (refreshToken) {
        cookieStore.set(REFRESH_TOKEN, refreshToken, {
          httpOnly: true,
          sameSite: "lax",
          path: "/",
        });
      }

      console.log(`[Proxy] Success response sent`);
      return response;
    }

    console.log(`[Proxy] Missing tokens in response`);
    return NextResponse.json(
      { message: "Invalid Credentials" },
      { status: 401 },
    );
  } catch (error) {
    console.error(`[Proxy] Error:`, error);
    return NextResponse.json(
      { message: "Server Error", error },
      { status: 500 },
    );
  }
}

export async function POST(
  request: Request,
  props: { params: Promise<{ url: string[] }> },
) {
  const params = await props.params;
  return handler(request, params, "POST");
}

export async function PUT(
  request: Request,
  props: { params: Promise<{ url: string[] }> },
) {
  const params = await props.params;
  return handler(request, params, "PUT");
}