/**
 * 📄 Proxy Route
 * API 프록시 라우트
 *
 * - 서버 API로의 요청 프록시 처리
 * - 쿠키 기반 인증 토큰 및 리프레시 토큰 관리
 * - POST 및 PUT 요청 핸들링
 * - 사용자 인증 정보 검증 및 응답 처리
 * - 에러 핸들링 및 상태 코드 반환
 * - 사이트 ID 및 헤더 설정
 */
import {
    ACCESS_TOKEN,
    AUTH_USER_ID,
    CLAIM_NAME,
    COOKIE_DOMAIN,
    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,
  };
  const deviceId = request.headers.get("X-Device-Id");
  if (deviceId) {
      headers["X-Device-Id"] = deviceId;
  }
   
  let body = {};
  const isRefreshHandler = params.url.includes("refresh");

  // 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();
    }

    const result = await fetch(`${SERVER_API_URL}/${params.url.join("/")}`, {
      method,
      headers,
      body: JSON.stringify(body),
    });

    if (!result.ok) {
      console.log("Invalid Credentials ");
      return NextResponse.json(
        { message: "Invalid Credentials" },
        { status: 401 },
      );
    }

    const accessToken = result.headers.get(ACCESS_TOKEN);
    const refreshToken = result.headers.get(REFRESH_TOKEN);
    const userId = result.headers.get(AUTH_USER_ID);

    if (accessToken && userId) {
      const response = NextResponse.json({
        [ACCESS_TOKEN]: accessToken,
        [AUTH_USER_ID]: userId,
      });

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

      return response;
    }

    return NextResponse.json(
      { message: "Invalid Credentials" },
      { status: 401 },
    );
  } catch (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");
}

function getCookieDomain(): string | undefined {
  if (typeof window === "undefined") return undefined;

  if (COOKIE_DOMAIN) return COOKIE_DOMAIN;

  const { hostname } = window.location;
  if (hostname === "localhost" || hostname === "127.0.0.1") return undefined;

  return hostname;
}