import { NextRequest, NextResponse } from "next/server";

export const dynamic = "force-dynamic";

const DROP = new Set(["host", "connection", "content-length", "transfer-encoding"]);

async function proxy(request: NextRequest, context: { params: Promise<{ path: string[] }> }) {
  const base = process.env.API_INTERNAL_URL;
  if (!base) {
    return NextResponse.json({ detail: "API_INTERNAL_URL is not set" }, { status: 500 });
  }
  const { path } = await context.params;
  const target = new URL(`${base.replace(/\/$/, "")}/${path.join("/")}`);
  target.search = request.nextUrl.search;

  const headers = new Headers();
  request.headers.forEach((value, key) => {
    if (!DROP.has(key.toLowerCase())) {
      headers.set(key, value);
    }
  });

  const hasBody = request.method !== "GET" && request.method !== "HEAD";
  const upstream = await fetch(target, {
    method: request.method,
    headers,
    body: hasBody ? await request.arrayBuffer() : undefined,
    cache: "no-store",
    redirect: "manual",
  });

  const responseHeaders = new Headers();
  upstream.headers.forEach((value, key) => {
    const name = key.toLowerCase();
    if (name === "content-encoding" || name === "content-length" || name === "transfer-encoding" || name === "set-cookie") {
      return;
    }
    responseHeaders.set(key, value);
  });
  const cookies = typeof upstream.headers.getSetCookie === "function" ? upstream.headers.getSetCookie() : [];
  for (const cookie of cookies) {
    responseHeaders.append("set-cookie", cookie);
  }

  return new NextResponse(await upstream.arrayBuffer(), {
    status: upstream.status,
    headers: responseHeaders,
  });
}

export const GET = proxy;
export const POST = proxy;
export const PUT = proxy;
export const PATCH = proxy;
export const DELETE = proxy;