import { NextRequest } from "next/server";

export const runtime = "nodejs";

export async function POST(request: NextRequest) {
  const backendBaseUrl = process.env.BACKEND_URL ?? "http://127.0.0.1:7860";
  const body = await request.text();

  const upstream = await fetch(`${backendBaseUrl}/api/chat`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body,
    cache: "no-store"
  });

  if (!upstream.ok || !upstream.body) {
    const text = await upstream.text();
    return new Response(text || "Upstream chat request failed.", {
      status: upstream.status || 500
    });
  }

  return new Response(upstream.body, {
    status: 200,
    headers: {
      "Content-Type": "text/event-stream",
      "Cache-Control": "no-cache, no-transform",
      Connection: "keep-alive"
    }
  });
}