import { NextResponse } from "next/server";

export const runtime = "nodejs";

const API_GATEWAY_URL =
  process.env.API_GATEWAY_URL ?? process.env.AI_SERVICE_URL ?? "http://localhost:8000";

function ragBaseUrl() {
  return API_GATEWAY_URL.replace(/\/v1\/rag(?:\/query)?\/?$/, "");
}

export async function GET(request: Request) {
  const drugId = new URL(request.url).searchParams.get("drug_id")?.trim() ?? "";
  if (!/^[a-z0-9_]{1,160}$/i.test(drugId)) {
    return NextResponse.json({ error: "invalid_drug_id" }, { status: 400 });
  }

  try {
    const upstream = await fetch(
      `${ragBaseUrl()}/v1/rag/sections?drug_id=${encodeURIComponent(drugId)}`,
      {
        headers: { "X-Client-Version": "1.0.0" },
        cache: "no-store",
        signal: AbortSignal.timeout(8_000),
      }
    );
    if (!upstream.ok) {
      return NextResponse.json({ error: "sections_unavailable" }, { status: upstream.status });
    }
    return NextResponse.json(await upstream.json());
  } catch {
    return NextResponse.json({ error: "sections_unavailable" }, { status: 502 });
  }
}