type IngestTextArgs = {
  fileSource: string;
  text: string;
};

export async function lightragIngestText(args: IngestTextArgs): Promise<{ trackId: string | null }> {
  const baseUrl = (process.env.LIGHTRAG_URL || "").trim().replace(/\/+$/, "");
  if (!baseUrl) {
    throw new Error("缺少环境变量：LIGHTRAG_URL");
  }

  const fileSource = String(args.fileSource ?? "").trim();
  if (!fileSource) {
    throw new Error("缺少 fileSource");
  }

  const text = String(args.text ?? "");
  if (!text.trim()) {
    return { trackId: null };
  }

  const apiKey = (process.env.LIGHTRAG_API_KEY || "").trim();
  const headers: Record<string, string> = { "Content-Type": "application/json" };
  if (apiKey) {
    headers["X-API-Key"] = apiKey;
  }

  // 说明：LightRAG(>=1.4.x) 使用 /documents/text 作为“文本入库”接口。
  const resp = await fetch(`${baseUrl}/documents/text`, {
    method: "POST",
    headers,
    body: JSON.stringify({ text, file_source: fileSource }),
  });

  if (!resp.ok) {
    const raw = await resp.text().catch(() => "");
    throw new Error(`LightRAG 入库失败：HTTP ${resp.status} ${raw.slice(0, 500)}`);
  }

  const data = (await resp.json().catch(() => null)) as unknown;
  const trackId = (() => {
    if (!data || typeof data !== "object") return null;
    const v = (data as Record<string, unknown>).track_id;
    return typeof v === "string" ? v : null;
  })();
  return { trackId };
}