import { withUser, ApiError } from "@/lib/api";
import { exportArenaSession } from "@/lib/arena/service";
import { LIMITS } from "@/lib/rate-limit";

export const dynamic = "force-dynamic";
type P = { id: string };

/** POST /api/arena/:id/export?format=markdown|json → file download (models, parameters, metrics, votes, responses). */
export const POST = withUser<P>(
  async ({ req, user }, { id }) => {
    const format = new URL(req.url).searchParams.get("format") ?? "markdown";
    if (format !== "markdown" && format !== "json" && format !== "md") throw new ApiError(400, "format must be markdown or json", "VALIDATION_ERROR");
    const out = await exportArenaSession(user.id, id, format === "json" ? "json" : "markdown");
    return new Response(out.body, { headers: { "Content-Type": out.contentType, "Content-Disposition": `attachment; filename="${out.filename}"`, "X-Filename": out.filename } });
  },
  { limit: { ...LIMITS.share, key: "arena-export" } },
);