import { cp, mkdir } from "node:fs/promises";
import { existsSync } from "node:fs";
import path from "node:path";
import { pathToFileURL } from "node:url";

export async function prepareStandalone(root = process.cwd()) {
  const standalone = path.join(root, ".next", "standalone");
  const server = path.join(standalone, "server.js");
  if (!existsSync(server)) {
    throw new Error("Standalone build not found. Run npm run build first.");
  }
  await mkdir(path.join(standalone, ".next"), { recursive: true });
  await cp(path.join(root, ".next", "static"), path.join(standalone, ".next", "static"), { recursive: true, force: true });
  if (existsSync(path.join(root, "public"))) {
    await cp(path.join(root, "public"), path.join(standalone, "public"), { recursive: true, force: true });
  }
}

if (process.argv[1] && import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) {
  await prepareStandalone();
}