import { promises as fs } from 'node:fs';
import path from 'node:path';

// Serves maplibre-gl dist files (worker + its relative imports) straight from
// node_modules so they always match the installed version. MapLibre cannot derive
// working URLs for these when bundled by Turbopack/webpack, and the worker script
// uses a relative import ("./maplibre-gl-shared.mjs") that must resolve against
// this same prefix.
export async function GET(_req: Request, ctx: { params: Promise<{ file: string }> }) {
  const { file } = await ctx.params;
  if (!/^[\w.-]+\.mjs$/.test(file)) return new Response('not found', { status: 404 });
  try {
    const body = await fs.readFile(
      path.join(process.cwd(), 'node_modules', 'maplibre-gl', 'dist', file),
    );
    return new Response(body, { headers: { 'content-type': 'text/javascript' } });
  } catch {
    return new Response('not found', { status: 404 });
  }
}