export function trackModelDownload(response, {id, postMessage}) {
  const reader = response.body?.getReader?.();
  if (!reader || typeof ReadableStream !== 'function' || typeof Response !== 'function') return response;

  const total = Number(response.headers.get('content-length')) || 0;
  let loaded = 0;
  const body = new ReadableStream({
    async pull(controller) {
      try {
        const {done, value} = await reader.read();
        if (done) {
          controller.close();
          return;
        }
        loaded += value.byteLength;
        postMessage({id, type: 'progress', progress: {loaded, total}});
        controller.enqueue(value);
      } catch (error) {
        controller.error(error);
      }
    },
    cancel(reason) {
      return reader.cancel(reason);
    },
  });

  return new Response(body, {
    status: response.status,
    statusText: response.statusText,
    headers: response.headers,
  });
}