// Helpers for resolving DANDI asset URLs and locating LINDI indexes.
// This mirrors what neurosift does in src/pages/NwbPage/hdf5Interface.ts.

export const extractAssetId = (downloadUrl: string): string | undefined => {
  // e.g. https://api.dandiarchive.org/api/assets/<assetId>/download/
  const m = downloadUrl.match(/\/assets\/([^/]+)\/download/);
  return m ? m[1] : undefined;
};

// DANDI download URLs are 302-redirected to a (signed) S3 object URL.
// We follow the redirect with a GET and then abort, because a HEAD request is
// rejected by CORS on the DANDI S3 bucket. We only want `response.url`.
export const resolveDandiDownloadUrl = async (url: string): Promise<string> => {
  const controller = new AbortController();
  try {
    const response = await fetch(url, { signal: controller.signal });
    const resolved = response.url || url;
    controller.abort();
    return resolved;
  } catch {
    controller.abort();
    return url;
  }
};

// neurosift hosts precomputed LINDI indexes for published dandisets here.
export const lindiUrlForAsset = (dandisetId: string, assetId: string): string =>
  `https://lindi.neurosift.org/dandi/dandisets/${dandisetId}/assets/${assetId}/nwb.lindi.json`;

export const lindiIndexExists = async (lindiUrl: string): Promise<boolean> => {
  try {
    const resp = await fetch(lindiUrl, { method: "HEAD" });
    return resp.ok;
  } catch {
    return false;
  }
};