/**
 * Extract a Vimeo numeric `videoId` from a URL.
 *
 * Supports:
 *   - vimeo.com/123456789
 *   - vimeo.com/123456789/HASH
 *   - player.vimeo.com/video/123456789
 *
 * Returns `null` if the URL does not match.
 */
export function extractVimeoId(input: string): string | null {
  let url: URL;
  try {
    url = new URL(input);
  } catch {
    return null;
  }
  const host = url.hostname.replace(/^www\./, '');
  if (host !== 'vimeo.com' && host !== 'player.vimeo.com') return null;

  // /video/<id> on player.vimeo.com, /<id> on vimeo.com.
  const match = url.pathname.match(/(?:^\/video\/|^\/)(\d+)/);
  return match ? match[1] : null;
}