/**
 * Names the site a link points at, as the app shows it: a link dump's title
 * when its page has none, a preview's site name, the digest's domain line and
 * the tint of a card without artwork. The server's link checks key on it too
 * (`canonical-url.ts`), so a link reads as the same site everywhere.
 *
 * @module
 */

/**
 * Returns `url`'s host without a leading `www.`; `URL` has already lowered
 * its case. `www.youtube.com` and `youtube.com` give `youtube.com`.
 */
export function siteHostOf(url: URL): string {
  return url.hostname.replace(/^www\./, "");
}

/**
 * Returns {@link siteHostOf} the URL `raw`, or undefined when `raw` isn't
 * one.
 */
export function siteHost(raw: string): string | undefined {
  try {
    return siteHostOf(new URL(raw));
  } catch {
    return undefined;
  }
}