/**
 * Whether a User-Agent string belongs to a phone or tablet.
 *
 * Used for one thing: choosing the results view before the first paint, when
 * the viewport is not yet known. A wrong answer is corrected client-side (see
 * HomeView's MAP_DEFAULT_MIN_WIDTH), so this errs towards "handheld" and is
 * kept deliberately small rather than a full UA parser.
 *
 * iPadOS reports a desktop Mac UA by default and so reads as desktop here,
 * which is the right call: a landscape iPad has room for the map layout.
 */
const HANDHELD = /Mobi|Android|iPhone|iPad|iPod|Tablet|Silk|Kindle|PlayBook|BlackBerry|Opera Mini|IEMobile/i;

export function isHandheldUserAgent(ua: string | null | undefined): boolean {
  return !!ua && HANDHELD.test(ua);
}