// Minimal relative-time formatter for chat lists. Matches the desktop's
// terse style ("Vor 5 Min", "Gestern", "12.05.").
export function formatRelativeTime(iso: string | null): string {
  if (!iso) return '';
  const then = new Date(iso).getTime();
  if (!Number.isFinite(then)) return '';
  const diffSec = (Date.now() - then) / 1000;
  if (diffSec < 60) return 'Gerade eben';
  if (diffSec < 3600) return 'Vor ' + Math.floor(diffSec / 60) + ' Min';
  if (diffSec < 86400) return 'Vor ' + Math.floor(diffSec / 3600) + ' Std';
  if (diffSec < 86400 * 2) return 'Gestern';
  const d = new Date(iso);
  return [
    String(d.getDate()).padStart(2, '0'),
    String(d.getMonth() + 1).padStart(2, '0'),
    String(d.getFullYear()).slice(-2),
  ].join('.');
}