/** Format a positive duration in seconds as a short human string. */
export function formatDurationSeconds(seconds: number): string {
  if (!Number.isFinite(seconds) || seconds <= 0) return "now";
  const d = Math.floor(seconds / 86400);
  const h = Math.floor((seconds % 86400) / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  if (d > 0 && h > 0) return `${d}d ${h}h`;
  if (d > 0) return `${d}d`;
  if (h > 0 && m > 0) return `${h}h ${m}m`;
  if (h > 0) return `${h}h`;
  if (m > 0) return `${m}m`;
  return "<1m";
}

export function formatDurationMs(ms: number): string {
  return formatDurationSeconds(ms / 1000);
}