/**
 * Builds a human-readable string from a number of seconds. Examples:
 * - "12s"
 * - "2m5s"
 * - "1h2m5s"
 */
export function secToHuman(sec: number | null): string {
  if (sec === null) {
    return "null";
  }

  sec = Math.round(Math.max(sec, 0));
  return [
    sec >= 3600 && `${Math.floor(sec / 3600)}h`,
    sec >= 60 && `${Math.floor((sec % 3600) / 60)}m`,
    sec >= 0 && `${sec % 60}s`,
  ]
    .filter(Boolean)
    .join("");
}