// public/views/icon_util.js — pure helpers (no DOM), unit-tested.
const GROUP_DEFAULT = {
  Network: 'router', Entertainment: 'tv', 'Smart Home': 'plug', Personal: 'phone'
};
export function autoDefaultIcon(grp) {
  return `set:devices:${GROUP_DEFAULT[grp] || 'unknown'}`;
}
// Note: bundled 'devices' icons are .svg; brand icons are served .png by the proxy.
export function resolveIcon(ref) {
  if (typeof ref !== 'string') return null;
  let m = ref.match(/^set:([a-z0-9-]+):([a-z0-9-]+)$/);
  if (m) return `/api/icon-sets/${m[1]}/${m[2]}.svg`;
  m = ref.match(/^brand:([a-z0-9-]+)$/);
  if (m) return `/api/icons/${m[1]}.png`;
  return null;
}
export function relativeTime(iso, now = Date.now()) {
  const t = typeof iso === 'number' ? iso : Date.parse(iso);
  const s = Math.max(0, Math.floor((now - t) / 1000));
  if (s < 60) return 'just now';
  if (s < 3600) return `${Math.floor(s / 60)}m ago`;
  if (s < 86400) return `${Math.floor(s / 3600)}h ago`;
  return `${Math.floor(s / 86400)}d ago`;
}