import { currentLocale, t } from '@/i18n';

export function formatBytes(bytes?: number | null): string {
  if (!bytes || bytes <= 0) return '—';
  const mb = bytes / (1024 * 1024);
  if (mb >= 1) return `${mb.toFixed(1)} MB`;
  const kb = bytes / 1024;
  return `${Math.max(1, Math.round(kb))} KB`;
}

/** Locale-aware short date, e.g. "12 Jun 2026" / "12 giu 2026". */
export function formatDate(iso?: string | null): string {
  if (!iso) return '—';
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return iso;
  try {
    return d.toLocaleDateString(currentLocale(), {
      day: '2-digit',
      month: 'short',
      year: 'numeric',
    });
  } catch {
    return d.toISOString().slice(0, 10);
  }
}

/** Whole days from now until `iso` (negative = past). */
export function daysUntil(iso?: string | null): number | null {
  if (!iso) return null;
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return null;
  return Math.ceil((d.getTime() - Date.now()) / 86_400_000);
}

/** Short human expiry label, e.g. "24 days", "Expired", "Valid". */
export function expiryLabel(status?: string | null, expiryDate?: string | null): string {
  if (status === 'expired') return t('expiry.expired');
  if (status === 'expiring') {
    const days = daysUntil(expiryDate);
    return days != null && days >= 0 ? t('expiry.days', { count: days }) : t('expiry.expiring');
  }
  return t('expiry.valid');
}