seahaven-ap/src/dashboard/invoice-date-format.ts

export function formatSlashDate(value: string | null | undefined): string {
  if (!value) {
    return "—";
  }
  const parsed = new Date(`${value.slice(0, 10)}T00:00:00`);
  if (Number.isNaN(parsed.getTime())) {
    return value;
  }
  return new Intl.DateTimeFormat("en-US", {
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
  }).format(parsed);
}

export function formatRelativeFromIsoDate(
  value: string | null | undefined,
  now: Date = new Date(),
): string {
  if (!value) {
    return "";
  }
  const parsed = new Date(`${value.slice(0, 10)}T00:00:00`);
  if (Number.isNaN(parsed.getTime())) {
    return "";
  }
  const diffMs = now.getTime() - parsed.getTime();
  const dayMs = 24 * 60 * 60 * 1000;
  const days = Math.max(0, Math.floor(diffMs / dayMs));
  if (days < 1) {
    return "today";
  }
  if (days < 30) {
    return days === 1 ? "1 day ago" : `${days} days ago`;
  }
  const months = Math.floor(days / 30);
  if (months < 12) {
    return months === 1 ? "1 month ago" : `${months} months ago`;
  }
  const years = Math.floor(months / 12);
  return years === 1 ? "1 year ago" : `${years} years ago`;
}