const DASH = "—";

const DATE_TIME_FORMATTER = new Intl.DateTimeFormat("en-GB", {
  timeZone: "UTC",
  year: "numeric",
  month: "2-digit",
  day: "2-digit",
  hour: "2-digit",
  minute: "2-digit",
  second: "2-digit",
  hour12: false,
});

const DATE_FORMATTER = new Intl.DateTimeFormat("en-GB", {
  timeZone: "UTC",
  year: "numeric",
  month: "2-digit",
  day: "2-digit",
});

function toValidDate(value?: string | Date | null): Date | null {
  if (!value) return null;
  const date = value instanceof Date ? value : new Date(value);
  return Number.isNaN(date.getTime()) ? null : date;
}

export function formatDateTime(value?: string | Date | null): string {
  const date = toValidDate(value);
  if (!date) return DASH;
  return `${DATE_TIME_FORMATTER.format(date)} UTC`;
}

export function formatDate(value?: string | Date | null): string {
  const date = toValidDate(value);
  if (!date) return DASH;
  return DATE_FORMATTER.format(date);
}