/**
 * @param datePar
 * @param month
 */
export function formatDate(
  datePar?: Date | string | null,
  month: "numeric" | "2-digit" | "long" | "short" | "narrow" = "long",
): string | null {
  if (!datePar) return null;

  const date = parseDate(datePar);
  const monthShort = new Intl.DateTimeFormat("cs", { month });
  return `${day.format(date)} ${monthShort.format(date)} ${year.format(date)}`;
}

const year = new Intl.DateTimeFormat("cs", { year: "numeric" });
const day = new Intl.DateTimeFormat("cs", { day: "2-digit" });

export function parseDate(date?: null): null;
export function parseDate(date: Date | string): Date;

export function parseDate(date?: Date | string | null): Date | null {
  if (!date) return null;

  if (date instanceof Date) return date;

  return new Date(date);
}

export function dateWithoutTimezone(date: Date): string {
  const tzoffset = date.getTimezoneOffset() * 60000; //offset in milliseconds
  return new Date(date.valueOf() - tzoffset)
    .toISOString()
    .slice(0, -1);
}