frontend/src/shared/lib/format.ts

export function formatDateTime(value: string | null | undefined, locale: string): string {
  if (!value) {
    return "-";
  }
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) {
    return "-";
  }
  return new Intl.DateTimeFormat(locale, {
    dateStyle: "medium",
    timeStyle: "short",
  }).format(date);
}

export function formatNumber(value: number, locale: string, maximumFractionDigits = 2): string {
  return new Intl.NumberFormat(locale, { maximumFractionDigits }).format(value);
}

export function formatDuration(milliseconds: number): string {
  if (milliseconds < 1000) {
    return `${milliseconds} ms`;
  }
  return `${(milliseconds / 1000).toFixed(milliseconds < 10000 ? 2 : 1)} s`;
}

export function toDateTimeLocal(value: string | null | undefined): string {
  if (!value) {
    return "";
  }
  const date = new Date(value);
  const offset = date.getTimezoneOffset() * 60_000;
  return new Date(date.getTime() - offset).toISOString().slice(0, 19);
}