// Small formatting helpers for the booth. Money is integer MINOR units (never a
// float — matches the tariff/ledger model); duration is whole minutes.

/** Format integer minor units + ISO-4217 currency as a major-unit string. */
export function formatMoney(amountMinor: number, currency: string): string {
  const major = amountMinor / 100;
  try {
    return new Intl.NumberFormat(undefined, { style: "currency", currency }).format(major);
  } catch {
    // Unknown/garbled currency code — fall back to a plain number + the code.
    return `${major.toFixed(2)} ${currency}`;
  }
}

/** Human duration between two ISO times, e.g. "2h 14m" / "47m" / "0m". */
export function formatDuration(fromIso: string, toIso: string): string {
  const ms = Date.parse(toIso) - Date.parse(fromIso);
  if (!Number.isFinite(ms) || ms < 0) return "—";
  const mins = Math.floor(ms / 60_000);
  const h = Math.floor(mins / 60);
  const m = mins % 60;
  return h > 0 ? `${h}h ${m}m` : `${m}m`;
}

/** Local time-of-day HH:MM:SS from an ISO string. */
export function formatTime(iso: string | null): string {
  if (!iso) return "—";
  const d = new Date(iso);
  return Number.isNaN(d.getTime()) ? "—" : d.toTimeString().slice(0, 8);
}