/** Shared display-formatting helpers for the backoffice. */

/** snake_case / SCREAMING_CASE → Title Case. */
export function humanize(value: string): string {
  return value
    .toLowerCase()
    .split(/[_\s]+/)
    .map((part) => part.charAt(0).toUpperCase() + part.slice(1))
    .join(" ");
}

export function formatDate(value: string | null | undefined): string {
  if (!value) return "—";
  const d = new Date(value);
  return Number.isNaN(d.getTime())
    ? "—"
    : d.toLocaleDateString(undefined, {
        year: "numeric",
        month: "short",
        day: "numeric",
      });
}

export function formatDateTime(value: string | null | undefined): string {
  if (!value) return "—";
  const d = new Date(value);
  return Number.isNaN(d.getTime())
    ? "—"
    : d.toLocaleString(undefined, {
        year: "numeric",
        month: "short",
        day: "numeric",
        hour: "2-digit",
        minute: "2-digit",
      });
}

/** Pass `fractionDigits` where cents matter; the default matches the legacy whole-figure display. */
export function formatMoney(
  amount: number,
  currency: string,
  fractionDigits?: number,
): string {
  return new Intl.NumberFormat(undefined, {
    style: "currency",
    currency,
    ...(fractionDigits === undefined
      ? { maximumFractionDigits: 0 }
      : {
          minimumFractionDigits: fractionDigits,
          maximumFractionDigits: fractionDigits,
        }),
  }).format(amount);
}

export function formatBytes(bytes: number): string {
  if (!bytes) return "0 B";
  const units = ["B", "KB", "MB", "GB"];
  const i = Math.floor(Math.log(bytes) / Math.log(1024));
  const value = bytes / Math.pow(1024, i);
  return `${value.toFixed(i === 0 ? 0 : 1)} ${units[i]}`;
}