/**
 * Toolkit - Currency Formatting
 * 
 * Utilities for formatting currency values.
 */

export type SupportedCurrency = "JPY" | "USD" | "EUR";

export interface CurrencyFormatOptions {
  locale?: string;
  showSymbol?: boolean;
  minimumFractionDigits?: number;
  maximumFractionDigits?: number;
}

/**
 * Format a number as currency
 */
export function formatCurrency(
  amount: number,
  currency: SupportedCurrency = "JPY",
  options: CurrencyFormatOptions = {}
): string {
  const {
    locale = "en-US",
    showSymbol = true,
    minimumFractionDigits,
    maximumFractionDigits,
  } = options;

  // JPY doesn't use decimal places
  const defaultFractionDigits = currency === "JPY" ? 0 : 2;

  const formatter = new Intl.NumberFormat(locale, {
    style: showSymbol ? "currency" : "decimal",
    currency: showSymbol ? currency : undefined,
    minimumFractionDigits: minimumFractionDigits ?? defaultFractionDigits,
    maximumFractionDigits: maximumFractionDigits ?? defaultFractionDigits,
  });

  return formatter.format(amount);
}

/**
 * Parse a currency string to a number
 */
export function parseCurrency(value: string): number | null {
  // Remove currency symbols, commas, and whitespace
  const cleaned = value.replace(/[¥$€,\s]/g, "");
  const parsed = Number.parseFloat(cleaned);
  return Number.isFinite(parsed) ? parsed : null;
}