/**
 * Toolkit - Currency Formatting
 * 
 * Simple currency formatting. Currency code comes from user's WHMCS profile.
 * Typically JPY for this application.
 */

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

/**
 * Format a number as currency using WHMCS currency data
 * 
 * @param amount - The numeric amount to format
 * @param currencyCode - Currency code from WHMCS API (e.g., "JPY", "USD", "EUR")
 * @param currencyPrefix - Currency symbol from WHMCS API (e.g., "¥", "$", "€")
 * 
 * @example
 * formatCurrency(1000, "JPY", "¥")     // ¥1,000
 * formatCurrency(1000, "USD", "$")    // $1,000.00
 * formatCurrency(1000, "EUR", "€")     // €1,000.00
 */
export function formatCurrency(
  amount: number, 
  currencyCode: string,
  currencyPrefix: string
): string {
  // Determine fraction digits based on currency
  const fractionDigits = currencyCode === "JPY" ? 0 : 2;
  
  // Format the number with appropriate decimal places
  const formattedAmount = amount.toLocaleString("en-US", {
    minimumFractionDigits: fractionDigits,
    maximumFractionDigits: fractionDigits,
  });

  // Add currency prefix
  return `${currencyPrefix}${formattedAmount}`;
}

/**
 * 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;
}