/** Normalize Iranian mobile to 09xxxxxxxxx, or null if invalid. */
export function normalizeMobile(input?: string | null): string | null {
  if (!input) return null;
  let digits = String(input).replace(/\D/g, '');
  if (digits.startsWith('98') && digits.length >= 12) {
    digits = `0${digits.slice(2)}`;
  }
  if (digits.startsWith('9') && digits.length === 10) {
    digits = `0${digits}`;
  }
  if (!/^09\d{9}$/.test(digits)) {
    return null;
  }
  return digits;
}

export function displayName(firstName: string, lastName: string) {
  return `${firstName} ${lastName}`.replace(/\s+/g, ' ').trim();
}