/** Normalise Ethiopian local phone (09…/07…) to E.164; pass email through unchanged. */
export function normaliseIdentifier(raw: string): string {
  const v = raw.trim();
  const digits = v.replace(/\D/g, "");
  if (digits.length >= 9 && (v.startsWith("0") || v.startsWith("+251"))) {
    const local = digits.startsWith("251") ? digits.slice(3) : digits.replace(/^0/, "");
    return `+251${local}`;
  }
  return v.toLowerCase();
}

/** Mask all but the first 7 chars of an E.164 phone for display. */
export const maskPhone = (p: string) =>
  p.length > 4 ? `${p.slice(0, 7)}${"*".repeat(Math.max(0, p.length - 7))}` : p;

/** Mask the local part of an email for display (j***e@example.com). */
export const maskEmail = (email: string) => {
  const [local, domain] = email.split("@");
  if (!local || !domain) return email;
  if (local.length <= 2) return `${local[0] ?? ""}***@${domain}`;
  return `${local[0]}***${local[local.length - 1]}@${domain}`;
};