import re

from django.core.exceptions import ValidationError
from django.utils.translation import gettext_lazy as _


_IRAN_MOBILE_RE = re.compile(r"^09\d{9}$")


def normalize_iran_mobile(value: str) -> str:
    if value is None:
        return ""
    digits = re.sub(r"\D", "", str(value))
    if not digits:
        return ""
    if digits.startswith("0098"):
        digits = "0" + digits[4:]
    elif digits.startswith("98") and len(digits) == 12:
        digits = "0" + digits[2:]
    elif digits.startswith("9") and len(digits) == 10:
        digits = "0" + digits
    return digits


def validate_iran_mobile(value: str) -> None:
    if not _IRAN_MOBILE_RE.match(value or ""):
        raise ValidationError(_("Enter a valid Iranian mobile number (09xxxxxxxxx)."))