"""
Shared validators used across multiple apps.
"""
import re

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

# Regex for a Saudi mobile number after stripping spaces/dashes/parens/plus.
# Accepts any of:
#   05XXXXXXXX   (10 digits, local with trunk 0)
#   5XXXXXXXX    (9 digits, no trunk)
#   9665XXXXXXXX (12 digits, country code without +)
#   +9665XXXXXXXX (13 digits, country code with +)
SAUDI_MOBILE_REGEX = re.compile(r"^(?:\+?966|0)?5\d{8}$")

# HTML5 form pattern equivalent (HTML anchors ^...$ implicitly).
# Exposed for reuse in widget attrs and template <input pattern="...">.
SAUDI_PHONE_HTML_PATTERN = r"(\+?966|0)?5[0-9]{8}"


def validate_saudi_phone(value):
    """
    Validate that ``value`` is a Saudi mobile number.

    Accepts the following formats (spaces, dashes and parentheses are ignored):
        05XXXXXXXX
        5XXXXXXXX
        9665XXXXXXXX
        +9665XXXXXXXX

    Stored value is returned unchanged (no normalization).
    Raises ``ValidationError`` if the number is not a valid Saudi mobile.
    """
    if value is None or value == "":
        return value

    cleaned = re.sub(r"[\s\-()]", "", str(value))
    if not SAUDI_MOBILE_REGEX.match(cleaned):
        raise ValidationError(
            _("Please enter a valid Saudi mobile number "
              "(e.g. 05XXXXXXXX or +9665XXXXXXXX)."),
            code="invalid_saudi_phone",
        )
    return value