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


class ComplexityPasswordValidator:
    """Validate that the password contains letters, digits and special characters.

    Rules:
    - At least one letter (a-z or A-Z)
    - At least one digit (0-9)
    - At least one special character (any non-alphanumeric)
    """

    def validate(self, password, user=None):
        has_letter = any(ch.isalpha() for ch in password)
        has_digit = any(ch.isdigit() for ch in password)
        has_special = any(not ch.isalnum() for ch in password)

        if not (has_letter and has_digit and has_special):
            raise ValidationError(
                _("This password must include at least one letter, one digit, and one special character."),
                code='password_not_complex_enough',
            )

    def get_help_text(self):
        return _("Your password must include at least one letter, one digit, and one special character.")