from marshmallow import ValidationError

from permissions.constants import vendor_star

EMAIL_MAX_TOTAL_LENGTH = 254
EMAIL_MAX_LOCAL_PART_LENGTH = 64


def is_employee_email(email: str) -> bool:
    """Determine if an email belongs to an employee based on its domain."""
    email_domain = email.split('@')[-1].lower()
    return email_domain in vendor_star.ALLOWED_VENDOR_STAR_EMAIL_DOMAINS


def validate_auth0_email_length(email: str) -> None:
    """Reject emails Auth0 will refuse: total > 254 or local part > 64."""
    if len(email) > EMAIL_MAX_TOTAL_LENGTH:
        raise ValidationError(
            f'Email exceeds maximum length of {EMAIL_MAX_TOTAL_LENGTH} characters.'
        )
    local_part = email.split('@')[0]
    if len(local_part) > EMAIL_MAX_LOCAL_PART_LENGTH:
        raise ValidationError(
            f'Email local part exceeds maximum length of {EMAIL_MAX_LOCAL_PART_LENGTH} characters.'
        )