"""
Shared Utility Functions
Common helpers used across the application
"""
import uuid
import re
from typing import TYPE_CHECKING

from app import config

if TYPE_CHECKING:
    from database.models import User


def generate_uuid() -> str:
    """Generate a new UUID string"""
    return str(uuid.uuid4())


def is_ldap_user(user: "User") -> bool:
    """Check if user is managed by LDAP (Authelia mode with no local password)"""
    return config.AUTHELIA_ENABLED and user.password_hash is None


def is_ldap_admin(user: "User") -> bool:
    """Check if user is an LDAP-managed admin"""
    return is_ldap_user(user) and user.role == "admin"


def validate_password(password: str) -> list[str]:
    """
    Validate password strength.
    Returns list of error messages (empty if valid).
    """
    errors = []
    if len(password) < 8:
        errors.append("at least 8 characters")
    if not re.search(r'[A-Z]', password):
        errors.append("one uppercase letter")
    if not re.search(r'[a-z]', password):
        errors.append("one lowercase letter")
    if not re.search(r'[0-9]', password):
        errors.append("one number")
    return errors


def format_password_errors(errors: list[str]) -> str:
    """Format password validation errors into a message"""
    if not errors:
        return ""
    return f"Password must contain: {', '.join(errors)}"


def get_notification_default(value, default):
    """Get notification setting value with default fallback"""
    return value if value is not None else default