1import hashlib
 2
 3
 4def get_gravatar_url(user):
 5    """Generate gravatar URL for the given user if they have an email address."""
 6    if not user or not hasattr(user, "email") or not user.email:
 7        return None
 8
 9    # Create hash of email
10    email_hash = hashlib.md5(user.email.lower().strip().encode("utf-8")).hexdigest()
11
12    # Return gravatar URL with default identicon fallback
13    return f"https://www.gravatar.com/avatar/{email_hash}?s=64&d=identicon"