import logging

logger = logging.getLogger(__name__)


def main(message: str) -> str:
    """Process and return a message string.

    This function takes a message string as input and returns it after validation.
    Currently it simply returns the input string, but could be extended to add
    processing logic as needed.

    Args:
        message: The input message string to process.

    Returns:
        The processed message string.

    Raises:
        ValueError: If message is empty or None.
    """
    if not message:
        logger.warning("Message is empty")
    else:
        logger.info(f"Processing message: '{message}'")
    return message


if __name__ == "__main__":
    pass
