"""Useful functions."""
import logging
import signal


def timed_input(message: str = None,
                timeout: int = 5):

    class TimeoutExpired(Exception):
        pass

    def interrupted(signal_number, stack_frame):
        """Called when read times out."""
        raise TimeoutExpired

    if message is None:
        message = f"Enter something within {timeout} seconds"

    signal.alarm(timeout)
    signal.signal(signal.SIGALRM, interrupted)
    try:
        given_input = input(message)
    except TimeoutExpired:
        given_input = None
        print()  # Print end of line
        logging.info("Timeout!")
    signal.alarm(0)
    return given_input