class Console:

    def __init__(self, prompt: str, unknown_text="Unknown Command. Try help to see all commands."):
        self.prompt = prompt
        self.unknown_text = unknown_text
        self.run = True
        self.help = {}
        self.commands = {}

        self.reg_command("help", "This help message", self._print_help)

    def reg_command(self, name, help_message, callback):
        self.help[name] = help_message
        self.commands[name] = callback

    def stop(self):
        self.run = False

    def _print_help(self):
        max_len = 0
        for i in self.help.keys():
            if len(i) > max_len:
                max_len = len(i)

        print("Available commands:")
        for name, text in self.help.items():
            print(f"{name:<{max_len}} -- {text}")

    def _start(self):
        while self.run:
            cmd = input(self.prompt).strip()
            if cmd not in self.commands:
                print(self.unknown_text)
                continue
            self.commands[cmd]()

    def start(self):
        try:
            self._start()
        except KeyboardInterrupt:
            pass