import readline
import sys
import time


class user_interface(dict):
    def __init__(self):
        super().__init__(self)
        self.add_command('quit', None)

    def run(self):
        readline.parse_and_bind("tab: complete")
        readline.set_completer(self.completer)
        print("\nEnter command: ")
        while (True):
            userfeedback = input('')
            command = userfeedback.split(' ')[0]
            if userfeedback == 'quit':
                break
            else:
                self.call_it(userfeedback)

    def call_it(self, userfeedback):
        args = userfeedback.split(" ")
        cmd = args.pop(0)
        cb = self.get(cmd)
        if callable(cb):
            cb(*args)
        else:
            print("Unknown command \"%s\"" % cmd)

    def add_command(self, name, callback):
        self[name] = callback

    def reduced_list(self, text):
        """
        Create reduced completation list
        """
        reduced_list = {}
        for cmd in self.keys():
            next_dot = cmd[len(text):].find('.')
            if next_dot >= 0:
                reduced_list[cmd[:len(text) + next_dot + 1]] = None
            else:
                reduced_list[cmd] = None
        return reduced_list.keys()

    def completer(self, text, state):
        """
        Our custom completer function
        """
        options = [x for x in self.reduced_list(text) if x.startswith(text)]
        return options[state]