import time
from abc import ABCMeta, abstractmethod


def main():
    p = PrinterProxy('Alice')
    print('名前は現在{}です'.format(p.get_printer_name()))
    p.set_printer_name('Bob')
    print('名前は現在{}です'.format(p.get_printer_name()))
    p.pprint('Hello, World')


class Printable(metaclass=ABCMeta):
    @abstractmethod
    def set_printer_name(self, name):
        pass

    @abstractmethod
    def get_printer_name(self):
        pass

    @abstractmethod
    def pprint(self, string):
        pass


class Printer(Printable):
    def __init__(self, name):
        self.__name = name

        self.__heavy_job('Printerのインスタンス({})を作成中'.format(self.__name))

    def set_printer_name(self, name):
        self.__name = name

    def get_printer_name(self):
        return self.__name

    def pprint(self, string):
        print('=== {} ==='.format(self.__name))
        print(string)

    def __heavy_job(self, msg):
        print(msg, end='')
        for _ in range(5):
            time.sleep(1)
            print('.', end='')

        print('完了')


class PrinterProxy(Printable):
    def __init__(self, name):
        self.__name = name
        self.__real = None

    def set_printer_name(self, name):
        if self.__real is not None:
            self.__real.set_printer_name(name)

        self.__name = name

    def get_printer_name(self):
        return self.__name

    def pprint(self, string):
        self.__realize()
        self.__real.pprint(string)

    def __realize(self):
        '''本人を生成'''
        if self.__real is None:
            self.__real = Printer(self.__name)


if __name__ == '__main__':
    main()