#!/usr/bin/env python
# coding:utf-8

def singleton(cls):
    _instance = {}

    def inner():
        if cls not in _instance:
            _instance[cls] = cls()
        return _instance[cls]

    return inner


@singleton
class NotificationHelper:
    def __init__(self):
        self.message = '########################################\n'
        self.at_people_list = []

    def append_at_people(self, people):
        if people not in self.at_people_list:
            self.at_people_list.append(people)

    def get_people_list(self):
        return self.at_people_list

    def clear_msg(self):
        self.message = '########################################\n'

    def append_msg(self, msg):
        self.message += msg + '\n'

    def append_end_msg(self):
        self.message += '########################################\n'

    def get_msg(self):
        return self.message