'''
Hyoer Ryu Policy Manager
'''


class PolicyManager(object):
    """
    Policy Manager

    Init policy:
     - Init from config (DB settings)
     - Init from database (Mongo)
    """
    _instance = None

    def __init__(self):
        super(PolicyManager, self).__init__()

    @staticmethod
    def get_instance():
        if PolicyManager._instance is None:
            PolicyManager._instance = PolicyManager()

        return PolicyManager._instance

    def add_policy(self, policy):
        pass

    def remove_policy(self, policy):
        pass

    def update_vswitch(self):
        pass

    def update_vlink(self):
        pass

    def update_vhost(self):
        pass
