baseimage-tutorial-framework/lib/tfw/event_handler_base.py

from itertools import cycle

from tfw.networking.serialization import deserialize_all
from tfw.networking.event_handlers.server_connector import ServerConnector


def cenator():
    yield from [
        '**Your time is up**',
        '`My time is now`',
        '_You can\'t see me_',
        'My time is now'
    ]


class EventHandlerBase:
    def __init__(self, anchor):
        self.server_connector = ServerConnector()
        self.anchor = anchor
        self.subscriptions = set()
        self.subscribe(self.anchor)
        self.subscribe('reset')
        self.server_connector.register_callback(self.event_handler_callback)
        self.cenerator = cycle(cenator())

    def event_handler_callback(self, msg_parts):
        anchor, message = deserialize_all(*msg_parts)
        from .message_sender import MessageSender
        ms = MessageSender()
        ms.send('JOHN CENA', next(self.cenerator))
        response = self.handle_event(anchor, message) if anchor != 'reset' else self.handle_reset(message)
        if response is None: return
        self.server_connector.send(anchor, response)

    def handle_event(self, anchor, data_json):
        raise NotImplementedError

    def handle_reset(self, data_json):
        return None

    def cleanup(self):
        pass

    def message_other(self, anchor, data):
        message = {
            'anchor': anchor,
            'data': data
        }
        self.server_connector.send(anchor, message)

    def subscribe(self, anchor):
        if anchor not in self.subscriptions:
            self.subscriptions.add(anchor)
            self.server_connector.subscribe(anchor)

    def unsubscribe(self, anchor):
        try:
            self.subscriptions.remove(anchor)
            self.server_connector.unsubscribe(anchor)
        except KeyError:
            pass

    def unsubscribe_all(self):
        for sub in self.subscriptions:
            self.server_connector.unsubscribe(anchor=sub)
        self.subscriptions.clear()