import json
import sseclient
from ._transport import Transport
from requests.exceptions import ConnectionError


class ServerSentEventsTransport(Transport):
    def __init__(self, session, connection):
        Transport.__init__(self, session, connection)
        self.__response = None

    def _get_name(self):
        return 'serverSentEvents'

    def start(self):
        self.__response = sseclient.SSEClient(self._get_url('connect'), session=self._session)
        self._session.get(self._get_url('start'))

        def _receive():
            try:
                for notification in self.__response:
                    if notification.data != 'initialized':
                        self._handle_notification(notification.data)
            except ConnectionError:
                raise ConnectionError

        return _receive

    def send(self, data):
        response = self._session.post(self._get_url('send'), data={'data': json.dumps(data)})
        parsed = json.loads(response.content)
        self._connection.received.fire(**parsed)

    def close(self):
        self._session.get(self._get_url('abort'))