blechreiz-website/eventplanner_gcal/models.py

import logging
import uuid
from eventplanner.models import Event
from django.contrib.auth.models import User

from apiclient.channel import Channel
from django.db import models

logger = logging.getLogger(__name__)


class UserGCalCoupling(models.Model):
    # For every user in this table the gcal coupling is activated
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    email = models.CharField(max_length=1024)


class GCalMapping(models.Model):
    """Mapping between event id at google and local event id"""
    gcal_id = models.CharField(max_length=64)
    event = models.OneToOneField(Event, primary_key=True, on_delete=models.CASCADE)


class GCalPushChannel(models.Model):
    """This table has either zero or one entry. Required to store if a channel already exists,
       when it expires and how to stop (renew) the channel
    """

    id = models.CharField(max_length=128, primary_key=True)
    address = models.CharField(max_length=256)
    token = models.CharField(max_length=128)
    resource_id = models.CharField(max_length=128)
    expiration = models.IntegerField()

    def toGChannel(self):
        return Channel('web_hook', self.id, self.token, self.address, self.expiration, resource_id=self.resource_id)

    @staticmethod
    def fromGChannel(gChannel):
        return GCalPushChannel(id=gChannel.id,
                               address=gChannel.address,
                               token=gChannel.token,
                               expiration=gChannel.expiration,
                               resource_id=gChannel.resource_id)

    @staticmethod
    def createNew(callbackUrl, service, ttl=None):
        gChannel = Channel('web_hook', str(uuid.uuid4()), 'blechreizGcal', callbackUrl, params={'ttl': int(ttl)})
        response = service.events().watch(calendarId='primary', body=gChannel.body()).execute()
        gChannel.update(response)

        dbChannel = GCalPushChannel.fromGChannel(gChannel)
        dbChannel.save()

    @staticmethod
    def stop(service, gChannel):
        channelService = service.channels()
        channelService.stop(body=gChannel.body()).execute()
        GCalPushChannel.fromGChannel(gChannel).delete()