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 )
    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 )


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()