from django.db.models import get_model
from django.db.utils import DatabaseError
from django.db.models.signals import post_save
from django.contrib.auth.models import User

from social_auth.signals import pre_update
from social_auth.backends.facebook import FacebookBackend
from tastypie.models import create_api_key

import logging
logger = logging.getLogger(__name__)

# get email from Facebook registration
def facebook_extra_values(sender, user, response, details, **kwargs):
    if response.get('email') is not None:
        user.email = response.get('email')
    return True

pre_update.connect(facebook_extra_values, sender=FacebookBackend)


# create Wishlist and UserProfile to associate with User
def create_user_objects(sender, created, instance, **kwargs):
    # use get_model to avoid circular import problem with models
    try:
        Wishlist = get_model('core', 'Wishlist')
        UserProfile = get_model('core', 'UserProfile')
        if created:
            Wishlist.objects.create(user=instance)
            UserProfile.objects.create(user=instance)
    except DatabaseError:
        # this can happen when creating superuser during syncdb since the
        # core_wishlist table doesn't exist yet
        return

post_save.connect(create_user_objects, sender=User)


# create API key for new User
post_save.connect(create_api_key, sender=User)

# handle any save, updates to a payment.Transaction

def handle_transaction_change(sender, instance, created, **kwargs):
    try:
        campaign = instance.campaign
        logger.info('Got the signal for Transaction %s w/ Campaign %s ', instance.id, campaign.id)
        return True
    except Exception, e:
        return False

post_save.connect(handle_transaction_change,sender=get_model('payment','Transaction'))