from django.contrib.sites.models import Site
from django.conf import settings
from django_cas.backends import CASBackend
from django.db import models, connection

from gestioncof.models import CofProfile

class COFCASBackend(CASBackend):
    def authenticate(self, ticket, service):
        """Authenticates CAS ticket and retrieves user data"""
        user = super(COFCASBackend, self).authenticate(ticket, service)
        try:
            profile = user.get_profile()
        except CofProfile.DoesNotExist:
            profile, created = CofProfile.objects.get_or_create(user = user)
            profile.save()
        if not profile.login_clipper:
            profile.login_clipper = user.username
            profile.save()
        if not user.email:
            user.email = settings.CAS_EMAIL_FORMAT % profile.login_clipper
            user.save()
        if profile.is_buro and not user.is_superuser:
            user.is_superuser = True
            user.is_staff = True
            user.save()
        return user

def context_processor (request):
    '''Append extra data to the context of the given request'''
    data = {
            "user": request.user,
            "site": Site.objects.get_current(),
           }
    return data

def lock_table(model):
    cursor = connection.cursor()
    table = model._meta.db_table
    cursor.execute("LOCK TABLES %s WRITE" % table)
    row = cursor.fetchone()
    return row

def unlock_table(model):
    cursor = connection.cursor()
    cursor.execute("UNLOCK TABLES")
    row = cursor.fetchone()
    return row