# Copyright (C) 2009 Lorenzo Gil Sanchez
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#            http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from django.conf import settings
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth.models import User


class Saml2Backend(ModelBackend):

    def authenticate(self, session_info=None):
        if session_info is None:
            return None

        if not session_info.has_key('ava'):
            return None

        ava = session_info['ava']
        username = ava[settings.SAML_USERNAME_ATTRIBUTE][0]

        modified = False
        try:
            user = User.objects.get(username=username)
        except User.DoesNotExist:
            user = User(username=username, password='')
            modified = True

        modified = modified or self._update_user_attributes(user, ava)

        if modified:
            user.save()

        return user

    def _update_user_attributes(self, user, attributes):
        """TODO"""