# django-openid-auth -  OpenID integration for django.contrib.auth
#
# Copyright (C) 2008-2010 Canonical Ltd.
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"""Glue between OpenID and django.contrib.auth."""

__metaclass__ = type

from django.conf import settings
from django.contrib.auth.models import User, Group
from openid.consumer.consumer import SUCCESS
from openid.extensions import ax, sreg, pape

from django_openid_auth import teams
from django_openid_auth.models import UserOpenID
from django_openid_auth.exceptions import (
    IdentityAlreadyClaimed,
    DuplicateUsernameViolation,
    MissingUsernameViolation,
    MissingPhysicalMultiFactor,
    RequiredAttributeNotReturned,
)

class OpenIDBackend:
    """A django.contrib.auth backend that authenticates the user based on
    an OpenID response."""

    def get_user(self, user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None

    def authenticate(self, **kwargs):
        """Authenticate the user based on an OpenID response."""
        # Require that the OpenID response be passed in as a keyword
        # argument, to make sure we don't match the username/password
        # calling conventions of authenticate.

        openid_response = kwargs.get('openid_response')
        if openid_response is None:
            return None

        if openid_response.status != SUCCESS:
            return None

        user = None
        try:
            user_openid = UserOpenID.objects.get(
                claimed_id__exact=openid_response.identity_url)
        except UserOpenID.DoesNotExist:
            if getattr(settings, 'OPENID_CREATE_USERS', False):