from django.contrib.auth.models import User

from rest_framework import viewsets
from rest_framework import mixins
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.decorators import detail_route

from .serializers import UserSerializer, DetailedUserSerializer

from ..tokens import token_generator
from ..views import BooktypeViewSetMixin
from ..security import IsAdminOrIsSelf
from .filters import UserFilter


class UserViewSet(
        mixins.CreateModelMixin, mixins.RetrieveModelMixin,
        mixins.UpdateModelMixin, mixins.ListModelMixin,
        BooktypeViewSetMixin, viewsets.GenericViewSet
        ):

    """
    API endpoint that allows users to be viewed or edited.

    list:
    Returns all the users in the system ordered by date joined

    create:
    Allows creating a new user

    retrieve:
    Returns an user instance

    partial_update:
    Executes a partial user instance update

    update:
    Executes a full user instance update
    """

    required_perms = ['api.manage_users']
    queryset = User.objects.all().order_by('-date_joined')
    serializer_class = UserSerializer
    filter_class = UserFilter

    @detail_route(url_path='session-token', permission_classes=[IsAdminOrIsSelf])
    def session_token(self, request, pk=None):
        """
        Returns a login token to be used to authenticate into the booktype
        instance platform.

        For admins:
            In order to use this token you need to set the booktype.api.middleware.AuthMiddleware
            into your MIDDLEWARE_CLASSES and also set the booktype.api.auth.Backend in the
            AUTHENTICATION_BACKENDS setting
        """

        user = self.get_object()
        return Response(
            {'token': token_generator.make_token(user)})


class CurrentUser(APIView):
    """
    Return full information about current user. 
    """
    def get(self, request, format=None):
        return Response(DetailedUserSerializer(request.user).data)