class LineUsersViewSet(mixins.ListModelMixin,
                       mixins.CreateModelMixin,
                       viewsets.GenericViewSet):
    serializer_class = LineUserSerializer

    def get_queryset(self):
        q = Role.objects.select_related('user').filter(line_id=self.kwargs['line_pk'])
        return get_object_or_404(Line, id=(self.kwargs['line_pk'])).workers.prefetch_related('role_set').all()


class LineUserSerializer(serializers.ModelSerializer):
    role = serializers.IntegerField(required=True, write_only=True)
    user_id = serializers.IntegerField(required=True, write_only=True)

    class Meta:
        model = get_user_model()
        fields = (
            'id',
            'user_id',
            'email',
            'first_name',
            'last_name',
            'date_joined',
            'role'

        )
        extra_kwargs = {
            'id': {'read_only': True},
            'email': {'read_only': True},
            'first_name': {'read_only': True},
            'last_name': {'read_only': True},
            'date_joined': {'read_only': True},

        }