# ...

class CategoryInput(graphene.InputObjectType):
    id = graphene.ID()
    name = graphene.String()


class TechnologyInput(graphene.InputObjectType):
    id = graphene.ID()
    name = graphene.String()


class ProjectInput(graphene.InputObjectType):
    title = graphene.String()
    text = graphene.String()
    category = graphene.Field(CategoryInput)
    technologies = graphene.List(TechnologyInput)


class CreateProject(graphene.Mutation):

    class Arguments:
        project_data = ProjectInput()

    id = graphene.Int()
    created_date = graphene.DateTime()
    owner = graphene.Field(UserType)

    project = graphene.Field(ProjectType)

    def mutate(self, info, project_data):
        user = info.context.user
        if user.is_anonymous:
            raise Exception('You must be logged in to make projects!')

        category = Category.objects.filter(id=project_data.category.id).first()
        if not category:
            raise Exception('Invalid category ID!')

        technologies = []
        for technologies_data in project_data.technologies:
            technology = Technology.objects.get(id=technologies_data.id)
            if technology is None:
                raise Exception('Invalid technology ID!')
            technologies.append(technology)

        project_instance = Project(owner_id=user.id, title=project_data.title, text=project_data.text,
                                   category=category)
        project_instance.save()
        project_instance.technologies.set(technologies)

        return CreateProject