from django.contrib.contenttypes.models import ContentType
from django.db.models import QuerySet

class PhotoableModel:
    """Mixin for models that can have photos attached."""

    def get_photos(self) -> QuerySet:
        """Get photos for this instance."""
        from media.models import Photo
        ct = ContentType.objects.get_for_model(self.__class__)
        return Photo.objects.filter(content_type=ct, object_id=self.pk)

    def add_photo(self, photo: 'Photo') -> None:
        """Add a photo to this instance."""
        from media.models import Photo
        ct = ContentType.objects.get_for_model(self.__class__)
        photo.content_type = ct
        photo.object_id = self.pk
        photo.save()