refactor: extract generation core service

apps/api/storage.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from typing import Callable
 from uuid import uuid4
 
 from django.core.files.base import ContentFile
@@ -7,7 +8,12 @@ from django.core.files.storage import default_storage
 from django.utils import timezone
 
 
-def save_generated_image(image: bytes, *, request=None) -> str:
+def save_generated_image(
+    image: bytes,
+    *,
+    url_builder: Callable[[str], str] | None = None,
+    request=None,
+) -> str:
     today = timezone.now()
     path = (
         "generated/images/"
@@ -16,6 +22,8 @@ def save_generated_image(image: bytes, *, request=None) -> str:
     )
     saved_path = default_storage.save(path, ContentFile(image))
     url = default_storage.url(saved_path)
+    if url_builder is not None and url.startswith("/"):
+        return url_builder(url)
     if request is not None and url.startswith("/"):
         return request.build_absolute_uri(url)
     return url