F(backend): add public media derivatives pipeline

apps/gallery/api/schemas.py

@@ -5,6 +5,7 @@ from typing import Optional
 
 from apps.blog.api.schemas import AuthorSchema
 from apps.gallery.models import Gallery
+from core.media import BLUR_VARIANT, PREVIEW_VARIANT, derivative_url
 
 
 class GallerySchema(ModelSchema):
@@ -12,12 +13,34 @@ class GallerySchema(ModelSchema):
     uploaded_by: AuthorSchema
     file_size_mb: float
     markdown_url: str
+    absolute_image_url: Optional[str] = None
+    absolute_image_preview_url: Optional[str] = None
+    absolute_image_blur_url: Optional[str] = None
 
     class Config:
         model = Gallery
         model_fields = ['id', 'title', 'description', 'image', 'alt_text',
                         'width', 'height', 'is_public', 'created_at']
 
+    @staticmethod
+    def resolve_absolute_image_url(obj, context):
+        request = context["request"]
+        if obj.image and hasattr(obj.image, "url"):
+            return request.build_absolute_uri(obj.image.url)
+        return None
+
+    @staticmethod
+    def resolve_absolute_image_preview_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.image, PREVIEW_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
+    @staticmethod
+    def resolve_absolute_image_blur_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.image, BLUR_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
 
 class GalleryCreateSchema(Schema):
     """Payload for creating a gallery entry."""

apps/gallery/api/views.py

@@ -63,6 +63,7 @@ def upload_image(request, file: UploadedFile = File(...), data: GalleryCreateSch
             alt_text=data.alt_text if data else "",
             is_public=data.is_public if data else True
         )
+        gallery_item._defer_image_processing = True
         
         # Save image
         filename = f"gallery/{uuid.uuid4().hex}.{file.name.split('.')[-1]}"

apps/gallery/models.py

@@ -1,13 +1,14 @@
 from django.db import models
 from django.conf import settings
 
-from PIL import Image
-
 from core.models import BaseModel
+from core.media import (
+    delete_image_derivatives_by_name,
+    get_image_previous_name,
+    safe_process_public_image,
+)
 
 
-MAX_IMAGE_FILE_SIZE_BYTES = 2 * 1024 * 1024
-
 class Gallery(BaseModel):
     title = models.CharField(max_length=200)
     description = models.TextField(blank=True)
@@ -27,47 +28,39 @@ class Gallery(BaseModel):
         return self.title
 
     def save(self, *args, **kwargs):
+        previous_image_name = get_image_previous_name(self, "image")
+        current_image_name = self.image.name if self.image else None
+        image_changed = previous_image_name != current_image_name
+
         super().save(*args, **kwargs)
-        
-        if self.image:
-            # Get file size
-            self.file_size = self.image.size
-            
-            # Get image dimensions
-            with Image.open(self.image.path) as img:
-                self.width, self.height = img.size
-            
-            # Compress image if it's too large
-            self.compress_image()
-            
-            # Update fields without triggering save again
-            Gallery.objects.filter(pk=self.pk).update(
-                file_size=self.file_size,
-                width=self.width,
-                height=self.height
+
+        if image_changed and previous_image_name:
+            delete_image_derivatives_by_name(
+                self.image.storage if self.image else None,
+                previous_image_name,
+                "gallery",
+                delete_original=True,
             )
 
-    def compress_image(self):
-        """Compress image if it's larger than 2MB or dimensions are too large"""
         if not self.image:
+            if image_changed:
+                Gallery.objects.filter(pk=self.pk).update(file_size=None, width=None, height=None)
             return
-            
-        with Image.open(self.image.path) as img:
-            # Convert to RGB if necessary
-            if img.mode in ("RGBA", "P"):
-                img = img.convert("RGB")
-            
-            # Resize if too large
-            max_size = (1920, 1080)
-            if img.size[0] > max_size[0] or img.size[1] > max_size[1]:
-                img.thumbnail(max_size, Image.Resampling.LANCZOS)
-            
-            # Compress if file size is too large
-            quality = 85
-        if self.file_size and self.file_size > MAX_IMAGE_FILE_SIZE_BYTES:
-            quality = 70
-            
-            img.save(self.image.path, "JPEG", quality=quality, optimize=True)
+
+        if getattr(self, "_defer_image_processing", False):
+            return
+
+        if image_changed:
+            result = safe_process_public_image(self.image, "gallery")
+            if result:
+                Gallery.objects.filter(pk=self.pk).update(
+                    file_size=result.file_size,
+                    width=result.width,
+                    height=result.height,
+                )
+                self.file_size = result.file_size
+                self.width = result.width
+                self.height = result.height
 
     @property
     def file_size_mb(self):

apps/gallery/tasks.py

@@ -1,20 +1,26 @@
-from celery import shared_task
-from PIL import Image
 import logging
 
+from celery import shared_task
+
+from core.media import safe_process_public_image
+
 logger = logging.getLogger(__name__)
 
 @shared_task
 def process_uploaded_image(gallery_id):
-    """Process uploaded image: compress, resize, extract metadata"""
+    """Process gallery image derivatives and refresh metadata."""
     try:
         from .models import Gallery
         gallery_item = Gallery.objects.get(id=gallery_id)
         
         if gallery_item.image:
-            # This will trigger the compression and metadata extraction
-            gallery_item.compress_image()
-            
+            result = safe_process_public_image(gallery_item.image, "gallery", force=True)
+            if result:
+                Gallery.objects.filter(pk=gallery_item.pk).update(
+                    file_size=result.file_size,
+                    width=result.width,
+                    height=result.height,
+                )
             logger.info(f"Processed image: {gallery_item.title}")
             return f"Processed image: {gallery_item.title}"