F(backend): add public media derivatives pipeline

apps/blog/api/schemas.py

@@ -5,6 +5,7 @@ from typing import Optional, List
 from datetime import datetime
 
 from apps.blog.models import Category, Tag, Comment
+from core.media import PREVIEW_VARIANT, THUMBNAIL_VARIANT, derivative_url
 
 
 class CategorySchema(ModelSchema):
@@ -23,6 +24,8 @@ class AuthorSchema(Schema):
     first_name: str
     last_name: str
     profile_picture: Optional[str] = None
+    profile_picture_thumbnail_url: Optional[str] = None
+    profile_picture_preview_url: Optional[str] = None
 
     @staticmethod
     def resolve_profile_picture(obj, context):
@@ -31,6 +34,18 @@ class AuthorSchema(Schema):
             return request.build_absolute_uri(obj.profile_picture.url)
         return None
 
+    @staticmethod
+    def resolve_profile_picture_thumbnail_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.profile_picture, THUMBNAIL_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
+    @staticmethod
+    def resolve_profile_picture_preview_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.profile_picture, PREVIEW_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
 class PostListSchema(Schema):
     id: int
     title: str
@@ -38,6 +53,9 @@ class PostListSchema(Schema):
     excerpt: str
     author: AuthorSchema
     featured_image: Optional[str] = None
+    absolute_featured_image_url: Optional[str] = None
+    absolute_featured_image_thumbnail_url: Optional[str] = None
+    absolute_featured_image_preview_url: Optional[str] = None
     status: str
     published_at: Optional[datetime] = None
     category: Optional[CategorySchema] = None
@@ -46,6 +64,25 @@ class PostListSchema(Schema):
     created_at: datetime
     reading_time: int
 
+    @staticmethod
+    def resolve_absolute_featured_image_url(obj, context):
+        request = context["request"]
+        if obj.featured_image and hasattr(obj.featured_image, "url"):
+            return request.build_absolute_uri(obj.featured_image.url)
+        return None
+
+    @staticmethod
+    def resolve_absolute_featured_image_thumbnail_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.featured_image, THUMBNAIL_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
+    @staticmethod
+    def resolve_absolute_featured_image_preview_url(obj, context):
+        request = context["request"]
+        url = derivative_url(obj.featured_image, PREVIEW_VARIANT)
+        return request.build_absolute_uri(url) if url else None
+
 class PostDetailSchema(PostListSchema):
     content: str
     content_html: str

apps/blog/models.py

@@ -5,6 +5,11 @@ from django.utils import timezone
 
 import markdown
 
+from core.media import (
+    delete_image_derivatives_by_name,
+    get_image_previous_name,
+    safe_process_public_image,
+)
 from core.models import BaseModel
 
 class Category(BaseModel):
@@ -67,6 +72,9 @@ class Post(BaseModel):
         return self.title
 
     def save(self, *args, **kwargs):
+        previous_image_name = get_image_previous_name(self, "featured_image")
+        current_image_name = self.featured_image.name if self.featured_image else None
+
         if not self.slug:
             self.slug = slugify(self.title)
         
@@ -84,6 +92,17 @@ class Post(BaseModel):
 
         super().save(*args, **kwargs)
 
+        if previous_image_name != current_image_name and previous_image_name:
+            delete_image_derivatives_by_name(
+                self.featured_image.storage if self.featured_image else None,
+                previous_image_name,
+                "blog_featured",
+                delete_original=True,
+            )
+
+        if previous_image_name != current_image_name and self.featured_image:
+            safe_process_public_image(self.featured_image, "blog_featured")
+
     @property
     def content_html(self):
         """Convert markdown content to HTML"""