Use social media preview images

bookwyrm/models/fields.py

@@ -415,7 +415,7 @@ class ImageField(ActivitypubFieldMixin, models.ImageField):
         activity[key] = formatted
 
     def field_to_activity(self, value, alt=None):
-        url = self.get_absolute_url(value)
+        url = get_absolute_url(value)
 
         if not url:
             return None
@@ -456,19 +456,19 @@ class ImageField(ActivitypubFieldMixin, models.ImageField):
             }
         )
 
-    # pylint: disable=no-self-use
-    def get_absolute_url(self, value):
-        """returns an absolute URL for the image"""
-        name = getattr(value, "name")
-        if not name:
-            return None
 
-        url = filepath_to_uri(name)
-        if url is not None:
-            url = url.lstrip("/")
-        url = urljoin(MEDIA_FULL_URL, url)
+def get_absolute_url(value):
+    """returns an absolute URL for the image"""
+    name = getattr(value, "name")
+    if not name:
+        return None
 
-        return url
+    url = filepath_to_uri(name)
+    if url is not None:
+        url = url.lstrip("/")
+    url = urljoin(MEDIA_FULL_URL, url)
+
+    return url
 
 
 class DateTimeField(ActivitypubFieldMixin, models.DateTimeField):

bookwyrm/models/status.py

@@ -190,9 +190,22 @@ class Status(OrderedCollectionPageMixin, BookWyrmModel):
                 activity.name = self.pure_name
             activity.type = self.pure_type
             books = [getattr(self, "book", None)] + list(self.mention_books.all())
-            covers = [
-                b.to_activity().get("cover") for b in books if b
-            ]
+            if len(books) == 1 and books[0].preview_image:
+                covers = [
+                    activitypub.Document(
+                        url=fields.get_absolute_url(books[0].preview_image),
+                        name=books[0].alt_text,
+                    )
+                ]
+            else:
+                covers = [
+                    activitypub.Document(
+                        url=fields.get_absolute_url(b.cover),
+                        name=b.alt_text,
+                    )
+                    for b in books
+                    if b and b.cover
+                ]
             activity.attachment = covers
         return activity