#419

backend/app/controllers/posts_controller.rb

@@ -49,7 +49,7 @@ class PostsController < ApplicationController
         filtered_posts
         .joins("LEFT JOIN (#{ pt_max_sql }) pt_max ON pt_max.post_id = posts.id")
         .reselect('posts.*', Arel.sql("#{ updated_at_all_sql } AS updated_at_all"))
-        .preload(:uploaded_user, :parents, :children,
+        .preload(:external_tags, :uploaded_user, :parents, :children,
                  post_tags: [:sections, { tag: [:deerjikists, :materials,
                                                 { tag_name: :wiki_page }] }])
         .with_attached_thumbnail
@@ -102,12 +102,14 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(:uploaded_user, :parents, :children,
-                                  post_tags: [:sections, { tag: [:deerjikists, :materials,
-                                                                 { tag_name: :wiki_page }] }])
-                         .with_attached_thumbnail
-                         .order('RAND()')
-                         .first
+    post =
+        filtered_posts
+        .preload(:uploaded_user, :parents, :children,
+                 post_tags: [:sections, { tag: [:deerjikists, :materials,
+                                                { tag_name: :wiki_page }] }])
+        .with_attached_thumbnail
+        .order('RAND()')
+        .first
     return head :not_found unless post
 
     render json: PostRepr.base(post, current_user)
@@ -426,8 +428,20 @@ class PostsController < ApplicationController
     end
   end
 
-  def tagged_post_ids_for(name) =
-      Post.joins(tags: :tag_name).where(tag_names: { name: }).select(:id)
+  def tagged_post_ids_for(name)
+    posts_by_internal_tags =
+        Post
+        .joins(tags: :tag_name)
+        .where(tag_names: { name: })
+        .select(:id)
+
+    posts_by_external_tags =
+        Post
+        .joins(:external_tags)
+        .where("CONCAT(external_tags.platform, ':', external_tags.name) = ?", name)
+
+    (posts_by_internal_tags + posts_by_external_tags).uniq(&:id)
+  end
 
   def sync_post_tags! post, desired_tags, sections
     desired_tags.each do |t|