Fix featured tags for remote accounts not being kept up to date (#33372)

app/lib/activitypub/activity/create.rb

@@ -53,6 +53,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     ApplicationRecord.transaction do
       @status = Status.create!(@params)
       attach_tags(@status)
+      attach_mentions(@status)
     end
 
     resolve_thread(@status)
@@ -160,6 +161,15 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     # not a big deal
     Trends.tags.register(status)
 
+    # Update featured tags
+    return if @tags.empty? || !status.distributable?
+
+    @account.featured_tags.where(tag_id: @tags.pluck(:id)).find_each do |featured_tag|
+      featured_tag.increment(status.created_at)
+    end
+  end
+
+  def attach_mentions(status)
     @mentions.each do |mention|
       mention.status = status
       mention.save

app/services/activitypub/process_status_update_service.rb

@@ -184,7 +184,26 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
   end
 
   def update_tags!
-    @status.tags = Tag.find_or_create_by_names(@raw_tags)
+    previous_tags = @status.tags.to_a
+    current_tags = @status.tags = Tag.find_or_create_by_names(@raw_tags)
+
+    return unless @status.distributable?
+
+    added_tags = current_tags - previous_tags
+
+    unless added_tags.empty?
+      @account.featured_tags.where(tag_id: added_tags.pluck(:id)).find_each do |featured_tag|
+        featured_tag.increment(@status.created_at)
+      end
+    end
+
+    removed_tags = previous_tags - current_tags
+
+    unless removed_tags.empty?
+      @account.featured_tags.where(tag_id: removed_tags.pluck(:id)).find_each do |featured_tag|
+        featured_tag.decrement(@status)
+      end
+    end
   end
 
   def update_mentions!