ActivityPub delivery (#4566)

* Deliver ActivityPub Like

* Deliver ActivityPub Undo-Like

* Deliver ActivityPub Create/Announce activities

* Deliver ActivityPub creates from mentions

* Deliver ActivityPub Block/Undo-Block

* Deliver ActivityPub Accept/Reject-Follow

* Deliver ActivityPub Undo-Follow

* Deliver ActivityPub Follow

* Deliver ActivityPub Delete activities

Incidentally fix #889

* Adjust BatchedRemoveStatusService for ActivityPub

* Add tests for ActivityPub workers

* Add tests for FollowService

* Add tests for FavouriteService, UnfollowService and PostStatusService

* Add tests for ReblogService, BlockService, UnblockService, ProcessMentionsService

* Add tests for AuthorizeFollowService, RejectFollowService, RemoveStatusService

* Add tests for BatchedRemoveStatusService

* Deliver updates to a local account to ActivityPub followers

* Minor adjustments

1 files changed, 18 insertions, 1 deletions

diff --git a/app/services/unfollow_service.rb b/app/services/unfollow_service.rb
index 388909586..10af75146 100644
--- a/app/services/unfollow_service.rb
+++ b/app/services/unfollow_service.rb
@@ -7,12 +7,29 @@ class UnfollowService < BaseService
   def call(source_account, target_account)
     follow = source_account.unfollow!(target_account)
     return unless follow
-    NotificationWorker.perform_async(build_xml(follow), source_account.id, target_account.id) unless target_account.local?
+    create_notification(follow) unless target_account.local?
     UnmergeWorker.perform_async(target_account.id, source_account.id)
+    follow
   end
 
   private
 
+  def create_notification(follow)
+    if follow.target_account.ostatus?
+      NotificationWorker.perform_async(build_xml(follow), follow.account_id, follow.target_account_id)
+    elsif follow.target_account.activitypub?
+      ActivityPub::DeliveryWorker.perform_async(build_json(follow), follow.account_id, follow.target_account.inbox_url)
+    end
+  end
+
+  def build_json(follow)
+    ActiveModelSerializers::SerializableResource.new(
+      follow,
+      serializer: ActivityPub::UndoFollowSerializer,
+      adapter: ActivityPub::Adapter
+    ).to_json
+  end
+
   def build_xml(follow)
     OStatus::AtomSerializer.render(OStatus::AtomSerializer.new.unfollow_salmon(follow))
   end