Mastodon API: Mark the conversation as read for the author when they send a new direct message

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -7,6 +7,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   alias Pleroma.Activity.Ir.Topics
   alias Pleroma.Config
   alias Pleroma.Conversation
+  alias Pleroma.Conversation.Participation
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Object.Containment
@@ -153,11 +154,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
       Notification.create_notifications(activity)
 
-      participations =
-        activity
-        |> Conversation.create_or_bump_for()
-        |> get_participations()
-
+      conversation = create_or_bump_conversation(activity, map["actor"])
+      participations = get_participations(conversation)
       stream_out(activity)
       stream_out_participations(participations)
       {:ok, activity}
@@ -182,7 +180,20 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  defp get_participations({:ok, %{participations: participations}}), do: participations
+  defp create_or_bump_conversation(activity, actor) do
+    with {:ok, conversation} <- Conversation.create_or_bump_for(activity),
+         %User{} = user <- User.get_cached_by_ap_id(actor),
+         Participation.mark_as_read(user, conversation) do
+      {:ok, conversation}
+    end
+  end
+
+  defp get_participations({:ok, conversation}) do
+    conversation
+    |> Repo.preload(:participations, force: true)
+    |> Map.get(:participations)
+  end
+
   defp get_participations(_), do: []
 
   def stream_out_participations(participations) do