3 files changed, 35 insertions, 13 deletions

diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index a112d4ced..6a0fdb433 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -693,12 +693,9 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   end
 
   def add_mention_tags(object) do
-    recipients = object["to"] ++ (object["cc"] || [])
-
     mentions =
-      recipients
-      |> Enum.map(fn ap_id -> User.get_cached_by_ap_id(ap_id) end)
-      |> Enum.filter(& &1)
+      object
+      |> Utils.get_notified_from_object()
       |> Enum.map(fn user ->
         %{"type" => "Mention", "href" => user.ap_id, "name" => "@#{user.nickname}"}
       end)
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index d81c824f0..fac91830a 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -1,11 +1,13 @@
 defmodule Pleroma.Web.ActivityPub.Utils do
-  alias Pleroma.{Repo, Web, Object, Activity, User}
+  alias Pleroma.{Repo, Web, Object, Activity, User, Notification}
   alias Pleroma.Web.Router.Helpers
   alias Pleroma.Web.Endpoint
   alias Ecto.{Changeset, UUID}
   import Ecto.Query
   require Logger
 
+  @supported_object_types ["Article", "Note", "Video", "Page"]
+
   # Some implementations send the actor URI as the actor field, others send the entire actor object,
   # so figure out what the actor's URI is based on what we have.
   def get_ap_id(object) do
@@ -95,6 +97,21 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     "#{Web.base_url()}/#{type}/#{UUID.generate()}"
   end
 
+  def get_notified_from_object(%{"type" => type} = object) when type in @supported_object_types do
+    fake_create_activity = %{
+      "to" => object["to"],
+      "cc" => object["cc"],
+      "type" => "Create",
+      "object" => object
+    }
+
+    Notification.get_notified_from_activity(%Activity{data: fake_create_activity}, false)
+  end
+
+  def get_notified_from_object(object) do
+    Notification.get_notified_from_activity(%Activity{data: object}, false)
+  end
+
   def create_context(context) do
     context = context || generate_id("contexts")
     changeset = Object.context_mapping(context)
@@ -164,7 +181,7 @@ defmodule Pleroma.Web.ActivityPub.Utils do
   Inserts a full object if it is contained in an activity.
   """
   def insert_full_object(%{"object" => %{"type" => type} = object_data})
-      when is_map(object_data) and type in ["Article", "Note", "Video", "Page"] do
+      when is_map(object_data) and type in @supported_object_types do
     with {:ok, _} <- Object.create(object_data) do
       :ok
     end
diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
index b22c4cc03..728f24c7e 100644
--- a/lib/pleroma/web/common_api/utils.ex
+++ b/lib/pleroma/web/common_api/utils.ex
@@ -34,21 +34,29 @@ defmodule Pleroma.Web.CommonAPI.Utils do
   end
 
   def to_for_user_and_mentions(user, mentions, inReplyTo, "public") do
-    to = ["https://www.w3.org/ns/activitystreams#Public"]
-
     mentioned_users = Enum.map(mentions, fn {_, %{ap_id: ap_id}} -> ap_id end)
-    cc = [user.follower_address | mentioned_users]
+
+    to = ["https://www.w3.org/ns/activitystreams#Public" | mentioned_users]
+    cc = [user.follower_address]
 
     if inReplyTo do
-      {to, Enum.uniq([inReplyTo.data["actor"] | cc])}
+      {Enum.uniq([inReplyTo.data["actor"] | to]), cc}
     else
       {to, cc}
     end
   end
 
   def to_for_user_and_mentions(user, mentions, inReplyTo, "unlisted") do
-    {to, cc} = to_for_user_and_mentions(user, mentions, inReplyTo, "public")
-    {cc, to}
+    mentioned_users = Enum.map(mentions, fn {_, %{ap_id: ap_id}} -> ap_id end)
+
+    to = [user.follower_address | mentioned_users]
+    cc = ["https://www.w3.org/ns/activitystreams#Public"]
+
+    if inReplyTo do
+      {Enum.uniq([inReplyTo.data["actor"] | to]), cc}
+    else
+      {to, cc}
+    end
   end
 
   def to_for_user_and_mentions(user, mentions, inReplyTo, "private") do