ignore incoming federated private comments

lib/federation/activity_pub/transmogrifier.ex

@@ -67,30 +67,31 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   def handle_incoming(%{"type" => "Create", "object" => %{"type" => "Note"} = object}) do
     Logger.info("Handle incoming to create notes")
 
-    with object_data when is_map(object_data) <-
-           object |> Converter.Comment.as_to_model_data(),
-         {:existing_comment, {:error, :comment_not_found}} <-
-           {:existing_comment, Discussions.get_comment_from_url_with_preload(object_data.url)},
-         object_data <- transform_object_data_for_discussion(object_data),
-         # Check should be better
+    case Converter.Comment.as_to_model_data(object) do
+      %{visibility: visibility, event_id: event_id}
+      when visibility != :public and event_id != nil ->
+        Logger.info("Tried to reply to an event with a private comment - ignore")
+        :error
 
-         {:ok, %Activity{} = activity, entity} <-
-           (if is_data_for_comment_or_discussion?(object_data) do
-              Logger.debug("Chosing to create a regular comment")
-              Actions.Create.create(:comment, object_data, false)
-            else
-              Logger.debug("Chosing to initialize or add a comment to a conversation")
-              Actions.Create.create(:discussion, object_data, false)
-            end) do
+      object_data when is_map(object_data) ->
+        case Discussions.get_comment_from_url_with_preload(object_data.url) do
+          {:error, :comment_not_found} ->
+            object_data = transform_object_data_for_discussion(object_data)
+
+            case create_comment_or_discussion(object_data) do
+              {:ok, %Activity{} = activity, entity} ->
                 {:ok, activity, entity}
-    else
-      {:existing_comment, {:ok, %Comment{} = comment}} ->
-        {:ok, nil, comment}
 
               {:error, :event_not_allow_commenting} ->
                 Logger.debug("Tried to reply to an event for which comments are closed")
                 :error
             end
+
+          {:ok, %Comment{} = comment} ->
+            # Object already exists
+            {:ok, nil, comment}
+        end
+    end
   end
 
   # Handles a `Create` activity for `Event` objects
@@ -1177,4 +1178,16 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   defp can_manage_event?(%Actor{} = _actor, %Event{} = _event) do
     false
   end
+
+  @spec create_comment_or_discussion(map()) ::
+          {:ok, Activity.t(), struct()} | {:error, atom() | Ecto.Changeset.t()}
+  defp create_comment_or_discussion(object_data) do
+    if is_data_for_comment_or_discussion?(object_data) do
+      Logger.debug("Chosing to create a regular comment")
+      Actions.Create.create(:comment, object_data, false)
+    else
+      Logger.debug("Chosing to initialize or add a comment to a conversation")
+      Actions.Create.create(:discussion, object_data, false)
+    end
+  end
 end

lib/federation/activity_stream/converter/comment.ex

@@ -50,6 +50,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
         Logger.debug("Inserting full comment")
         Logger.debug(inspect(object))
 
+
         data = %{
           text: object["content"],
           url: object["id"],

lib/federation/activity_stream/converter/event.ex

@@ -230,8 +230,6 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Event do
     end
   end
 
-  @ap_public "https://www.w3.org/ns/activitystreams#Public"
-
   defp get_visibility(object), do: if(@ap_public in object["to"], do: :public, else: :unlisted)
 
   @spec date_to_string(DateTime.t() | nil) :: String.t()

test/fixtures/mastodon-post-activity-private.json

@@ -16,23 +16,15 @@
         }
     ],
     "actor": "https://framapiaf.org/users/admin",
-    "cc": [
-        "https://framapiaf.org/users/admin/followers",
-        "http://mobilizon.com/@tcit"
-    ],
-    "id": "https://framapiaf.org/users/admin/statuses/99512778738411822/activity",
+    "id": "https://framapiaf.org/users/admin/statuses/19512778738411823/activity",
     "nickname": "lain",
     "object": {
-        "atomUri": "https://framapiaf.org/users/admin/statuses/99512778738411822",
+        "atomUri": "https://framapiaf.org/users/admin/statuses/19512778738411823",
         "attachment": [],
         "attributedTo": "https://framapiaf.org/users/admin",
-        "cc": [
-            "https://framapiaf.org/users/admin/followers",
-            "https://framapiaf.org/users/tcit"
-        ],
-        "content": "<p><span class=\"h-card\"><a href=\"https://framapiaf.org/users/tcit\" class=\"u-url mention\">@<span>tcit</span></a></span></p>",
+        "content": "<p><span class=\"h-card\"><a href=\"https://framapiaf.org/users/tcit\" class=\"u-url mention\">@<span>tcit</span></a></span> here is a private message</p>",
         "conversation": "tag:mastodon.example.org,2018-02-12:objectId=20:objectType=Conversation",
-        "id": "https://framapiaf.org/users/admin/statuses/99512778738411822",
+        "id": "https://framapiaf.org/users/admin/statuses/19512778738411823",
         "inReplyTo": null,
         "inReplyToAtomUri": null,
         "published": "2018-02-12T14:08:20Z",
@@ -49,7 +41,7 @@
             "https://framapiaf.org/users/tcit"
         ],
         "type": "Note",
-        "url": "https://framapiaf.org/@admin/99512778738411822"
+        "url": "https://framapiaf.org/@admin/19512778738411823"
     },
     "published": "2018-02-12T14:08:20Z",
     "signature": {