Fix following groups + Add interface to manage followers

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/federation/activity_pub/activity_pub.ex

@@ -50,7 +50,6 @@ defmodule Mobilizon.Federation.ActivityPub do
 
   alias Mobilizon.Web.Endpoint
   alias Mobilizon.Web.Email.{Admin, Group, Mailer}
-  alias Mobilizon.Web.Email.Follow, as: FollowMailer
 
   require Logger
 
@@ -320,13 +319,22 @@ defmodule Mobilizon.Federation.ActivityPub do
   @doc """
   Make an actor follow another
   """
-  def follow(%Actor{} = follower, %Actor{} = followed, activity_id \\ nil, local \\ true) do
+  def follow(
+        %Actor{} = follower,
+        %Actor{} = followed,
+        activity_id \\ nil,
+        local \\ true,
+        additional \\ %{}
+      ) do
     with {:different_actors, true} <- {:different_actors, followed.id != follower.id},
-         {:ok, %Follower{} = follower} <-
-           Actors.follow(followed, follower, activity_id, false),
-         :ok <- FollowMailer.send_notification_to_admins(follower),
-         follower_as_data <- Convertible.model_to_as(follower),
-         {:ok, activity} <- create_activity(follower_as_data, local),
+         {:ok, activity_data, %Follower{} = follower} <-
+           Types.Actors.follow(
+             follower,
+             followed,
+             local,
+             Map.merge(additional, %{"activity_id" => activity_id})
+           ),
+         {:ok, activity} <- create_activity(activity_data, local),
          :ok <- maybe_federate(activity) do
       {:ok, activity, follower}
     else

lib/federation/activity_pub/transmogrifier.ex

@@ -302,6 +302,10 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
               do_handle_incoming_accept_join(accepted_object, actor)} do
       {:ok, activity, object}
     else
+      {:object_not_found, {:error, "Follow already accepted"}} ->
+        Logger.info("Follow was already accepted. Ignoring.")
+        :error
+
       {:object_not_found, nil} ->
         Logger.warn(
           "Unable to process Accept activity #{inspect(id)}. Object #{inspect(accepted_object)} wasn't found."
@@ -761,6 +765,10 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
 
       {:ok, activity, follow}
     else
+      {:follow, {:ok, %Follower{approved: true} = _follow}} ->
+        Logger.debug("Follow already accepted")
+        {:error, "Follow already accepted"}
+
       {:follow, _} ->
         Logger.debug(
           "Tried to handle an Accept activity but it's not containing a Follow activity"
@@ -770,9 +778,6 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
 
       {:same_actor} ->
         {:error, "Actor who accepted the follow wasn't the target. Quite odd."}
-
-      {:ok, %Follower{approved: true} = _follow} ->
-        {:error, "Follow already accepted"}
     end
   end
 

lib/federation/activity_pub/types/actors.ex

@@ -1,7 +1,7 @@
 defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
   @moduledoc false
   alias Mobilizon.Actors
-  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Actors.{Actor, Follower, Member}
   alias Mobilizon.Federation.ActivityPub
   alias Mobilizon.Federation.ActivityPub.Audience
   alias Mobilizon.Federation.ActivityPub.Types.Entity
@@ -9,6 +9,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
   alias Mobilizon.Service.Formatter.HTML
   alias Mobilizon.Service.Notifications.Scheduler
+  alias Mobilizon.Web.Email.Follow, as: FollowMailer
   alias Mobilizon.Web.Endpoint
   import Mobilizon.Federation.ActivityPub.Utils, only: [make_create_data: 2, make_update_data: 2]
 
@@ -130,6 +131,15 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
     end
   end
 
+  def follow(%Actor{} = follower_actor, %Actor{} = followed, _local, additional) do
+    with {:ok, %Follower{} = follower} <-
+           Mobilizon.Actors.follow(followed, follower_actor, additional["activity_id"], false),
+         :ok <- FollowMailer.send_notification_to_admins(follower),
+         follower_as_data <- Convertible.model_to_as(follower) do
+      approve_if_manually_approves_followers(follower, follower_as_data)
+    end
+  end
+
   defp prepare_args_for_actor(args) do
     args
     |> maybe_sanitize_username()
@@ -189,4 +199,21 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
       {:ok, activity_data, member}
     end
   end
+
+  defp approve_if_manually_approves_followers(
+         %Follower{} = follower,
+         follow_as_data
+       ) do
+    unless follower.target_actor.manually_approves_followers do
+      {:accept,
+       ActivityPub.accept(
+         :follow,
+         follower,
+         true,
+         %{"actor" => follower.actor.url}
+       )}
+    end
+
+    {:ok, follow_as_data, follower}
+  end
 end