Add Undo of Follow Activity insertion

lib/pleroma/user.ex

@@ -2,7 +2,8 @@ defmodule Pleroma.User do
   use Ecto.Schema
   import Ecto.Changeset
   import Ecto.Query
-  alias Pleroma.{Repo, User, Activity, Object}
+  alias Pleroma.{Repo, User, Object}
+  alias Pleroma.Web.ActivityPub.ActivityPub
 
   schema "users" do
     field :bio, :string
@@ -91,9 +92,10 @@ defmodule Pleroma.User do
       following = follower.following
       |> List.delete(ap_followers)
 
-      follower
+      { :ok, follower } = follower
       |> follow_changeset(%{following: following})
       |> Repo.update
+      { :ok, follower, ActivityPub.fetch_latest_follow(follower, followed)}
     else
       { :error, "Not subscribed!" }
     end

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -174,6 +174,16 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     Repo.all(query)
   end
 
+  def fetch_latest_follow(%User{ap_id: follower_id},
+                          %User{ap_id: followed_id}) do
+    query = from activity in Activity,
+      where: fragment("? @> ?", activity.data, ^%{type: "Follow", actor: follower_id,
+                                                  object: followed_id}),
+      order_by: [desc: :inserted_at],
+      limit: 1
+    Repo.one(query)
+  end
+
   def upload(file) do
     data = Upload.store(file)
     Repo.insert(%Object{data: data})

lib/pleroma/web/twitter_api/twitter_api.ex

@@ -129,11 +129,17 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
     end
   end
 
-  def unfollow(%User{} = follower, params) do
+def unfollow(%User{} = follower, params) do
     with { :ok, %User{} = unfollowed } <- get_user(params),
-         { :ok, follower } <- User.unfollow(follower, unfollowed)
+         { :ok, follower, follow_activity } <- User.unfollow(follower, unfollowed),
+         { :ok, _activity } <- ActivityPub.insert(%{
+           "type" => "Undo",
+           "actor" => follower.ap_id,
+           "object" => follow_activity, # get latest Follow for these users
+           "published" => make_date()
+         })
     do
-      { :ok, follower, unfollowed}
+      { :ok, follower, unfollowed }
     else
       err -> err
     end