From 27cd1374e3c1768a1a0b8abb40d5b56e6e021d2d Mon Sep 17 00:00:00 2001
From: Egor Kislitsyn <egor@kislitsyn.com>
Date: Tue, 12 Nov 2019 18:48:14 +0700
Subject: [PATCH] Add a notification for Move activities

---
 lib/pleroma/notification.ex                 | 33 ++++++++++-----------
 lib/pleroma/web/common_api/utils.ex         | 21 +++++++++----
 test/web/activity_pub/activity_pub_test.exs |  9 ++++++
 3 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/lib/pleroma/notification.ex b/lib/pleroma/notification.ex
index b7ecf51e4..f37e7ec67 100644
--- a/lib/pleroma/notification.ex
+++ b/lib/pleroma/notification.ex
@@ -251,10 +251,13 @@ def create_notifications(%Activity{data: %{"to" => _, "type" => "Create"}} = act
     end
   end
 
-  def create_notifications(%Activity{data: %{"to" => _, "type" => type}} = activity)
-      when type in ["Like", "Announce", "Follow"] do
-    users = get_notified_from_activity(activity)
-    notifications = Enum.map(users, fn user -> create_notification(activity, user) end)
+  def create_notifications(%Activity{data: %{"type" => type}} = activity)
+      when type in ["Like", "Announce", "Follow", "Move"] do
+    notifications =
+      activity
+      |> get_notified_from_activity()
+      |> Enum.map(&create_notification(activity, &1))
+
     {:ok, notifications}
   end
 
@@ -276,19 +279,15 @@ def create_notification(%Activity{} = activity, %User{} = user) do
 
   def get_notified_from_activity(activity, local_only \\ true)
 
-  def get_notified_from_activity(
-        %Activity{data: %{"to" => _, "type" => type} = _data} = activity,
-        local_only
-      )
-      when type in ["Create", "Like", "Announce", "Follow"] do
-    recipients =
-      []
-      |> Utils.maybe_notify_to_recipients(activity)
-      |> Utils.maybe_notify_mentioned_recipients(activity)
-      |> Utils.maybe_notify_subscribers(activity)
-      |> Enum.uniq()
-
-    User.get_users_from_set(recipients, local_only)
+  def get_notified_from_activity(%Activity{data: %{"type" => type}} = activity, local_only)
+      when type in ["Create", "Like", "Announce", "Follow", "Move"] do
+    []
+    |> Utils.maybe_notify_to_recipients(activity)
+    |> Utils.maybe_notify_mentioned_recipients(activity)
+    |> Utils.maybe_notify_subscribers(activity)
+    |> Utils.maybe_notify_followers(activity)
+    |> Enum.uniq()
+    |> User.get_users_from_set(local_only)
   end
 
   def get_notified_from_activity(_, _local_only), do: []
diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
index 88a5f434a..43b67d0f0 100644
--- a/lib/pleroma/web/common_api/utils.ex
+++ b/lib/pleroma/web/common_api/utils.ex
@@ -451,6 +451,8 @@ def maybe_notify_to_recipients(
     recipients ++ to
   end
 
+  def maybe_notify_to_recipients(recipients, _), do: recipients
+
   def maybe_notify_mentioned_recipients(
         recipients,
         %Activity{data: %{"to" => _to, "type" => type} = data} = activity
@@ -484,12 +486,8 @@ def maybe_notify_subscribers(recipients, %Activity{
     recipients
   end
 
-  def maybe_notify_subscribers(
-        recipients,
-        %Activity{data: %{"actor" => actor, "type" => type}} = activity
-      )
-      when type == "Create" do
-    with %User{} = user <- User.get_cached_by_ap_id(actor) do
+  def maybe_notify_subscribers(recipients, %Activity{data: %{"type" => "Create"}} = activity) do
+    with %User{} = user <- User.get_cached_by_ap_id(activity.actor) do
       subscriber_ids =
         user
         |> User.subscribers()
@@ -502,6 +500,17 @@ def maybe_notify_subscribers(
 
   def maybe_notify_subscribers(recipients, _), do: recipients
 
+  def maybe_notify_followers(recipients, %Activity{data: %{"type" => "Move"}} = activity) do
+    with %User{} = user <- User.get_cached_by_ap_id(activity.actor) do
+      user
+      |> User.get_followers()
+      |> Enum.map(& &1.ap_id)
+      |> Enum.concat(recipients)
+    end
+  end
+
+  def maybe_notify_followers(recipients, _), do: recipients
+
   def maybe_extract_mentions(%{"tag" => tag}) do
     tag
     |> Enum.filter(fn x -> is_map(x) && x["type"] == "Mention" end)
diff --git a/test/web/activity_pub/activity_pub_test.exs b/test/web/activity_pub/activity_pub_test.exs
index 6c5e5d38e..bbae3fcf1 100644
--- a/test/web/activity_pub/activity_pub_test.exs
+++ b/test/web/activity_pub/activity_pub_test.exs
@@ -8,6 +8,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubTest do
 
   alias Pleroma.Activity
   alias Pleroma.Builders.ActivityBuilder
+  alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ActivityPub
@@ -1464,6 +1465,14 @@ test "create" do
 
       assert User.following?(follower_move_opted_out, old_user)
       refute User.following?(follower_move_opted_out, new_user)
+
+      activity = %Activity{activity | object: nil}
+
+      assert [%Notification{activity: ^activity}] =
+               Notification.for_user_since(follower, ~N[2019-04-13 11:22:33])
+
+      assert [%Notification{activity: ^activity}] =
+               Notification.for_user_since(follower_move_opted_out, ~N[2019-04-13 11:22:33])
     end
 
     test "old user must be in the new user's `also_known_as` list" do