Add an endpoint to get multiple statuses by IDs

lib/pleroma/activity.ex

@@ -173,6 +173,13 @@ defmodule Pleroma.Activity do
     |> Repo.one()
   end
 
+  def all_by_ids_with_object(ids) do
+    Activity
+    |> where([a], a.id in ^ids)
+    |> with_preloaded_object()
+    |> Repo.all()
+  end
+
   def by_object_ap_id(ap_id) do
     from(
       activity in Activity,

lib/pleroma/web/mastodon_api/controllers/mastodon_api_controller.ex

@@ -427,6 +427,20 @@ defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
     |> render("index.json", %{activities: activities, for: user, as: :activity})
   end
 
+  def get_statuses(%{assigns: %{user: user}} = conn, %{"ids" => ids}) do
+    limit = 100
+
+    activities =
+      ids
+      |> Enum.take(limit)
+      |> Activity.all_by_ids_with_object()
+      |> Enum.filter(&Visibility.visible_for_user?(&1, user))
+
+    conn
+    |> put_view(StatusView)
+    |> render("index.json", activities: activities, for: user, as: :activity)
+  end
+
   def get_status(%{assigns: %{user: user}} = conn, %{"id" => id}) do
     with %Activity{} = activity <- Activity.get_by_id_with_object(id),
          true <- Visibility.visible_for_user?(activity, user) do

lib/pleroma/web/router.ex

@@ -443,6 +443,7 @@ defmodule Pleroma.Web.Router do
       get("/timelines/tag/:tag", MastodonAPIController, :hashtag_timeline)
       get("/timelines/list/:list_id", MastodonAPIController, :list_timeline)
 
+      get("/statuses", MastodonAPIController, :get_statuses)
       get("/statuses/:id", MastodonAPIController, :get_status)
       get("/statuses/:id/context", MastodonAPIController, :get_context)