Clean unconfirmed users

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

lib/service/workers/clean_unconfirmed_users_worker.ex

@@ -0,0 +1,31 @@
+defmodule Mobilizon.Service.Workers.CleanUnconfirmedUsersWorker do
+  @moduledoc """
+  Worker to clean unattached media
+  """
+
+  use Oban.Worker, queue: "background"
+  alias Mobilizon.Service.CleanUnconfirmedUsers
+
+  @grace_period Mobilizon.Config.get([:instance, :unconfirmed_user_grace_period_hours], 48)
+
+  @impl Oban.Worker
+  def perform(%Job{}) do
+    if Mobilizon.Config.get!([:instance, :remove_unconfirmed_users]) and should_perform?() do
+      CleanUnconfirmedUsers.clean()
+    end
+  end
+
+  @spec should_perform? :: boolean()
+  defp should_perform? do
+    case Cachex.get(:key_value, "last_media_cleanup") do
+      {:ok, %DateTime{} = last_media_cleanup} ->
+        DateTime.compare(
+          last_media_cleanup,
+          DateTime.add(DateTime.utc_now(), @grace_period * -3600)
+        ) == :lt
+
+      _ ->
+        true
+    end
+  end
+end