Create WrapperAuthenticator and simplify Authenticator behaviour

Speeds up recompilation by reducing compile-time cycles

lib/pleroma/web/auth/wrapper_authenticator.ex

@@ -0,0 +1,42 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Auth.WrapperAuthenticator do
+  @behaviour Pleroma.Web.Auth.Authenticator
+
+  defp implementation do
+    Pleroma.Config.get(
+      Pleroma.Web.Auth.Authenticator,
+      Pleroma.Web.Auth.PleromaAuthenticator
+    )
+  end
+
+  @impl true
+  def get_user(plug), do: implementation().get_user(plug)
+
+  @impl true
+  def create_from_registration(plug, registration),
+    do: implementation().create_from_registration(plug, registration)
+
+  @impl true
+  def get_registration(plug), do: implementation().get_registration(plug)
+
+  @impl true
+  def handle_error(plug, error),
+    do: implementation().handle_error(plug, error)
+
+  @impl true
+  def auth_template do
+    # Note: `config :pleroma, :auth_template, "..."` support is deprecated
+    implementation().auth_template() ||
+      Pleroma.Config.get([:auth, :auth_template], Pleroma.Config.get(:auth_template)) ||
+      "show.html"
+  end
+
+  @impl true
+  def oauth_consumer_template do
+    implementation().oauth_consumer_template() ||
+      Pleroma.Config.get([:auth, :oauth_consumer_template], "consumer.html")
+  end
+end