Refactor admin interface under namespace

app/controllers/admin/setting_groups_controller.rb

@@ -0,0 +1,27 @@
+class Admin::SettingGroupsController < ApplicationController
+  before_action :set_setting_group, only: [:show, :update]
+
+  def index
+    @setting_groups = SettingGroup.all
+  end
+
+  def show; end
+
+  def update
+    if @setting_group.update(setting_group_params)
+      redirect_to [:admin, @setting_group]
+    else
+      render 'show'
+    end
+  end
+
+  private
+
+  def set_setting_group
+    @setting_group = SettingGroup.find(params[:id])
+  end
+
+  def setting_group_params
+    params.require(:setting_group).permit(settings_attributes: [:value, :id])
+  end
+end