routes.rb

# We can't use dynamic segment for the festivals because ActiveAdmin can't
# include it to default_url_options. So all named routes in admin will break.
Festival::KEYS.each do |festival_key|
  scope festival_key do
    scope ':locale', defaults: {locale: I18n.locale} do
      devise_for :admin_users, ActiveAdmin::Devise.config
      ActiveAdmin.routes(self)
    end
  end
end