module Concerns::Localizable
  extend ActiveSupport::Concern

  included do
    around_action :localize
  end

  def localize
    return false if set_locale === false
    yield
    set_language_header
  end

  def default_url_options(options = {})
    super.merge({ locale: I18n.locale })
  end

  private

  def set_locale
    if request.get? && params[:locale].blank?
      redirect_to request.query_parameters.merge(locale: I18n.default_locale)
      return false
    else
      I18n.locale = params[:locale] || I18n.default_locale
    end
  end

  def set_language_header
    response.headers['Content-Language'] = I18n.locale.to_s
  end
end