def current_user_session
    return @current_user_session if defined?(@current_user_session)
    @current_user_session = UserSession.find
  end

  def current_user
    return @current_user if defined?(@current_user)
    @current_user = current_user_session && current_user_session.user
    @current_user ||= login_as_trial_user
  end

  def login_as_trial_user
    name = "anonymous_#{session[:session_id]}"
    UserSession.create(User.find_by_username(name) ||
                               User.create(
                               :username => name,
                               :password => name,
                               :password_confirmation => name,
                               :role => "guest",
                               :email => "change@this.com")
    end
     @current_user_session = UserSession.find
     current_user
  end