once-campfire/app/controllers/concerns/tracked_room_visit.rb

module TrackedRoomVisit
  extend ActiveSupport::Concern

  included do
    helper_method :last_room_visited
  end

  def remember_last_room_visited
    cookies.permanent[:last_room] = @room.id
  end

  def last_room_visited
    Current.user.rooms.find_by(id: cookies[:last_room]) || default_room
  end

  private
    def default_room
      Current.user.rooms.original
    end
end