module Concernz
  module AstronomicalObject
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'astronomical_object_id'

      # AstronomicalObject is involved in Orbit and Orbit is around AstronomicalObject
      belongs_to :center_via_orbit, :class_name => 'AstronomicalObject', :foreign_key => :orbit_center_astronomical_object_id

      # Orbit is around AstronomicalObject and Orbit involves AstronomicalObject
      has_many :astronomical_objects_via_orbit, :class_name => 'AstronomicalObject', :foreign_key => :orbit_center_astronomical_object_id, :dependent => :destroy

      validates :astronomical_object_code, :presence => true
    end
  end
end