module Raddar
  class Followership < ActiveRecord::Base
    belongs_to :user
    belongs_to :followable, polymorphic: true, inverse_of: :followers

    validates :user_id, presence: true, uniqueness: { scope: [:followable_id, :followable_type] }
    validates :followable_id, presence: true

    validate :user_and_followable_must_be_different


    private

    def user_and_followable_must_be_different
      if self.user.present? && self.user == self.followable
        self.errors[:base] << 'User cannot follow himself/herself.'
      end
    end
  end
end