class Register < ActiveRecord::Base
    has_many :additions

  def sales_subtotal
    usedbook + newbook + medref + medsup + reference + insignia + coursepack + office + cards + greek + food + giftcard
  end

  def sales_subtractions
    shipping + tax + voids + onaccount + refunds + payouts + discounts
  end

  def sales_totals
    sales_subtotal - sales_subtractions
  end

  def addition_amounts
    self.additions.collect{ |addition| addition.amount }
  end

  def addition_totals
    self.additions_amounts.inject( 0 ) { |sum,x| sum+x }
  end

#  def additions
#    additions = @additions.sum
#  end
end