module Comee
  module Core
    class AdditionalItem < ApplicationRecord
      before_save { self.total_price = unit_price * quantity }
      after_save :update_invoice
      after_destroy :update_invoice
      belongs_to :invoice

      validates :description, presence: true
      validates :quantity, :unit_price, presence: true, numericality: {greater_than: 0}

      def update_invoice
        invoice.calculate_total_price
        invoice.calculate_vat
        invoice.save!
      end
    end
  end
end