POS-Server/app/models/pre_sale.rb

class PreSale < ActiveRecord::Base
	belongs_to :customer
	belongs_to :user
	belongs_to :open_cash_register
	belongs_to :product
	belongs_to :special_price

	has_one :cash_register, :through => :open_cash_register
	has_one :pointsale, :through => :cash_register
		
	enum sale_type: [ :credit, :cash, :reserved ]

	validates :customer_id , :presence => { message: "Debe seleccionar cliente para la venta." }, :on => [:create, :update]
	validates :open_cash_register_id , :presence => { message: "Debe seleccionar caja registradora." }, :on => [:create, :update]
	validates :sale_type, presence: { message: "Debe seleccionar tipo de venta." }, :on => [:create, :update]

	# before_save :get_totals

	def get_totals
	    special_price = SpecialPrice.find_by(:customer_id => self.customer_id, :product_id => self.product_id)
	    unless special_price.blank?
	     	self.special_price_id = special_price.id
	     	discount_per_unit = special_price.get_unit_discount(self.unit_price)
	      	self.discount = discount_per_unit * self.quantity
	    end

	    self.discount += self.haggle
		self.amount = self.quantity * self.unit_price
		self.tax = 0.0
		if self.product.include_sale_tax == 1
			self.tax = ((PosConfig.first.tax_percent / 100) * self.amount).round(2)
		end
		self.total = (self.amount - self.discount) + self.tax
		return true
	end
end