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
    promotion = product.get_promotion
    special_price = SpecialPrice.find_by(customer_id: customer_id, product_id: product_id)
    discount_per_unit =
      if promotion.present?
        self.promotion_id = promotion.id
        (promotion.percent / 100) * unit_price
      elsif special_price.present?
        self.special_price_id = special_price.id
        special_price.get_unit_discount(unit_price)
      else
        0
      end
    self.unit_price_w_discount = (unit_price - discount_per_unit).round(2)
    self.discount = (discount_per_unit * quantity).round(2)
    self.amount = (quantity * unit_price_w_discount)
    self.tax = 0.0
    if product.include_sale_tax?
      self.tax = ((PosConfig.first.tax_percent / 100) * amount).round(2)
    end
    haggle_discount =
      if haggle > 0
        haggle.round(2)
      elsif haggle_percent > 0
        ((haggle_percent.to_f / 100) * amount).round(2)
      else
        0
      end
    self.amount -= haggle_discount if haggle_discount.present?
    self.total = amount + tax
    true
  end
end