class Invoice < ApplicationRecord
  belongs_to :user
  belongs_to :user_firm
  belongs_to :customer
  has_many :invoice_products, inverse_of: :invoice, dependent: :destroy
  accepts_nested_attributes_for :invoice_products, allow_destroy: true

  def netto_amount
    invoice_products.sum('invoice_products.netto_price * invoice_products.qty')
  end

  def products_with_tax(vat_id)
    self.invoice_products.joins(:product => :vat).where('vats.id = ?',vat_id)
  end

  def products_with_tax_sum_arr(vat_id)
    sum = 0.0
    vat = 0.0
    total = 0.0
    for invoice_product in self.invoice_products.joins(:product => :vat).where('vats.id = ?',vat_id)
      sum += invoice_product.netto_price * invoice_product.qty
      vat += (invoice_product.netto_price * (invoice_product.product.vat.tax_rate/100)) * invoice_product.qty
      total += (invoice_product.netto_price * (invoice_product.product.vat.tax_rate/100 + 1)) * invoice_product.qty
    end
    return [sum,vat,total]
  end

end