class Quickbooks::Model::Invoice

def billing_email_address=(email_address_string)
  self.bill_email = EmailAddress.new(email_address_string)
end

def billing_email_bcc_address=(email_address_string)
  self.bill_email_bcc = EmailAddress.new(email_address_string)
end

def billing_email_cc_address=(email_address_string)
  self.bill_email_cc = EmailAddress.new(email_address_string)
end

def email_status_for_delivery?
  email_status == EMAIL_STATUS_NEED_TO_SEND
end

def existence_of_customer_ref
  if customer_ref.nil? || (customer_ref && customer_ref.value == 0)
    errors.add(:customer_ref, "CustomerRef is required and must be a non-zero value.")
  end
end

def required_bill_email_if_email_delivery
  return unless email_status_for_delivery?
  if bill_email.nil?
    errors.add(:bill_email, "BillEmail is required if EmailStatus=NeedToSend")
  end
end

def wants_billing_email_sent!
  self.email_status = EMAIL_STATUS_NEED_TO_SEND
end