private void GenerateInvoice(Activity activity) { if (activity is null) { return; } List <Service> services = activity.ActivitiesServices.Select(s => s.Service).ToList(); ServiceInvoice serviceInvoice = new ServiceInvoice { Client = activity.Client, ClientId = activity.ClientId, PaymentMethod = PaymentMethod.None, State = InvoiceState.Generated, IVA = 0.19M, GenerationDate = DateTime.Now }; services.ForEach(service => { serviceInvoice.AddDetail(service); }); serviceInvoice.CalculateTotal(); _serviceInvoicesRepository.Insert(serviceInvoice); }