public string CalculateInvoice(IEnumerable <OrderItemModel> invoiceItems)
{
InvoiceModel invoice = new InvoiceModel();
invoice.AddToInvoice(invoiceItems);
invoicesHistory.Add(invoice);
StringBuilder sb = new StringBuilder($"Invoice #{invoicesHistory.Count}\n\n");
sb.AppendLine("Pos. Name Qty. Sum");
sb.AppendLine("-----------------------------------------------------------------");
int i = 0;
decimal invoiceTotal = 0.00M;
foreach (var item in invoiceItems)
{
var catalogItem = catalog.First(x => x.ItemId == item.ItemId);
decimal sum = invoiceSumCalculator.CalculatePrice(catalogItem.Type, item.Quantity);
invoiceTotal += sum;
sb.AppendLine($"{(++i).ToString().PadLeft(4)} {catalogItem.Name.PadRight(40)} {item.Quantity.ToString().PadLeft(6)} {sum.ToString().PadLeft(12)}");
}
sb.AppendLine("-----------------------------------------------------------------");
sb.AppendLine($"Total {invoiceTotal.ToString().PadLeft(59)}\n\n");
int loyalty = invoice.CalculateLoyalty(catalog);
int totalLoyalty = invoicesHistory.Sum(x => x.CalculateLoyalty(catalog));
sb.Append($"Loyalty points added: {loyalty.ToString().PadLeft(3)} Total loyalty points: {totalLoyalty.ToString().PadLeft(3)}");
return(sb.ToString());
}
