public static Bill CalculerPrice(Order order)
        {
            // Variable

            Bill billFacture = new Bill();
            decimal sumArticle = 0;
            decimal totalSum = 0;
            decimal totalSumTX = 0;

            // parcour d'une facture
            for (int i = 0; i < order.Prices.Length; i++)
            {

                sumArticle = order.Prices[i] * order.Quantities[i];
                totalSum += sumArticle;

                switch (order.Country)
                {

                    case "DE":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "FR":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "RO":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "NL":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "EL":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "LV":
                    totalSumTX = Math.Round(totalSum * (1.2m), 2);
                    break;
                    case "UK":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "PL":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "BG":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "IE":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "CI":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "DK":
                    totalSumTX = Math.Round(totalSum * (1.21m), 2);
                    break;
                    case "IT":
                    totalSumTX = Math.Round(totalSum * (1.25m), 2);
                    break;
                    case "LU":
                    totalSumTX = Math.Round(totalSum * (1.25m), 2);
                    break;
                    case "ES":
                    totalSumTX = Math.Round(totalSum * (1.19m), 2);
                    break;
                    case "PT":
                    totalSumTX = Math.Round(totalSum * (1.23m), 2);
                    break;
                    case "SE":
                    totalSumTX = Math.Round(totalSum * (1.23m), 2);
                    break;
                    case "HR":
                    totalSumTX = Math.Round(totalSum * (1.23m), 2);
                    break;
                    case "LT":
                    totalSumTX = Math.Round(totalSum * (1.23m), 2);
                    break;
                }

            }

            // Ajout de la Reduction

            if (order.Reduction != "PAY THE PRICE")
            {
                if (totalSumTX >= 1000)
                {

                    totalSumTX = totalSumTX - (totalSumTX*(0.03m));
                }
                if (totalSumTX >= 5000)
                {
                    totalSumTX = totalSumTX - (totalSumTX*(0.05m));
                }
                if (totalSumTX >= 7000)
                {
                    totalSumTX = totalSumTX - (totalSumTX*(0.07m));
                }
                if (totalSumTX >= 10000)
                {
                    totalSumTX = totalSumTX - (totalSumTX*(0.10m));
                }
                if (totalSumTX >= 50000)
                {
                    totalSumTX = totalSumTX - (totalSumTX*(0.15m));
                }

            }
            billFacture.total = totalSumTX;
            return billFacture;
        }
        public static Bill CalculerBill(Order commande)
        {
            Bill facture = new Bill();
            //if (commande.Reduction!="STANDARD")
            //    return null;

            decimal[] totalPrices = new decimal[commande.Prices.Length];

            for (int i = 0; i < commande.Prices.Length; i++)
            {
                //Calcul des taxes relatives au pays

                switch (commande.Country)
                {
                    case "ES":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.19m;
                        break;
                    case "AT":
                        totalPrices[i] = (commande.Prices[i] * commande.Quantities[i]) * 1.22m;
                        break;
                    case "DE":
                        totalPrices[i] = (commande.Prices[i] * commande.Quantities[i]) * 1.20m;
                        break;
                    case "UK":
                        totalPrices[i] = (commande.Prices[i] * commande.Quantities[i]) * 1.21m;
                        break;
                    case "FR":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    case "IT":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.25m;
                        break;
                    case "PL":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.21m;
                        break;
                    case "RO":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    case "NL":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    case "BE":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.24m;
                        break;
                    case "EL":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    case "CZ":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.19m;
                        break;
                    case "PT":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.23m;
                        break;
                    case "HU":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.27m;
                        break;
                    case "SE":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.23m;
                        break;
                    case "BG":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.21m;
                        break;
                    case "DK":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.21m;
                        break;
                    case "FI":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.17m;
                        break;
                    case "SK":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.18m;
                        break;
                    case "IE":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.21m;
                        break;
                    case "HR":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.23m;
                        break;
                    case "LT":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.23m;
                        break;
                    case "SI":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.24m;
                        break;
                    case "LV":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    case "EE":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.22m;
                        break;
                    case "CY":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.21m;
                        break;
                    case "LU":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.25m;
                        break;
                    case "MT":
                        totalPrices[i] = (commande.Prices[i]*commande.Quantities[i])*1.20m;
                        break;
                    default:
                        return null;

                };

            }
            decimal total = totalPrices.Sum();

            //Applcation des réductions
            Bill bill = new Bill();
            if (commande.Reduction == "PAY THE PRICE")
                bill.total = Math.Round(total,2);
            else if (commande.Reduction == "STANDARD")
            {
                if (total >= 1000)
                {
                    decimal reduction = total*0.03m;
                    total = total - reduction;
                }
                else if (total >= 5000)
                {
                    decimal reduction = total*0.05m;
                    total = total - reduction;
                }
                else if (total >= 7000)
                {
                    decimal reduction = total*0.07m;
                    total = total - reduction;
                }
                else if (total >= 10000)
                {
                    decimal reduction = total*0.10m;
                    total = total - reduction;
                }
                else if (total >= 50000)
                {
                    decimal reduction = total*0.15m;
                    total = total - reduction;
                }

                total = Math.Round(total, 2);
                bill.total = total;
            }
            else
            {
                bill = null;
            }
            return bill;
        }