public class SalesDiscountProvider : Dynamicweb.Extensibility.ConfigurableAddIn 

[AddInName("Total price discount")]
 [AddInDescription("If the total sum of the products purchased on an order is equal or bigger that the specified amount a discount will be triggered.") ]
 public class TotalSalesPriceDiscount : SalesDiscountProvider
{
    #region Fields
    private string _MoreLess = "";
    private double _BuyLimit = 1000.0;
    private DiscountValueHandler _DiscountValue = new DiscountValueHandler();
    #endregion
 
    #region Properties
    [AddInParameter("Condition"), AddInParameterEditor(typeof(Editors.MoreLessParameterEditor), "")]
    public string MoreLess
    {
        get { return _MoreLess; }
        set { _MoreLess = value; }
    }
 
    [AddInParameter("Order buylimit"), AddInParameterEditor(typeof(Editors.TextParameterEditor), "")]
    public double BuyLimit
    {
        get { return _BuyLimit; }
        set { _BuyLimit = value; }
    }
 
    [AddInParameter("Discount"), AddInParameterEditor(typeof(Editors.DiscountValueEditor), "")]
    public string DiscountValue
    {
        get
        {
            if (_DiscountValue == null)
                _DiscountValue = new DiscountValueHandler();
            return _DiscountValue.Value;
        }
        set
        {
            if (_DiscountValue == null)
                _DiscountValue = new DiscountValueHandler();
            _DiscountValue.Value = value;
        }
    }
    #endregion

    #region Methods
    public override void ProcessOrder(Order _order)
    {
        bool AmountValid = false;
        if (this.MoreLess == ">" && _order.PriceBeforeFees.Price > this.BuyLimit)
            AmountValid = true;
        else if (this.MoreLess == ">=" && _order.PriceBeforeFees.Price >= this.BuyLimit)
            AmountValid = true;
        else if (this.MoreLess == "==" && _order.PriceBeforeFees.Price == this.BuyLimit)
            AmountValid = true;
        else if (this.MoreLess == "<" && _order.PriceBeforeFees.Price < this.BuyLimit)
            AmountValid = true;
        else if (this.MoreLess == "<=" && _order.PriceBeforeFees.Price <= this.BuyLimit)
            AmountValid = true;
    
        if (AmountValid == true)
        {
            if (this._DiscountValue.Type == DiscountTypes.Product || this._DiscountValue.Type == DiscountTypes.Products)
            {
                foreach (Products.Product product in this._DiscountValue.Products)
                {
                    OrderLine line = new OrderLine();
                    line.OrderID = _order.ID;
                    line.Order = _order;
                    line.ProductID = product.ID;
                    line.ProductVariantID = product.VariantID;
                    line.Quantity = 1;
                    line.Modified = DateTime.Now;
                    line.ProductName = product.Name;
                    line.ProductNumber = product.Number;
                    line.Reference = "Default.aspx?ID=" + PageId + "&ProductID=" + product.ID + "&VariantID=" + product.VariantID;
                    line.Type = base.ChkString(base.ChkNumber(OrderLine.OrderLineType.Discount));
                    line.PageID = PageId;
                    line.Product = product;
                    _order.OrderLines.Add(line, false);
                }
            }
            else
            {
                // Calculate discount
                double discountPrice = 0;
                // How are we going to calculate this?
                if (this._DiscountValue.Type == DiscountTypes.Percent)
                {
                    discountPrice = (_order.PriceBeforeFees.Price / 100) * this._DiscountValue.Amount;
                }
                else if (this._DiscountValue.Type == DiscountTypes.FixedAmount)
                {
                    discountPrice = this._DiscountValue.Amount;
                }
                // Get rawprice of the discount.
                PriceRaw rawprice = new PriceRaw(discountPrice, Dynamicweb.eCommerce.Common.Application.DefaultCurrency);
                // Convert to a calculated price
                Prices.PriceCalculated CalcPrice = new Prices.PriceCalculated(rawprice);
                CalcPrice.PriceWithoutVAT = CalcPrice.PriceWithVAT;
                CalcPrice.VATPercent = 0;
                CalcPrice.VAT = 0;
                // We need a negative value
                discountPrice = CalcPrice.Price - (CalcPrice.Price * 2);
                // Add a new order line
                OrderLine line = new OrderLine();
                line.Order = _order;
                line.Quantity = 1;
                line.ProductName = this.DiscountName;
                line.SetUnitPrice(discountPrice);
                line.Type = base.ChkString(base.ChkNumber(OrderLine.OrderLineType.Discount));
                // Insert orderline
                _order.OrderLines.Add(line, false);
           }
       }
    }
    #endregion

 }