namespace CustomProviders
{
    /// <summary>
    /// Customized CustomShippingOptionInfoProvider provider.
    /// </summary>
    public class CustomShippingOptionInfoProvider : ShippingOptionInfoProvider
    {
        /// <summary>
        /// Calculates shipping cost for the given shopping cart. Shipping free limit is applied. Shipping taxes are not included. Result is in site main currency. 
        /// </summary>
        /// <param name="cartObj">Shopping cart object</param>
        protected override double CalculateShippingInternal(ShoppingCartInfo cartObj)
        {

            // Check validity
            if (cartObj != null && cartObj.ShoppingCartShippingOptionID != 0 && ShippingOptionInfoProvider.GetShippingOptionInfo(cartObj.ShoppingCartShippingOptionID) != null)
            { 
                // Check free shipping conditions
                if (cartObj.TotalUnits > 10 && Convert.ToString(ShippingOptionInfoProvider.GetShippingOptionInfo(cartObj.ShoppingCartShippingOptionID)["ShippingOptionName"]).ToLower() == "alaska")
                {
                    return 0;
                }
            }
            return base.CalculateShippingInternal(cartObj);
        }
    }
}