/// <summary>
        /// Get active gift cards that are applied by a customer
        /// </summary>
        /// <param name="customer">Customer</param>
        /// <returns>Active gift cards</returns>
        public virtual IList<GiftCard> GetActiveGiftCardsAppliedByCustomer(Customer customer)
        {
            var result = new List<GiftCard>();
            if (customer == null)
                return result;

            string[] couponCodes = customer.ParseAppliedGiftCardCouponCodes();
            foreach (var couponCode in couponCodes)
            {
                var giftCards = GetAllGiftCards(null, null, null, true, couponCode);
                foreach (var gc in giftCards)
                {
                    if (gc.IsGiftCardValid())
                        result.Add(gc);
                }
            }

            return result;
        }