public async Task AddItemAsync()

in src/cart/src/cartstore/ValkeyCartStore.cs [122:170]
43 lines of code
4 McCabe index (conditional complexity)

    public async Task AddItemAsync(string userId, string productId, int quantity)
    {
        var stopwatch = Stopwatch.StartNew();
        _logger.LogInformation("AddItemAsync called with userId={userId}, productId={productId}, quantity={quantity}", userId, productId, quantity);

        try
        {
            EnsureRedisConnected();

            var db = _redis.GetDatabase();

            // Access the cart from the cache
            var value = await db.HashGetAsync(userId, CartFieldName);

            Oteldemo.Cart cart;
            if (value.IsNull)
            {
                cart = new Oteldemo.Cart
                {
                    UserId = userId
                };
                cart.Items.Add(new Oteldemo.CartItem { ProductId = productId, Quantity = quantity });
            }
            else
            {
                cart = Oteldemo.Cart.Parser.ParseFrom(value);
                var existingItem = cart.Items.SingleOrDefault(i => i.ProductId == productId);
                if (existingItem == null)
                {
                    cart.Items.Add(new Oteldemo.CartItem { ProductId = productId, Quantity = quantity });
                }
                else
                {
                    existingItem.Quantity += quantity;
                }
            }

            await db.HashSetAsync(userId, new[]{ new HashEntry(CartFieldName, cart.ToByteArray()) });
            await db.KeyExpireAsync(userId, TimeSpan.FromMinutes(60));
        }
        catch (Exception ex)
        {
            throw new RpcException(new Status(StatusCode.FailedPrecondition, $"Can't access cart storage. {ex}"));
        }
        finally
        {
            addItemHistogram.Record(stopwatch.ElapsedTicks);
        }
    }