public async Task Put()

in src/Modules/SimplCommerce.Module.Pricing/Areas/Pricing/Controllers/CartRuleApiController.cs [133:204]
66 lines of code
9 McCabe index (conditional complexity)

        public async Task<IActionResult> Put(long id, [FromBody] CartRuleForm model)
        {
            if (ModelState.IsValid)
            {
                var cartRule = await _cartRuleRepository.Query()
                    .Include(x => x.Coupons)
                    .Include(x => x.Products)
                    .FirstOrDefaultAsync(x => x.Id == id);
                if(cartRule == null)
                {
                    return NotFound();
                }

                cartRule.Name = model.Name;
                cartRule.Description = model.Description;
                cartRule.StartOn = model.StartOn;
                cartRule.EndOn = model.EndOn;
                cartRule.IsActive = model.IsActive;
                cartRule.IsCouponRequired = model.IsCouponRequired;
                cartRule.RuleToApply = model.RuleToApply;
                cartRule.DiscountAmount = model.DiscountAmount;
                cartRule.DiscountStep = model.DiscountStep;
                cartRule.MaxDiscountAmount = model.MaxDiscountAmount;
                cartRule.UsageLimitPerCoupon = model.UsageLimitPerCoupon;
                cartRule.UsageLimitPerCustomer = model.UsageLimitPerCustomer;

                if (model.IsCouponRequired && !string.IsNullOrWhiteSpace(model.CouponCode))
                {
                    var coupon = cartRule.Coupons.FirstOrDefault();
                    if (coupon == null)
                    {
                        coupon = new Coupon
                        {
                            CartRule = cartRule,
                            Code = model.CouponCode
                        };

                        cartRule.Coupons.Add(coupon);
                    }
                    else
                    {
                        coupon.Code = model.CouponCode;
                    }
                }

                foreach (var item in model.Products)
                {
                    var cartRuleProduct = cartRule.Products.FirstOrDefault(x => x.ProductId == item.Id);
                    if (cartRuleProduct == null)
                    {
                        cartRuleProduct = new CartRuleProduct
                        {
                            CartRule = cartRule,
                            ProductId = item.Id
                        };
                        cartRule.Products.Add(cartRuleProduct);
                    }
                }

                var modelProductIds = model.Products.Select(x => x.Id);
                var deletedProducts = cartRule.Products.Where(x => !modelProductIds.Contains(x.ProductId)).ToList();
                foreach(var item in deletedProducts)
                {
                    item.CartRule = null;
                    cartRule.Products.Remove(item);
                }

                await _cartRuleRepository.SaveChangesAsync();
                return Accepted();
            }
            return BadRequest(ModelState);
        }