private async Task AddOrDeleteProductVariation()

in src/Modules/SimplCommerce.Module.Catalog/Areas/Catalog/Controllers/ProductApiController.cs [700:783]
75 lines of code
10 McCabe index (conditional complexity)

        private async Task AddOrDeleteProductVariation(User loginUser,  ProductForm model, Product product)
        {
            foreach (var productVariationVm in model.Product.Variations)
            {
                var productLink = product.ProductLinks.Where(x => x.LinkType == ProductLinkType.Super).FirstOrDefault(x => x.LinkedProduct.Name == productVariationVm.Name);
                if (productLink == null)
                {
                    productLink = new ProductLink
                    {
                        LinkType = ProductLinkType.Super,
                        Product = product,
                        LinkedProduct = product.Clone()
                    };

                    productLink.LinkedProduct.CreatedById = loginUser.Id;
                    productLink.LinkedProduct.LatestUpdatedById = loginUser.Id;
                    productLink.LinkedProduct.Name = productVariationVm.Name;
                    productLink.LinkedProduct.Slug = StringHelper.ToUrlFriendly(productVariationVm.Name);
                    productLink.LinkedProduct.Sku = productVariationVm.Sku;
                    productLink.LinkedProduct.Gtin = productVariationVm.Gtin;
                    productLink.LinkedProduct.Price = productVariationVm.Price;
                    productLink.LinkedProduct.OldPrice = productVariationVm.OldPrice;
                    productLink.LinkedProduct.NormalizedName = productVariationVm.NormalizedName;
                    productLink.LinkedProduct.HasOptions = false;
                    productLink.LinkedProduct.IsVisibleIndividually = false;
                    if(product.ThumbnailImage != null)
                    {
                        productLink.LinkedProduct.ThumbnailImage = new Media { FileName = product.ThumbnailImage.FileName };
                    }

                    await MapProductVariantImageFromVm(productVariationVm, productLink.LinkedProduct);

                    foreach (var combinationVm in productVariationVm.OptionCombinations)
                    {
                        productLink.LinkedProduct.AddOptionCombination(new ProductOptionCombination
                        {
                            OptionId = combinationVm.OptionId,
                            Value = combinationVm.Value,
                            SortIndex = combinationVm.SortIndex
                        });
                    }

                    var productPriceHistory = CreatePriceHistory(loginUser, productLink.LinkedProduct);
                    productLink.LinkedProduct.PriceHistories.Add(productPriceHistory);

                    product.AddProductLinks(productLink);
                }
                else
                {
                    var isPriceChanged = false;
                    if(productLink.LinkedProduct.Price != productVariationVm.Price ||
                        productLink.LinkedProduct.OldPrice != productVariationVm.OldPrice)
                    {
                        isPriceChanged = true;
                    }

                    productLink.LinkedProduct.LatestUpdatedById = loginUser.Id;
                    productLink.LinkedProduct.LatestUpdatedOn = DateTimeOffset.Now;
                    productLink.LinkedProduct.Sku = productVariationVm.Sku;
                    productLink.LinkedProduct.Gtin = productVariationVm.Gtin;
                    productLink.LinkedProduct.Price = productVariationVm.Price;
                    productLink.LinkedProduct.OldPrice = productVariationVm.OldPrice;
                    productLink.LinkedProduct.IsDeleted = false;
                    productLink.LinkedProduct.StockTrackingIsEnabled = product.StockTrackingIsEnabled;

                    await MapProductVariantImageFromVm(productVariationVm, productLink.LinkedProduct);

                    if (isPriceChanged)
                    {
                        var productPriceHistory = CreatePriceHistory(loginUser, productLink.LinkedProduct);
                        productLink.LinkedProduct.PriceHistories.Add(productPriceHistory);
                    }
                }
            }

            foreach (var productLink in product.ProductLinks.Where(x => x.LinkType == ProductLinkType.Super))
            {
                if (model.Product.Variations.All(x => x.Name != productLink.LinkedProduct.Name))
                {
                    _productLinkRepository.Remove(productLink);
                    productLink.LinkedProduct.IsDeleted = true;
                }
            }
        }