props/Props/Extensions/ProductListingExtensions.cs

using Microsoft.AspNetCore.Builder;
using Props.Shop.Framework;

namespace Props.Extensions
{
    public static class ProductListingExtensions
    {
        public static float? GetRatingToPriceRatio(this ProductListing productListing)
        {
            int reviewFactor = productListing.ReviewCount.HasValue ? productListing.ReviewCount.Value : 1;
            int purchaseFactor = productListing.PurchaseCount.HasValue ? productListing.PurchaseCount.Value : 1;
            return (productListing.Rating * (reviewFactor > purchaseFactor ? reviewFactor : purchaseFactor)) / (productListing.LowerPrice * productListing.UpperPrice);
        }


    }
}