using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace EssentialTools.Models

{

    public class Product

    {

        public int ProductId { get; set; }

        public string Name { get; set; }

        public string Description { get; set; }

        public decimal Price { get; set; }

        public string Category { set; get; }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace EssentialTools.Models

{

    public class LinqValueCalculator

    {

        public decimal ValueProducts(IEnumerable<Product> products)

        {

            return products.Sum(p => p.Price);

        }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace EssentialTools.Models

{

    public class ShoppingCart

    {

        private LinqValueCalculator _calculator;

        public ShoppingCart(LinqValueCalculator calculator)

        {

            _calculator = calculator;

        }

        public IEnumerable<Product> Products { get; set; }

        public decimal CalculateProductTotal()

        {

            return _calculator.ValueProducts(Products);

        }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace EssentialTools.Controllers

{

    public class HomeController : Controller

    {

        public ActionResult Index()

        {

            return View();

        }

    }

}