Exercise Files

Ch07/07_02_Begin/Website/Controllers/CartController.cs

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+using HPlusSports.Models;
+using System;
+using System.Data.Entity.Validation;
+using System.Linq;
+using System.Web.Mvc;
+
+namespace HPlusSports.Controllers
+{
+    public class CartController : Controller
+    {
+        private readonly HPlusSportsDbContext _context;
+
+        public CartController()
+            : this(new HPlusSportsDbContext())
+        {
+        }
+
+        public CartController(HPlusSportsDbContext context)
+        {
+            _context = context;
+        }
+
+        public ActionResult Index()
+        {
+            var cart = GetCart();
+
+            if (cart.Items.Any())
+                return View("Cart", cart);
+
+            return View("EmptyCart");
+        }
+
+        public ActionResult Add(string sku, int quantity = 1)
+        {
+            var product = _context.Products.FirstOrDefault(x => x.SKU == sku);
+
+            var cart = GetCart();
+
+            var item = cart.Items.FirstOrDefault(x => x.SKU == sku);
+
+            if (item == null)
+            {
+                item = new ShoppingCartItem
+                {
+                    SKU = product?.SKU,
+                    Name = product?.Name,
+                    MSRP = (product?.MSRP).GetValueOrDefault(),
+                    Price = (product?.Price).GetValueOrDefault(),
+                    Quantity = quantity,
+                };
+
+                cart.Items.Add(item);
+            }
+            else
+            {
+                item.Quantity += quantity;
+            }
+
+            if (item.Quantity <= 0)
+            {
+                cart.Items.Remove(item);
+            }
+
+            try
+            {
+                _context.SaveChanges();
+            }
+            catch (DbEntityValidationException ex)
+            {
+                var errors = ex.EntityValidationErrors.SelectMany(x => x.ValidationErrors);
+
+                foreach (var error in errors)
+                {
+                    ModelState.AddModelError(error.PropertyName, error.ErrorMessage);
+                }
+            }
+
+            if (!ModelState.IsValid)
+            {
+                return View();
+            }
+
+            TempData.SuccessMessage($"Successfully added {item.Name} to the cart");
+
+            return RedirectToAction("Index", "Cart");
+        }
+
+        public ActionResult Remove(long id)
+        {
+            var cart = GetCart();
+
+            var item = cart.Items.FirstOrDefault(x => x.Id == id);
+
+            if (item == null)
+            {
+                ModelState.AddModelError("", "Missing or invalid cart item");
+                return View();
+            }
+
+            cart.Items.Remove(item);
+
+            _context.SaveChanges();
+
+            return RedirectToAction("Index", "Cart");
+        }
+
+        private ShoppingCart GetCart()
+        {
+            var userId = GetUserId(this);
+
+            var cart =
+                _context.ShoppingCarts
+                    .Include("Items")
+                    .FirstOrDefault(x => x.UserId == userId);
+
+            if (cart == null)
+            {
+                cart = new ShoppingCart { UserId = userId };
+                _context.ShoppingCarts.Add(cart);
+                _context.SaveChanges();
+            }
+
+            cart.Recalculate();
+
+            return cart;
+        }
+
+        // Overwriteable function for unit testing
+        internal Func<Controller, string> GetUserId =
+            (controller) => controller.User.Identity.Name;
+    }
+}