Added Taxable to Products

Added the ability to tax products for sale

RMData/dbo/Stored Procedures/spProductGetAll.sql

@@ -3,7 +3,7 @@ AS
 BEGIN
 	SET NOCOUNT ON;
 
-	select Id, ProductName, [Description], RetailPrice, QuantityInStock
+	select Id, ProductName, [Description], RetailPrice, QuantityInStock, IsTaxable
 	from [dbo].[Product]
 	order by ProductName;
 END

RMData/dbo/Tables/Product.sql

@@ -6,5 +6,6 @@
     [RetailPrice] MONEY NOT NULL,
     [QuantityInStock] INT NOT NULL DEFAULT 1,
     [CreatedDate] DATETIME2 NOT NULL DEFAULT getutcdate(), 
-    [LastModified] DATETIME2 NOT NULL DEFAULT getutcdate()
+    [LastModified] DATETIME2 NOT NULL DEFAULT getutcdate(), 
+    [IsTaxable] BIT NOT NULL DEFAULT 1
 )

RMDataManagerLibrary/Models/ProductModel.cs

@@ -12,5 +12,6 @@ namespace RMDataManagerLibrary.Models
         public string Description { get; set; }
         public decimal RetailPrice { get; set; }
         public int QuantityInStock { get; set; }
+        public bool IsTaxable { get; set; }
     }
 }

RMWPFInterfaceLibrary/Helpers/ConfigHelper.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace RMWPFInterfaceLibrary.Helpers
+{
+    public class ConfigHelper : IConfigHelper
+    {
+        public decimal GetTaxRate()
+        {
+            string rateText = ConfigurationManager.AppSettings["taxRate"];
+
+            bool isValidTaxRate = Decimal.TryParse(rateText, out decimal output);
+
+            if (isValidTaxRate == false)
+            {
+                throw new ConfigurationErrorsException("The taxRate is not setup properly");
+            }
+
+            return output;
+        }
+    }
+}

RMWPFInterfaceLibrary/Helpers/IConfigHelper.cs

@@ -0,0 +1,7 @@
+namespace RMWPFInterfaceLibrary.Helpers
+{
+    public interface IConfigHelper
+    {
+        decimal GetTaxRate();
+    }
+}

RMWPFInterfaceLibrary/Models/ProductModel.cs

@@ -13,5 +13,6 @@ namespace RMWPFInterfaceLibrary.Models
         public string Description { get; set; }
         public decimal RetailPrice { get; set; }
         public int QuantityInStock { get; set; }
+        public bool IsTaxable { get; set; }
     }
 }

RMWPFInterfaceLibrary/RMWPFInterfaceLibrary.csproj

@@ -52,6 +52,8 @@
     <Compile Include="Api\IAPIHelper.cs" />
     <Compile Include="Api\IProductEndPoint.cs" />
     <Compile Include="Api\ProductEndPoint.cs" />
+    <Compile Include="Helpers\ConfigHelper.cs" />
+    <Compile Include="Helpers\IConfigHelper.cs" />
     <Compile Include="Models\AuthenticatedUser.cs" />
     <Compile Include="Models\CartItemModel.cs" />
     <Compile Include="Models\ILoggedInUserModel.cs" />

RMWPFUserInterface/App.config

@@ -2,6 +2,7 @@
 <configuration>
 	<appSettings>
 		<add key="api" value="https://localhost:44372/" />
+		<add key="taxRate" value="8.75" />
 	</appSettings>
     <startup> 
         <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />

RMWPFUserInterface/BootStrapper.cs

@@ -1,5 +1,6 @@
 using Caliburn.Micro;
 using RMWPFInterfaceLibrary.Api;
+using RMWPFInterfaceLibrary.Helpers;
 using RMWPFInterfaceLibrary.Models;
 using RMWPFUserInterface.Helpers;
 using RMWPFUserInterface.ViewModels;
@@ -29,11 +30,12 @@ namespace RMWPFUserInterface
         {
             _container.Instance(_container)
                 .PerRequest<IProductEndPoint, ProductEndPoint>();
-                
+
             _container
                 .Singleton<IWindowManager, WindowManager>()
                 .Singleton<IEventAggregator, EventAggregator>()
                 .Singleton<ILoggedInUserModel, LoggedInUserModel>()
+                .Singleton<IConfigHelper, ConfigHelper>()
                 .Singleton<IAPIHelper, APIHelper>();    
 
             GetType().Assembly.GetTypes()

RMWPFUserInterface/ViewModels/SalesViewModel.cs

@@ -1,5 +1,6 @@
 using Caliburn.Micro;
 using RMWPFInterfaceLibrary.Api;
+using RMWPFInterfaceLibrary.Helpers;
 using RMWPFInterfaceLibrary.Models;
 using System;
 using System.Collections.Generic;
@@ -13,9 +14,11 @@ namespace RMWPFUserInterface.ViewModels
     public class SalesViewModel : Screen
     {
         IProductEndPoint _productEndPoint;
-        public SalesViewModel(IProductEndPoint productEndPoint)
+        IConfigHelper _configHelper;
+        public SalesViewModel(IProductEndPoint productEndPoint, IConfigHelper configHelper)
         {
             _productEndPoint = productEndPoint;
+            _configHelper = configHelper;
         }
 
         protected override async void OnViewLoaded(object view)
@@ -84,33 +87,53 @@ namespace RMWPFUserInterface.ViewModels
         public string SubTotal 
         { 
             get
-            {
-                decimal subTotal = 0;
-
-                foreach (var item in Cart)
-                {
-                    subTotal += item.Product.RetailPrice * item.QuantityInCart;
-                }
-
-                return subTotal.ToString("C");
+            { 
+                return CalculateSubTotal().ToString("C");
             }
         }
 
+        private decimal CalculateSubTotal()
+        {
+            decimal subTotal = 0;
+
+            foreach (var item in Cart)
+            {
+                subTotal += item.Product.RetailPrice * item.QuantityInCart;
+            }
+
+            return subTotal;
+        }
+
         public string Tax
         {
             get
             {
-                // replace with calulation;
-                return "$0.00";
+                return CalculateTax().ToString("C");
             }
         }
 
+        private decimal CalculateTax()
+        {
+            decimal taxAmount = 0;
+            decimal TaxRate = _configHelper.GetTaxRate()/100;
+
+            foreach (var item in Cart)
+            {
+                if (item.Product.IsTaxable)
+                {
+                    taxAmount += (item.Product.RetailPrice * item.QuantityInCart * TaxRate);
+                }
+            }
+
+            return taxAmount;
+        }
+
         public string Total
         {
             get
             {
-                // replace with calulation;
-                return "$0.00";
+                decimal total = CalculateSubTotal() + CalculateTax();
+                return total.ToString("C");
             }
         }
 
@@ -149,6 +172,8 @@ namespace RMWPFUserInterface.ViewModels
             SelectedProduct.QuantityInStock -= ItemQuantity;
             ItemQuantity = 1;
             NotifyOfPropertyChange(() => SubTotal);
+            NotifyOfPropertyChange(() => Tax);
+            NotifyOfPropertyChange(() => Total);
             Cart.ResetBindings();
         }
 
@@ -166,6 +191,8 @@ namespace RMWPFUserInterface.ViewModels
         public void RemoveFromCart()
         {
             NotifyOfPropertyChange(() => SubTotal);
+            NotifyOfPropertyChange(() => Tax);
+            NotifyOfPropertyChange(() => Total);
         }
 
         public bool CanCheckOut