Implement simple repository pattern (#1)

Implement simple repository pattern

src/Todo.CLI/Handlers/ListCommandHandler.cs

@@ -13,7 +13,7 @@ public static ICommandHandler Create(IServiceProvider serviceProvider)
         {
             return CommandHandler.Create(async () =>
             {
-                var todoItemRetriever = (ITodoItemRetriever)serviceProvider.GetService(typeof(ITodoItemRetriever));
+                var todoItemRetriever = (ITodoItemRepository)serviceProvider.GetService(typeof(ITodoItemRepository));
                 var todoItems = await todoItemRetriever.ListAsync();
                 foreach (var item in todoItems)
                 {

src/Todo.CLI/Program.cs

@@ -9,6 +9,7 @@
 using Todo.Core;
 using Microsoft.Graph;
 using Todo.CLI.Auth;
+using Todo.Core.Repository;
 
 namespace Todo.CLI
 {
@@ -25,7 +26,7 @@ static int Main(string[] args)
 
             var services = new ServiceCollection()
                 .AddSingleton(typeof(TodoCliConfiguration), todoCliConfig)
-                .AddTransient<ITodoItemRetriever>(factory => new TodoItemRetriever(TodoCliAuthenticationProviderFactory.GetAuthenticationProvider(factory)));
+                .AddTransient<ITodoItemRepository>(factory => new TodoItemRepository(TodoCliAuthenticationProviderFactory.GetAuthenticationProvider(factory)));
 
             var serviceProvider = services.BuildServiceProvider();
 

src/Todo.Core/Model/TodoItem.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Todo.Core.Model
+{
+    public class TodoItem
+    {
+        public string Subject { get; set; }
+    }
+}

src/Todo.Core/ITodoItemRetriever.cs → src/Todo.Core/Repository/ITodoItemRepository.cs

@@ -3,11 +3,12 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
+using Todo.Core.Model;
 
 namespace Todo.Core
 {
-    public interface ITodoItemRetriever
+    public interface ITodoItemRepository
     {
-        Task<IEnumerable<OutlookTask>> ListAsync();
+        Task<IEnumerable<TodoItem>> ListAsync();
     }
 }

src/Todo.Core/Repository/RepositoryBase.cs

@@ -0,0 +1,17 @@
+using Microsoft.Graph;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Todo.Core.Repository
+{
+    public abstract class RepositoryBase
+    {
+        protected IAuthenticationProvider AuthenticationProvider { get; }
+
+        public RepositoryBase(IAuthenticationProvider authenticationProvider)
+        {
+            AuthenticationProvider = authenticationProvider;
+        }
+    }
+}

src/Todo.Core/Repository/TodoItemRepository.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Graph;
+using Todo.Core.Model;
+
+namespace Todo.Core.Repository
+{
+    public class TodoItemRepository : RepositoryBase, ITodoItemRepository
+    {
+        public TodoItemRepository(IAuthenticationProvider authenticationProvider)
+            : base(authenticationProvider)
+        {
+        }
+
+        public async Task<IEnumerable<TodoItem>> ListAsync()
+        {
+            var graphServiceClient = new GraphServiceClient(AuthenticationProvider);
+            var tasks = await graphServiceClient.Me.Outlook.Tasks.Request().GetAsync();
+            return tasks.Select(task => new TodoItem() 
+            { 
+                Subject = task.Subject
+            });
+        }
+    }
+}