Refactor CLI (#81)

DiscordChatExporter.Cli/Verbs/UpdateAppVerb.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Threading.Tasks;
+using DiscordChatExporter.Cli.Verbs.Options;
+using DiscordChatExporter.Core.Services;
+
+namespace DiscordChatExporter.Cli.Verbs
+{
+    public class UpdateAppVerb : Verb<UpdateAppOptions>
+    {
+        public UpdateAppVerb(UpdateAppOptions options) 
+            : base(options)
+        {
+        }
+
+        public override async Task ExecuteAsync()
+        {
+            // Get update service
+            var container = new Container();
+            var updateService = container.Resolve<IUpdateService>();
+
+            // TODO: this is configured only for GUI
+            // Get update version
+            var updateVersion = await updateService.CheckPrepareUpdateAsync();
+
+            if (updateVersion != null)
+            {
+                Console.WriteLine($"Updating to version {updateVersion}");
+
+                updateService.NeedRestart = false;
+                updateService.FinalizeUpdate();
+            }
+            else
+            {
+                Console.WriteLine("There are no application updates available.");
+            }
+        }
+    }
+}