Duplicate instance check

Artemis/Artemis/ArtemisBootstrapper.cs

@@ -1,8 +1,13 @@
-using System.Windows;
+using System.Diagnostics;
+using System.Linq;
+using System.Windows;
+using System.Windows.Forms;
 using Artemis.ViewModels;
 using Autofac;
 using Caliburn.Micro;
 using Caliburn.Micro.Autofac;
+using Application = System.Windows.Application;
+using MessageBox = System.Windows.Forms.MessageBox;
 
 namespace Artemis
 {
@@ -10,6 +15,7 @@ namespace Artemis
     {
         public ArtemisBootstrapper()
         {
+            CheckDuplicateInstances();
             Initialize();
         }
 
@@ -27,5 +33,16 @@ namespace Artemis
         {
             DisplayRootViewFor<SystemTrayViewModel>();
         }
+
+        private void CheckDuplicateInstances()
+        {
+            var processes = Process.GetProcesses();
+            if (processes.Count(p => p.ProcessName == "Artemis") < 2)
+                return;
+
+            MessageBox.Show("An instance of Artemis is already running (check your system tray).",
+                "Artemis  (╯°□°）╯︵ ┻━┻", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+            Application.Current.Shutdown();
+        }
     }
 }