From 89a72a50cf7b23f2a363ed81b325e70c0dcf3119 Mon Sep 17 00:00:00 2001
From: Mark McDowall <markus.mcd5@gmail.com>
Date: Wed, 11 Sep 2013 08:35:58 -0700
Subject: [PATCH] Better error message when port is in use

---
 NzbDrone.Host/NzbDrone.Host.csproj       |  1 +
 NzbDrone.Host/Owin/OwinHostController.cs | 23 ++++++++++++++++++++++-
 NzbDrone.Host/Owin/PortInUseException.cs | 15 +++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 NzbDrone.Host/Owin/PortInUseException.cs

diff --git a/NzbDrone.Host/NzbDrone.Host.csproj b/NzbDrone.Host/NzbDrone.Host.csproj
index 49c4850bd..ad7214da7 100644
--- a/NzbDrone.Host/NzbDrone.Host.csproj
+++ b/NzbDrone.Host/NzbDrone.Host.csproj
@@ -125,6 +125,7 @@
     <Compile Include="Owin\NlogTextWriter.cs" />
     <Compile Include="Owin\OwinServiceProvider.cs" />
     <Compile Include="Owin\OwinTraceOutputFactory.cs" />
+    <Compile Include="Owin\PortInUseException.cs" />
     <Compile Include="PlatformValidation.cs" />
     <Compile Include="MainAppContainerBuilder.cs" />
     <Compile Include="ApplicationModes.cs" />
diff --git a/NzbDrone.Host/Owin/OwinHostController.cs b/NzbDrone.Host/Owin/OwinHostController.cs
index 9968b22bb..8eabe82b5 100644
--- a/NzbDrone.Host/Owin/OwinHostController.cs
+++ b/NzbDrone.Host/Owin/OwinHostController.cs
@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Net;
+using System.Reflection;
 using Microsoft.Owin.Hosting;
 using NLog;
 using NzbDrone.Common.EnvironmentInfo;
@@ -50,7 +52,26 @@ namespace NzbDrone.Host.Owin
 
             _logger.Info("starting server on {0}", _urlAclAdapter.UrlAcl);
 
-            _host = WebApp.Start(OwinServiceProviderFactory.Create(), options, BuildApp);
+            try
+            {
+                _host = WebApp.Start(OwinServiceProviderFactory.Create(), options, BuildApp);
+            }
+            catch (TargetInvocationException ex)
+            {
+                if (ex.InnerException == null)
+                {
+                    throw ex;
+                }
+
+                if (ex.InnerException as HttpListenerException == null)
+                {
+                    throw ex;
+                }
+
+                throw new PortInUseException("Port {0} is already in use, please ensure NzbDrone is not already running.",
+                                             ex,
+                                             _configFileProvider.Port);
+            }
         }
 
         private void BuildApp(IAppBuilder appBuilder)
diff --git a/NzbDrone.Host/Owin/PortInUseException.cs b/NzbDrone.Host/Owin/PortInUseException.cs
new file mode 100644
index 000000000..5f6ea8f48
--- /dev/null
+++ b/NzbDrone.Host/Owin/PortInUseException.cs
@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using NzbDrone.Common.Exceptions;
+
+namespace NzbDrone.Host.Owin
+{
+    public class PortInUseException : NzbDroneException
+    {
+        public PortInUseException(string message, Exception innerException, params object[] args) : base(message, innerException, args)
+        {
+        }
+    }
+}