Catch refused connection to "open.spotify.com"

The client itself is blocking the connection either through the firewall or by redirecting the host address in the "hosts" file.

Author: aleab

Toastify/Properties/Resources.Designer.cs

@@ -124,8 +124,7 @@ Delete the "{0}" file and restart the application to recreate the settings file.
 The application will be started with default settings.</value>
   </data>
   <data name="ERROR_STARTUP_SPOTIFY" xml:space="preserve">
-    <value>An error occurred when trying to start Spotify.
-Please, start it manually and then restart the application.</value>
+    <value>An error occurred when trying to start Spotify.</value>
   </data>
   <data name="ERROR_STARTUP_PROCESS" xml:space="preserve">
     <value>Could not find Spotify process!
@@ -136,7 +135,7 @@ If Spotify is running, please open an issue at github.com/aleab/toastify.</value
 Please restart the application.</value>
   </data>
   <data name="ERROR_STARTUP_SPOTIFY_API_CONNECT" xml:space="preserve">
-    <value>An error occurred when trying to start Spotify: Toastify was not able to connect with Spotify.</value>
+    <value>Toastify was not able to connect with Spotify.</value>
   </data>
   <data name="ERROR_STARTUP_SPOTIFY_API_STATUS_NULL" xml:space="preserve">
     <value>An error occurred when trying to connect with Spotify: SpotifyAPI returned a null status.
@@ -225,4 +224,12 @@ Look for the blue icon in your system tray.</value>
   <data name="toastify_loading_spotify_9" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\SystemTrayAnimation\toastify_loading_spotify_9.ico;System.Drawing.Icon, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
+  <data name="ERROR_STARTUP_SPOTIFY_API_CONNECTION_BLOCKED" xml:space="preserve">
+    <value>An error occurred when trying to connect with Spotify.
+The firewall might have blocked the connection to "open.spotify.com".</value>
+  </data>
+  <data name="ERROR_STARTUP_SPOTIFY_API_CONNECTION_BLOCKED_HOSTS" xml:space="preserve">
+    <value>An error occurred when trying to connect with Spotify.
+The host address "open.spotify.com" might have been redirected by the client. Check your "hosts" file (%WinDir%\System32\drivers\etc\hosts) and delete any entry containing "open.spotify.com".</value>
+  </data>
 </root>

Toastify/Properties/Resources.resx

@@ -107,6 +107,7 @@
     <Reference Include="System.Drawing" />
     <Reference Include="System.Management" />
     <Reference Include="System.Net" />
+    <Reference Include="System.Net.Http" />
     <Reference Include="System.Windows.Forms" />
     <Reference Include="System.Xaml" />
     <Reference Include="System.Xml" />

Toastify/Toastify.csproj

@@ -17,7 +17,7 @@ public ApplicationStartupException(string message) : this(message, true)
         {
         }
 
-        public ApplicationStartupException(string message, bool spotifyStatus) : base($"{CreateMessage(spotifyStatus)}\n\nAdditional details\n{message}")
+        public ApplicationStartupException(string message, bool spotifyStatus) : base($"{CreateMessage(spotifyStatus)}\nAdditional details:\n{message}")
         {
         }
 

Toastify/src/Core/ApplicationStartupException.cs

@@ -6,6 +6,9 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Net;
+using System.Net.Http;
+using System.Net.Sockets;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Windows;
 using System.Windows.Threading;
@@ -174,8 +177,7 @@ private void StartSpotify_WorkerTaskCompleted(object sender, RunWorkerCompletedE
                         logger.Error("Error while starting Spotify.", applicationStartupException);
 
                         string errorMsg = Properties.Resources.ERROR_STARTUP_SPOTIFY;
-                        string techDetails = $"Technical details\n{applicationStartupException.Message}";
-                        MessageBox.Show($"{errorMsg}\n\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
+                        MessageBox.Show($"{errorMsg}\n{applicationStartupException.Message}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
 
                         Analytics.TrackException(applicationStartupException, true);
                     }
@@ -188,7 +190,7 @@ private void StartSpotify_WorkerTaskCompleted(object sender, RunWorkerCompletedE
                         if (webException.Status == WebExceptionStatus.ProtocolError)
                             status += $" ({(webException.Response as HttpWebResponse)?.StatusCode}, \"{(webException.Response as HttpWebResponse)?.StatusDescription}\")";
                         string techDetails = $"Technical details: {webException.Message}\n{webException.HResult}, {status}";
-                        MessageBox.Show($"{errorMsg}\n\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
+                        MessageBox.Show($"{errorMsg}\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
 
                         Analytics.TrackException(webException, true);
                     }
@@ -198,7 +200,7 @@ private void StartSpotify_WorkerTaskCompleted(object sender, RunWorkerCompletedE
 
                         string errorMsg = Properties.Resources.ERROR_UNKNOWN;
                         string techDetails = $"Technical Details: {e.Error.Message}\n{e.Error.StackTrace}";
-                        MessageBox.Show($"{errorMsg}\n\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
+                        MessageBox.Show($"{errorMsg}\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
 
                         Analytics.TrackException(e.Error, true);
                     }
@@ -209,7 +211,7 @@ private void StartSpotify_WorkerTaskCompleted(object sender, RunWorkerCompletedE
 
                     string errorMsg = Properties.Resources.ERROR_STARTUP_SPOTIFY;
                     const string techDetails = "Technical Details: timeout";
-                    MessageBox.Show($"{errorMsg}\n\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
+                    MessageBox.Show($"{errorMsg}\n{techDetails}", "Toastify", MessageBoxButton.OK, MessageBoxImage.Error);
                 }
 
                 // Terminate Toastify
@@ -288,6 +290,34 @@ private void ConnectWithSpotify(DoWorkEventArgs e)
                 }
                 catch (WebException ex)
                 {
+                    if (ex.InnerException is SocketException socketException && socketException.SocketErrorCode == SocketError.ConnectionRefused)
+                    {
+                        bool hostRedirected = Regex.IsMatch(socketException.Message, @"(127\.0\.0\.1|localhost|0\.0\.0\.0):80(?![0-9]+)", RegexOptions.IgnoreCase | RegexOptions.Compiled);
+
+                        // Check if "open.spotify.com" is blocked by the firewall or redirected in the hosts file
+                        using (HttpClient http = new HttpClient())
+                        {
+                            using (HttpRequestMessage request = new HttpRequestMessage())
+                            {
+                                request.Method = HttpMethod.Head;
+                                request.RequestUri = new Uri("http://open.spotify.com");
+                                request.Headers.Add("User-Agent", "Spotify (1.0.50.41368.gbd68dbef)");
+
+                                try
+                                {
+                                    using (http.SendAsync(request).Result) { }
+                                }
+                                catch
+                                {
+                                    logger.Error("Couldn't access \"open.spotify.com\": the client blocked the connection to the host.");
+                                    throw new ApplicationStartupException(hostRedirected
+                                        ? Properties.Resources.ERROR_STARTUP_SPOTIFY_API_CONNECTION_BLOCKED_HOSTS
+                                        : Properties.Resources.ERROR_STARTUP_SPOTIFY_API_CONNECTION_BLOCKED, false);
+                                }
+                            }
+                        }
+                    }
+
                     logger.Warn("WebException while connecting to Spotify.", ex);
                 }
             } while (!connected && !signaled);

Toastify/src/Core/Spotify.cs

@@ -44,15 +44,17 @@ public static Vector BringRectInsideWorkingArea(Rect rect)
         {
             Vector vector = new Vector();
             Rect totalRect = GetTotalWorkingArea();
-            if (!totalRect.Contains(rect))
-            {
-                vector.X = rect.Right > totalRect.Right
-                    ? totalRect.Right - rect.Right
-                    : rect.Left < totalRect.Left ? totalRect.Left - rect.Left : 0.0;
-                vector.Y = rect.Bottom > totalRect.Bottom
-                    ? totalRect.Bottom - rect.Bottom
-                    : rect.Top < totalRect.Top ? totalRect.Top - rect.Top : 0.0;
-            }
+
+            if (totalRect.Contains(rect))
+                return vector;
+
+            vector.X = rect.Right > totalRect.Right
+                ? totalRect.Right - rect.Right
+                : rect.Left < totalRect.Left ? totalRect.Left - rect.Left : 0.0;
+            vector.Y = rect.Bottom > totalRect.Bottom
+                ? totalRect.Bottom - rect.Bottom
+                : rect.Top < totalRect.Top ? totalRect.Top - rect.Top : 0.0;
+
             return vector;
         }