Stability improvement:

.gitignore

@@ -1,4 +1,4 @@
-# Build Folders (you can keep bin if you'd like, to store dlls and pdbs)
+# Build Folders (you can keep bin if you'd like, to store dlls and pdbs)
 [Bb]in/
 [Oo]bj/
 

SpotifyAPI.Example/WebControl.cs

@@ -7,6 +7,7 @@
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Threading.Tasks;
 using System.Windows.Forms;
 using Image = System.Drawing.Image;
 
@@ -26,14 +27,7 @@ public WebControl()
             InitializeComponent();
 
             _savedTracks = new List<FullTrack>();
-            _auth = new ImplicitGrantAuth
-            {
-                RedirectUri = "http://localhost:8000",
-                ClientId = "26d287105e31491889f3cd293d85bfea",
-                Scope = Scope.UserReadPrivate | Scope.UserReadEmail | Scope.PlaylistReadPrivate | Scope.UserLibraryRead | Scope.UserReadPrivate | Scope.UserFollowRead | Scope.UserReadBirthdate | Scope.UserTopRead,
-                State = "XSS"
-            };
-            _auth.OnResponseReceivedEvent += _auth_OnResponseReceivedEvent;
+
         }
 
         private void _auth_OnResponseReceivedEvent(Token token, string state)
@@ -57,7 +51,7 @@ private void _auth_OnResponseReceivedEvent(Token token, string state)
                 AccessToken = token.AccessToken,
                 TokenType = token.TokenType
             };
-            InitialSetup();
+
         }
 
         private async void InitialSetup()
@@ -129,8 +123,32 @@ private List<SimplePlaylist> GetPlaylists()
 
         private void authButton_Click(object sender, EventArgs e)
         {
-            _auth.StartHttpServer(8000);
-            _auth.DoAuth();
+            Task.Run(() => RunAuthentication());
+        }
+
+        private async void RunAuthentication()
+        {
+            WebAPIFactory webApiFactory = new WebAPIFactory(
+                "http://localhost",
+                8000,
+                "26d287105e31491889f3cd293d85bfea",
+                Scope.UserReadPrivate | Scope.UserReadEmail | Scope.PlaylistReadPrivate | Scope.UserLibraryRead |
+                Scope.UserReadPrivate | Scope.UserFollowRead | Scope.UserReadBirthdate | Scope.UserTopRead,
+                TimeSpan.FromSeconds(20));
+
+            try
+            {
+                _spotify = await webApiFactory.GetWebApi();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show(ex.Message);
+            }
+
+            if (_spotify == null)
+                return;
+
+            InitialSetup();
         }
     }
 }

SpotifyAPI/Local/SpotifyLocalAPI.cs

@@ -8,7 +8,7 @@
 
 namespace SpotifyAPI.Local
 {
-    public class SpotifyLocalAPI
+    public class SpotifyLocalAPI : IDisposable
     {
         [DllImport("user32.dll")]
         private static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, int dwExtraInfo);
@@ -49,7 +49,7 @@ public ISynchronizeInvoke SynchronizingObject
         private const int KeyeventfKeyup = 0x2;
 
         private readonly RemoteHandler _rh;
-        private readonly Timer _eventTimer;
+        private Timer _eventTimer;
         private StatusResponse _eventStatusResponse;
 
         public event EventHandler<TrackChangeEventArgs> OnTrackChange;
@@ -60,13 +60,17 @@ public ISynchronizeInvoke SynchronizingObject
 
         public event EventHandler<TrackTimeChangeEventArgs> OnTrackTimeChange;
 
-        public SpotifyLocalAPI()
+        public SpotifyLocalAPI(int timerIntervall = 50)
         {
             _rh = new RemoteHandler();
+            AttachTimer(timerIntervall);
+        }
 
+        private void AttachTimer(int intervall)
+        {
             _eventTimer = new Timer
             {
-                Interval = 50,
+                Interval = intervall,
                 AutoReset = false,
                 Enabled = false
             };
@@ -333,5 +337,13 @@ public static void RunSpotifyWebHelper()
                 Process.Start(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), @"spotify\spotifywebhelper.exe"));
             }
         }
+
+        public void Dispose()
+        {
+            if (_eventTimer == null)
+                return;
+            _eventTimer.Enabled = false;
+            _eventTimer.Elapsed -= ElapsedTick;
+        }
     }
 }

SpotifyAPI/SpotifyAPI.csproj

@@ -58,6 +58,7 @@
     </Compile>
     <Compile Include="Local\Models\SpotifyUri.cs" />
     <Compile Include="Local\VolumeMixerControl.cs" />
+    <Compile Include="Web\Auth\WebAPIFactory.cs" />
     <Compile Include="Web\Enums\TimeRangeType.cs" />
     <Compile Include="Web\IClient.cs" />
     <Compile Include="Local\Models\CFID.cs" />

SpotifyAPI/Web/Auth/WebApiFactory.cs

@@ -0,0 +1,87 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using SpotifyAPI.Web.Enums;
+using SpotifyAPI.Web.Models;
+
+namespace SpotifyAPI.Web.Auth
+{
+    public class WebAPIFactory
+    {
+        private readonly string _redirectUrl;
+        private readonly int _listeningPort;
+        private readonly string _clientId;
+        private readonly TimeSpan _timeout;
+        private readonly Scope _scope;
+
+        public WebAPIFactory(string redirectUrl, int listeningPort, string clientId, Scope scope, TimeSpan timeout)
+        {
+            _redirectUrl = redirectUrl;
+            _listeningPort = listeningPort;
+            _clientId = clientId;
+            _scope = scope;
+            _timeout = timeout;
+        }
+
+        public Task<SpotifyWebAPI> GetWebApi()
+        {
+            var authentication = new ImplicitGrantAuth
+            {
+                RedirectUri = $"{_redirectUrl}:{_listeningPort}",
+                ClientId = _clientId,
+                Scope = _scope,
+                State = "XSS"
+            };
+
+            AutoResetEvent authenticationWaitFlag = new AutoResetEvent(false);
+            SpotifyWebAPI spotifyWebApi = null;
+            authentication.OnResponseReceivedEvent += (token, state) =>
+            {
+                spotifyWebApi = HandleSpotifyResponse(state, token);
+                authenticationWaitFlag.Set();
+            };
+
+            try
+            {
+                authentication.StartHttpServer(_listeningPort);
+
+                authentication.DoAuth();
+
+                authenticationWaitFlag.WaitOne(_timeout);
+                if (spotifyWebApi == null)
+                    throw new TimeoutException($"No valid response received for the last {_timeout.TotalSeconds} seconds");
+            }
+            finally
+            {
+                authentication.StopHttpServer();
+            }
+
+            return Task.FromResult(spotifyWebApi);
+        }
+
+        private static SpotifyWebAPI HandleSpotifyResponse(string state, Token token)
+        {
+            if (state != "XSS")
+                throw new SpotifyWebApiException($"Wrong state '{state}' received.");
+
+            if (token.Error != null)
+                throw new SpotifyWebApiException($"Error: {token.Error}");
+
+            var spotifyWebApi = new SpotifyWebAPI
+            {
+                UseAuth = true,
+                AccessToken = token.AccessToken,
+                TokenType = token.TokenType
+            };
+
+            return spotifyWebApi;
+        }
+    }
+
+    [Serializable]
+    public class SpotifyWebApiException : Exception
+    {
+        public SpotifyWebApiException(string message) : base(message)
+        { }
+    }
+}

SpotifyAPI/Web/SimpleHttpServer.cs

@@ -1,10 +1,14 @@
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.IO;
+using System.Linq;
 using System.Net;
 using System.Net.Sockets;
+using System.Text;
 using System.Threading;
+using System.Threading.Tasks;
 using System.Web;
 
 // offered to the public domain for any use with no restriction
@@ -33,34 +37,17 @@ public HttpProcessor(HttpServer srv)
             _srv = srv;
         }
 
-        private string StreamReadLine(Stream inputStream)
+        private string[] GetIncomingRequest(Stream inputStream)
         {
-            string data = "";
-            while (_isActive)
-            {
-                var nextChar = inputStream.ReadByte();
-                if (nextChar == '\n')
-                {
-                    break;
-                }
-                if (nextChar == '\r')
-                {
-                    continue;
-                }
-                if (nextChar == -1)
-                {
-                    Thread.Sleep(1);
-                    continue;
-                }
-                data += Convert.ToChar(nextChar);
-            }
-            return data;
+            var buffer = new byte[4096];
+            var read = inputStream.Read(buffer, 0, buffer.Length);
+
+            var inputData = Encoding.ASCII.GetString(buffer.Take(read).ToArray());
+            return inputData.Split('\n').Select(s => s.Trim()).Where(s => !string.IsNullOrEmpty(s)).ToArray();
         }
 
-        public void Process(object tcpClient)
+        public void Process(TcpClient socket)
         {
-            TcpClient socket = tcpClient as TcpClient;
-
             // we can't use a StreamReader for input, because it buffers up extra data on us inside it's
             // "processed" view of the world, and we want the data raw after the headers
             _inputStream = new BufferedStream(socket.GetStream());
@@ -69,8 +56,11 @@ public void Process(object tcpClient)
             OutputStream = new StreamWriter(new BufferedStream(socket.GetStream()));
             try
             {
-                ParseRequest();
-                ReadHeaders();
+                var requestLines = GetIncomingRequest(_inputStream);
+
+                ParseRequest(requestLines.First());
+                ReadHeaders(requestLines.Skip(1));
+
                 if (HttpMethod.Equals("GET"))
                 {
                     HandleGetRequest();
@@ -80,19 +70,17 @@ public void Process(object tcpClient)
                     HandlePostRequest();
                 }
             }
-            catch
+            catch (Exception ex)
             {
                 WriteFailure();
             }
             OutputStream.Flush();
             _inputStream = null;
             OutputStream = null;
-            socket.Close();
         }
 
-        public void ParseRequest()
+        public void ParseRequest(string request)
         {
-            string request = StreamReadLine(_inputStream);
             string[] tokens = request.Split(' ');
             if (tokens.Length < 2)
             {
@@ -102,10 +90,9 @@ public void ParseRequest()
             HttpUrl = tokens[1];
         }
 
-        public void ReadHeaders()
+        public void ReadHeaders(IEnumerable<string> requestLines)
         {
-            string line;
-            while ((line = StreamReadLine(_inputStream)) != null)
+            foreach(var line in requestLines)
             {
                 if (string.IsNullOrEmpty(line))
                 {
@@ -219,16 +206,8 @@ public void Listen()
                 _listener = new TcpListener(IPAddress.Any, Port);
                 _listener.Start();
 
-                using (HttpProcessor processor = new HttpProcessor(this))
-                {
-                    while (IsActive)
-                    {
-                        TcpClient s = _listener.AcceptTcpClient();
-                        Thread thread = new Thread(processor.Process);
-                        thread.Start(s);
-                        Thread.Sleep(1);
-                    }
-                }
+                _listener.BeginAcceptTcpClient(AcceptTcpConnection, _listener);
+
             }
             catch (SocketException e)
             {
@@ -237,6 +216,28 @@ public void Listen()
             }
         }
 
+        private void AcceptTcpConnection(IAsyncResult ar)
+        {
+            TcpListener listener = (TcpListener)ar.AsyncState;
+            try
+            {
+                var tcpCLient = listener.EndAcceptTcpClient(ar);
+                using (HttpProcessor processor = new HttpProcessor(this))
+                {
+                    processor.Process(tcpCLient);
+                }
+            }
+            catch (ObjectDisposedException)
+            {
+                // Ignore
+            }
+
+            if (!IsActive)
+                return;
+            //listener.Start();
+            listener.BeginAcceptTcpClient(AcceptTcpConnection, listener);
+        }
+
         public abstract void HandleGetRequest(HttpProcessor p);
 
         public abstract void HandlePostRequest(HttpProcessor p, StreamReader inputData);
@@ -315,6 +316,8 @@ public override void HandleGetRequest(HttpProcessor p)
                                              "window.location = hashes" +
                                              "</script>" +
                                              "<h1>Spotify Auth successful!<br>Please copy the URL and paste it into the application</h1></body></html>");
+                    p.OutputStream.Flush();
+                    p.OutputStream.Close();
                     return;
                 }
                 string url = p.HttpUrl;
@@ -345,8 +348,12 @@ public override void HandleGetRequest(HttpProcessor p)
                             State = col.Get(3)
                         });
                     });
+                    p.OutputStream.Flush();
+                    p.OutputStream.Close();
                 }
             }
+
+
             t.Start();
         }