1 files changed, 207 insertions, 0 deletions
diff --git a/modules/mono/editor/GodotTools/GodotTools.IdeConnection/GodotIdeConnection.cs b/modules/mono/editor/GodotTools/GodotTools.IdeConnection/GodotIdeConnection.cs
new file mode 100644
index 0000000000..e7e81f175e
--- /dev/null
+++ b/modules/mono/editor/GodotTools/GodotTools.IdeConnection/GodotIdeConnection.cs
@@ -0,0 +1,207 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Net.Sockets;
+using System.Text;
+
+namespace GodotTools.IdeConnection
+{
+    public abstract class GodotIdeConnection : IDisposable
+    {
+        protected const string Version = "1.0";
+
+        protected static readonly string ClientHandshake = $"Godot Ide Client Version {Version}";
+        protected static readonly string ServerHandshake = $"Godot Ide Server Version {Version}";
+
+        private const int ClientWriteTimeout = 8000;
+        private readonly TcpClient tcpClient;
+
+        private TextReader clientReader;
+        private TextWriter clientWriter;
+
+        private readonly object writeLock = new object();
+
+        private readonly Func<Message, bool> messageHandler;
+
+        public event Action Connected;
+
+        private ILogger logger;
+
+        public ILogger Logger
+        {
+            get => logger ?? (logger = new ConsoleLogger());
+            set => logger = value;
+        }
+
+        public bool IsDisposed { get; private set; } = false;
+
+        public bool IsConnected => tcpClient.Client != null && tcpClient.Client.Connected;
+
+        protected GodotIdeConnection(TcpClient tcpClient, Func<Message, bool> messageHandler)
+        {
+            this.tcpClient = tcpClient;
+            this.messageHandler = messageHandler;
+        }
+
+        public void Start()
+        {
+            try
+            {
+                if (!StartConnection())
+                    return;
+
+                string messageLine;
+                while ((messageLine = ReadLine()) != null)
+                {
+                    if (!MessageParser.TryParse(messageLine, out Message msg))
+                    {
+                        Logger.LogError($"Received message with invalid format: {messageLine}");
+                        continue;
+                    }
+
+                    Logger.LogDebug($"Received message: {msg}");
+
+                    if (msg.Id == "close")
+                    {
+                        Logger.LogInfo("Closing connection");
+                        return;
+                    }
+
+                    try
+                    {
+                        try
+                        {
+                            Debug.Assert(messageHandler != null);
+
+                            if (!messageHandler(msg))
+                                Logger.LogError($"Received unknown message: {msg}");
+                        }
+                        catch (Exception e)
+                        {
+                            Logger.LogError($"Message handler for '{msg}' failed with exception", e);
+                        }
+                    }
+                    catch (Exception e)
+                    {
+                        Logger.LogError($"Exception thrown from message handler. Message: {msg}", e);
+                    }
+                }
+            }
+            catch (Exception e)
+            {
+                Logger.LogError($"Unhandled exception in the Godot Ide Connection thread", e);
+            }
+            finally
+            {
+                Dispose();
+            }
+        }
+
+        private bool StartConnection()
+        {
+            NetworkStream clientStream = tcpClient.GetStream();
+
+            clientReader = new StreamReader(clientStream, Encoding.UTF8);
+
+            lock (writeLock)
+                clientWriter = new StreamWriter(clientStream, Encoding.UTF8);
+
+            clientStream.WriteTimeout = ClientWriteTimeout;
+
+            if (!WriteHandshake())
+            {
+                Logger.LogError("Could not write handshake");
+                return false;
+            }
+
+            if (!IsValidResponseHandshake(ReadLine()))
+            {
+                Logger.LogError("Received invalid handshake");
+                return false;
+            }
+
+            Connected?.Invoke();
+
+            Logger.LogInfo("Godot Ide connection started");
+
+            return true;
+        }
+
+        private string ReadLine()
+        {
+            try
+            {
+                return clientReader?.ReadLine();
+            }
+            catch (Exception e)
+            {
+                if (IsDisposed)
+                {
+                    var se = e as SocketException ?? e.InnerException as SocketException;
+                    if (se != null && se.SocketErrorCode == SocketError.Interrupted)
+                        return null;
+                }
+
+                throw;
+            }
+        }
+
+        public bool WriteMessage(Message message)
+        {
+            Logger.LogDebug($"Sending message {message}");
+            
+            var messageComposer = new MessageComposer();
+
+            messageComposer.AddArgument(message.Id);
+            foreach (string argument in message.Arguments)
+                messageComposer.AddArgument(argument);
+
+            return WriteLine(messageComposer.ToString());
+        }
+
+        protected bool WriteLine(string text)
+        {
+            if (clientWriter == null || IsDisposed || !IsConnected)
+                return false;
+
+            lock (writeLock)
+            {
+                try
+                {
+                    clientWriter.WriteLine(text);
+                    clientWriter.Flush();
+                }
+                catch (Exception e)
+                {
+                    if (!IsDisposed)
+                    {
+                        var se = e as SocketException ?? e.InnerException as SocketException;
+                        if (se != null && se.SocketErrorCode == SocketError.Shutdown)
+                            Logger.LogInfo("Client disconnected ungracefully");
+                        else
+                            Logger.LogError("Exception thrown when trying to write to client", e);
+
+                        Dispose();
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        protected abstract bool WriteHandshake();
+        protected abstract bool IsValidResponseHandshake(string handshakeLine);
+
+        public void Dispose()
+        {
+            if (IsDisposed)
+                return;
+
+            IsDisposed = true;
+
+            clientReader?.Dispose();
+            clientWriter?.Dispose();
+            ((IDisposable) tcpClient)?.Dispose();
+        }
+    }
+}