1 files changed, 332 insertions, 0 deletions
diff --git a/modules/mono/editor/GodotTools/GodotTools.IdeMessaging/Client.cs b/modules/mono/editor/GodotTools/GodotTools.IdeMessaging/Client.cs
new file mode 100644
index 0000000000..d069651dd3
--- /dev/null
+++ b/modules/mono/editor/GodotTools/GodotTools.IdeMessaging/Client.cs
@@ -0,0 +1,332 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using Newtonsoft.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using GodotTools.IdeMessaging.Requests;
+using GodotTools.IdeMessaging.Utils;
+
+namespace GodotTools.IdeMessaging
+{
+    // ReSharper disable once UnusedType.Global
+    public sealed class Client : IDisposable
+    {
+        private readonly ILogger logger;
+
+        private readonly string identity;
+
+        private string MetaFilePath { get; }
+        private GodotIdeMetadata godotIdeMetadata;
+        private readonly FileSystemWatcher fsWatcher;
+
+        private readonly IMessageHandler messageHandler;
+
+        private Peer peer;
+        private readonly SemaphoreSlim connectionSem = new SemaphoreSlim(1);
+
+        private readonly Queue<NotifyAwaiter<bool>> clientConnectedAwaiters = new Queue<NotifyAwaiter<bool>>();
+        private readonly Queue<NotifyAwaiter<bool>> clientDisconnectedAwaiters = new Queue<NotifyAwaiter<bool>>();
+
+        // ReSharper disable once UnusedMember.Global
+        public async Task<bool> AwaitConnected()
+        {
+            var awaiter = new NotifyAwaiter<bool>();
+            clientConnectedAwaiters.Enqueue(awaiter);
+            return await awaiter;
+        }
+
+        // ReSharper disable once UnusedMember.Global
+        public async Task<bool> AwaitDisconnected()
+        {
+            var awaiter = new NotifyAwaiter<bool>();
+            clientDisconnectedAwaiters.Enqueue(awaiter);
+            return await awaiter;
+        }
+
+        // ReSharper disable once MemberCanBePrivate.Global
+        public bool IsDisposed { get; private set; }
+
+        // ReSharper disable once MemberCanBePrivate.Global
+        public bool IsConnected => peer != null && !peer.IsDisposed && peer.IsTcpClientConnected;
+
+        // ReSharper disable once EventNeverSubscribedTo.Global
+        public event Action Connected
+        {
+            add
+            {
+                if (peer != null && !peer.IsDisposed)
+                    peer.Connected += value;
+            }
+            remove
+            {
+                if (peer != null && !peer.IsDisposed)
+                    peer.Connected -= value;
+            }
+        }
+
+        // ReSharper disable once EventNeverSubscribedTo.Global
+        public event Action Disconnected
+        {
+            add
+            {
+                if (peer != null && !peer.IsDisposed)
+                    peer.Disconnected += value;
+            }
+            remove
+            {
+                if (peer != null && !peer.IsDisposed)
+                    peer.Disconnected -= value;
+            }
+        }
+
+        ~Client()
+        {
+            Dispose(disposing: false);
+        }
+
+        public async void Dispose()
+        {
+            if (IsDisposed)
+                return;
+
+            using (await connectionSem.UseAsync())
+            {
+                if (IsDisposed) // lock may not be fair
+                    return;
+                IsDisposed = true;
+            }
+
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
+
+        private void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                peer?.Dispose();
+                fsWatcher?.Dispose();
+            }
+        }
+
+        public Client(string identity, string godotProjectDir, IMessageHandler messageHandler, ILogger logger)
+        {
+            this.identity = identity;
+            this.messageHandler = messageHandler;
+            this.logger = logger;
+
+            string projectMetadataDir = Path.Combine(godotProjectDir, ".mono", "metadata");
+
+            MetaFilePath = Path.Combine(projectMetadataDir, GodotIdeMetadata.DefaultFileName);
+
+            // FileSystemWatcher requires an existing directory
+            if (!File.Exists(projectMetadataDir))
+                Directory.CreateDirectory(projectMetadataDir);
+
+            fsWatcher = new FileSystemWatcher(projectMetadataDir, GodotIdeMetadata.DefaultFileName);
+        }
+
+        private async void OnMetaFileChanged(object sender, FileSystemEventArgs e)
+        {
+            if (IsDisposed)
+                return;
+
+            using (await connectionSem.UseAsync())
+            {
+                if (IsDisposed)
+                    return;
+
+                if (!File.Exists(MetaFilePath))
+                    return;
+
+                var metadata = ReadMetadataFile();
+
+                if (metadata != null && metadata != godotIdeMetadata)
+                {
+                    godotIdeMetadata = metadata.Value;
+                    _ = Task.Run(ConnectToServer);
+                }
+            }
+        }
+
+        private async void OnMetaFileDeleted(object sender, FileSystemEventArgs e)
+        {
+            if (IsDisposed)
+                return;
+
+            if (IsConnected)
+            {
+                using (await connectionSem.UseAsync())
+                    peer?.Dispose();
+            }
+
+            // The file may have been re-created
+
+            using (await connectionSem.UseAsync())
+            {
+                if (IsDisposed)
+                    return;
+
+                if (IsConnected || !File.Exists(MetaFilePath))
+                    return;
+
+                var metadata = ReadMetadataFile();
+
+                if (metadata != null)
+                {
+                    godotIdeMetadata = metadata.Value;
+                    _ = Task.Run(ConnectToServer);
+                }
+            }
+        }
+
+        private GodotIdeMetadata? ReadMetadataFile()
+        {
+            using (var reader = File.OpenText(MetaFilePath))
+            {
+                string portStr = reader.ReadLine();
+
+                if (portStr == null)
+                    return null;
+
+                string editorExecutablePath = reader.ReadLine();
+
+                if (editorExecutablePath == null)
+                    return null;
+
+                if (!int.TryParse(portStr, out int port))
+                    return null;
+
+                return new GodotIdeMetadata(port, editorExecutablePath);
+            }
+        }
+
+        private async Task AcceptClient(TcpClient tcpClient)
+        {
+            logger.LogDebug("Accept client...");
+
+            using (peer = new Peer(tcpClient, new ClientHandshake(), messageHandler, logger))
+            {
+                // ReSharper disable AccessToDisposedClosure
+                peer.Connected += () =>
+                {
+                    logger.LogInfo("Connection open with Ide Client");
+
+                    while (clientConnectedAwaiters.Count > 0)
+                        clientConnectedAwaiters.Dequeue().SetResult(true);
+                };
+
+                peer.Disconnected += () =>
+                {
+                    while (clientDisconnectedAwaiters.Count > 0)
+                        clientDisconnectedAwaiters.Dequeue().SetResult(true);
+                };
+                // ReSharper restore AccessToDisposedClosure
+
+                try
+                {
+                    if (!await peer.DoHandshake(identity))
+                    {
+                        logger.LogError("Handshake failed");
+                        return;
+                    }
+                }
+                catch (Exception e)
+                {
+                    logger.LogError("Handshake failed with unhandled exception: ", e);
+                    return;
+                }
+
+                await peer.Process();
+
+                logger.LogInfo("Connection closed with Ide Client");
+            }
+        }
+
+        private async Task ConnectToServer()
+        {
+            var tcpClient = new TcpClient();
+
+            try
+            {
+                logger.LogInfo("Connecting to Godot Ide Server");
+
+                await tcpClient.ConnectAsync(IPAddress.Loopback, godotIdeMetadata.Port);
+
+                logger.LogInfo("Connection open with Godot Ide Server");
+
+                await AcceptClient(tcpClient);
+            }
+            catch (SocketException e)
+            {
+                if (e.SocketErrorCode == SocketError.ConnectionRefused)
+                    logger.LogError("The connection to the Godot Ide Server was refused");
+                else
+                    throw;
+            }
+        }
+
+        // ReSharper disable once UnusedMember.Global
+        public async void Start()
+        {
+            fsWatcher.Changed += OnMetaFileChanged;
+            fsWatcher.Deleted += OnMetaFileDeleted;
+            fsWatcher.EnableRaisingEvents = true;
+
+            using (await connectionSem.UseAsync())
+            {
+                if (IsDisposed)
+                    return;
+
+                if (IsConnected)
+                    return;
+
+                if (!File.Exists(MetaFilePath))
+                {
+                    logger.LogInfo("There is no Godot Ide Server running");
+                    return;
+                }
+
+                var metadata = ReadMetadataFile();
+
+                if (metadata != null)
+                {
+                    godotIdeMetadata = metadata.Value;
+                    _ = Task.Run(ConnectToServer);
+                }
+                else
+                {
+                    logger.LogError("Failed to read Godot Ide metadata file");
+                }
+            }
+        }
+
+        public async Task<TResponse> SendRequest<TResponse>(Request request)
+            where TResponse : Response, new()
+        {
+            if (!IsConnected)
+            {
+                logger.LogError("Cannot write request. Not connected to the Godot Ide Server.");
+                return null;
+            }
+
+            string body = JsonConvert.SerializeObject(request);
+            return await peer.SendRequest<TResponse>(request.Id, body);
+        }
+
+        public async Task<TResponse> SendRequest<TResponse>(string id, string body)
+            where TResponse : Response, new()
+        {
+            if (!IsConnected)
+            {
+                logger.LogError("Cannot write request. Not connected to the Godot Ide Server.");
+                return null;
+            }
+
+            return await peer.SendRequest<TResponse>(id, body);
+        }
+    }
+}