chore: add connect/disconnect notifications on Coder Connect

App/App.xaml.cs

@@ -27,7 +27,7 @@
 
 namespace Coder.Desktop.App;
 
-public partial class App : Application, IDispatcherQueueManager
+public partial class App : Application, IDispatcherQueueManager, INotificationHandler
 {
     private const string MutagenControllerConfigSection = "MutagenController";
     private const string UpdaterConfigSection = "Updater";
@@ -91,6 +91,7 @@ public App()
         services.AddSingleton<IAgentApiClientFactory, AgentApiClientFactory>();
 
         services.AddSingleton<IDispatcherQueueManager>(_ => this);
+        services.AddSingleton<INotificationHandler>(_ => this);
         services.AddSingleton<ICredentialBackend>(_ =>
             new WindowsCredentialBackend(WindowsCredentialBackend.CoderCredentialsTargetName));
         services.AddSingleton<ICredentialManager, CredentialManager>();
@@ -335,4 +336,13 @@ public void RunInUiThread(DispatcherQueueHandler action)
         }
         dispatcherQueue.TryEnqueue(action);
     }
+
+    public void HandleNotificationActivation(IDictionary<string, string> args)
+    {
+        var app = (App)Current;
+        if (app != null && app.TrayWindow != null)
+        {
+            app.TrayWindow.Tray_Open();
+        }
+    }
 }

App/Services/UserNotifier.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using Coder.Desktop.App.Views;
 using Microsoft.Extensions.Logging;
 using Microsoft.Windows.AppNotifications;
 using Microsoft.Windows.AppNotifications.Builder;
@@ -20,17 +21,40 @@ public interface IUserNotifier : INotificationHandler, IAsyncDisposable
     public void UnregisterHandler(string name);
 
     public Task ShowErrorNotification(string title, string message, CancellationToken ct = default);
-    public Task ShowActionNotification(string title, string message, string handlerName, IDictionary<string, string>? args = null, CancellationToken ct = default);
+    /// <summary>
+    /// This method allows to display a Windows-native notification with an action defined in
+    /// <paramref name="handlerName"/> and provided <paramref name="args"/>.
+    /// </summary>
+    /// <param name="title">Title of the notification.</param>
+    /// <param name="message">Message to be displayed in the notification body.</param>
+    /// <param name="handlerName">Handler should be e.g. <c>nameof(Handler)</c> where <c>Handler</c>
+    /// implements <see cref="Coder.Desktop.App.Services.INotificationHandler" />.
+    /// If handler is <c>null</c> the action will open Coder Desktop.</param>
+    /// <param name="args">Arguments to be provided to the handler when executing the action.</param>
+    public Task ShowActionNotification(string title, string message, string? handlerName, IDictionary<string, string>? args = null, CancellationToken ct = default);
 }
 
-public class UserNotifier(ILogger<UserNotifier> logger, IDispatcherQueueManager dispatcherQueueManager) : IUserNotifier
+public class UserNotifier : IUserNotifier
 {
     private const string CoderNotificationHandler = "CoderNotificationHandler";
+    private const string DefaultNotificationHandler = "DefaultNotificationHandler";
 
     private readonly AppNotificationManager _notificationManager = AppNotificationManager.Default;
+    private readonly ILogger<UserNotifier> _logger;
+    private readonly IDispatcherQueueManager _dispatcherQueueManager;
 
     private ConcurrentDictionary<string, INotificationHandler> Handlers { get; } = new();
 
+    public UserNotifier(ILogger<UserNotifier> logger, IDispatcherQueueManager dispatcherQueueManager,
+        INotificationHandler notificationHandler)
+    {
+        _logger = logger;
+        _dispatcherQueueManager = dispatcherQueueManager;
+        var defaultHandlerAdded = Handlers.TryAdd(DefaultNotificationHandler, notificationHandler);
+        if (!defaultHandlerAdded)
+            throw new Exception($"UserNotifier failed to be initialized with {nameof(DefaultNotificationHandler)}");
+    }
+
     public ValueTask DisposeAsync()
     {
         return ValueTask.CompletedTask;
@@ -50,6 +74,8 @@ public void RegisterHandler(string name, INotificationHandler handler)
 
     public void UnregisterHandler(string name)
     {
+        if (name == nameof(DefaultNotificationHandler))
+            throw new InvalidOperationException($"You cannot remove '{name}'.");
         if (!Handlers.TryRemove(name, out _))
             throw new InvalidOperationException($"No handler with the name '{name}' is registered.");
     }
@@ -61,8 +87,11 @@ public Task ShowErrorNotification(string title, string message, CancellationToke
         return Task.CompletedTask;
     }
 
-    public Task ShowActionNotification(string title, string message, string handlerName, IDictionary<string, string>? args = null, CancellationToken ct = default)
+    public Task ShowActionNotification(string title, string message, string? handlerName, IDictionary<string, string>? args = null, CancellationToken ct = default)
     {
+        if (handlerName == null)
+            handlerName = nameof(DefaultNotificationHandler); // Use default handler if no handler name is provided
+
         if (!Handlers.TryGetValue(handlerName, out _))
             throw new InvalidOperationException($"No action handler with the name '{handlerName}' is registered.");
 
@@ -90,19 +119,19 @@ public void HandleNotificationActivation(IDictionary<string, string> args)
 
         if (!Handlers.TryGetValue(handlerName, out var handler))
         {
-            logger.LogWarning("no action handler '{HandlerName}' found for notification activation, ignoring", handlerName);
+            _logger.LogWarning("no action handler '{HandlerName}' found for notification activation, ignoring", handlerName);
             return;
         }
 
-        dispatcherQueueManager.RunInUiThread(() =>
+        _dispatcherQueueManager.RunInUiThread(() =>
         {
             try
             {
                 handler.HandleNotificationActivation(args);
             }
             catch (Exception ex)
             {
-                logger.LogWarning(ex, "could not handle activation for notification with handler '{HandlerName}", handlerName);
+                _logger.LogWarning(ex, "could not handle activation for notification with handler '{HandlerName}", handlerName);
             }
         });
     }

App/Views/TrayWindow.xaml.cs

@@ -9,9 +9,12 @@
 using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Documents;
 using Microsoft.UI.Xaml.Media.Animation;
 using System;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
+using System.Threading;
 using System.Threading.Tasks;
 using Windows.Graphics;
 using Windows.System;
@@ -33,17 +36,23 @@ public sealed partial class TrayWindow : Window
     private int _lastWindowHeight;
     private Storyboard? _currentSb;
 
+    private VpnLifecycle curVpnLifecycle = VpnLifecycle.Stopped;
+    private RpcLifecycle curRpcLifecycle = RpcLifecycle.Disconnected;
+
     private readonly IRpcController _rpcController;
     private readonly ICredentialManager _credentialManager;
     private readonly ISyncSessionController _syncSessionController;
     private readonly IUpdateController _updateController;
+    private readonly IUserNotifier _userNotifier;
     private readonly TrayWindowLoadingPage _loadingPage;
     private readonly TrayWindowDisconnectedPage _disconnectedPage;
     private readonly TrayWindowLoginRequiredPage _loginRequiredPage;
     private readonly TrayWindowMainPage _mainPage;
 
-    public TrayWindow(IRpcController rpcController, ICredentialManager credentialManager,
+    public TrayWindow(
+        IRpcController rpcController, ICredentialManager credentialManager,
         ISyncSessionController syncSessionController, IUpdateController updateController,
+        IUserNotifier userNotifier,
         TrayWindowLoadingPage loadingPage,
         TrayWindowDisconnectedPage disconnectedPage, TrayWindowLoginRequiredPage loginRequiredPage,
         TrayWindowMainPage mainPage)
@@ -52,6 +61,7 @@ public TrayWindow(IRpcController rpcController, ICredentialManager credentialMan
         _credentialManager = credentialManager;
         _syncSessionController = syncSessionController;
         _updateController = updateController;
+        _userNotifier = userNotifier;
         _loadingPage = loadingPage;
         _disconnectedPage = disconnectedPage;
         _loginRequiredPage = loginRequiredPage;
@@ -142,9 +152,54 @@ private void SetPageByState(RpcModel rpcModel, CredentialModel credentialModel,
         }
     }
 
+    private void MaybeNotifyUser(RpcModel rpcModel)
+    {
+        // This method is called when the state changes, but we don't want to notify
+        // the user if the state hasn't changed.
+        var isRpcLifecycleChanged = rpcModel.RpcLifecycle == RpcLifecycle.Disconnected && curRpcLifecycle != rpcModel.RpcLifecycle;
+        var isVpnLifecycleChanged = (rpcModel.VpnLifecycle == VpnLifecycle.Started || rpcModel.VpnLifecycle == VpnLifecycle.Stopped) && curVpnLifecycle != rpcModel.VpnLifecycle;
+
+        if (!isRpcLifecycleChanged && !isVpnLifecycleChanged)
+        {
+            return;
+        }
+
+        var oldRpcLifeycle = curRpcLifecycle;
+        var oldVpnLifecycle = curVpnLifecycle;
+        curRpcLifecycle = rpcModel.RpcLifecycle;
+        curVpnLifecycle = rpcModel.VpnLifecycle;
+
+        var messages = new List<string>();
+
+        if (oldRpcLifeycle != RpcLifecycle.Disconnected && curRpcLifecycle == RpcLifecycle.Disconnected)
+        {
+            messages.Add("Disconnected from Coder background service.");
+        }
+
+        if (oldVpnLifecycle != curVpnLifecycle)
+        {
+            switch (curVpnLifecycle)
+            {
+                case VpnLifecycle.Started:
+                    messages.Add("Coder Connect started.");
+                    break;
+                case VpnLifecycle.Stopped:
+                    messages.Add("Coder Connect stopped.");
+                    break;
+            }
+        }
+
+        if (messages.Count == 0) return;
+        if (_aw.IsVisible) return;
+
+        var message = string.Join(" ", messages);
+        _userNotifier.ShowActionNotification(message, string.Empty, null, null, CancellationToken.None);
+    }
+
     private void RpcController_StateChanged(object? _, RpcModel model)
     {
         SetPageByState(model, _credentialManager.GetCachedCredentials(), _syncSessionController.GetState());
+        MaybeNotifyUser(model);
     }
 
     private void CredentialManager_CredentialsChanged(object? _, CredentialModel model)
@@ -297,7 +352,7 @@ private void Window_Activated(object sender, WindowActivatedEventArgs e)
     }
 
     [RelayCommand]
-    private void Tray_Open()
+    public void Tray_Open()
     {
         MoveResizeAndActivate();
     }