Add system notifications when a model system finishes.

Author: JamesVaughan

src/XTMF2.GUI/SystemAlert.cs

@@ -19,14 +19,16 @@ You should have received a copy of the GNU General Public License
 using System;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
+using System.Text;
 using XTMF2.GUI.Properties;
 
 namespace XTMF2.GUI;
 
 /// <summary>
-/// Plays OS-native audio alerts without requiring any extra NuGet packages.
+/// Plays OS-native audio alerts and sends desktop notifications without requiring
+/// any extra NuGet packages.
 /// All methods are fire-and-forget; failures are silently swallowed so a missing
-/// audio device or absent sound file never crashes the application.
+/// audio device, notification daemon, or absent sound file never crashes the application.
 /// </summary>
 internal static class SystemAlert
 {
@@ -76,19 +78,151 @@ public static void PlayError()
 
     // ── helpers ───────────────────────────────────────────────────────────
 
+    /// <summary>
+    /// Shows a desktop system notification that a run finished successfully.
+    /// Fire-and-forget; failures are silently swallowed.
+    /// </summary>
+    public static void ShowRunFinished(string runName)
+        => ShowNotification("XTMF2", $"Run '{runName}' finished successfully.");
+
+    /// <summary>
+    /// Shows a desktop system notification that a run encountered an error.
+    /// Fire-and-forget; failures are silently swallowed.
+    /// </summary>
+    public static void ShowRunFailed(string runName)
+        => ShowNotification("XTMF2", $"Run '{runName}' encountered an error.");
+
+    private static void ShowNotification(string title, string message)
+    {
+        try
+        {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                ShowWindowsToast(title, message);
+            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+                TryLaunch("osascript",
+                    $"-e 'display notification \"{Escape(message)}\" with title \"{Escape(title)}\"'");
+            else
+                ShowLinuxNotification(title, message);
+        }
+        catch { /* never crash on a missing notification daemon */ }
+    }
+
+    /// <summary>
+    /// Sends a Linux/BSD desktop notification.
+    /// Tries tools in order, stopping at the first that succeeds (exit code 0).
+    /// <list type="number">
+    ///   <item><c>gdbus call</c> – part of GLib (<c>libglib2.0-bin</c>); handles the
+    ///     <c>a{sv}</c> hints dict correctly via GVariant text format.  Present on
+    ///     KDE, GNOME, and most other desktops.</item>
+    ///   <item><c>notify-send</c> – fallback for systems that have <c>libnotify-bin</c>
+    ///     but not <c>gdbus</c>.</item>
+    /// </list>
+    /// See: https://specifications.freedesktop.org/notification-spec/latest/
+    /// </summary>
+    private static void ShowLinuxNotification(string title, string message)
+    {
+        // gdbus call with GVariant text format:
+        //   "[]"  → empty as (array of strings, actions)
+        //   "{}"  → empty a{sv} (hints dict) — cannot be expressed with dbus-send
+        //   7000  → expire timeout in ms
+        var gdbusCmdArgs = string.Join(" ",
+            "call --session",
+            "--dest org.freedesktop.Notifications",
+            "--object-path /org/freedesktop/Notifications",
+            "--method org.freedesktop.Notifications.Notify",
+            $"\"{Escape(title)}\"",
+            "0",
+            "\"dialog-information\"",
+            $"\"{Escape(title)}\"",
+            $"\"{Escape(message)}\"",
+            "\"[]\"",
+            "\"{}\"",
+            "7000");
+
+        if (!TryLaunchAndWait("gdbus", gdbusCmdArgs))
+            TryLaunchAndWait("notify-send",
+                $"--icon=dialog-information \"{Escape(title)}\" \"{Escape(message)}\"");
+    }
+
+    /// <summary>
+    /// Sends a Windows 10/11 toast notification via PowerShell's WinRT bindings.
+    /// Uses <c>-EncodedCommand</c> (Base64 UTF-16LE) so the run name never needs
+    /// to be shell-quoted.
+    /// </summary>
+    private static void ShowWindowsToast(string title, string message)
+    {
+        // Escape XML special characters so the inline XML literal is valid.
+        var xmlTitle   = XmlEscape(title);
+        var xmlMessage = XmlEscape(message);
+
+        var script = $"""
+$xml = [Windows.Data.Xml.Dom.XmlDocument,Windows.Data.Xml.Dom.XmlDocument,ContentType=WindowsRuntime]::new()
+$xml.LoadXml('<toast><visual><binding template="ToastGeneric"><text>{xmlTitle}</text><text>{xmlMessage}</text></binding></visual></toast>')
+$toast = [Windows.UI.Notifications.ToastNotification,Windows.UI.Notifications,ContentType=WindowsRuntime]::new($xml)
+[Windows.UI.Notifications.ToastNotificationManager,Windows.UI.Notifications,ContentType=WindowsRuntime]::CreateToastNotifier('XTMF2').Show($toast)
+""";
+        // Encode as UTF-16LE, Base64 — bypasses all shell-quoting issues.
+        var encoded = Convert.ToBase64String(Encoding.Unicode.GetBytes(script));
+
+        // Prefer pwsh (PowerShell 7+); fall back to the inbox powershell.exe.
+        if (!TryLaunch("pwsh", $"-NonInteractive -WindowStyle Hidden -EncodedCommand {encoded}"))
+            TryLaunch("powershell", $"-NonInteractive -WindowStyle Hidden -EncodedCommand {encoded}");
+    }
+
+    private static string XmlEscape(string s) => s
+        .Replace("&",  "&amp;")
+        .Replace("<",  "&lt;")
+        .Replace(">",  "&gt;")
+        .Replace("'",  "&apos;")
+        .Replace("\"", "&quot;");
+
+    /// <summary>Escapes double-quotes and backslashes for embedding in a shell argument.</summary>
+    private static string Escape(string s) => s.Replace("\\", "\\\\").Replace("\"", "\\\"");
+
+    // ── process helpers ───────────────────────────────────────────────────
+
+    /// <summary>
+    /// Launches <paramref name="exe"/> fire-and-forget.
+    /// Returns <c>true</c> if the process started; does not check the exit code.
+    /// Use for audio playback where we never need to fall back on failure.
+    /// </summary>
     private static bool TryLaunch(string exe, string args)
     {
         try { LaunchDetached(exe, args); return true; }
         catch { return false; }
     }
 
+    /// <summary>
+    /// Launches <paramref name="exe"/>, waits up to 3 s for it to finish, and returns
+    /// <c>true</c> only when the process exits with code 0.
+    /// Use for notification commands where we need to try the next fallback on failure.
+    /// </summary>
+    private static bool TryLaunchAndWait(string exe, string args)
+    {
+        try
+        {
+            var psi = new ProcessStartInfo(exe, args)
+            {
+                UseShellExecute        = false,
+                RedirectStandardOutput = true,  // suppress gdbus return-value output
+                RedirectStandardError  = true,  // suppress error text
+                CreateNoWindow         = true,
+            };
+            using var proc = Process.Start(psi);
+            if (proc is null) return false;
+            proc.WaitForExit(3000);
+            return proc.ExitCode == 0;
+        }
+        catch { return false; }
+    }
+
     private static void LaunchDetached(string exe, string args)
     {
         var psi = new ProcessStartInfo(exe, args)
         {
             UseShellExecute        = false,
-            RedirectStandardOutput = false,
-            RedirectStandardError  = false,
+            RedirectStandardOutput = true,  // suppress any incidental output
+            RedirectStandardError  = true,
             CreateNoWindow         = true,
         };
         using var proc = Process.Start(psi);

src/XTMF2.GUI/ViewModels/RunsViewModel.cs

@@ -73,7 +73,11 @@ internal void NotifyFinished(string runId)
     {
         var vm = FindRun(runId);
         if (vm is null) return;
-        Dispatcher.UIThread.Post(() => vm.MarkFinished());
+        Dispatcher.UIThread.Post(() =>
+        {
+            vm.MarkFinished();
+            SystemAlert.ShowRunFinished(vm.RunName);
+        });
     }
 
     /// <summary>
@@ -83,7 +87,11 @@ internal void NotifyError(string runId, string errorMessage, string stack)
     {
         var vm = FindRun(runId);
         if (vm is null) return;
-        Dispatcher.UIThread.Post(() => vm.MarkError(errorMessage, stack));
+        Dispatcher.UIThread.Post(() =>
+        {
+            vm.MarkError(errorMessage, stack);
+            SystemAlert.ShowRunFailed(vm.RunName);
+        });
     }
 
     /// <summary>