Soft-LTS/App.xaml.cs

using System.IO;
using System.Reflection;
using System.Text.Json;
using System.Threading;
using System.Windows;
using System.Windows.Forms;
using PrinterMonitor.Configuration;
using PrinterMonitor.Services;
using PrinterMonitor.ViewModels;
using PrinterMonitor.Views;

namespace PrinterMonitor;

public partial class App : System.Windows.Application
{
    private static Mutex? _singleInstanceMutex;
    private AppSettings? _settings;
    private PrinterService? _printerService;
    private NotifyIcon? _notifyIcon;
    private MainWindow? _mainWindow;

    protected override async void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);

        // Sicherstellen, dass nur eine Instanz läuft
        _singleInstanceMutex = new Mutex(true, "DS-Soft-LTS-PrinterMonitor", out bool isNewInstance);
        if (!isNewInstance)
        {
            System.Windows.MessageBox.Show(
                "DS Soft-LTS läuft bereits.", "Bereits gestartet",
                MessageBoxButton.OK, MessageBoxImage.Information);
            Shutdown();
            return;
        }

        // Konfiguration laden
        var configPath = Path.Combine(AppContext.BaseDirectory, "appsettings.json");

        try
        {
            if (File.Exists(configPath))
            {
                var json = await File.ReadAllTextAsync(configPath);
                _settings = JsonSerializer.Deserialize<AppSettings>(json, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] Fehler beim Laden der Konfiguration: {ex.Message}");
        }

        if (_settings == null)
        {
            System.Windows.MessageBox.Show("Konfigurationsdatei nicht gefunden/lesbar");
            Shutdown();
            return;
        }

        var validationErrors = _settings.Validate();
        if (validationErrors.Count > 0)
        {
            var msg = "Konfigurationsfehler:\n\n" + string.Join("\n", validationErrors);
            System.Windows.MessageBox.Show(msg, "Konfigurationsfehler",
                MessageBoxButton.OK, MessageBoxImage.Warning);
        }

        // PrinterService starten (Monitoring + TCP-Push)
        _printerService = new PrinterService(_settings);
        await _printerService.StartAsync();

        // Tray-Icon erstellen
        CreateTrayIcon();
    }

    private void CreateTrayIcon()
    {
        System.Drawing.Icon? icon = null;
        try
        {
            // Stream explizit disposen: Icon lädt Daten sofort, Stream danach nicht mehr nötig
            using var stream = GetResourceStream(new Uri("pack://application:,,,/Resources/app.ico"))?.Stream;
            if (stream != null)
                icon = new System.Drawing.Icon(stream);
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] Tray-Icon konnte nicht geladen werden: {ex.Message}");
        }

        _notifyIcon = new System.Windows.Forms.NotifyIcon
        {
            Icon = icon,
            Text = $"DS Soft-LTS v{MainViewModel.VersionString}",
            Visible = true,
            ContextMenuStrip = CreateTrayMenu()
        };

        _notifyIcon.DoubleClick += (s, e) => ShowWindow();
    }

    private ContextMenuStrip CreateTrayMenu()
    {
        var menu = new ContextMenuStrip();

        var showItem = new ToolStripMenuItem("Anzeigen");
        showItem.Click += (s, e) => ShowWindow();
        menu.Items.Add(showItem);

        menu.Items.Add(new ToolStripSeparator());

        var exitItem = new ToolStripMenuItem("Beenden");
        exitItem.Click += (s, e) => ExitApplication();
        menu.Items.Add(exitItem);

        return menu;
    }

    private void ShowWindow()
    {
        if (_mainWindow == null)
        {
            var mainVm = new MainViewModel(_printerService!, _settings!);
            _mainWindow = new MainWindow { DataContext = mainVm };
            _mainWindow.Closed += MainWindowClosed;
        }

        _mainWindow.Show();
        _mainWindow.WindowState = WindowState.Normal;
        _mainWindow.Activate();
    }

    private void ExitApplication()
    {
        // Fenster schließen ohne Hide-Abfangen
        if (_mainWindow != null)
        {
            _mainWindow.Closed -= MainWindowClosed;
            _mainWindow.Close();
            _mainWindow = null;
        }

        // Tray-Icon entfernen (wird in OnExit erneut geprüft)
        if (_notifyIcon != null)
        {
            _notifyIcon.Visible = false;
            _notifyIcon.Dispose();
            _notifyIcon = null;
        }

        // Shutdown() loest OnExit aus, das den Service synchron disposed.
        Shutdown();
    }

    private void MainWindowClosed(object? sender, EventArgs e)
    {
        // DashboardViewModel disposen: stoppt den DispatcherTimer (verhindert Timer-Leak)
        if (_mainWindow?.DataContext is MainViewModel vm)
            vm.Dashboard.Dispose();
        _mainWindow = null;
    }

    protected override void OnExit(ExitEventArgs e)
    {
        if (_notifyIcon != null)
        {
            _notifyIcon.Visible = false;
            _notifyIcon.Dispose();
            _notifyIcon = null;
        }

        try
        {
            // Timeout von 3 Sek.: SelectEndpoint (OPC UA) ist ein synchron-blockierender
            // Netzwerkaufruf ohne CancellationToken – GetAwaiter().GetResult() würde
            // ewig warten und Environment.Exit(0) wird nie erreicht.
            // Task.Wait(TimeSpan) gibt nach spätestens 3 Sek. auf.
            var disposeTask = _printerService?.DisposeAsync().AsTask() ?? Task.CompletedTask;
            if (!disposeTask.Wait(TimeSpan.FromSeconds(3)))
                Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] Warnung: PrinterService-Dispose nach 3 Sek. abgebrochen");
            _printerService = null;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] Fehler beim Beenden des PrinterService: {ex.Message}");
        }

        base.OnExit(e);

        // Alle verbleibenden Foreground-Threads (z. B. OPC UA intern, Sockets)
        // hart beenden - verhindert Zombie-Prozesse im Task-Manager.
        Environment.Exit(0);
    }
}