LehrerApp/LehrerApp.Desktop/App.axaml.cs

using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using LehrerApp.Core.Services;
using LehrerApp.Data;
using LehrerApp.Desktop.Services;
using LehrerApp.Desktop.ViewModels;
using LehrerApp.Desktop.ViewModels.Groups;
using LehrerApp.Desktop.ViewModels.Students;
using LehrerApp.Desktop.Views;
using Microsoft.Extensions.DependencyInjection;

namespace LehrerApp.Desktop;

public class App : Application
{
    public static IServiceProvider Services { get; private set; } = null!;

    public override void Initialize() => AvaloniaXamlLoader.Load(this);

    public override void OnFrameworkInitializationCompleted()
    {
        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
        {
            // Verschlüsselte Datenbank (13.3.4): Passwort abfragen, bevor die Datenbank
            // (und damit BuildServices, das sie öffnet) angefasst wird.
            if (AppBootstrapper.IsDbEncrypted())
            {
                var promptVm = new DbPasswordPromptViewModel(
                    new DatabaseEncryptionService(), AppBootstrapper.ResolveDbPath());
                var promptWindow = new DbPasswordPromptWindow { DataContext = promptVm };
                promptVm.OnUnlocked = password =>
                {
                    AppBootstrapper.DbPassword = password;
                    StartMainApp(desktop);
                    promptWindow.Close();
                };
                desktop.MainWindow = promptWindow;
            }
            else
            {
                StartMainApp(desktop);
            }
        }

        base.OnFrameworkInitializationCompleted();
    }

    private static void StartMainApp(IClassicDesktopStyleApplicationLifetime desktop)
    {
        Services = AppBootstrapper.BuildServices();
        Services.GetRequiredService<AppLogger>().Info("Anwendung gestartet.");
        GlobalExceptionHandler.AttachNotifications(Services.GetRequiredService<NotificationService>());

        var mainVm = Services.GetRequiredService<MainWindowViewModel>();
        WireCallbacks(mainVm);
        var main = new MainWindow { DataContext = mainVm };
        desktop.MainWindow = main;
        main.Show();
    }

    private static void WireCallbacks(MainWindowViewModel main)
    {
        // GroupList → GroupDetail  (OnAddGroup wird in GroupListView.axaml.cs verdrahtet)
        var gl = Services.GetRequiredService<GroupListViewModel>();
        gl.OnNavigateToDetail = (id, tab) => main.NavigateToGroupDetail(id, tab);

        // Dashboard → GroupDetail (Chips)
        var dash = Services.GetRequiredService<DashboardViewModel>();
        dash.OnNavigateToGroup = id => main.NavigateToGroupDetail(id);

        // StudentList → StudentDetail + Anlegen
        var sl = Services.GetRequiredService<StudentListViewModel>();
        sl.OnNavigateToDetail = id => main.NavigateToStudent(id);
        sl.OnAddStudent       = () => ShowAddStudentDialog();
    }

    private static async Task ShowAddStudentDialog()
    {
        var vm = new ViewModels.Students.AddStudentDialogViewModel(
            Services.GetRequiredService<Core.Interfaces.IStudentRepository>());
        var dialog = new Views.Students.AddStudentDialog { DataContext = vm };
        if (Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime { MainWindow: { } owner })
            await dialog.ShowDialog<bool>(owner);
    }
}