GSS2Rework/GSS2.Test/App.axaml.cs

using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using Avalonia.Threading;

using GSS2.Test.ViewModels;
using GSS2.Test.Views;
using GSS2.UI.Core;
using GSS2.UI.Core.Services;
using GSS2.UI.Core.ViewModels;

namespace GSS2.Test;

public partial class App : Application
{
    public override void Initialize()
    {
        AvaloniaXamlLoader.Load(this);
    }

    public override void OnFrameworkInitializationCompleted()
    {
        if (ApplicationLifetime is null)
            throw new InvalidOperationException("Application framework initialization cannot be fulfilled, ApplicationLifetime is null");

        var loggerFactory = Program.ApplicationHost.Services.GetRequiredService<ILoggerFactory>();
        var navigationService = Program.ApplicationHost.Services.GetRequiredService<NavigationService>();

        switch (ApplicationLifetime)
        {
            case IClassicDesktopStyleApplicationLifetime desktop:
                Console.WriteLine("Application running in classic style");
                
                desktop.Startup += (_, _) => Program.ApplicationHost.RunAsync();
                desktop.Exit += (_, _) => Program.ApplicationHost.StopAsync();

                var mainWindowViewModelLogger = loggerFactory.CreateLogger<MainWindowViewModel>();
                var mainWindow = new MainWindow()
                {
                    DataContext = new MainWindowViewModel(mainWindowViewModelLogger)
                };
                desktop.MainWindow = mainWindow;

                Program.ShutdownRequested += (_, _) => Dispatcher.UIThread.Invoke(() => desktop.MainWindow?.Close());
                break;

            case ISingleViewApplicationLifetime singleView:
                Console.WriteLine("Application running in single view style");
                break;

            default:
                throw new InvalidOperationException($"Application framework initialization cannot be fulfilled, ApplicationLifetime has unknown type inherited from: {string.Join(", ", ApplicationLifetime.GetType().GetInterfaces().Select(i => i.FullName))}");

        }
        
        var mainViewLogger = loggerFactory.CreateLogger<MainView>();
        var mainView = new MainView(mainViewLogger)
        {
            DataContext = Program.ApplicationHost.Services.GetRequiredService<MainViewModel>()
        };
        navigationService.NavigateTo(mainView);

        base.OnFrameworkInitializationCompleted();
    }

}