wabbajack/Wabbajack.App/Screens/LauncherViewModel.cs

using System.Diagnostics;
using System.Linq;
using System.Reactive;
using System.Reactive.Disposables;
using System.Reactive.Linq;
using System.Threading.Tasks;
using Avalonia.Media.Imaging;
using GameFinder.StoreHandlers.Origin.DTO;
using Microsoft.CodeAnalysis;
using Microsoft.Extensions.Logging;
using ReactiveUI;
using ReactiveUI.Fody.Helpers;
using Wabbajack.App.Extensions;
using Wabbajack.App.Messages;
using Wabbajack.App.Models;
using Wabbajack.App.ViewModels;
using Wabbajack.Common;
using Wabbajack.DTOs;
using Wabbajack.DTOs.SavedSettings;
using Wabbajack.Paths;
using Wabbajack.Paths.IO;

namespace Wabbajack.App.Screens
{
    public class LauncherViewModel : ViewModelBase, IActivatableViewModel, IReceiver<ConfigureLauncher>
    {

        [Reactive]
        public AbsolutePath InstallFolder { get; set; }
        
        [Reactive]
        public IBitmap Image { get; set; }
        
        [Reactive]
        public InstallationConfigurationSetting? Setting { get; set; }
        
        [Reactive]
        public string Title { get; set; }

        public ReactiveCommand<Unit, Unit> PlayButton;
        private readonly ILogger<LauncherViewModel> _logger;

        public LauncherViewModel(ILogger<LauncherViewModel> logger, InstallationStateManager manager)
        {
            Activator = new ViewModelActivator();
            PlayButton = ReactiveCommand.Create(() =>
            {
                StartGame().FireAndForget();
            });
            _logger = logger;
            
            this.WhenActivated(disposables =>
            {
                this.WhenAnyValue(v => v.InstallFolder)
                    .SelectAsync(disposables, async folder => await manager.GetByInstallFolder(folder))
                    .ObserveOn(RxApp.MainThreadScheduler)
                    .Where(v => v != null)
                    .BindTo(this, vm => vm.Setting)
                    .DisposeWith(disposables);

                this.WhenAnyValue(v => v.Setting)
                    .Where(v => v != default)
                    .Select(v => new Bitmap((v!.Image).ToString()))
                    .BindTo(this, vm => vm.Image)
                    .DisposeWith(disposables);

                this.WhenAnyValue(v => v.Setting)
                    .Where(v => v is { Metadata: { } })
                    .Select(v => $"{v!.Metadata!.Title} v{v!.Metadata.Version}")
                    .BindTo(this, vm => vm.Title)
                    .DisposeWith(disposables);

            });
        }

        private async Task StartGame()
        {
            var mo2Path = InstallFolder.Combine("ModOrganizer.exe");
            var gamePath = GameRegistry.Games.Values.Select(g => g.MainExecutable)
                .Where(ge => ge != null)
                .Select(ge => InstallFolder.Combine(ge!))
                .FirstOrDefault(ge => ge.FileExists());
            if (mo2Path.FileExists())
            {
                Process.Start(mo2Path.ToString());
            }
            else if (gamePath.FileExists())
            {
                Process.Start(gamePath.ToString());
            }
            else
            {
                _logger.LogError("No way to launch game, no acceptable executable found");
            }
        }

        public void Receive(ConfigureLauncher val)
        {
            InstallFolder = val.InstallFolder;
        }
    }
}