From e28b2431009878a18c3e83065068545d70447493 Mon Sep 17 00:00:00 2001
From: Jan Nedbal <jan.nedbal@apertia.cz>
Date: Tue, 14 Apr 2026 13:15:44 +0200
Subject: [PATCH] launcher: scaffold avalonia main window, view models, and
 settings dialog

Adds the Avalonia App, MainWindow (900x560 fixed, dark-red banner, left
status/progress column, right news panel) and a modal SettingsDialog with
language + dev-mode override. MainWindowViewModel binds to the orchestrator
through IProgress, throttles UI updates to ~10 Hz via a DispatcherTimer
flush, drives state-specific status text and Play-button gating, fetches
previous-manifest notes best-effort, and forces a red status banner with
Play disabled on a SignatureFailed result.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 src/Metin2Launcher/UI/App.axaml               |   8 +
 src/Metin2Launcher/UI/App.axaml.cs            |  28 ++
 src/Metin2Launcher/UI/MainWindow.axaml        | 104 +++++++
 src/Metin2Launcher/UI/MainWindow.axaml.cs     |  17 ++
 src/Metin2Launcher/UI/SettingsDialog.axaml    |  40 +++
 src/Metin2Launcher/UI/SettingsDialog.axaml.cs |  27 ++
 .../UI/ViewModels/MainWindowViewModel.cs      | 274 ++++++++++++++++++
 .../UI/ViewModels/SettingsDialogViewModel.cs  |  50 ++++
 8 files changed, 548 insertions(+)
 create mode 100644 src/Metin2Launcher/UI/App.axaml
 create mode 100644 src/Metin2Launcher/UI/App.axaml.cs
 create mode 100644 src/Metin2Launcher/UI/MainWindow.axaml
 create mode 100644 src/Metin2Launcher/UI/MainWindow.axaml.cs
 create mode 100644 src/Metin2Launcher/UI/SettingsDialog.axaml
 create mode 100644 src/Metin2Launcher/UI/SettingsDialog.axaml.cs
 create mode 100644 src/Metin2Launcher/UI/ViewModels/MainWindowViewModel.cs
 create mode 100644 src/Metin2Launcher/UI/ViewModels/SettingsDialogViewModel.cs

diff --git a/src/Metin2Launcher/UI/App.axaml b/src/Metin2Launcher/UI/App.axaml
new file mode 100644
index 0000000..48b44fe
--- /dev/null
+++ b/src/Metin2Launcher/UI/App.axaml
@@ -0,0 +1,8 @@
+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="Metin2Launcher.UI.App"
+             RequestedThemeVariant="Light">
+  <Application.Styles>
+    <FluentTheme />
+  </Application.Styles>
+</Application>
diff --git a/src/Metin2Launcher/UI/App.axaml.cs b/src/Metin2Launcher/UI/App.axaml.cs
new file mode 100644
index 0000000..5fde887
--- /dev/null
+++ b/src/Metin2Launcher/UI/App.axaml.cs
@@ -0,0 +1,28 @@
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+using Metin2Launcher.UI.ViewModels;
+
+namespace Metin2Launcher.UI;
+
+public partial class App : Application
+{
+    public static MainWindowViewModel? MainViewModel { get; set; }
+
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            var vm = MainViewModel ?? new MainWindowViewModel();
+            desktop.MainWindow = new MainWindow { DataContext = vm };
+            vm.AttachWindow(desktop.MainWindow);
+            desktop.MainWindow.Opened += async (_, _) => await vm.StartUpdateAsync();
+        }
+        base.OnFrameworkInitializationCompleted();
+    }
+}
diff --git a/src/Metin2Launcher/UI/MainWindow.axaml b/src/Metin2Launcher/UI/MainWindow.axaml
new file mode 100644
index 0000000..863927e
--- /dev/null
+++ b/src/Metin2Launcher/UI/MainWindow.axaml
@@ -0,0 +1,104 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="Metin2Launcher.UI.MainWindow"
+        Width="900" Height="560"
+        CanResize="False"
+        WindowStartupLocation="CenterScreen"
+        SystemDecorations="Full"
+        Title="{Binding WindowTitle}">
+  <Grid RowDefinitions="100,*">
+    <!-- Banner -->
+    <Border Grid.Row="0" Background="#8B0000">
+      <Grid>
+        <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="2">
+          <TextBlock Text="{Binding BannerTitle}"
+                     FontSize="32" FontWeight="Bold"
+                     Foreground="White"
+                     HorizontalAlignment="Center"/>
+          <TextBlock Text="{Binding BannerVersion}"
+                     FontSize="12"
+                     Foreground="#FFD7D7"
+                     HorizontalAlignment="Center"/>
+        </StackPanel>
+        <StackPanel Orientation="Horizontal"
+                    HorizontalAlignment="Right"
+                    VerticalAlignment="Top"
+                    Margin="0,8,12,0"
+                    Spacing="6">
+          <Button Content="⚙" Width="32" Height="32"
+                  Foreground="White" Background="Transparent"
+                  BorderBrush="#FFFFFF44" BorderThickness="1"
+                  ToolTip.Tip="{Binding SettingsTooltip}"
+                  Command="{Binding OpenSettingsCommand}"/>
+          <Button Content="✕" Width="32" Height="32"
+                  Foreground="White" Background="Transparent"
+                  BorderBrush="#FFFFFF44" BorderThickness="1"
+                  ToolTip.Tip="{Binding CloseTooltip}"
+                  Command="{Binding ExitCommand}"/>
+        </StackPanel>
+      </Grid>
+    </Border>
+
+    <!-- Body -->
+    <Grid Grid.Row="1" ColumnDefinitions="300,*">
+      <!-- Left -->
+      <Border Grid.Column="0" Padding="20" Background="#F4F4F4">
+        <Grid RowDefinitions="Auto,Auto,Auto,*,Auto">
+          <TextBlock Grid.Row="0"
+                     Text="{Binding StatusText}"
+                     FontSize="18" FontWeight="SemiBold"
+                     TextWrapping="Wrap"
+                     Foreground="{Binding StatusForeground}"/>
+          <ProgressBar Grid.Row="1"
+                       Margin="0,16,0,4"
+                       Height="18"
+                       Minimum="0" Maximum="100"
+                       Value="{Binding ProgressValue}"
+                       IsIndeterminate="{Binding IsIndeterminate}"/>
+          <TextBlock Grid.Row="2"
+                     Text="{Binding ProgressPercentText}"
+                     FontSize="12"
+                     Foreground="#555"/>
+          <TextBlock Grid.Row="3"
+                     Margin="0,12,0,0"
+                     Text="{Binding DetailText}"
+                     FontSize="12"
+                     TextWrapping="Wrap"
+                     Foreground="#444"/>
+          <StackPanel Grid.Row="4"
+                      Orientation="Horizontal"
+                      Spacing="10"
+                      HorizontalAlignment="Left">
+            <Button Content="{Binding PlayLabel}"
+                    Width="110" Height="38"
+                    FontSize="16" FontWeight="SemiBold"
+                    Background="#8B0000" Foreground="White"
+                    IsEnabled="{Binding CanPlay}"
+                    Command="{Binding PlayCommand}"/>
+            <Button Content="{Binding ExitLabel}"
+                    Width="110" Height="38"
+                    FontSize="14"
+                    Command="{Binding ExitCommand}"/>
+          </StackPanel>
+        </Grid>
+      </Border>
+
+      <!-- Right -->
+      <Border Grid.Column="1" Padding="20" Background="White">
+        <DockPanel>
+          <TextBlock DockPanel.Dock="Top"
+                     Text="{Binding NewsTitle}"
+                     FontSize="16" FontWeight="SemiBold"
+                     Margin="0,0,0,8"/>
+          <ScrollViewer HorizontalScrollBarVisibility="Disabled"
+                        VerticalScrollBarVisibility="Auto">
+            <TextBlock Text="{Binding NewsText}"
+                       TextWrapping="Wrap"
+                       FontSize="13"
+                       Foreground="#222"/>
+          </ScrollViewer>
+        </DockPanel>
+      </Border>
+    </Grid>
+  </Grid>
+</Window>
diff --git a/src/Metin2Launcher/UI/MainWindow.axaml.cs b/src/Metin2Launcher/UI/MainWindow.axaml.cs
new file mode 100644
index 0000000..1fe8a02
--- /dev/null
+++ b/src/Metin2Launcher/UI/MainWindow.axaml.cs
@@ -0,0 +1,17 @@
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Metin2Launcher.UI;
+
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+
+    private void InitializeComponent()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+}
diff --git a/src/Metin2Launcher/UI/SettingsDialog.axaml b/src/Metin2Launcher/UI/SettingsDialog.axaml
new file mode 100644
index 0000000..1616b80
--- /dev/null
+++ b/src/Metin2Launcher/UI/SettingsDialog.axaml
@@ -0,0 +1,40 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="Metin2Launcher.UI.SettingsDialog"
+        Width="460" Height="280"
+        CanResize="False"
+        WindowStartupLocation="CenterOwner"
+        Title="{Binding Title}">
+  <Grid Margin="20" RowDefinitions="Auto,Auto,Auto,Auto,Auto,*,Auto">
+    <TextBlock Grid.Row="0" Text="{Binding LanguageLabel}" FontWeight="SemiBold"/>
+    <ComboBox Grid.Row="1"
+              Margin="0,4,0,12"
+              Width="200" HorizontalAlignment="Left"
+              ItemsSource="{Binding Languages}"
+              SelectedItem="{Binding SelectedLanguage}"
+              DisplayMemberBinding="{Binding Display}"/>
+
+    <TextBlock Grid.Row="2" Text="{Binding ManifestUrlLabel}" FontWeight="SemiBold"/>
+    <TextBox Grid.Row="3"
+             Margin="0,4,0,8"
+             Text="{Binding ManifestUrl}"
+             IsEnabled="{Binding DevMode}"/>
+    <CheckBox Grid.Row="4"
+              Content="{Binding DevModeLabel}"
+              IsChecked="{Binding DevMode}"
+              Margin="0,0,0,4"/>
+    <TextBlock Grid.Row="5"
+               Text="{Binding NoteLabel}"
+               FontSize="11" Foreground="#666"
+               TextWrapping="Wrap"/>
+
+    <StackPanel Grid.Row="6"
+                Orientation="Horizontal"
+                HorizontalAlignment="Right"
+                Spacing="8"
+                Margin="0,12,0,0">
+      <Button Content="{Binding OkLabel}" Width="90" Click="OnOk"/>
+      <Button Content="{Binding CancelLabel}" Width="90" Click="OnCancel"/>
+    </StackPanel>
+  </Grid>
+</Window>
diff --git a/src/Metin2Launcher/UI/SettingsDialog.axaml.cs b/src/Metin2Launcher/UI/SettingsDialog.axaml.cs
new file mode 100644
index 0000000..37bdaf5
--- /dev/null
+++ b/src/Metin2Launcher/UI/SettingsDialog.axaml.cs
@@ -0,0 +1,27 @@
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Metin2Launcher.UI;
+
+public partial class SettingsDialog : Window
+{
+    public SettingsDialog()
+    {
+        InitializeComponent();
+    }
+
+    private void InitializeComponent()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    private void OnOk(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        Close(true);
+    }
+
+    private void OnCancel(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        Close(false);
+    }
+}
diff --git a/src/Metin2Launcher/UI/ViewModels/MainWindowViewModel.cs b/src/Metin2Launcher/UI/ViewModels/MainWindowViewModel.cs
new file mode 100644
index 0000000..4e7db21
--- /dev/null
+++ b/src/Metin2Launcher/UI/ViewModels/MainWindowViewModel.cs
@@ -0,0 +1,274 @@
+using System.Diagnostics;
+using System.IO;
+using System.Text;
+using System.Threading;
+using Avalonia.Controls;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Media;
+using Avalonia.Threading;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Metin2Launcher.Config;
+using Metin2Launcher.GameLaunch;
+using Metin2Launcher.Localization;
+using Metin2Launcher.Logging;
+using Metin2Launcher.Manifest;
+using Metin2Launcher.Orchestration;
+
+namespace Metin2Launcher.UI.ViewModels;
+
+public sealed partial class MainWindowViewModel : ObservableObject
+{
+    private readonly string _clientRoot;
+    private readonly string _stateDir;
+    private readonly string _settingsPath;
+    private readonly LauncherSettings _settings;
+    private readonly HttpClient _http;
+    private MainWindow? _window;
+
+    // Throttling
+    private UpdateProgress? _pendingProgress;
+    private readonly object _progressLock = new();
+    private DispatcherTimer? _flushTimer;
+
+    [ObservableProperty] private string _statusText = "";
+    [ObservableProperty] private string _detailText = "";
+    [ObservableProperty] private string _newsText = "";
+    [ObservableProperty] private double _progressValue;
+    [ObservableProperty] private bool _isIndeterminate;
+    [ObservableProperty] private bool _canPlay;
+    [ObservableProperty] private IBrush _statusForeground = Brushes.Black;
+    [ObservableProperty] private string _progressPercentText = "";
+
+    public string WindowTitle => Loc.Get("window.title");
+    public string BannerTitle => Loc.Get("banner.title");
+    public string BannerVersion => Loc.Get("banner.version", "0.1-dev");
+    public string PlayLabel => Loc.Get("button.play");
+    public string ExitLabel => Loc.Get("button.exit");
+    public string SettingsTooltip => Loc.Get("button.settings");
+    public string CloseTooltip => Loc.Get("button.close");
+    public string NewsTitle => Loc.Get("news.title");
+
+    private LauncherState _state = LauncherState.Idle;
+    private LoadedManifest? _lastManifest;
+    private bool _signatureBlocked;
+
+    public MainWindowViewModel()
+    {
+        _clientRoot = Directory.GetCurrentDirectory();
+        _stateDir = Path.Combine(_clientRoot, LauncherConfig.StateDirName);
+        Directory.CreateDirectory(_stateDir);
+        _settingsPath = Path.Combine(_stateDir, "launcher-settings.json");
+        _settings = LauncherSettings.Load(_settingsPath);
+        Loc.SetLocale(_settings.Locale);
+        Loc.Changed += OnLocaleChanged;
+
+        _http = new HttpClient { Timeout = LauncherConfig.BlobFetchTimeout };
+        _http.DefaultRequestHeaders.UserAgent.ParseAdd("Metin2Launcher/0.1");
+
+        _statusText = Loc.Get("status.idle");
+        _newsText = "";
+    }
+
+    public void AttachWindow(Window w) => _window = w as MainWindow;
+
+    private void OnLocaleChanged()
+    {
+        OnPropertyChanged(nameof(WindowTitle));
+        OnPropertyChanged(nameof(BannerTitle));
+        OnPropertyChanged(nameof(BannerVersion));
+        OnPropertyChanged(nameof(PlayLabel));
+        OnPropertyChanged(nameof(ExitLabel));
+        OnPropertyChanged(nameof(SettingsTooltip));
+        OnPropertyChanged(nameof(CloseTooltip));
+        OnPropertyChanged(nameof(NewsTitle));
+        // Refresh status text from current state
+        ApplyState(_state);
+    }
+
+    public async Task StartUpdateAsync()
+    {
+        // ~10 Hz UI flush timer
+        _flushTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(100) };
+        _flushTimer.Tick += (_, _) => FlushProgress();
+        _flushTimer.Start();
+
+        var orchestrator = new UpdateOrchestrator(_clientRoot, _settings, _http);
+        var progress = new Progress<UpdateProgress>(p =>
+        {
+            lock (_progressLock) { _pendingProgress = p; }
+        });
+
+        UpdateOrchestrator.Result? result = null;
+        try
+        {
+            using var cts = new CancellationTokenSource(LauncherConfig.TotalUpdateTimeout);
+            result = await Task.Run(() => orchestrator.RunAsync(progress, cts.Token));
+        }
+        catch (ManifestSignatureException)
+        {
+            _signatureBlocked = true;
+            ApplyState(LauncherState.SignatureFailed);
+            FlushProgress();
+            return;
+        }
+        catch (Exception ex)
+        {
+            Log.Error("update flow crashed, falling back to offline launch", ex);
+            ApplyState(LauncherState.OfflineFallback);
+        }
+
+        FlushProgress();
+
+        if (result is not null)
+        {
+            _lastManifest = result.Manifest;
+            ApplyState(result.FinalState);
+            await TryFetchNewsAsync(result.Manifest);
+        }
+
+        _flushTimer?.Stop();
+    }
+
+    private void FlushProgress()
+    {
+        UpdateProgress? p;
+        lock (_progressLock) { p = _pendingProgress; _pendingProgress = null; }
+        if (p is null) return;
+
+        if (p.Manifest is not null) _lastManifest = p.Manifest;
+        ApplyState(p.State);
+
+        if (p.Percent.HasValue)
+        {
+            IsIndeterminate = false;
+            ProgressValue = p.Percent.Value;
+            ProgressPercentText = $"{(int)p.Percent.Value}%";
+        }
+        else
+        {
+            IsIndeterminate = true;
+            ProgressPercentText = "";
+        }
+
+        if (!string.IsNullOrEmpty(p.Detail))
+            DetailText = p.Detail!;
+    }
+
+    private void ApplyState(LauncherState s)
+    {
+        _state = s;
+        StatusText = s switch
+        {
+            LauncherState.Idle => Loc.Get("status.idle"),
+            LauncherState.FetchingManifest => Loc.Get("status.fetchingManifest"),
+            LauncherState.VerifyingSignature => Loc.Get("status.verifyingSignature"),
+            LauncherState.Diffing => Loc.Get("status.diffing"),
+            LauncherState.Downloading => Loc.Get("status.downloading"),
+            LauncherState.Applying => Loc.Get("status.applying"),
+            LauncherState.UpToDate => Loc.Get("status.upToDate"),
+            LauncherState.OfflineFallback => Loc.Get("status.offlineFallback"),
+            LauncherState.SignatureFailed => Loc.Get("status.signatureFailed"),
+            LauncherState.Launching => Loc.Get("status.launching"),
+            _ => "",
+        };
+
+        StatusForeground = s == LauncherState.SignatureFailed ? Brushes.DarkRed : Brushes.Black;
+
+        var indeterminate = s is LauncherState.FetchingManifest
+            or LauncherState.VerifyingSignature
+            or LauncherState.Diffing;
+        IsIndeterminate = indeterminate;
+
+        if (s is LauncherState.UpToDate or LauncherState.OfflineFallback)
+        {
+            ProgressValue = 100;
+            ProgressPercentText = "100%";
+        }
+
+        CanPlay = !_signatureBlocked
+                  && s is LauncherState.UpToDate
+                              or LauncherState.OfflineFallback;
+    }
+
+    private async Task TryFetchNewsAsync(LoadedManifest? loaded)
+    {
+        if (loaded is null)
+        {
+            NewsText = Loc.Get("news.empty");
+            return;
+        }
+
+        var sb = new StringBuilder();
+        sb.AppendLine($"v{loaded.Manifest.Version}  ({loaded.Manifest.CreatedAt})");
+        sb.AppendLine();
+        sb.AppendLine(string.IsNullOrWhiteSpace(loaded.Manifest.Notes) ? "—" : loaded.Manifest.Notes);
+
+        var prev = loaded.Manifest.Previous;
+        if (!string.IsNullOrEmpty(prev))
+        {
+            try
+            {
+                var manifestUrl = _settings.EffectiveManifestUrl();
+                var baseUri = new Uri(manifestUrl);
+                var prevUrl = new Uri(baseUri, $"manifests/{prev}.json").ToString();
+                var json = await _http.GetStringAsync(prevUrl);
+                var prevManifest = System.Text.Json.JsonSerializer.Deserialize<Manifest.Manifest>(json);
+                if (prevManifest is not null && !string.IsNullOrWhiteSpace(prevManifest.Notes))
+                {
+                    sb.AppendLine();
+                    sb.AppendLine();
+                    sb.AppendLine(Loc.Get("news.previousHeader", prev));
+                    sb.AppendLine(prevManifest.Notes);
+                }
+            }
+            catch
+            {
+                // best effort
+            }
+        }
+
+        NewsText = sb.ToString();
+    }
+
+    [RelayCommand]
+    private void Exit()
+    {
+        if (Avalonia.Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime d)
+            d.Shutdown(0);
+        else
+            Environment.Exit(0);
+    }
+
+    [RelayCommand]
+    private void Play()
+    {
+        if (!CanPlay) return;
+        ApplyState(LauncherState.Launching);
+        var ok = GameProcess.Launch(_clientRoot, LauncherConfig.GameExecutable);
+        if (ok)
+        {
+            if (Avalonia.Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime d)
+                d.Shutdown(0);
+        }
+        else
+        {
+            // Re-enable so user can retry
+            CanPlay = true;
+        }
+    }
+
+    [RelayCommand]
+    private async Task OpenSettings()
+    {
+        if (_window is null) return;
+        var dialogVm = new SettingsDialogViewModel(_settings);
+        var dialog = new SettingsDialog { DataContext = dialogVm };
+        var ok = await dialog.ShowDialog<bool>(_window);
+        if (!ok) return;
+
+        dialogVm.ApplyTo(_settings);
+        _settings.Save(_settingsPath);
+        Loc.SetLocale(_settings.Locale);
+    }
+}
diff --git a/src/Metin2Launcher/UI/ViewModels/SettingsDialogViewModel.cs b/src/Metin2Launcher/UI/ViewModels/SettingsDialogViewModel.cs
new file mode 100644
index 0000000..c0d6d15
--- /dev/null
+++ b/src/Metin2Launcher/UI/ViewModels/SettingsDialogViewModel.cs
@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using CommunityToolkit.Mvvm.ComponentModel;
+using Metin2Launcher.Config;
+using Metin2Launcher.Localization;
+
+namespace Metin2Launcher.UI.ViewModels;
+
+public sealed class LanguageOption
+{
+    public string Code { get; }
+    public string Display { get; }
+    public LanguageOption(string code, string display) { Code = code; Display = display; }
+    public override string ToString() => Display;
+}
+
+public sealed partial class SettingsDialogViewModel : ObservableObject
+{
+    [ObservableProperty] private LanguageOption _selectedLanguage;
+    [ObservableProperty] private string _manifestUrl;
+    [ObservableProperty] private bool _devMode;
+
+    public List<LanguageOption> Languages { get; }
+
+    public string Title => Loc.Get("settings.title");
+    public string LanguageLabel => Loc.Get("settings.language");
+    public string ManifestUrlLabel => Loc.Get("settings.manifestUrl");
+    public string DevModeLabel => Loc.Get("settings.devMode");
+    public string NoteLabel => Loc.Get("settings.note");
+    public string OkLabel => Loc.Get("button.ok");
+    public string CancelLabel => Loc.Get("button.cancel");
+
+    public SettingsDialogViewModel(LauncherSettings settings)
+    {
+        Languages = new List<LanguageOption>
+        {
+            new("cs", Loc.Get("settings.language.cs")),
+            new("en", Loc.Get("settings.language.en")),
+        };
+        _selectedLanguage = Languages.Find(l => l.Code == settings.Locale) ?? Languages[0];
+        _manifestUrl = settings.ManifestUrlOverride ?? LauncherConfig.ManifestUrl;
+        _devMode = settings.DevMode;
+    }
+
+    public void ApplyTo(LauncherSettings settings)
+    {
+        settings.Locale = SelectedLanguage.Code;
+        settings.DevMode = DevMode;
+        settings.ManifestUrlOverride = ManifestUrl == LauncherConfig.ManifestUrl ? null : ManifestUrl;
+    }
+}