using Avalonia;
using Avalonia.Controls;
using Avalonia.Headless.XUnit;
using Avalonia.Threading;
using Avalonia.VisualTree;
using AvParser.Core.Settings;
using AvParser.UI.Localization;
using AvParser.UI.Navigation;
using AvParser.UI.ViewModels;
using AvParser.UI.Views;
using ReactiveUI.Primitives.Concurrency;

namespace AvParser.UI.HeadlessTests;

public sealed class LocalizationViewTests : IDisposable
{
    /// <summary>Leaves the localizer where the rest of the assembly expects it.</summary>
    public void Dispose() => Localizer.Instance.SetLanguage(AppLanguage.English);

    private static (ShellView View, ShellViewModel ViewModel) ShowShell()
    {
        var navigation = new NavigationService([new FakePage("Page.Dashboard"), new FakePage("Page.Parse")]);
        var viewModel = new ShellViewModel(navigation, new FakeThemeService(), ImmediateSequencer.Instance);
        var view = new ShellView { DataContext = viewModel };

        new Window
        {
            Width = 1400,
            Height = 800,
            Content = view,
        }.Show();

        Dispatcher.UIThread.RunJobs();
        return (view, viewModel);
    }

    private static IReadOnlyList<string> RailLabels(Visual view) =>
        [
            .. view.GetVisualDescendants()
                .OfType<TextBlock>()
                .Where(block => block.Classes.Contains("navLabel"))
                .Select(block => block.Text ?? string.Empty),
        ];

    [AvaloniaFact]
    public void Rendered_text_follows_the_language_without_rebuilding_the_view()
    {
        Localizer.Instance.SetLanguage(AppLanguage.English);
        var (view, _) = ShowShell();

        var english = RailLabels(view);
        english.ShouldBe(["Dashboard", "Parse"]);

        Localizer.Instance.SetLanguage(AppLanguage.Russian);
        Dispatcher.UIThread.RunJobs();

        // The same controls, not a rebuilt tree: this is the whole point of binding through the
        // localizer's indexer rather than resolving strings once at load.
        RailLabels(view).ShouldBe(["Обзор", "Разбор"]);
    }

    [AvaloniaFact]
    public void The_title_bar_follows_the_language_too()
    {
        Localizer.Instance.SetLanguage(AppLanguage.English);
        var (view, viewModel) = ShowShell();

        var title = view.GetVisualDescendants().OfType<TextBlock>().Single(block => block.Name == "ShellTitle");
        title.Text.ShouldBe("Dashboard");

        Localizer.Instance.SetLanguage(AppLanguage.Russian);
        Dispatcher.UIThread.RunJobs();

        viewModel.Title.ShouldBe("Обзор");
        title.Text.ShouldBe("Обзор");
    }

    [AvaloniaFact]
    public void Loc_markup_resolves_a_static_caption()
    {
        Localizer.Instance.SetLanguage(AppLanguage.Russian);
        var (view, _) = ShowShell();

        // Tooltips come from {l:Loc} rather than from a view model, so they exercise the markup
        // extension itself.
        var toggle = view.GetVisualDescendants().OfType<Button>().Single(button => button.Name == "PaneToggle");

        ToolTip.GetTip(toggle).ShouldBe("Показать или скрыть навигацию");
    }
}