using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using Microsoft.Data.Sqlite;
using Xunit;
using ytLive.Controls;
using ytLive.Models;
using ytLive.Services;
using ytLive.ViewModels;

namespace ytLive.Tests;

[Collection("RealApp")]
public sealed class SelectedLayerPreviewHitTestingTests
{
    private readonly RealAppHost _app;

    public SelectedLayerPreviewHitTestingTests(RealAppHost app) => _app = app;

    [Fact]
    public void ListSelectedBrandLogo_WinsPreviewHitTesting_UntilDeselected()
    {
        _app.Run(Run);
    }

    private static void Run()
    {
        var tempDb = System.IO.Path.Combine(System.IO.Path.GetTempPath(), $"ytLlive-selected-layer-{Guid.NewGuid():N}.db");
        MainViewModel.LayoutPathOverride = tempDb;
        MainWindow? window = null;
        try
        {
            using (var schema = new LayoutStore(tempDb)) { }
            SqliteConnection.ClearAllPools();

            window = new MainWindow();
            var vm = (MainViewModel)window.DataContext;
            var scene = vm.StagedScene!;
            var logo = scene.Elements.OfType<Source>().Single(source => source.IsBrandLogo);
            logo.X = 420;
            logo.Y = 300;
            logo.Width = 300;
            logo.Height = 180;

            var webcam = new WebcamSceneConfig
            {
                WebcamId = "test-camera",
                Name = "Webcam",
                X = logo.X,
                Y = logo.Y,
                Width = logo.Width,
                Height = logo.Height,
            };
            scene.Elements.Add(webcam);
            var originalOrder = scene.Elements.ToArray();

            window.Show();
            window.Activate();
            window.Topmost = true;
            window.UpdateLayout();

            var leftPanel = (LeftPanel)window.FindName("LeftPanel")!;
            var sourceList = (ListBox)leftPanel.FindName("SourceList")!;
            var preview = (PreviewPane)window.FindName("PreviewPane")!;
            var canvasGrid = (FrameworkElement)preview.FindName("CanvasGrid")!;
            var overlayElements = (ItemsControl)preview.FindName("OverlayElements")!;
            var logoContainer = (UIElement)overlayElements.ItemContainerGenerator.ContainerFromItem(logo)!;
            var webcamContainer = (UIElement)overlayElements.ItemContainerGenerator.ContainerFromItem(webcam)!;
            var pointInCanvas = new Point(logo.X + 100, logo.Y + 60);
            var pointInWindow = canvasGrid.TransformToVisual(window).Transform(pointInCanvas);

            // The brand logo is drawn in BrandLogoOverlay above the blur host (2026-11-01), so its
            // canvas presenter is collapsed and the overlay is what the eye sees. Hit-testing
            // follows the eye: the logo wins a click inside its bounds.
            Assert.Equal(Visibility.Collapsed, logoContainer.Visibility);
            Assert.Same(logo, preview.HitElementAt(vm, pointInCanvas));

            sourceList.SelectedItem = logo;
            window.UpdateLayout();

            Assert.True(ReferenceEquals(logo, vm.SelectedElement), "Selecting the layer-list row must select the brand logo.");
            Assert.Same(logo, preview.HitElementAt(vm, pointInCanvas));

            // …and with nothing selected the logo still wins inside its own bounds, because it is
            // drawn above every layer. The webcam shares that rect in this test, so it is the
            // covered case: you reach it from the layer list, not by clicking through the logo.
            vm.SelectedElement = null;
            window.UpdateLayout();
            Assert.Same(logo, preview.HitElementAt(vm, new Point(logo.X + 5, logo.Y + 5)));
            Assert.Equal(originalOrder, scene.Elements);

            sourceList.SelectedItem = null;
            window.UpdateLayout();

            Assert.Null(vm.SelectedElement);
            // The logo still owns a click inside its bounds after deselection (it is the topmost
            // layer in both the compositor and the preview), and the canvas presenter stays
            // collapsed because BrandLogoOverlay is what draws it.
            Assert.Equal(Visibility.Collapsed, logoContainer.Visibility);
            Assert.Same(logo, preview.HitElementAt(vm, pointInCanvas));
            Assert.Equal(originalOrder, scene.Elements);
        }
        finally
        {
            window?.Close();
            MainViewModel.LayoutPathOverride = null;
            SqliteConnection.ClearAllPools();
            try { System.IO.File.Delete(tempDb); } catch { }
        }
    }

    private static SceneElement? ElementAt(System.Windows.IInputElement? hit)
    {
        DependencyObject? current = hit as DependencyObject;
        while (current != null)
        {
            if (current is FrameworkElement { DataContext: SceneElement element })
                return element;
            current = current is Visual or System.Windows.Media.Media3D.Visual3D
                ? VisualTreeHelper.GetParent(current)
                : LogicalTreeHelper.GetParent(current);
        }
        return null;
    }
}