using System;
using System.IO;
using System.Linq;
using Xunit;
using ytLive.Models;
using ytLive.ViewModels;

namespace ytLive.Tests;

/// <summary>
/// The (+) menu's Blur entry is Live-scene only, and it is bound — so the view model has to
/// re-notify `CanAddBlur` whenever the staged scene changes. It did not, and the option stayed
/// collapsed for the rest of the session (build 1082: "it no longer appears as an option").
/// </summary>
[Collection("MainViewModelLayoutPath")]
public class BlurMenuAvailabilityTests
{
    private static MainViewModel NewVm(out string dbPath)
    {
        dbPath = Path.Combine(Path.GetTempPath(), $"llamacasty-blurmenu-{Guid.NewGuid():N}.db");
        MainViewModel.LayoutPathOverride = dbPath;
        return new MainViewModel();
    }

    [Fact]
    public void Blur_is_offered_on_the_live_scene_only_and_the_flag_is_re_notified()
    {
        var vm = NewVm(out var dbPath);
        try
        {
            var live = vm.Scenes.First(s => SceneCatalog.Is(s.Name, SceneCatalog.Live));
            var chat = vm.Scenes.First(s => SceneCatalog.Is(s.Name, SceneCatalog.Chat));

            vm.StagedScene = live;
            Assert.True(vm.CanAddBlur, "the Live scene must offer the blur layer");
            vm.StagedScene = chat;
            Assert.False(vm.CanAddBlur, "other scenes must not offer a desktop blur");

            // The regression: a bound property with no notification never re-evaluates.
            var notified = 0;
            vm.PropertyChanged += (_, e) => { if (e.PropertyName == nameof(MainViewModel.CanAddBlur)) notified++; };
            vm.StagedScene = live;
            Assert.True(notified > 0, "changing the staged scene must re-notify CanAddBlur");
        }
        finally
        {
            MainViewModel.LayoutPathOverride = null;
            try { File.Delete(dbPath); } catch (IOException) { }
        }
    }
}