MrBot.Net/MRBot/Services/WindowManagerService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using LavishScriptAPI;
using LavishVMAPI;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MRBot.UI;

namespace MRBot.Services;

internal sealed class WindowManagerService : BackgroundService
{
    private readonly IHostApplicationLifetime _applicationLifetime;
    private readonly ILogger<WindowManagerService> _logger;
    private readonly List<IWindow> _activeWindows = new();
    private readonly List<IWindow> _inactiveWindows;

    public WindowManagerService(IEnumerable<IWindow> windows, IHostApplicationLifetime applicationLifetime, ILogger<WindowManagerService> logger)
    {
        _applicationLifetime = applicationLifetime;
        _logger = logger;
        _inactiveWindows = windows.ToList();
    }

    private void RemoveWindow(object sender, LSEventArgs args)
    {
        var window = sender as IWindow;
        if(window == null) return;
        _activeWindows.Remove(window);
        _inactiveWindows.Add(window);
        window.Hide();
        window?.Dispose();

        if (_activeWindows.Count == 0)
        {
            _applicationLifetime.StopApplication();
        }
    }
    
    private void OpenWindow(string windowName)
    {
        var window = _inactiveWindows.FirstOrDefault(w => w.Name == windowName);
        if (window == null) return;
        _inactiveWindows.Remove(window);
        _activeWindows.Add(window);
        window.Show();
        window.OnWindowClose += RemoveWindow;
    }

    public override Task StartAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Starting window manager");
        return base.StartAsync(cancellationToken);
    }

    private void ServiceLoopAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            Thread.Sleep(500);
            Frame.Wait(false);
        }
    }
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        OpenWindow(WindowNames.MainWindow);
        await Task.Factory.StartNew(() =>
        {
            ServiceLoopAsync(stoppingToken);
        }, stoppingToken, TaskCreationOptions.LongRunning, TaskScheduler.Default);
    }
    
    public override void Dispose()
    {
        foreach (var window in _activeWindows)
        {
            window.OnWindowClose -= RemoveWindow;
            window.Dispose();
        }
        base.Dispose();
    }
}