// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file, You can obtain one at https://opensource.org/licenses/MIT.
// Copyright (C) Leszek Pomianowski and WPF UI Contributors.
// All Rights Reserved.

using Microsoft.Extensions.Hosting;

using WPFluent.Gallery.Services.Contracts;
using WPFluent.Gallery.Views.Pages;
using WPFluent.Gallery.Views.Windows;

namespace WPFluent.Gallery.Services;

/// <summary>
/// Managed host of the application.
/// </summary>
public class ApplicationHostService : IHostedService
{
    private readonly IServiceProvider _serviceProvider;

    public ApplicationHostService(IServiceProvider serviceProvider)
    {
        // If you want, you can do something with these services at the beginning of loading the application.
        _serviceProvider = serviceProvider;
    }

    /// <summary>
    /// Triggered when the application host is ready to start the service.
    /// </summary>
    /// <param name="cancellationToken">Indicates that the start process has been aborted.</param>
    public Task StartAsync(CancellationToken cancellationToken)
    {
        return HandleActivationAsync();
    }

    /// <summary>
    /// Triggered when the application host is performing a graceful shutdown.
    /// </summary>
    /// <param name="cancellationToken">Indicates that the shutdown process should no longer be graceful.</param>
    public Task StopAsync(CancellationToken cancellationToken)
    {
        return Task.CompletedTask;
    }

    /// <summary>
    /// Creates main window during activation.
    /// </summary>
    private Task HandleActivationAsync()
    {
        if (Application.Current.Windows.OfType<MainWindow>().Any())
        {
            return Task.CompletedTask;
        }

        IWindow mainWindow = _serviceProvider.GetRequiredService<IWindow>();
        mainWindow.Loaded += OnMainWindowLoaded;
        mainWindow?.Show();

        return Task.CompletedTask;
    }

    private void OnMainWindowLoaded(object sender, RoutedEventArgs e)
    {
        if (sender is not MainWindow mainWindow)
        {
            return;
        }

        _ = mainWindow.NavigationView.Navigate(typeof(DashboardPage));
    }
}