using System;
using Microsoft.Extensions.Logging;
using AuroraDesk.Core.Interfaces;
using ReactiveUI;
using Microsoft.Extensions.DependencyInjection;

namespace AuroraDesk.Presentation.ViewModels;

/// <summary>
/// 应用程序级别的 ViewModel，实现 IScreen 接口
/// </summary>
public class AppViewModel : ReactiveObject, IScreen
{
    public RoutingState Router { get; }

    private MainWindowViewModel? _mainWindowViewModel;
    private readonly IServiceProvider _serviceProvider;

    /// <summary>
    /// MainWindowViewModel 的延迟初始化属性
    /// 重构后：通过依赖注入获取，而不是直接 new，这样可以正确注入所有依赖
    /// </summary>
    public MainWindowViewModel MainWindowViewModel
    {
        get
        {
            if (_mainWindowViewModel == null)
            {
                // 通过依赖注入获取 MainWindowViewModel，确保所有依赖（INavigationStateService, ITabManagementService）正确注入
                // 传入 this 作为 IScreen 参数
                _mainWindowViewModel = ActivatorUtilities.CreateInstance<MainWindowViewModel>(
                    _serviceProvider, 
                    this);
            }
            return _mainWindowViewModel;
        }
    }

    public AppViewModel(IServiceProvider serviceProvider)
    {
        Router = new RoutingState();
        _serviceProvider = serviceProvider;
        // 注意：MainWindowViewModel 延迟创建，避免循环依赖
        // MainWindowViewModel 将在首次访问时创建
    }
}