YZWater3/src/YZWater.Core/Services/ThemeService.cs

using CommunityToolkit.Mvvm.ComponentModel;

namespace YZWater.Core.Services;

/// <summary>
/// 主题切换服务（纯状态管理，不依赖 Avalonia）
/// </summary>
public partial class ThemeService : ObservableObject
{
    private static ThemeService? _instance;
    public static ThemeService Instance => _instance ??= new ThemeService();

    [ObservableProperty]
    private bool _isDarkTheme = true;

    /// <summary>
    /// 主题变更事件（由 App.axaml.cs 订阅执行实际切换）
    /// </summary>
    public event Action? ThemeChanged;

    private ThemeService() { }

    /// <summary>
    /// 切换主题
    /// </summary>
    public void ToggleTheme()
    {
        IsDarkTheme = !IsDarkTheme;
        ThemeChanged?.Invoke();
    }
}