using Cysharp.Threading.Tasks;

/// <summary>
/// UI返回键策略接口
/// </summary>
public interface IUIBackStrategy
{
    /// <summary>
    /// 处理返回键
    /// </summary>
    /// <param name="window">触发返回的窗口</param>
    /// <returns>是否成功处理</returns>
    UniTask<bool> HandleBack(UIWindow window);
}

/// <summary>
/// 策略1：不响应返回键
/// </summary>
public class UIBackStrategy_None : IUIBackStrategy
{
    public async UniTask<bool> HandleBack(UIWindow window)
    {
        // 不响应，返回false让下一个窗口处理
        await UniTask.CompletedTask;
        return false;
    }
}

/// <summary>
/// 策略2：关闭自己
/// </summary>
public class UIBackStrategy_CloseSelf : IUIBackStrategy
{
    public async UniTask<bool> HandleBack(UIWindow window)
    {
        if (window != null)
        {
            window.CloseWindow(destroy: true);
            DebugUtil.Log($"[BackStrategy] Close window: {window.WindowName}");
            await UniTask.CompletedTask;
            return true;
        }
        return false;
    }
}

/// <summary>
/// 策略3：什么都不做（拦截返回键但不执行任何操作）
/// 适用场景：剧情播放中、加载中等不希望用户中断的场景
/// </summary>
public class UIBackStrategy_DoNothing : IUIBackStrategy
{
    public async UniTask<bool> HandleBack(UIWindow window)
    {
        // 拦截返回键，但什么都不做
        DebugUtil.Log($"[BackStrategy] Back blocked by: {window?.WindowName}");
        await UniTask.CompletedTask;
        return true; // 返回true表示已处理，阻止继续传递
    }
}

/// <summary>
/// 策略4：弹出退出游戏确认界面
/// 适用场景：主界面、登录界面等根界面
/// </summary>
public class UIBackStrategy_ShowExitConfirm : IUIBackStrategy
{
    public async UniTask<bool> HandleBack(UIWindow window)
    {
        // 检查退出确认界面是否已经打开
        if (!UIManager.Instance.CheckWindowCreated(UINameConst.UIBackReturn))
        {
            await UIManager.Instance.CreateAndOpenWindow(UINameConst.UIBackReturn);
            DebugUtil.Log($"[BackStrategy] Show exit confirm from: {window?.WindowName}");
        }
        return true;
    }
}

/// <summary>
/// 返回策略工厂
/// </summary>
public static class UIBackStrategyFactory
{
    private static UIBackStrategy_None _noneStrategy;
    private static UIBackStrategy_CloseSelf _closeSelfStrategy;
    private static UIBackStrategy_DoNothing _doNothingStrategy;
    private static UIBackStrategy_ShowExitConfirm _showExitConfirmStrategy;

    /// <summary>
    /// 根据策略类型创建策略实例
    /// </summary>
    public static IUIBackStrategy CreateStrategy(UIBackStrategyType strategyType)
    {
        switch (strategyType)
        {
            case UIBackStrategyType.PassThrough:
                return GetNoneStrategy();
            case UIBackStrategyType.CloseSelf:
                return GetCloseSelfStrategy();
            case UIBackStrategyType.Intercept:
                return GetDoNothingStrategy();
            case UIBackStrategyType.ShowExitConfirm:
                return GetShowExitConfirmStrategy();
            default:
                return GetCloseSelfStrategy(); // 默认关闭自己
        }
    }

    /// <summary>
    /// 获取"不响应"策略实例（单例）
    /// </summary>
    public static IUIBackStrategy GetNoneStrategy()
    {
        if (_noneStrategy == null)
            _noneStrategy = new UIBackStrategy_None();
        return _noneStrategy;
    }

    /// <summary>
    /// 获取"关闭自己"策略实例（单例）
    /// </summary>
    public static IUIBackStrategy GetCloseSelfStrategy()
    {
        if (_closeSelfStrategy == null)
            _closeSelfStrategy = new UIBackStrategy_CloseSelf();
        return _closeSelfStrategy;
    }

    /// <summary>
    /// 获取"什么都不做"策略实例（单例）
    /// </summary>
    public static IUIBackStrategy GetDoNothingStrategy()
    {
        if (_doNothingStrategy == null)
            _doNothingStrategy = new UIBackStrategy_DoNothing();
        return _doNothingStrategy;
    }

    /// <summary>
    /// 获取"弹出退出确认"策略实例（单例）
    /// </summary>
    public static IUIBackStrategy GetShowExitConfirmStrategy()
    {
        if (_showExitConfirmStrategy == null)
            _showExitConfirmStrategy = new UIBackStrategy_ShowExitConfirm();
        return _showExitConfirmStrategy;
    }
}