using System;
using System.Collections;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace SWRIS.Converters
{
    public class CollectionToVisibilityConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            // 处理 null 值
            if (value == null)
                return Visibility.Collapsed;

            // 处理集合类型
            if (value is ICollection collection)
                return collection.Count > 0 ? Visibility.Visible : Visibility.Collapsed;

            // 处理 IEnumerable（不推荐，因为可能触发多次枚举）
            if (value is IEnumerable enumerable)
            {
                var enumerator = enumerable.GetEnumerator();
                try
                {
                    return enumerator.MoveNext() ? Visibility.Visible : Visibility.Collapsed;
                }
                finally
                {
                    if (enumerator is IDisposable disposable)
                        disposable.Dispose();
                }
            }

            // 其他类型默认显示
            return Visibility.Visible;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}