using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Data;

namespace MainShell.Converter
{
    public class WidthToMarginConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            double actualWidth = 0;
            if (value is double d) actualWidth = d;

            double expanded = 200;
            double extra = 0;

            if (parameter is string s)
            {
                var parts = s.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
                if (parts.Length >= 1 && double.TryParse(parts[0], out var p0)) expanded = p0;
                if (parts.Length >= 2 && double.TryParse(parts[1], out var p1)) extra = p1;
            }

            // 计算右侧 Margin：
            // 当 actualWidth == expanded 时返回 0（不偏移）
            // 当 actualWidth 减小时会返回正值，从而把 ToggleButton 向左推（或根据需要调整公式）
            double right = Math.Max(0, expanded - actualWidth) + extra;

            // 根据布局需要你可以修改这里返回的 Thickness 的哪一项（Left/Right）
            return new Thickness(-30, 0, 0, 0);
        }

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