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

namespace NeumUI.Converters.Internal;

/// <summary>
/// IntensityToSlotShadowMarginConverter 类用于将阴影强度（double类型）转换为阴影边距（Thickness类型）。此转换器特别适用于需要根据阴影强度动态调整UI元素阴影边距的场景。
/// 该类实现了IValueConverter接口，提供了从双精度浮点数到厚度值的单向转换逻辑。转换过程中，基于输入的强度值计算出一个偏移量，并以此构建新的 Thickness 实例来表示阴影边距。
/// 注意：此转换器不支持反向转换操作。
/// </summary>
[ValueConversion(typeof(double), typeof(Thickness))]
internal class IntensityToSlotShadowMarginConverter : IValueConverter
{
    public static readonly IntensityToSlotShadowMarginConverter Instance = new();

    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        var intensity = (double)(value ?? 0);
        //此处与中央Margin匹配
        var offset = 4 + intensity * 4;
        return new Thickness(0, 0, offset, offset);
    }

    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        return Binding.DoNothing;
    }
}