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

namespace Melskin.Converters.Internal
{
    internal class ProgressToAngleConverter : IMultiValueConverter
    {
        public readonly static ProgressToAngleConverter Instance = new ProgressToAngleConverter();

        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            // 防御性检查：检查 UnsetValue 或 Null
            if (values == null || values.Length < 2 ||
                values[0] == System.Windows.DependencyProperty.UnsetValue || values[0] == null ||
                values[1] == System.Windows.DependencyProperty.UnsetValue || values[1] == null)
            {
                return System.Windows.Media.Geometry.Empty;
            }

            double value = System.Convert.ToDouble(values[0]);
            double max = System.Convert.ToDouble(values[1]);

            if (max <= 0) return System.Windows.Media.Geometry.Empty;

            // 确保百分比在 0-0.9999 之间
            double percent = (value / max) <= 0 ? 0 : (value / max) >= 1 ? 0.9999 : value / max;
            double angle = percent * 360;

            double size = 100;
            double stroke = 10;
            double center = size / 2;
            double radius = (size - stroke) / 2; // 半径 45

            double rad = (angle - 90) * Math.PI / 180;
            double x = center + radius * Math.Cos(rad);
            double y = center + radius * Math.Sin(rad);

            bool isLargeArc = angle > 180;

            Point startPoint = new Point(center, center - radius);
            Point endPoint = new Point(x, y);

            PathFigure figure = new PathFigure { StartPoint = startPoint, IsClosed = false };
            figure.Segments.Add(new ArcSegment(
                endPoint,
                new Size(radius, radius),
                0,
                isLargeArc,
                SweepDirection.Clockwise,
                true));

            return new PathGeometry(new[] { figure });
        }



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