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

namespace HC_APTBS.Converters
{
    /// <summary>
    /// Maps a 0-100 percentage to a pixel value against a reference height supplied
    /// via <see cref="IValueConverter.Convert"/>'s <c>parameter</c>. Used by
    /// <see cref="HC_APTBS.Views.UserControls.GraphicIndicatorView"/> to project the
    /// tolerance band and target marker onto the fixed-height gauge track.
    /// </summary>
    public sealed class PercentToPixelsConverter : IValueConverter
    {
        /// <inheritdoc/>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            double percent = value switch
            {
                double d => d,
                float  f => f,
                int    i => i,
                _        => 0.0
            };

            double height = parameter switch
            {
                double d                                        => d,
                string s when double.TryParse(s, NumberStyles.Float, CultureInfo.InvariantCulture, out var parsed) => parsed,
                _                                               => 0.0
            };

            if (double.IsNaN(percent) || double.IsNaN(height) || height <= 0) return 0.0;
            return Math.Clamp(percent, 0.0, 100.0) / 100.0 * height;
        }

        /// <inheritdoc/>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
            => throw new NotSupportedException();
    }
}