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

using WPFDark.Internals;

namespace WPFDark.Controls.Converters
{
    public class IndentToMarginConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var thickness = new Thickness(0);
            if (values is null)
                return thickness;

            if (!(values[0] is TreeViewItem item))
                return thickness;

            var length = 19.0;

            if (values.Length == 2)
                if (values[1] is double v)
                    length = v;

            var k = length * item.GetDepth();

            // ReSharper disable once CompareOfFloatsByEqualityOperator
            if (k == 0)
                return thickness;

            if (_thicknessCache.TryGetValue(k, out var result) == false)
            {
                result = new Thickness(k, 0, 0, 0);

                _thicknessCache.Add(k, result);
            }

            return result;
        }

        private static readonly LruCache<double, object> _thicknessCache = new LruCache<double, object>(8);

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