using System;
using System.Collections.Generic;

namespace WingAIDiagnosisService.Carotid.Utilities
{
    public class GeneralFormulas
    {
        public static bool StatisticsThickness(List<float> thicknessList, out float max,
            out float min, out float average, out float variance)
        {
            max = 0;
            min = 0;
            average = 0;
            variance = 0;
            if (thicknessList != null && thicknessList.Count > 1)
            {
                max = thicknessList[0];
                min = thicknessList[1];
                float sum = 0;
                variance = StandardDeviation(thicknessList);

                foreach (var value in thicknessList)
                {
                    if (value > max)
                    {
                        max = value;
                    }
                    else if (value < min)
                    {
                        min = value;
                    }
                    sum += value;
                }
                average = sum / thicknessList.Count;
                return true;
            }
            return false;
        }

        private static float StandardDeviation(IList<float> thickness)
        {
            float variance = 0;
            if (thickness != null && thickness.Count > 0)
            {
                double sum = 0;
                for (var i = 0; i < thickness.Count; i++)
                {
                    sum += thickness[i];
                }
                var avg = (float)(sum / thickness.Count);

                foreach (var value in thickness)
                {
                    variance += (float)Math.Pow(value - avg, 2);
                }

                variance = (float)Math.Sqrt((variance / thickness.Count));
            }

            return variance;
        }
    }
}