using DTS.Common.Utilities;
using DTS.Common.Utilities.SaeJ211;
using System.Linq;

namespace DTS.Utilities
{
    public static class DataConditioning
    {
        /// <summary>
        /// returns an integer part of a string that might contain a decimal
        /// </summary>
        /// <param name="o"></param>
        /// <returns></returns>
        public static int GetIntegerIfPossible(object o)
        {
            if (null == o) { throw new System.Exception("expected non null input parameter"); }
            var s = o.ToString();
            var index = s.IndexOf(".");
            if (index == 0) { return 0; }
            if (index > 0) { s = s.Substring(0, index); }
            return int.Parse(s);
        }
        /// <summary>
        /// Gets Zered EU data given a time window to average
        /// </summary>
        /// <param name="euData"></param>
        /// <param name="sampleRate"></param>
        /// <param name="triggerSample"></param>
        /// <param name="startTime"></param>
        /// <param name="endTime"></param>
        /// <returns></returns>
        public static double[] GetAverageOverTimeEuData(
            double[] euData,
            double sampleRate,
            double triggerSample,
            double startTime,
            double endTime)
        {
            double[] zeroedEuData;
            var duration = endTime - startTime; //.3 - .2 = .1
            var startSample = (int)(triggerSample + (startTime * sampleRate));
            var endSample = (int)(startSample + (duration * sampleRate));
            var numSamples = endSample - startSample;
            if (numSamples <= 0) return euData;
            if (numSamples > euData.Length) return euData;
            var averagingSamples = new double[numSamples];
            var i = 0;
            for (var sampleNum = startSample; sampleNum < endSample; sampleNum++)
            {
                averagingSamples[i] = euData[sampleNum];
                i++;
            }
            var average = averagingSamples.Average();

            var zeroedDataIndex = 0;
            zeroedEuData = new double[euData.Length];
            foreach (var sample in euData)
            {
                zeroedEuData[zeroedDataIndex] = sample - average; //If average is a negative number, the sample will be increased
                zeroedDataIndex++;
            }
            return zeroedEuData;
        }

        public static double[] GetFilteredZeroedEUData(
            double[] euData,
            int filterRate,
            double sampleRate,
            double triggerSample,
            double startTime,
            double endTime)
        {
            return GetFilteredEUData(GetAverageOverTimeEuData(euData, sampleRate, triggerSample, startTime, endTime), filterRate, sampleRate);
        }

        public static double[] GetFilteredEUData(double[] euData, int filterRate, double sampleRate)
        {
            if (filterRate <= 0) return euData;
            var filterUtility = new FilterUtility
            {
                Cfc = ChannelFilter.AdHoc,
                AdHocFrequency = filterRate,
                SampleRate = sampleRate
            };
            var filteredData = filterUtility.ApplyFilter(euData);
            return filteredData;
        }
    }
}