Pivot Points

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;

namespace cAlgo.Indicators
{
    [Indicator(IsOverlay = true, TimeZone = TimeZones.EasternStandardTime, AccessRights = AccessRights.None)]
    public class PivotPoints : Indicator
    {
        private DateTime _previousPeriodStartTime;
        private int _previousPeriodStartIndex;
        private TimeFrame PivotTimeFrame;

        Color pivotColor = Color.White;
        Color supportColor = Color.Red;
        Color resistanceColor = Color.Green;

        [Parameter("Show Labels", DefaultValue = true)]
        public bool ShowLabels { get; set; }

        [Parameter("Pivot Color", DefaultValue = "White")]
        public string PivotColor { get; set; }
        [Parameter("Support Color", DefaultValue = "Red")]
        public string SupportColor { get; set; }
        [Parameter("Resistance Color", DefaultValue = "Green")]
        public string ResistanceColor { get; set; }

        protected override void Initialize()
        {
            if (TimeFrame <= TimeFrame.Hour)
                PivotTimeFrame = TimeFrame.Daily;
            else if (TimeFrame < TimeFrame.Daily)
            {
                PivotTimeFrame = TimeFrame.Weekly;
            }
            else
                PivotTimeFrame = TimeFrame.Monthly;

            pivotColor = Color.FromName(PivotColor);
            supportColor = Color.FromName(SupportColor);
            resistanceColor = Color.FromName(ResistanceColor);
        }

        private DateTime GetStartOfPeriod(TimeFrame tf, DateTime dateTime)
        {
            return CutToOpenByNewYork(tf, dateTime, PivotTimeFrame);
        }

        private DateTime GetEndOfPeriod(DateTime dateTime)
        {
            if (TimeFrame == TimeFrame.Weekly)
            {
                return new DateTime(dateTime.Year, 1, 1).AddYears(1);
            }

            if (PivotTimeFrame == TimeFrame.Monthly)
            {
                return new DateTime(dateTime.Year, dateTime.Month, 1).AddMonths(1);
            }

            if (PivotTimeFrame == TimeFrame.Weekly)
            {
                int diff = (7 + (dateTime.DayOfWeek - DayOfWeek.Sunday)) % 7;
                return dateTime.AddDays(-1 * diff).Date;
            }

            return AddPeriod(CutToOpenByNewYork(TimeFrame, dateTime, PivotTimeFrame), PivotTimeFrame);
        }

        public override void Calculate(int index)
        {
            if (TimeFrame == TimeFrame.Monthly)
                return;

            var currentPeriodStartTime = GetStartOfPeriod(TimeFrame, Bars.OpenTimes[index]);
            if (currentPeriodStartTime == _previousPeriodStartTime)
                return;

            if (index > 0)
                CalculatePivots(_previousPeriodStartTime, _previousPeriodStartIndex, currentPeriodStartTime, index);

            _previousPeriodStartTime = currentPeriodStartTime;
            _previousPeriodStartIndex = index;
        }

        private void CalculatePivots(DateTime startTime, int startIndex, DateTime startTimeOfNextPeriod, int index)
        {
            var high = Bars.HighPrices[startIndex];
            var low = Bars.LowPrices[startIndex];
            var close = Bars.ClosePrices[startIndex];
            var i = startIndex + 1;

            while (GetStartOfPeriod(TimeFrame, Bars.OpenTimes[i]) == startTime && i < Bars.ClosePrices.Count)
            {
                high = Math.Max(high, Bars.HighPrices[i]);
                low = Math.Min(low, Bars.LowPrices[i]);
                close = Bars.ClosePrices[i];

                i++;
            }

            var pivotStartTime = startTimeOfNextPeriod;
            var pivotEndTime = GetEndOfPeriod(startTimeOfNextPeriod);

            var pivot = (high + low + close) / 3;

            var r1 = 2 * pivot - low;
            var s1 = 2 * pivot - high;

            var r2 = pivot + high - low;
            var s2 = pivot - high + low;

            var r3 = high + 2 * (pivot - low);
            var s3 = low - 2 * (high - pivot);

            Chart.DrawTrendLine("pivot " + startIndex, pivotStartTime, pivot, pivotEndTime, pivot, Color.White);
            Chart.DrawTrendLine("r1 " + startIndex, pivotStartTime, r1, pivotEndTime, r1, resistanceColor);
            Chart.DrawTrendLine("r2 " + startIndex, pivotStartTime, r2, pivotEndTime, r2, resistanceColor);
            Chart.DrawTrendLine("r3 " + startIndex, pivotStartTime, r3, pivotEndTime, r3, resistanceColor);
            Chart.DrawTrendLine("s1 " + startIndex, pivotStartTime, s1, pivotEndTime, s1, supportColor);
            Chart.DrawTrendLine("s2 " + startIndex, pivotStartTime, s2, pivotEndTime, s2, supportColor);
            Chart.DrawTrendLine("s3 " + startIndex, pivotStartTime, s3, pivotEndTime, s3, supportColor);

            if (!ShowLabels)
                return;

            var dr1 = (int)Math.Abs((pivot - r1) / Symbol.PipSize);
            var dr2 = (int)Math.Abs((pivot - r2) / Symbol.PipSize);
            var dr3 = (int)Math.Abs((pivot - r3) / Symbol.PipSize);
            var ds1 = (int)Math.Abs((pivot - s1) / Symbol.PipSize);
            var ds2 = (int)Math.Abs((pivot - s2) / Symbol.PipSize);
            var ds3 = (int)Math.Abs((pivot - s3) / Symbol.PipSize);

            Chart.DrawText("Lpivot " + startIndex, "P", index, pivot, pivotColor);
            Chart.DrawText("Lr1 " + startIndex, string.Format("R1 ({0})", dr1), index, r1, resistanceColor);
            Chart.DrawText("Lr2 " + startIndex, string.Format("R2 ({0})", dr2), index, r2, resistanceColor);
            Chart.DrawText("Lr3 " + startIndex, string.Format("R3 ({0})", dr3), index, r3, resistanceColor);
            Chart.DrawText("Ls1 " + startIndex, string.Format("S1 ({0})", ds1), index, s1, supportColor);
            Chart.DrawText("Ls2 " + startIndex, string.Format("S2 ({0})", ds2), index, s2, supportColor);
            Chart.DrawText("Ls3 " + startIndex, string.Format("S3 ({0})", ds3), index, s3, supportColor);
        }


        private static DateTime CutToOpenByNewYork(TimeFrame tf, DateTime date, TimeFrame timeFrame)
        {
            if (tf == TimeFrame.Weekly)
            {
                return new DateTime(date.Year, 1, 1, 0, 0, 0, DateTimeKind.Unspecified);
            }

            if (timeFrame == TimeFrame.Daily)
            {
                var hourShift = (date.Hour + 24 - 17) % 24;
                return new DateTime(date.Year, date.Month, date.Day, date.Hour, 0, 0, DateTimeKind.Unspecified).AddHours(-hourShift);
            }

            if (timeFrame == TimeFrame.Weekly)
                return GetStartOfTheWeek(date);

            if (timeFrame == TimeFrame.Monthly)
            {
                return new DateTime(date.Year, date.Month, 1, 0, 0, 0, DateTimeKind.Unspecified);
            }

            throw new ArgumentException(string.Format("Unknown timeframe: {0}", timeFrame), "timeFrame");
        }

        private static DateTime GetStartOfTheWeek(DateTime dateTime)
        {
            return dateTime.Date.AddDays((double)DayOfWeek.Sunday - (double)dateTime.Date.DayOfWeek).AddHours(-7);
        }


        public DateTime AddPeriod(DateTime dateTime, TimeFrame timeFrame)
        {
            if (timeFrame == TimeFrame.Daily)
            {
                return dateTime.AddDays(1);
            }
            if (timeFrame == TimeFrame.Weekly)
            {
                return dateTime.AddDays(7);
            }
            if (timeFrame == TimeFrame.Monthly)
                return dateTime.AddMonths(1);

            throw new ArgumentException(string.Format("Unknown timeframe: {0}", timeFrame), "timeFrame");
        }

    }
}