VWAP

//------------------------------------------------------------------------------
//
// Индикатор VWAP. Copyright (c) 2019 Ilya Smirnov. All rights reserved.
//
//------------------------------------------------------------------------------
 
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.Serialization;
using System.Windows.Media;
using TigerTrade.Chart.Base;
using TigerTrade.Chart.Base.Enums;
using TigerTrade.Chart.Indicators.Common;
using TigerTrade.Chart.Indicators.Drawings;
using TigerTrade.Chart.Indicators.Drawings.Enums;
using TigerTrade.Chart.Indicators.Enums;
using TigerTrade.Core.Utils.Time;
 
namespace TigerTrade.Chart.Indicators.Custom
{
    [DataContract(Name = "VWAPIndicator", Namespace = "http://schemas.datacontract.org/2004/07/TigerTrade.Chart.Indicators.Custom")]
    [Indicator("X_VWAP", "*VWAP", true, Type = typeof(VWAPIndicator))]
    internal sealed class VWAPIndicator : IndicatorBase
    {
        private IndicatorPeriodType _period;
 
        [DataMember(Name = "Period")]
        [Category("Параметры"), DisplayName("Период")]
        public IndicatorPeriodType Period
        {
            get => _period;
            set
            {
                if (value == _period)
                {
                    return;
                }
 
                _period = value;
 
                StdDevCache.Clear();
 
                OnPropertyChanged();
            }
        }
 
        private TimeSpan? _startTime;
 
        [DataMember(Name = "StartTime")]
        [Category("Параметры"), DisplayName("Время")]
        public TimeSpan? StartTime
        {
            get => _startTime;
            set
            {
                if (value.Equals(_startTime))
                {
                    return;
                }
 
                _startTime = value;
 
                StdDevCache.Clear();
 
                OnPropertyChanged();
            }
        }
 
        private IndicatorPriceType _priceType;
 
        [DataMember(Name = "PriceType")]
        [Category("Параметры"), DisplayName("Цена")]
        public IndicatorPriceType PriceType
        {
            get => _priceType;
            set
            {
                if (value == _priceType)
                {
                    return;
                }
 
                _priceType = value;
 
                StdDevCache.Clear();
 
                OnPropertyChanged();
            }
        }
 
        private List<decimal> _stdDevs;
 
        [DataMember(Name = "StdDevs")]
        [Category("Параметры"), DisplayName("StdDevs")]
        public List<decimal> StdDevs
        {
            get => _stdDevs ?? (StdDevs = new List<decimal>());
            set
            {
                if (Equals(value, _stdDevs))
                {
                    return;
                }
 
                _stdDevs = value;
             
                OnPropertyChanged();
            }
        }
 
        private ChartSeries _vwapSeries;
 
        [DataMember(Name = "VWAP")]
        [Category("ChartIndicatorsCharts"), DisplayName("VWAP")]
        public ChartSeries VWAPSeries
        {
            get => _vwapSeries ?? (_vwapSeries = new ChartSeries(ChartSeriesType.Line, Colors.Blue));
            private set
            {
                if (Equals(value, _vwapSeries))
                {
                    return;
                }
 
                _vwapSeries = value;
 
                OnPropertyChanged();
            }
        }
 
        private ChartSeries _stdDevSeries;
     
        [DataMember(Name = "StdDev")]
        [Category("ChartIndicatorsCharts"), DisplayName("StdDev")]
        public ChartSeries StdDevSeries
        {
            get => _stdDevSeries ?? (_stdDevSeries = new ChartSeries(ChartSeriesType.Line, Colors.Red));
            private set
            {
                if (Equals(value, _stdDevSeries))
                {
                    return;
                }
 
                _stdDevSeries = value;
 
                OnPropertyChanged();
            }
        }
 
        public VWAPIndicator()
        {
            Period = IndicatorPeriodType.Day;
 
            StartTime = null;
 
            PriceType = IndicatorPriceType.Median;
 
            StdDevs.Add(1);
            StdDevs.Add(2);
        }
 
        private List<double> _stdDevCache;
     
        private List<double> StdDevCache => _stdDevCache ?? (_stdDevCache = new List<double>(1000));
 
        protected override void Execute()
        {
            var date = Helper.Date;
            var price = Helper.Price(_priceType);
            var vol = Helper.Volume;
 
            var vwap = new double[date.Length];
            var stdDev = new double[date.Length];
            var splits = new bool[date.Length];
 
            var calcStdDevs = StdDevs.Count > 0;
 
            if (date.Length < StdDevCache.Count)
            {
                StdDevCache.Clear();
            }
 
            var lastSequence = -1;
 
            var cumVolumePrice = 0.0;
            var cumVolume = 0.0;
 
            var newDayIndex = 0;
 
            double timeOffset;
 
            if (StartTime.HasValue)
            {
                var oaBaseDate = DateTime.FromOADate(0);
 
                timeOffset = -oaBaseDate.Add(StartTime.Value).ToOADate();
            }
            else
            {
                timeOffset = TimeHelper.GetSessionOffset(DataProvider.Symbol.Exchange);
            }
 
            for (var i = 0; i < date.Length; i++)
            {
                var sequence = -1;
 
                switch (Period)
                {
                    case IndicatorPeriodType.Day:
 
                        sequence = DataProvider.Period.GetSequence(ChartPeriodType.Day, 1, date[i], timeOffset);
 
                        break;
 
                    case IndicatorPeriodType.Week:
 
                        sequence = DataProvider.Period.GetSequence(ChartPeriodType.Week, 1, date[i], timeOffset);
 
                        break;
 
                    case IndicatorPeriodType.Month:
 
                        sequence = DataProvider.Period.GetSequence(ChartPeriodType.Month, 1, date[i], timeOffset);
 
                        break;
                }
 
                if (sequence != lastSequence)
                {
                    lastSequence = sequence;
 
                    newDayIndex = i;
 
                    cumVolumePrice = 0.0;
                    cumVolume = 0.0;
 
                    splits[i] = true;
                }
 
                cumVolumePrice += price[i] * vol[i];
                cumVolume += vol[i];
 
                if (cumVolume == 0)
                {
                    continue;
                }
 
                vwap[i] = cumVolumePrice / cumVolume;
 
                if (calcStdDevs)
                {
                    if (i < StdDevCache.Count)
                    {
                        stdDev[i] = StdDevCache[i];
                    }
                    else
                    {
                        var variance = 0.0;
 
                        for (var j = newDayIndex; j < i; j++)
                        {
                            variance += (vol[j]/cumVolume)*(price[j] - vwap[i])*(price[j] - vwap[i]);
                        }
 
                        stdDev[i] = Math.Sqrt(variance);
 
                        StdDevCache.Add(stdDev[i]);
                    }
                }
            }
 
            var vwapSeries = new IndicatorSeriesData(vwap, VWAPSeries)
            {
                Style =
                {
                    DisableMinMax = true
                }
            };
 
            Series.Add(vwapSeries);
 
            if (calcStdDevs)
            {
                foreach (var dev in StdDevs)
                {
                    if (dev <= 0)
                    {
                        continue;
                    }
 
                    var stdDevPos = new double[date.Length];
                    var stdDevNeg = new double[date.Length];
 
                    var d = (double) dev;
 
                    for (var i = 0; i < date.Length; i++)
                    {
                        stdDevPos[i] = vwap[i] + stdDev[i] * d;
                        stdDevNeg[i] = vwap[i] - stdDev[i] * d;
                    }
 
                    var stdDevPosSeries = new IndicatorSeriesData(stdDevPos, StdDevSeries)
                    {
                        Style = {DisableMinMax = true}
                    };
 
                    var stdDevNegSeries = new IndicatorSeriesData(stdDevNeg, StdDevSeries)
                    {
                        Style = {DisableMinMax = true}
                    };
 
                    Series.Add(stdDevPosSeries, stdDevNegSeries);
                }
            }
 
            foreach (var series in Series)
            {
                series.UserData["S"] = splits;
                series.UserData["SE"] = false;
            }
        }
 
        public override void ApplyColors(IChartTheme theme)
        {
            VWAPSeries.AllColors = theme.GetNextColor();
            StdDevSeries.AllColors = theme.GetNextColor();
 
            base.ApplyColors(theme);
        }
 
        public override void CopyTemplate(IndicatorBase indicator, bool style)
        {
            var i = (VWAPIndicator)indicator;
 
                       Period = i.Period;
            PriceType = i.PriceType;
 
            StdDevs = i.StdDevs.ToList();
 
            VWAPSeries.CopyTheme(i.VWAPSeries);
            StdDevSeries.CopyTheme(i.StdDevSeries);
 
            base.CopyTemplate(indicator, style);
        }
    }
}