namespace QuantConnect.Indicators
{
    public class RelativeStrengthIndex : IndicatorBase
    {
        public readonly ExponentialMovingAverage UpDays;
        public readonly ExponentialMovingAverage DownDays;

        private DataPoint<decimal> previousInput; 

        public RelativeStrengthIndex(string name, int period) 
            : base(name)
        {
            UpDays = new ExponentialMovingAverage(string.Format("[{0}]" + "_UP_EMA{1}", name, period), period);
            DownDays = new ExponentialMovingAverage(string.Format("[{0}]" + "_DOWN_EMA{1}", name, period), period);
        }

        public override bool IsReady
        {
            get { return UpDays.IsReady && DownDays.IsReady; }
        }

        protected override decimal ComputeNextValue(DataPoint<decimal> previousValue, DataPoint<decimal> input)
        {
            if (input.Data > previousInput.Data)
            {
                UpDays.Update(input.WithNewData(input.Data - previousInput.Data));
            }
            else if (input.Data < previousInput.Data)
            {
                DownDays.Update(input.WithNewData(previousInput.Data - input.Data));
            }

            previousInput = input;
            if (DownDays.Samples < 5)
            {
                return 50;
            }

            var rs = UpDays.Value.Data/DownDays.Value.Data;
            return 100m - (100m/(1 + rs));
        }
    }
}

using System;
using System.Collections.Generic;
using QuantConnect.Models;

namespace QuantConnect.Indicators
{
    /// <summary>
    /// Shows how we can compose indicators by wrapping them around other indicators
    /// </summary>
    public class IndicatorAlgorithmDemo : QCAlgorithm
    {
        private IIndicator smaHigh;
        private IIndicator emaLow;
        private IIndicator rsiClose;
        private WrappedIndicator macdSimpleOpen;
        private WrappedIndicator macdExponentialClose;
        private WrappedIndicator rsiOfMacdSimpleOpen;

        private const string SPY = "SPY";

        public override void Initialize()
        {
            SetCash(25000);
            SetStartDate(2007, 01, 01);
            SetEndDate(2011, 01, 01);

            AddSecurity(SecurityType.Equity, SPY);

            // easily define common indicators
            smaHigh = SMA(25);
            emaLow = EMA(35);

            var sma9 = SMA(9);
            var macds = MACD(14, 26, "sMACD(14,26)");

            // easily compose multiple indicators, here we define an sma signal line for
            // our sma macd
            macdSimpleOpen = sma9.Of(macds);

            var ema9 = EMA(9, "eMACD-EMA9");
            var macde = MACD(14, 26, "eMACD(14,26)", MovingAverageType.Exponential);

            // here we define an ema signal line for our ema macd
            macdExponentialClose = ema9.Of(macde);

            var rsi = RSI(14);
            rsiOfMacdSimpleOpen = rsi.Of(macdSimpleOpen, "RSI of MACD");

            rsiClose = RSI(14);
        }

        private DateTime previous;
        public override void OnTradeBar(Dictionary<string, TradeBar> data)
        {
            // when pumping data throw an indictor 'machine' we only need to pump from
            // the outter most parts, so in this case, sma, ema, macdSimple, and macdExponential
            // the 'interior' indicators in the macds (sma9, ema9, macd in Initialize()) are handled by the instance

            // we'll only get updates once per day
            TradeBar bar;
            if (data.TryGetValue(SPY, out bar) && bar.Time.Date != previous.Date)
            {
                previous = bar.Time;

                // we can decide what data to send to each indicator

                try
                {
                    var dataPoint = CreateDataPoint(bar.Time, bar.High);
                    smaHigh.Update(dataPoint);

                    dataPoint = CreateDataPoint(bar.Time, bar.Low);
                    emaLow.Update(dataPoint);

                    // calling update on this one will 'turn the crank' for the
                    // interior indicators as well (macdSimpleOpen and its interior indicators)
                    dataPoint = CreateDataPoint(bar.Time, bar.Open);
                    rsiOfMacdSimpleOpen.Update(dataPoint);

                    dataPoint = CreateDataPoint(bar.Time, bar.Close);
                    macdExponentialClose.Update(dataPoint);
                    rsiClose.Update(dataPoint);

                    Plot("Price", "Close", bar.Close);
                    Plot("Price", "SMA14 High", smaHigh.Value.Data);
                    Plot("Price", "EMA14 Low", emaLow.Value.Data);

                    // here we use the Root property on the WrappedIndicator to get access
                    // to the underlying MACD data, and then the Wrapped (or just Value) is the signal line

                    Plot("sMACD", "MACD", macdSimpleOpen.Root.Value.Data);
                    Plot("sMACD", "Signal", macdSimpleOpen.Value.Data);

                    Plot("eMACD", "MACD", macdExponentialClose.Root.Value.Data);
                    Plot("eMACD", "Signal", macdExponentialClose.Value.Data);

                    Plot("RSI of MACD", "10*(5+MACD)", 10 * (5 + macdSimpleOpen.Value.Data));
                    Plot("RSI of MACD", "RSI of MACD", rsiOfMacdSimpleOpen.Value.Data);

                    Plot("RSI", "RSI", rsiClose.Value.Data);

                    Log("updated and plotted!");
                }
                catch (Exception ex)
                {
                    Error(ex.Message + "\r\n\r\n" + ex.StackTrace);
                }
            }
        }

        public static IIndicator SMA(int period, string name = null)
        {
            return new SimpleMovingAverage(name ?? "SMA" + period, period);
        }
        public static IIndicator EMA(int period, string name = null)
        {
            return new ExponentialMovingAverage(name ?? "EMA" + period, period);
        }
        public static IIndicator MACD(int fast, int slow, string name = null, MovingAverageType type = MovingAverageType.Simple)
        {
            return new MovingAverageConverganceDivergance(name ?? string.Format("{0}MACD({1}, {2})", fast, slow, GetMACDPrefix(type)), fast, slow, type);
        }
        public static IIndicator RSI(int period, string name = null)
        {
            return new RelativeStrengthIndex(name ?? "RSI" + period, period);
        }

        private static string GetMACDPrefix(MovingAverageType type)
        {
            if (type == MovingAverageType.Simple) return "s";
            if (type == MovingAverageType.Exponential) return "e";
            throw new ArgumentOutOfRangeException("type", type, "Received unexpected value of type: " + type);
        }

        public static DataPoint<T> CreateDataPoint<T>(DateTime time, T data)
        {
            return new DataPoint<T>(time, data);
        }
    }
}

namespace QuantConnect.Indicators
{
    public class ExponentialMovingAverage : IndicatorBase
    {
        private readonly decimal _k;
        private readonly int _period;

        public ExponentialMovingAverage(string name, int period)
            : base(name)
        {
            _period = period;
            _k = 2 / ((decimal)period + 1);
        }

        public override bool IsReady
        {
            get { return Samples >= _period; }
        }

        protected override decimal ComputeNextValue(DataPoint<decimal> previousValue, DataPoint<decimal> input)
        {
            // our first data point just return identity
            if (Samples == 1)
            {
                return input.Data;
            }
            return input.Data * _k + previousValue.Data * (1 - _k);
        }
    }
}

namespace QuantConnect.Indicators
{
    /// <summary>
    /// Represents a forward-only in time time series filter
    /// </summary>
    public interface IIndicator
    {
        /// <summary>
        ///     Gets a name for this indicator
        /// </summary>
        string Name { get; }

        /// <summary>
        ///     Gets a flag indicating when this indicator is ready and fully initialized
        /// </summary>
        bool IsReady { get; }

        /// <summary>
        ///     Gets the current state of this indicator. If the state has not been updated
        ///     then the time on the value will equal DateTime.MinValue.
        /// </summary>
        DataPoint<decimal> Value { get; }

        /// <summary>
        ///     Gets the number of samples processed by this indicator
        /// </summary>
        int Samples { get; }

        /// <summary>
        ///     Updates the state of this indicator with the given value and returns true
        ///     if this indicator is ready, false otherwise
        /// </summary>
        /// <param name="input">The value to use to update this indicator</param>
        /// <returns>True if this indicator is ready, false otherwise</returns>
        bool Update(DataPoint<decimal> input);

        /// <summary>
        ///     Resets this indicator to its initial state
        /// </summary>
        void Reset();
    }
}

using System;

namespace QuantConnect.Indicators
{
    /// <summary>
    /// Represents the basic functionality of conforming to the IIndicator interface invariants
    /// </summary>
    public abstract class IndicatorBase : IIndicator
    {
        // the most recent time data was given to this indicator
        private DateTime _previous;

        protected IndicatorBase(string name)
        {
            Name = name;
        }

        /// <summary>
        ///     Gets a name for this indicator
        /// </summary>
        public string Name { get; private set; }

        /// <summary>
        ///     Gets a flag indicating when this indicator is ready and fully initialized
        /// </summary>
        public abstract bool IsReady { get; }

        /// <summary>
        ///     Gets the current state of this indicator. If the state has not been updated
        ///     then the time on the value will equal DateTime.MinValue.
        /// </summary>
        public DataPoint<decimal> Value { get; private set; }

        /// <summary>
        ///     Gets the number of samples processed by this indicator
        /// </summary>
        public int Samples { get; private set; }

        /// <summary>
        ///     Updates the state of this indicator with the given value and returns true
        ///     if this indicator is ready, false otherwise
        /// </summary>
        /// <param name="input">The value to use to update this indicator</param>
        /// <returns>True if this indicator is ready, false otherwise</returns>
        public bool Update(DataPoint<decimal> input)
        {
            if (input.Time < _previous)
            {
                // if we receive a time in the past, throw
                throw new ArgumentException("This is a forward only indicator.");
            }
            if (input.Time != _previous)
            {
                // if the time isn't the current time, then it must be future,
                // compute a new value and update our previous time
                Samples++;
                _previous = input.Time;
                decimal nextValue = ComputeNextValue(Value, input);
                Value = input.WithNewData(nextValue);
            }
            // this is when _previous==time and we've already computed
            // so do nothing and return IsReady
            // else { } 
            return IsReady;
        }

        /// <summary>
        ///     Resets this indicator to its initial state
        /// </summary>
        public virtual void Reset()
        {
            Value = new DataPoint<decimal>(DateTime.MinValue, default(decimal));
        }

        /// <summary>
        ///     Computes the next value of this indicator from the given state
        /// </summary>
        /// <param name="previousValue">The most recent value of this indicator</param>
        /// <param name="input">The input given to the indicator</param>
        /// <returns>A new value for this indicator</returns>
        protected abstract decimal ComputeNextValue(DataPoint<decimal> previousValue, DataPoint<decimal> input);
    }
}

namespace QuantConnect.Indicators
{
    public static class IndicatorExtensions
    {
        /// <summary>
        /// Wraps an indicator with another indicator allowing composability
        /// </summary>
        /// <param name="wrapper">The exterior indicator</param>
        /// <param name="root">The interior indicator</param>
        /// <param name="name">An optional name for this indicator, if null, a name like wrapper.Name{root.Name} will be specified</param>
        /// <returns></returns>
        public static WrappedIndicator Of(this IIndicator wrapper, IIndicator root, string name = null)
        {
            name = name ?? string.Format("{0}{{{1}}}", wrapper.Name, root.Name);
            return new WrappedIndicator(name, wrapper, root);
        }
    }
}

using System.Collections.ObjectModel;

namespace QuantConnect.Indicators
{
    /// <summary>
    /// Manages indicators and their plotting
    /// </summary>
    public class IndicatorManager : KeyedCollection<string, IIndicator>
    {
        protected override string GetKeyForItem(IIndicator item)
        {
            return item.Name;
        }

        /// <summary>
        /// Updates each item in this collection with the specified data
        /// </summary>
        /// <param name="input"></param>
        public void Update(DataPoint<decimal> input)
        {
            foreach (var indicator in Items)
            {
                indicator.Update(input);
            }
        }

        public void Plot(QCAlgorithm algorithm)
        {
            foreach (var indicator in Items)
            {
                algorithm.Plot("Indicators", indicator.Name, indicator.Value.Data);
            }
        }
    }
}

namespace QuantConnect.Indicators
{
    public class MovingAverageConverganceDivergance : IndicatorBase
    {
        public readonly IIndicator Fast;
        public readonly IIndicator Slow;

        public MovingAverageConverganceDivergance(string name, int fastPeriod, int slowPeriod, MovingAverageType type = MovingAverageType.Simple) 
            : base(name)
        {
            switch (type)
            {
                case MovingAverageType.Simple:
                    Fast = new SimpleMovingAverage(string.Format("[{0}]_MACD_SMA{1}", name, fastPeriod), fastPeriod);
                    Slow = new SimpleMovingAverage(string.Format("[{0}]_MACD_SMA{1}", name, slowPeriod), slowPeriod);
                    break;
                case MovingAverageType.Exponential:
                    Fast = new ExponentialMovingAverage(string.Format("[{0}]_MACD_EMA{1}", name, fastPeriod), fastPeriod);
                    Slow = new ExponentialMovingAverage(string.Format("[{0}]_MACD_EMA{1}", name, slowPeriod), slowPeriod);
                    break;
            }
        }

        public override bool IsReady
        {
            // check both just in case someone wants them flipped, since we don't enforce
            // that one is actually 'slower' than the other
            get { return Slow.IsReady && Fast.IsReady; }
        }

        protected override decimal ComputeNextValue(DataPoint<decimal> previousValue, DataPoint<decimal> input)
        {
            Fast.Update(input);
            Slow.Update(input);
            return Fast.Value.Data - Slow.Value.Data;
        }
    }
}

namespace QuantConnect.Indicators
{
    public enum MovingAverageType
    {
        Simple,
        Exponential
    }
}

namespace QuantConnect.Indicators
{
    public class SimpleMovingAverage : WindowIndicator
    {
        private decimal _sum;
        public SimpleMovingAverage(string name, int period) : base(name, period)
        {
        }

        protected override decimal ComputeNextValue(IReadOnlyWindow<DataPoint<decimal>> window, DataPoint<decimal> previousValue, DataPoint<decimal> input)
        {
            _sum += input.Data;
            if (window.Samples > window.Count) // this is different that window.IsReady by 1 sample
            {
                _sum -= window.MostRecentlyRemoved.Data;
            }
            return _sum/window.Count;
        }
    }
}

namespace QuantConnect.Indicators
{
    /// <summary>
    ///     Represents an indicator that acts on a rolling window of data
    /// </summary>
    public abstract class WindowIndicator : IndicatorBase
    {
        // a window of data over a certain look back period
        private readonly RollingWindow<DataPoint<decimal>> _window;

        /// <summary>
        ///     Initializes a new instance of the WindowIndicator class
        /// </summary>
        /// <param name="name">The name of this indicator</param>
        /// <param name="period">The number of data points to hold in the window</param>
        protected WindowIndicator(string name, int period)
            : base(name)
        {
            _window = new RollingWindow<DataPoint<decimal>>(period);
        }

        /// <summary>
        ///     Gets a flag indicating when this indicator is ready and fully initialized
        /// </summary>
        public override bool IsReady
        {
            get { return _window.IsReady; }
        }

        /// <summary>
        ///     Computes the next value of this indicator from the given state
        /// </summary>
        /// <param name="previousValue">The most recent value of this indicator</param>
        /// <param name="input">The input given to the indicator</param>
        /// <returns>A new value for this indicator</returns>
        protected override decimal ComputeNextValue(DataPoint<decimal> previousValue, DataPoint<decimal> input)
        {
            _window.Add(input);
            return ComputeNextValue(_window, previousValue, input);
        }

        /// <summary>
        ///     Resets this indicator to its initial state
        /// </summary>
        public override void Reset()
        {
            base.Reset();
            _window.Clear();
        }

        /// <summary>
        ///     Computes the next value for this indicator from the given state.
        /// </summary>
        /// <param name="window">The window of data held in this indicator</param>
        /// <param name="previousValue">The previous value of this indicator</param>
        /// <param name="input">The input value to this indicator on this time step</param>
        /// <returns>A new value for this indicator</returns>
        protected abstract decimal ComputeNextValue(IReadOnlyWindow<DataPoint<decimal>> window, DataPoint<decimal> previousValue, DataPoint<decimal> input);
    }
}

namespace QuantConnect.Indicators
{
    /// <summary>
    /// Provides a means of piping data from one indicator to another, allowing composability
    /// </summary>
    public class WrappedIndicator : IIndicator
    {
        /// <summary>
        ///     Creates a new wrapped indicator that acts as wrapper { root }
        ///     So, if we have the root= Momentum and wrapper = SMA, then its like
        ///     having SMA of Momentum
        /// </summary>
        /// <param name="name">The name of this indicator</param>
        /// <param name="wrapper">The wrapper, or external indicator</param>
        /// <param name="root">The root, or interior indicator</param>
        public WrappedIndicator(string name, IIndicator wrapper, IIndicator root)
        {
            Wrapper = wrapper;
            Root = root;
            Name = name;
        }

        /// <summary>
        ///     Gets the root, or interior indicator.
        /// </summary>
        public IIndicator Root { get; private set; }

        /// <summary>
        ///     Gets the wrapper, or exterior indicator
        /// </summary>
        public IIndicator Wrapper { get; private set; }

        /// <summary>
        ///     Gets a name for this indicator
        /// </summary>
        public string Name { get; private set; }

        /// <summary>
        ///     Gets a flag indicating when this indicator is ready and fully initialized
        /// </summary>
        public bool IsReady
        {
            get { return Wrapper.IsReady; }
        }

        /// <summary>
        ///     Gets the current state of this indicator. If the state has not been updated
        ///     then the time on the value will equal DateTime.MinValue.
        /// </summary>
        public DataPoint<decimal> Value
        {
            get { return Wrapper.Value; }
        }

        /// <summary>
        ///     Gets the number of samples processed by this indicator
        /// </summary>
        public int Samples { get; private set; }

        /// <summary>
        ///     Updates the state of this indicator with the given value and returns true
        ///     if this indicator is ready, false otherwise
        /// </summary>
        /// <param name="input">The value to use to update this indicator</param>
        /// <returns>True if this indicator is ready, false otherwise</returns>
        public bool Update(DataPoint<decimal> input)
        {
            Samples++;
            Root.Update(input);
            if (Root.IsReady)
            {
                // we purposefully don't start sending data to the wrapper until the root is ready, since in reality
                // we need to wait until the root is ready before we can start 'readying' the wrapper
                Wrapper.Update(Root.Value);
            }
            return IsReady;
        }

        /// <summary>
        ///     Resets this indicator to its initial state
        /// </summary>
        public void Reset()
        {
            Root.Reset();
            Wrapper.Reset();
        }
    }
}

using System;

namespace QuantConnect
{
    public static class DataPoint
    {
        public static DataPoint<T> Create<T>(DateTime time, T value)
        {
            // this method provides some type inference convience so we need not specify the type parameter
            return new DataPoint<T>(time, value);
        }
    }

    /// <summary>
    /// Represents a piece of data at a specific time
    /// </summary>
    /// <typeparam name="T">The type of data</typeparam>
    public struct DataPoint<T>
    {
        public readonly T Data;
        public readonly DateTime Time;

        public DataPoint(DateTime time, T data) 
            : this()
        {
            Time = time;
            Data = data;
        }

        public DataPoint<T> WithNewData(T newData)
        {
            return new DataPoint<T>(Time, newData);
        }
    }
}

using System;
using System.Collections;
using System.Collections.Generic;

namespace QuantConnect
{
    /// <summary>
    ///     Interface type used to pass windows around without worry of external modification
    /// </summary>
    /// <typeparam name="T">The type of data in the window</typeparam>
    public interface IReadOnlyWindow<out T> : IEnumerable<T>
    {
        /// <summary>
        ///     Gets the size of this window
        /// </summary>
        int Size { get; }

        /// <summary>
        ///     Gets the current number of elements in this window
        /// </summary>
        int Count { get; }

        /// <summary>
        /// Gets the number of samples that have been added to this window over its lifetime
        /// </summary>
        decimal Samples { get; }
        
        /// <summary>
        ///     Indexes into this window, where index 0 is the most recently
        ///     entered value
        /// </summary>
        /// <param name="i">the index, i</param>
        /// <returns>the ith most recent entry</returns>
        T this[int i] { get; }

        /// <summary>
        ///     Gets a value indicating whether or not this window is ready, i.e,
        ///     it has been filled to its capacity, this is when the Size==Count
        /// </summary>
        bool IsReady { get; }

        /// <summary>
        /// Gets the most recently removed item from the window. This is the
        /// piece of data that just 'fell off' as a result of the most recent
        /// add. If no items have been removed, this will throw an exception.
        /// </summary>
        T MostRecentlyRemoved { get; }
    }

    /// <summary>
    ///     This is a window that allows for list access semantics,
    ///     where this[0] refers to the most recent item in the
    ///     window and this[Count-1] refers to the last item in the window
    /// </summary>
    /// <typeparam name="T">The type of data in the window</typeparam>
    public class RollingWindow<T> : IReadOnlyWindow<T>
    {
        private int _tail;
        private decimal _samples;
        private T _mostRecentlyRemoved;
        private readonly List<T> _list;
        private readonly object _lock = new object();

        /// <summary>
        ///     Gets the size of this window
        /// </summary>
        public int Size
        {
            get { return _list.Capacity; }
        }

        /// <summary>
        ///     Gets the current number of elements in this window
        /// </summary>
        public int Count
        {
            get { return _list.Count; }
        }

        /// <summary>
        /// Gets the number of samples that have been added to this window over its lifetime
        /// </summary>
        public decimal Samples
        {
            get { return _samples; }
        }

        public T MostRecentlyRemoved
        {
            get
            {
                if (!IsReady)
                {
                    throw new InvalidOperationException("No items have been removed yet!");
                }
                return _mostRecentlyRemoved;
            }
        }

        public RollingWindow(int size)
        {
            _list = new List<T>(size);
        }

        /// <summary>
        ///     Indexes into this window, where index 0 is the most recently
        ///     entered value
        /// </summary>
        /// <param name="i">the index, i</param>
        /// <returns>the ith most recent entry</returns>
        public T this[int i]
        {
            get { return _list[(Count + _tail - i - 1)%Count]; }
            set { _list[Count + _tail - i - 1] = value; }
        }

        /// <summary>
        ///     Gets a value indicating whether or not this window is ready, i.e,
        ///     it has been filled to its capacity, this is when the Size==Count
        /// </summary>
        public bool IsReady
        {
            get { return Size == Count; }
        }

        /// <summary>
        ///     Adds an item to this window and shifts all other elements
        /// </summary>
        /// <param name="item">The item to be added</param>
        public void Add(T item)
        {
            lock (_lock)
            {
                _samples++;
                if (Size == Count)
                {
                    // keep track of what's the last element
                    // so we can reindex on this[ int ]
                    _mostRecentlyRemoved = _list[_tail];
                    _list[_tail] = item;
                    _tail = (_tail + 1)%Size;
                }
                else
                {
                    _list.Add(item);
                }
            }
        }

        /// <summary>
        ///     Clears this window of all data
        /// </summary>
        public void Clear()
        {
            lock (_lock)
            {
                _list.Clear();
            }
        }

        public IEnumerator<T> GetEnumerator()
        {
            // we make a copy on purpose so the enumerator isn't tied 
            // to a mutable object, well it is still mutable but out of scope
            var temp = new List<T>(Count);
            lock (_lock)
            {
                for (int i = 0; i < Count; i++)
                {
                    temp.Add(this[i]);
                }
            }
            return temp.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }
}