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

namespace QuantConnect {

    /// <summary>
    ///  vvvvvv UPDATE TO YOUR CORE ALGORITHM CLASS NAME HERE: vvvv   "QCUMartingalePositionSizing" ==> "MyAlgorithm"
    /// </summary>
    public partial class CustomDataSourceAlgorithm : QCAlgorithm
    {

        public void CustomSetHoldings(string symbol, decimal percentage, bool liquidateExistingHoldings = false) {
            
            decimal cash = Portfolio.Cash;
            decimal currentHoldingQuantity = Portfolio[symbol].Quantity;
            
            //Range check values:
            if (percentage > 1) percentage = 1;
            if (percentage < -1) percentage = -1;
            
            //If they triggered a liquidate
            if (liquidateExistingHoldings) {
                foreach (string holdingSymbol in Portfolio.Keys) {
                    if (holdingSymbol != symbol) {
                        //Go through all existing holdings, market order the inverse quantity
                        Order(holdingSymbol,  -Portfolio[holdingSymbol].Quantity);
                    }
                }
            }
            
            //Now rebalance the symbol requested:
            decimal targetHoldingQuantity = Math.Floor((percentage * Portfolio.TotalPortfolioValue) / Securities[symbol].Price);
            
            decimal netHoldingQuantity = targetHoldingQuantity - currentHoldingQuantity;
            if (Math.Abs(netHoldingQuantity) > 0) {
                Order(symbol, (int)netHoldingQuantity);
            }
            
            return;
        }
    }
}

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

namespace QuantConnect {

    /// <summary>
    /// Custom Data Type: USD/INR data from Quandl
    /// http://www.quandl.com/BNP/USDINR-Currency-Exchange-Rate-USD-vs-INR
    /// </summary>
    public class DollarRupee : BaseData
    {
        public decimal Open = 0;
        public decimal High = 0;
        public decimal Low = 0;
        public decimal Close = 0;

        public DollarRupee()
        {
            this.Symbol = "USDINR";
        }
        
        public override string GetSource(SubscriptionDataConfig config, DateTime date, DataFeedEndpoint datafeed)
        {
            return "https://www.dropbox.com/s/w71phighrsh8uu0/USDINR.csv?dl=1";
        }
        
        public override BaseData Reader(SubscriptionDataConfig config, string line, DateTime date, DataFeedEndpoint datafeed)
        {
            //New USDINR object
            DollarRupee currency = new DollarRupee();

            try
            {
                string[] data = line.Split(',');
                //Dates must be in the format YYYY-MM-DD. If your data source does not have this format, you must use
                //DateTime.ParseExact() and explicit declare the format your data source has.
                currency.Time = DateTime.Parse(data[0]);
                currency.Close = Convert.ToDecimal(data[1]);
                currency.Symbol = "USDINR";
                currency.Value = currency.Close;
            }
            catch {
                
            }

            return currency;
        }
    }
}

using System;
using System.Collections;
using System.Collections.Generic;
using QuantConnect.Securities;
using QuantConnect.Models;
using System.Linq;
using MathNet.Numerics.Statistics;

namespace QuantConnect
{
    /// <summary>
    /// 3.0 CUSTOM DATA SOURCE: USE YOUR OWN MARKET DATA (OPTIONS, FOREX, FUTURES, DERIVATIVES etc).
    /// 
    /// The new QuantConnect Lean Backtesting Engine is incredibly flexible and allows you to define your own data source. 
    /// 
    /// This includes any data source which has a TIME and VALUE. These are the *only* requirements. To demonstrate this we're loading
    /// in "Nifty" data. This by itself isn't special, the cool part is next:
    /// 
    /// We load the "Nifty" data as a tradable security we're calling "NIFTY".
    /// 
    /// </summary>
    public partial class CustomDataSourceAlgorithm : QCAlgorithm
    {
        //Create variables for analyzing Nifty
        CorrelationPair today = new CorrelationPair();
        List<CorrelationPair> prices = new List<CorrelationPair>();
        int minimumCorrelationHistory = 11;
        
        public override void Initialize()
        {
            SetStartDate(1998, 1, 1);
            SetEndDate(2014, 7, 25);

            //Set the cash for the strategy:
            SetCash(100000);

            //Define the symbol and "type" of our generic data:
            AddData<DollarRupee>("USDINR");
            AddData<Nifty>("NIFTY");
        }
        

        public void OnData(DollarRupee data)
        {
            today = new CorrelationPair(data.Time);
            today.Add("USDINR", data.Close);
        }
        
        public void OnData(Nifty data)
        {
            try
            {
                today.Add("NIFTY", data.Close);
                if (today.Date == data.Time)
                {
                    prices.Add(today);
                    
                    if(prices.Count > minimumCorrelationHistory)
                    {
                        prices.RemoveAt(0);    
                    }
                }
                
                if (prices.Count < 2)
                {
                    return;
                }
                
                string maxAsset = "";
                double maxGain = -9999;
                
                foreach(string i in today.Prices.Keys)
                {
                    double last = (from pair in prices select pair.Prices[i]).Last();
                    double first = (from pair in prices select pair.Prices[i]).First();
                    double gain = (last - first) / first;
                    if (gain > maxGain)
                    {
                        maxAsset = i;
                        maxGain = gain;
                    }
                }
                
                //Strategy
                if (maxAsset != "") 
                {
                    CustomSetHoldings(maxAsset, 1, true);
                }
            }
            catch(Exception err)
            {
                Debug( "Error: " + err.Message );
            }
        }
       
        //Plot Nifty
        public override void OnEndOfDay()
        {
            if (today.Prices.ContainsKey("NIFTY")) 
            {
                if(today.Prices["NIFTY"] != 0 && today.Date.DayOfWeek == DayOfWeek.Wednesday)
                {
                    Plot("NIFTY", today.Prices["NIFTY"]);
                }
                if(today.Prices["USDINR"] != 0 && today.Date.DayOfWeek == DayOfWeek.Wednesday)
                {
                    Plot("USDINR", today.Prices["USDINR"]);
                }
            }
        }
    }
}

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

namespace QuantConnect {    

    /// <summary>
    /// Custom Data Type: CNX Nifty data from NSE
    /// http://www.nseindia.com/
    /// </summary>
    public class Nifty : BaseData
    {
        public decimal Open = 0;
        public decimal High = 0;
        public decimal Low = 0;
        public decimal Close = 0;

        public Nifty()
        {
            this.Symbol = "NIFTY";
        }
        
        public override string GetSource(SubscriptionDataConfig config, DateTime date, DataFeedEndpoint datafeed)
        {
            return "https://www.dropbox.com/s/9dzb6spi38rweit/CNXNIFTY.csv?dl=1";
        }
        
        public override BaseData Reader(SubscriptionDataConfig config, string line, DateTime date, DataFeedEndpoint datafeed)
        {
            //New Nifty object
            Nifty index = new Nifty();

            try
            {
                //Example File Format:
                //Date,       Open       High        Low       Close     Volume      Turnover
                //2011-09-13  7792.9    7799.9     7722.65    7748.7    116534670    6107.78
                string[] data = line.Split(',');
                //Dates must be in the format YYYY-MM-DD. If your data source does not have this format, you must use
                //DateTime.ParseExact() and explicit declare the format your data source has.
                index.Time = DateTime.Parse(data[0]);
                index.Open = Convert.ToDecimal(data[1]);
                index.High = Convert.ToDecimal(data[2]);
                index.Low = Convert.ToDecimal(data[3]);
                index.Close = Convert.ToDecimal(data[4]);
                index.Symbol = "NIFTY";
                //We need to de
                index.Value = index.Close;
            }
            catch {
                
            }

            return index;
        }
    }
}

using System;
using System.Collections;
using System.Collections.Generic;
using QuantConnect.Securities;
using QuantConnect.Models;
using System.Linq;
using MathNet.Numerics.Statistics;

namespace QuantConnect {

    /// <summary>
    /// Make a list of common dates to hold price data
    /// </summary>
    public class CorrelationPair
    {
        public DateTime Date = new DateTime();
        public Dictionary<string, double> Prices = new Dictionary<string, double>();
        
        public CorrelationPair()
        {
            Prices = new Dictionary<string, double>();
            Date = new DateTime();
        }
        
        public void Add(string symbol, decimal price)
        {
            Prices.Add(symbol, Convert.ToDouble(price));
        }
        
        public CorrelationPair(DateTime date)
        {
            Date = date.Date;
            Prices = new Dictionary<string, double>();
        }

    }
}