package cc.glsn.v15.fincalc;

import java.io.FileInputStream;
import java.io.File;
import java.io.PrintStream;
import java.io.FileOutputStream;
import java.util.Scanner;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.LinkedList;
import java.util.Collection;
import java.util.TreeMap;
import java.util.TreeSet;

public class PerfTrack
{
	public static String ListPath="/home/clash/projects/invest";
	
	public static void main(String Args[]) throws Exception
	{
		new PerfTrack(Args);
	}

	private ValueList investList;
	private ValueList valueList;
	private SimpleDateFormat sdf;

	public PerfTrack(String Args[]) throws Exception
	{
		if (Args.length < 2)
		{
			System.out.println("Options:");
			System.out.println("addinv <acct> <amt> <date>");
			System.out.println("addval <acct> <amt> <date>");
			System.out.println("report <acct>");
			System.out.println();
			System.out.println("All dates in format: YYYYMMDD");
			return;
		}
		
		String acct=Args[1];
		
		String InvestListPath=ListPath +"/" + acct + "/invest-list.txt";
		String ValueListPath=ListPath +"/" + acct + "/value-list.txt";
		
		investList=new ValueList(new Scanner(new FileInputStream(InvestListPath)));
		valueList=new ValueList(new Scanner(new FileInputStream(ValueListPath)));
		sdf=new SimpleDateFormat("yyyyMMdd");

		if (Args[0].equals("addinv"))
		{
			double amt=new Double(Args[2]);
			Date d=sdf.parse(Args[3]);
			System.out.println("Adding investment: $" + amt + " " + sdf.format(d));

			investList.addValue(new ValuePoint(d,amt));
			safeSave(InvestListPath,investList);

		}
		if (Args[0].equals("addval"))
		{
			double amt=new Double(Args[2]);
			Date d=sdf.parse(Args[3]);
			System.out.println("Adding value: $" + amt + " " + sdf.format(d));

			valueList.addValue(new ValuePoint(d,amt));
			safeSave(ValueListPath,valueList);

		}
		if (Args[0].equals("report"))
		{
			ValuePoint start=new ValuePoint(new Date(0),0.0);
			ValuePoint end=null;
			for(ValuePoint p : valueList.getAllPoints())
			{
				if ((end==null) || (p.getTime().compareTo(end.getTime()) > 0))
				{
					end=p;
				}
			}
			
			
			System.out.println("Total effective return per year: "
			        + printRate(getContInterestRate(start,end,investList.getAllPoints())));
			
			TreeMap<Date,Double> rates=getAllRates(investList,valueList);
			for(Date d : rates.keySet())
			{
			    //System.out.println("" + d + ": " + rates.get(d));
			}
			
			Date first=valueList.getOrderedPoints().first().getTime();
			Date last=valueList.getOrderedPoints().last().getTime();
			//TreeMap<Date,String> month=getTaggedDatesForMonthly(first,last);
			printReport(getTaggedDatesForMonthly(first,last),rates);
			
			//System.out.println(month);
			System.out.println("Note: all numbers are in CCI yearly");
		}
	}
	
	
	private void safeSave(String path, ValueList list) throws Exception
	{
		String tmp_path=path +".tmp";
		File real_file=new File(path);
		File tmp_file=new File(tmp_path);

		tmp_file.delete();
		FileOutputStream fos=new FileOutputStream(tmp_path);
		PrintStream out=new PrintStream(fos);
		list.write(out);
		out.close();

		real_file.delete();
		tmp_file.renameTo(real_file);
	}

	private void printReport(TreeMap<Date,String> tags, TreeMap<Date,Double> rates)
	{
	    ArrayList<Date> dates=new ArrayList<Date>();
	    dates.addAll(tags.keySet());
	    
	    for(int i=0; i<dates.size()-1; i++)
	    {
	        double rate=getRateBetween(rates,dates.get(i),dates.get(i+1));
	        System.out.println(tags.get(dates.get(i)) +": " + printRate(rate));
	    }
	    
	}
	
	private TreeMap<Date,Double> getAllRates(ValueList invest_list, ValueList value_list)
	{
	    TreeMap<Date,Double> out=new TreeMap<Date,Double>();
	    
	    ValuePoint start=null;
	    ValuePoint end=new ValuePoint(new Date(0l),0.0);
	    
	    for(ValuePoint p : value_list.getOrderedPoints())
	    {
	        start=end;
	        end=p;
	        
	        Collection<ValuePoint> invest_group=invest_list.getPointsInRange(start.getTime(),end.getTime());
	        double rate=getContInterestRate(start,end,invest_group);
	        out.put(start.getTime(), rate);
	    }
	    
	    
	    return out;
	    
	}
	
	private double getRateBetween(TreeMap<Date,Double> rates, Date start, Date end)
	{
	    Date highest_before=null;
	    for(Date d : rates.keySet())
	    {
	        if (d.compareTo(start) <= 0)
	        {
	            if ((highest_before==null) || (d.compareTo(highest_before) > 0))
	            {
	                highest_before=d;
	            }
	        }
	    }
	    TreeMap<Date,Double> changes=new TreeMap<Date,Double>(rates.subMap(start, end));
	    
	    ValuePoint p_a=null;
	    ValuePoint p_b=new ValuePoint(start,100);
	    double rate=rates.get(highest_before);
	    
	    for(Date d : changes.keySet())
	    {
	        p_a=p_b;
	        LinkedList<ValuePoint> fake_list=new LinkedList<ValuePoint>();
	        fake_list.add(p_a);
	        
	        double amt=getValueForRate(fake_list,rate,d);
	        p_b=new ValuePoint(d,amt);
	        rate=changes.get(d);
	    }
        p_a=p_b;
        LinkedList<ValuePoint> fake_list=new LinkedList<ValuePoint>();
        fake_list.add(p_a);
        
        double amt=getValueForRate(fake_list,rate,end);
        
        double r=getContInterestRate(new ValuePoint(start,100),new ValuePoint(end,amt),new LinkedList<ValuePoint>());
        
        //System.out.println("From: " + start + " To: " + end + " 100->" + amt);
        return r;
	}
	
	
	
	/**
	 * Get the continiously componded interest rate for the given start, end and investment list.
	 * 
	 * rate is per year.
	 * 
	 * @param start
	 * @param end
	 * @param invest_list
	 * @return
	 */
	private double getContInterestRate(ValuePoint start, ValuePoint end, Collection<ValuePoint> invest_list)
	{
		LinkedList<ValuePoint> inputs=new LinkedList<ValuePoint>();
		inputs.add(start);
		inputs.addAll(invest_list);
		return getContInterestRate(inputs,end,-10.0,10.0);


	}

	/**
	 * binary search for correct rate
	 * @param lst
	 * @param end
	 * @param min
	 * @param max
	 * @return
	 */
	private double getContInterestRate(LinkedList<ValuePoint> lst, ValuePoint end,double min, double max)
	{
		double target=end.getValue();
		double mid=(min+max)/2.0;
		if (Math.abs(min-max) < 0.00001) return mid;
		double sum=getValueForRate(lst,mid,end.getTime());

		if (sum < target)
		{
			return getContInterestRate(lst,end,mid,max);
		}
		else
		{
			return getContInterestRate(lst,end,min,mid);
		}

	}

	/*
	 * returns the final sum for the given list of investments (or starting values),
	 * interest rate and end date.
	 * 
	 * Calculated using A=pe^(rt)
	 * 
	 */
	private double getValueForRate(LinkedList<ValuePoint> lst, double rate, Date end_date)
	{
				
		double sum=0.0;
		for(ValuePoint vp : lst)
		{
			Date start_date=vp.getTime();
			double time_delta=end_date.getTime() - start_date.getTime();
			time_delta/=1000.0; //to seconds
			time_delta/=86400.0; //to days
			
			sum += vp.getValue() * Math.exp(rate * time_delta / 356.0);
		}
		return sum;

	}
	
	private TreeMap<Date,String> getTaggedDatesForMonthly(Date first, Date last)
	{
	    TreeMap<Date,String> out=new TreeMap<Date,String>();
	    
	    Calendar c=new GregorianCalendar();
	    
	    c.setTime(first);
	    c.set(Calendar.DAY_OF_MONTH, 1);
	    c.set(Calendar.HOUR_OF_DAY, 0);
	    c.set(Calendar.MINUTE,0);	    
	    c.set(Calendar.SECOND,0);
	    c.set(Calendar.MILLISECOND,0);
	    
	    TreeSet<String> Tags=new TreeSet<String>();
	    
	    {
	        Calendar c2=new GregorianCalendar();
	        c2.setTime(last);
	        c2.add(Calendar.MONTH, 1);
	        last=c2.getTime();
	        
	    }

	    while(c.getTime().before(last))
	    {
	        int m=c.get(Calendar.MONTH)+1;
	        int y=c.get(Calendar.YEAR);
	        
	        String z="";
	        if (m<10) z="0";
	        String tag="" + y + "/" + z + m;
	        
	        if (!Tags.contains(tag))
	        {
	            Tags.add(tag);
	            out.put(c.getTime(), tag);
	            //System.out.println(tag);
	        }
	        
	       
	        c.add(Calendar.MONTH, 1);
	        //System.out.println(c.getTime());
	    }
	    
	    
	    return out;
	    
	    
	}
	
	private String printRate(double rate)
	{
	    DecimalFormat df=new DecimalFormat("0.####");
	    
	    return df.format(rate);
	    
	    
	}

	
}