/*********************************************************************
 * *
 * *  file:    AlgInterpolation.h
 * *
 * *  copyright:   Shanghai Baosight Software Co., Ltd.
 * *
 * *  author: zoufuzhou
 * *********************************************************************/
#ifndef _ALG_INTERPOLATION_H
#define _ALG_INTERPOLATION_H

#include <string>
#include <iostream>
#include <vector>

using namespace std;


template <typename T> class AlgorithmInterpolation
{
  public:

    /*
	* Insert linear data between two points
	* percentage: There is a partial proportion between two points
	*/
    static T linear(T start,T end,double percentage)
    {
      T ret;
      ret = (start*(1-percentage)+end*percentage);
      ret = (T)((long)(ret*1000 +0.5))/1000;
      return ret;
    }


	/*
	* Insert linear data proportionally into an array
	* outsize: Output the number of data in the array
	*/
    static void linear(vector<T>& iodata,int outsize)
    {
      interpolation(iodata,outsize,"linear");
    }

	/*
	* Insert neighbor data between two points
	* percentage: There is a partial proportion between two points
	*/
    static T neighbor(T start,T end,double percentage)
    {
      if(percentage<0.5)return start;
      else return end;
    }

	/*
	* Insert neighbor data proportionally into an array
	* outsize: Output the number of data in the array
	*/
    static void neighbor(vector<T>& iodata,int outsize)
    {
      interpolation(iodata,outsize,"neighbor");
    }

  private:

    static void interpolation(vector<T>& iodata,int outlength,const string& mode)
    {
      vector<T> vtemp;
      vector<int> vpos;

      double range = (double)outlength/(iodata.size()-1);
      for(int i=0;i<iodata.size();i++)
      {
        /*if(i == 0)
        {
          vpos.push_back(0);
        }else*/
        {
          vpos.push_back(i*range);
        }
      }

      for(int i=0,pos=0; i<outlength;i++)
      {
		if( i == vpos[pos])
        {
          vtemp.push_back(iodata[pos]);
		  if(pos < vpos.size()-1)
		  {
			pos++;
		  }
          continue;
        }
        else if(i > vpos[pos] && pos < vpos.size()-1 )
        {
		  pos++;
          --i;
          continue;
        }
        else
        {
          double percentage = (double)(i-vpos[pos-1])/(vpos[pos] - vpos[pos-1]);
          if(mode == "neighbor")
          {
            vtemp.push_back(neighbor(iodata[pos-1],iodata[pos],percentage));
          }
          else
          {
            vtemp.push_back(linear(iodata[pos-1],iodata[pos],percentage));
          }
        }
      }
      iodata.clear();
      iodata = vtemp;
      vtemp.clear();
      vpos.clear();
    }
};

#endif