/**
   \file data_loaders.hpp
   \brief a set of classes used to load data_set from std::istream
   \author Junhua Gu
 */

#ifndef DATA_LOADERS_H
#define DATA_LOADERS_H

#define OPT_HEADER

#include <core/fitter.hpp>
#include <data_sets/default_data_set.hpp>
#include <iostream>
#include <fstream>
#include <sstream>
#include <cmath>

namespace opt_utilities
{
  template <typename Ty, typename Tx>
  class dl_x_y_ye;

  template <typename Ty, typename Tx>
  std::istream& operator>>(std::istream& ifs, dl_x_y_ye<Ty,Tx>& dl);

  template <typename Ty, typename Tx>
  class dl_x_xe_y_ye;

  template <typename Ty, typename Tx>
  std::istream& operator>>(std::istream& ifs, dl_x_xe_y_ye<Ty,Tx>& dl);

  template <typename Ty, typename Tx>
  class dl_x_xu_xl_y_yu_yl;

  template <typename Ty, typename Tx>
  std::istream& operator>> (std::istream& ifs, dl_x_xu_xl_y_yu_yl<Ty,Tx>& dl);


  /**
     loading data from file in format [x] [y] [y error]
   */
  template <typename Ty, typename Tx>
  class dl_x_y_ye
  {
  private:
    default_data_set<Ty,Tx> ds;
  public:
    data_set<Ty,Tx>& get_data_set()
    {
      return ds;
    }

    void load_from(std::istream& ifs)
    {
      Tx x;
      Tx x_err(0);
      Ty y;
      Ty y_err(0);
      std::string line;
      while (std::getline(ifs, line))
        {
          if (line.empty())
            continue;

          /* 3-column data: [x] [y] [y_error] */
          std::istringstream iss(line);
          if ((iss >> x >> y >> y_err))
            {
              data<Ty,Tx> d(x,y,y_err,y_err,x_err,x_err);
              ds.add_data(d);
            }
          else
            {
              /* skip unmatched line */
              std::cerr << "SKIP LINE: " << line << std::endl;
            }
        }
    }

    void load_from(const char* name)
    {
      std::ifstream ifs(name);
      load_from(ifs);
    }
  };


  /**
     stream operator
   */
  template <typename Ty, typename Tx>
  std::istream& operator>>(std::istream& ifs, dl_x_y_ye<Ty,Tx>& dl)
  {
    dl.load_from(ifs);
    return ifs;
  }


  /**
     loading data from stream with file

     [x] [x error] [y] [y error]
   */
  template <typename Ty, typename Tx>
  class dl_x_xe_y_ye
  {
  private:
    default_data_set<Ty,Tx> ds;
  public:
    data_set<Ty,Tx>& get_data_set()
    {
      return ds;
    }

    void load_from(std::istream& ifs)
    {
      Tx x;
      Tx x_err(0);
      Ty y;
      Ty y_err(0);
      std::string line;
      while (std::getline(ifs, line))
        {
          if (line.empty())
            continue;

          /* 4-column data: [x] [x_error] [y] [y_error] */
          std::istringstream iss(line);
          if ((iss >> x >> x_err >> y >> y_err))
            {
              data<Ty,Tx> d(x,y,y_err,y_err,x_err,x_err);
              ds.add_data(d);
            }
          else
            {
              /* skip unmatched line */
              std::cerr << "SKIP LINE: " << line << std::endl;
            }
        }
    }

    void load_from(const char* name)
    {
      std::ifstream ifs(name);
      load_from(ifs);
    }
  };


  /**
     stream operator
   */
  template <typename Ty, typename Tx>
  std::istream& operator>>(std::istream& ifs, dl_x_xe_y_ye<Ty,Tx>& dl)
  {
    dl.load_from(ifs);
    return ifs;
  }


  /**
     loading data from stream with format

     [x] [x lower error] [x upper error] [y] [y lower error] [y upper error]
   */
  template <typename Ty, typename Tx>
  class dl_x_xu_xl_y_yu_yl
  {
  private:
    default_data_set<Ty,Tx> ds;
  public:
    data_set<Ty,Tx>& get_data_set()
    {
      return ds;
    }
    void load_from(std::istream& ifs)
    {
      Tx x;
      Tx xl(0), xu(0);
      Ty y;
      Ty yl(0), yu(0);
      std::string line;
      while (std::getline(ifs, line))
        {
          if (line.empty())
            continue;

          /* 4-column data: [x] [x_error] [y] [y_error] */
          std::istringstream iss(line);
          if ((iss >> x >> xu >> xl >> y >> yu >> yl))
            {
              xu = std::abs(xu);
              xl = std::abs(xl);
              yu = std::abs(yu);
              yl = std::abs(yl);
              data<Ty,Tx> d(x,y,yl,yu,xl,xu);
              ds.add_data(d);
            }
          else
            {
              /* skip unmatched line */
              std::cerr << "SKIP LINE: " << line << std::endl;
            }
        }
    }

    void load_from(const char* name)
    {
      std::ifstream ifs(name);
      load_from(ifs);
    }
  };


  /**
     stream operator
   */
  template <typename Ty, typename Tx>
  std::istream& operator>> (std::istream& ifs, dl_x_xu_xl_y_yu_yl<Ty,Tx>& dl)
  {
    dl.load_from(ifs);
    return ifs;
  }
}

#endif
//EOF