/*
 PLSI: Probabilistic Latent Semantic Indexing Tool

 $Id: matrix.cpp,v 1.6 2003/03/27 08:23:57 taku-ku Exp $;

 Copyright (C) 2002 Taku Kudo  All rights reserved.
 This is free software with ABSOLUTELY NO WARRANTY.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 02111-1307, USA
*/

#include "matrix.h"
#include "common.h"
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdexcept>
#include <fstream>
#include <strstream>

namespace PLSI
{
  feature_node *str2feature_node (const char *s)
  {
    try {
      unsigned int elmnum = 0;
      unsigned int len = strlen (s);

      for (unsigned int i = 0; i < len; i++) if (s[i] == ':') elmnum++;

      feature_node *_x = new feature_node[elmnum + 1];
      unsigned int j = 0;
      for (unsigned int i = 0; j < elmnum && i < len;) {
	while (i < len && isspace (s[i])) i++;
	_x[j].index = atoi (s + i);
	while (i + 1 < len && s[i] != ':') i++;
	_x[j].value = atof (s + i + 1);
	j++;
	while (i < len && !isspace (s[i])) i++;
      }

      // dumy index
      _x[j].index = -1;
      _x[j].value = 0;
      return _x;
    }

    catch (std::exception &e) {
      throw std::runtime_error (e.what ());
    }
  }

  void Matrix::clear ()
  {
    row = col = 0;
    for (unsigned int i = 0; i < row; i++) delete [] matrix[i];
    delete [] matrix;
    matrix = 0;
  }

  bool Matrix::read (const char *filename) 
  {
    try {
      clear ();
      std::ifstream is (filename);
      if (! is) throw std::runtime_error ("cannot open ");

      std::string line;
      unsigned int i = 0;
      while (std::getline (is, line)) {
	if (line.empty () || line[0] == '#') continue;
	feature_node *fn = str2feature_node (line.c_str());
	for (unsigned int j = 0; fn[j].index != -1; j++)
	  col = _max (col, (unsigned int)fn[j].index + 1);
	matrix = _append (matrix, i, fn, (feature_node *)0);
	i++;
      }

      row = i;

      unsigned int *tmp = new unsigned int [col];
      for (unsigned int i = 0; i < row; i++) {
	feature_node *fn = this->getFeatureNode(i);
	for (unsigned int j = 0; fn[j].index != -1; j++) {
	  tmp[fn[j].index]++;
	}
      }

      for (unsigned int i = 0; i < col; i++) {
	if (tmp[i] == 0) {
	  delete [] tmp;
	  std::strstream ss;
	  ss << "empty feature index (" << i << ") is found " << '\0';
	  throw std::runtime_error (ss.str());
	}
      }

      delete [] tmp;
      is.close();
      return true;
    }

    catch (std::exception &e) {
      clear ();
      std::strstream ss;
      ss << "Matrix::read(): " << e.what() << " [" << filename << "]" << '\0';
      throw std::runtime_error (ss.str());
      return false;
    }
  }
}