/*    This file is part of the Gudhi Library. The Gudhi library
 *    (Geometric Understanding in Higher Dimensions) is a generic C++
 *    library for computational topology.
 *
 *    Author(s):       Pawel Dlotko
 *
 *    Copyright (C) 2015  INRIA (France)
 *
 *    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 3 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, see <http://www.gnu.org/licenses/>.
 */



#include <gudhi/reader_utils.h>
#include <gudhi/Persistence_intervals.h>

#include <iostream>



using namespace Gudhi;
using namespace Gudhi::Persistence_representations;


int main( int argc , char** argv )
{
	std::cout << "This program compute a plot of persistence Betti numbers. The input parameter is a file with persistence intervals. \n";
	std::cout << "The second optional parameter of a program is the dimension of the persistence that is to be used. If your file contains only birth-death pairs, you can skip this parameter\n";
	if ( argc < 2 )
	{
		std::cout << "To run this program, please provide the name of a file with persistence diagram and number of dominant intervals you would like to get \n";
		return 1;
	}
	unsigned dimension = std::numeric_limits<unsigned>::max();
	int dim = -1;
	if ( argc > 2 )
	{
		dim = atoi( argv[2] );
	} 
	if ( dim >= 0 )
	{
		dimension = (unsigned)dim;
	}
	
	
	std::stringstream gnuplot_script;
	gnuplot_script << argv[1] << "_Gnuplot_script";
	std::ofstream out;
	out.open( gnuplot_script.str().c_str() );
	
	Persistence_intervals p( argv[1] , dimension );
	std::vector< std::pair< double , size_t > > pbns = p.compute_persistent_betti_numbers();	
	
	//set up the ranges so that we see the image well.
	double xRangeBegin = pbns[0].first;
	double xRangeEnd = pbns[ pbns.size()-1 ].first;
	double yRangeBegin = 0;
	double yRangeEnd = 0;
	for ( size_t i = 0 ; i != pbns.size() ; ++i )
	{
		if ( pbns[i].second > yRangeEnd )yRangeEnd = pbns[i].second;
	}
	xRangeBegin -= (xRangeEnd -xRangeBegin)/100.0;
	xRangeEnd += (xRangeEnd -xRangeBegin)/100.0;
	yRangeEnd += yRangeEnd/100;
	
	
	out << "set xrange [" << xRangeBegin << " : " << xRangeEnd << "]" << std::endl;
    out << "set yrange [" << yRangeBegin << " : " << yRangeEnd << "]" << std::endl;	
	out << "plot '-' using 1:2 notitle with lp " << std::endl;    
	double previous_y = 0;
	for ( size_t i = 0 ; i != pbns.size() ; ++i )
	{
		out << pbns[i].first << " " << previous_y << std::endl;
		out << pbns[i].first << " " << pbns[i].second << std::endl;
		previous_y = pbns[i].second;
	}		
	out << std::endl;
	out.close();
	
	std::cout << "To visualize, open gnuplot and type: load \'" << gnuplot_script.str().c_str() << "\'" << std::endl;
			
	return 0;
}