#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <cmath>

#include "linear_svm.h"

namespace mpt
{

linear_svm::linear_svm( const std::string &w2_path )
{
    load_w2( w2_path );
}

linear_svm::~linear_svm()
{

}

//   h=histogram representation [1xFEATURE_VECTOR_LENGTH]
double
linear_svm::decision( const std::vector<double> &histogram )
{
	double y = 0.0;

    if( feature_vector_length != histogram.size() )
    {
        std::cerr << "Bad histogram length. Should be: " << feature_vector_length << ". Is: " << histogram.size() << std::endl;
        return 0.0;
    }

	for( unsigned int i = 0; i < feature_vector_length; ++i )
    {
		y += histogram[i] * w2[i];
	}

	return y;
}

void
linear_svm::load_w2( const std::string &path )
{
    std::ifstream ifs( path.c_str() );

    w2.clear();

    while( ifs.good() && !ifs.eof() )
    {
        double val;
        if( ifs >> val )
        {
            w2.push_back( val );
        }
    }

    if( w2.size() != feature_vector_length )
    {
        // throw an exception
        std::cerr << "Vector w2 is not the right size: " << w2.size() << std::endl;
    }
}

} // end namespace mpt