#ifndef POINT_FILE_READER_HH
#define POINT_FILE_READER_HH

#include <fstream>
#include <sstream>
#include <string>
#include <vector>


struct point_reader{
    
    int num_columns;
    
    point_reader( void )
    : num_columns( 0 )
    { }
    
    bool isFloat( std::string myString )
    {
        std::istringstream iss(myString);
        double f;
        //iss >> std::noskipws >> f; // noskipws considers leading whitespace invalid
        // Check the entire string was consumed and if either failbit or badbit is set
        iss >> f;
        return iss.eof() && !iss.fail();
    }
    
    template< typename real_t >
    void read_points_from_file( std::string fname, float vfac_, std::vector<real_t>& p )
    {
        std::ifstream ifs(fname.c_str());
        if( !ifs )
        {
            printf("region_ellipsoid_plugin::read_points_from_file : Could not open file \'%s\'",fname.c_str());
            throw std::runtime_error("region_ellipsoid_plugin::read_points_from_file : cannot open point file.");
        }
        
        int colcount = 0, colcount1 = 0, row = 0;
        p.clear();
        
        while( ifs )
        {
            std::string s;
            if( !getline(ifs,s) )break;
            std::stringstream ss(s);
            colcount1 = 0;
            while(ss)
            {
                if( !getline(ss,s,' ') ) break;
                if( !isFloat( s ) ) continue;
                p.push_back( strtod(s.c_str(),NULL) );
                
                if( row == 0 )
                    colcount++;
                else
                    colcount1++;
            }
            ++row;
            
            if( row>1 && colcount != colcount1 )
                printf("error on line %d of input file",row);
            
            //std::cout << std::endl;
        }
        
        printf("region point file appears to contain %d columns",colcount);
        
        if( p.size()%3 != 0 && p.size()%6 != 0 )
        {
            printf("Region point file \'%s\' does not contain triplets (%d elems)",fname.c_str(),p.size());
            throw std::runtime_error("region_ellipsoid_plugin::read_points_from_file : file does not contain triplets.");
        }
        
        
        double x0[3] = { p[0],p[1],p[2] }, dx;
        
        if( colcount == 3 )
        {
            // only positions are given
            
            for( size_t i=3; i<p.size(); i+=3 )
            {
                for( size_t j=0; j<3; ++j )
                {
                    dx = p[i+j]-x0[j];
                    if( dx < -0.5 ) dx += 1.0;
                    else if( dx > 0.5 ) dx -= 1.0;
                    p[i+j] = x0[j] + dx;
                }
            }
        }
        else if( colcount == 6 )
        {
            // positions and velocities are given
            
            //... include the velocties to unapply Zeldovich approx.
            
            for( size_t j=3; j<6; ++j )
            {
                dx = (p[j-3]-p[j]/vfac_)-x0[j-3];
                if( dx < -0.5 ) dx += 1.0;
                else if( dx > 0.5 ) dx -= 1.0;
                p[j] = x0[j-3] + dx;
            }
            
            for( size_t i=6; i<p.size(); i+=6 )
            {
                for( size_t j=0; j<3; ++j )
                {
                    dx = p[i+j]-x0[j];
                    if( dx < -0.5 ) dx += 1.0;
                    else if( dx > 0.5 ) dx -= 1.0;
                    p[i+j] = x0[j] + dx;
                }
                
                for( size_t j=3; j<6; ++j )
                {
                    dx = (p[i+j-3]-p[i+j]/vfac_)-x0[j-3];
                    if( dx < -0.5 ) dx += 1.0;
                    else if( dx > 0.5 ) dx -= 1.0;
                    p[i+j] = x0[j-3] + dx;
                }
            }
        }
        else
            printf("Problem interpreting the region point file \'%s\'", fname.c_str() );
        
        num_columns = colcount;
    }
    
    
};


#endif