#include <fstream>
#include <string>
#include <cerrno>
#include <iostream>
#include <sstream>
#include <limits>

std::string get_file_contents(const char *filename)
{
  std::ifstream in(filename, std::ios::in | std::ios::binary);
  if (in)
  {
    std::string contents;
    in.seekg(0, std::ios::end);
    contents.resize(in.tellg());
    in.seekg(0, std::ios::beg);
    in.read(&contents[0], contents.size());
    in.close();
    return(contents);
  }
  throw(errno);
}

void parse_csvs(const std::string& csvs)
{
    std::stringstream strm( csvs );
    // discard the first line, which is column headers;
    std::string line;
    if (!getline( strm, line ))
    {
        std::cout << "Error parsing file." << std::endl;
        return;
    }
    unsigned frame_count = 0;
    double min_fps = std::numeric_limits<double>::max();
    double max_fps = 0.0;
    double fps_accum = 0.0;
    while ( getline( strm, line ) )
    {
        ++frame_count;
        double fps = 1000.0 / atof( line.c_str() );
        fps_accum += fps;
        if ( fps < min_fps )
            min_fps = fps;
        if ( fps > max_fps )
            max_fps = fps;
    }
    if ( frame_count == 0 )
    {
        std::cout << "Error: no frames read." << std::endl;
        return;
    }
    std::cout << "\n" << "Frame Count: " << frame_count << "\n";
    std::cout << "Minimum FPS: " << min_fps << "\n";
    std::cout << "Maximum FPS: " << max_fps << "\n";
    std::cout << "Average FPS: " << fps_accum / frame_count << std::endl;

    
}

int main( int argc, char* argv[] )
{
    // usage: bf4parse <filename>
    // check number of arguments.should be 2 (progname filename)
    if ( argc != 2 )
    {
        std::cout << "Usage: bf4parse <filename>" << std::endl;
        return 1;
    }
    std::string csvs;
    try {
        csvs = get_file_contents( argv[1] );
    }
    catch( ... ) {
        std::cout << "Error reading file. errno: " << errno << std::endl;
    }

    parse_csvs( csvs );
    return 0;
}