#include <iostream>
#include <fstream>
#include <stdexcept>
#include <iomanip>
#include <string>
#include <opencv2/objdetect.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/video.hpp>
#include <opencv2/videoio.hpp>

using namespace cv;
using namespace std;
typedef vector<vector<float> > HogData;


const char* keys =
{
  "{ help h      |                     | print help message }"
  "{ directory d |                     | images directory}"
};

static void computeHOG(HOGDescriptor &hog, Mat &img, HogData &hogdata, int value)
{
  Mat gray;
  cvtColor(img, gray, COLOR_BGR2GRAY );
  resize(gray, gray, Size(80, 80));
  hog.winSize = Size(80,80);
  vector<Point> positions;
  vector<float> descriptor;
  hog.compute(gray,descriptor,cv::Size(8,8),cv::Size(0,0),positions);
  descriptor.insert(descriptor.begin(),value);
  hogdata.push_back(descriptor);
}

int main(int argc, char** argv)
{
  CommandLineParser parser(argc, argv, keys);
  HogData hogdata;

  HOGDescriptor hog;

  string pattern_glob = "";
  if (parser.has("directory"))
  {
      pattern_glob = parser.get<string>("directory");
  }

  if (!pattern_glob.empty())
  {
      //Read from input image files
      vector<String> filenames;
      //Read from video file
      Mat frame;
      int value;

      if (!pattern_glob.empty())
      {
          String folder(pattern_glob);
          glob(folder, filenames);
      }

      vector<String>::const_iterator it_image = filenames.begin();

      for (; it_image != filenames.end(); ++it_image)
      {
          cout << "\nRead: " << *it_image << endl;
          value = ((string) *it_image).at(((((string) *it_image).find_first_of("/")) + 1)) - '0';
          cout << "Real value : " << value << endl;
          frame = imread(*it_image);

          if (!frame.empty())
          {
              computeHOG(hog, frame, hogdata, value);
          }

      }
  }
  ofstream myfile ("resultHOGElliot.data", ofstream::trunc);
  cout << hogdata.at(0).size() << endl;
  if (myfile.is_open())
    {
      for (vector<float> vf : hogdata) {
          for (float f : vf) {
              myfile << setprecision(2) << f << ",";
          }
          myfile <<'\b';  //Cursor moves 1 position backwards
          myfile << endl;
      }
      myfile.close();
    }

  return 0;
}