//g++ -std=c++11 `pkg-config --cflags opencv` Fix.cpp -o Saliency `pkg-config --libs opencv`

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"

#include "opencv2/core/cuda.hpp"
#include "opencv2/cudaimgproc.hpp"
#include "opencv2/cudafilters.hpp"
#include "opencv2/cudawarping.hpp"
#include "opencv2/cudaarithm.hpp"

#include <time.h>
#include <cmath>
#include <vector>
#include <iostream>
#include <string>

using namespace cv;
using namespace cv::cuda;
using namespace std;

void Perform_Saliency (Mat& Input, Mat& Saliency);

int main( int argc, char** argv )
{
  // VideoCapture stream(0);

  for(int i = 1; i < argc; i++){
    Mat Input, ObjFound, Saliency;
    vector<Rect> boundRect;
    const string name = argv[i];

    while(true){
      //stream >> Input;
      Input = imread(name);
      imshow("Input", Input);
      int k = waitKey(1);

      if (char(k) == '1'){

    clock_t time = clock();

    Saliency = Mat(Input.size(), Input.type());

    Perform_Saliency (Input, Saliency);

    printf("Time taken: %.2fs\n", (double)(clock() - time) / CLOCKS_PER_SEC);

    imshow("Saliency", Saliency);

      }
      else if (char(k) == '/'){break;}

    }
  }
  return 0;
}

void Perform_Saliency (Mat& Input, Mat& Saliency){

  int Pyramid_Size = 5;

  cv::cvtColor(Input, Input , CV_BGR2GRAY);

  GpuMat compare(Input);

  GaussianBlur(Input, Input, Size(5,5), 0,0);

  GpuMat DownUp(Input);

  //  DownUp = Input.clone();
  DownUp.convertTo(DownUp, CV_32F);
  compare.convertTo(compare, CV_32F);

  for (int i = 0; i < Pyramid_Size; i++){
    pyrDown(DownUp, DownUp, Size(DownUp.cols/2, DownUp.rows/2));
  }

  for (int i = 0; i < Pyramid_Size; i++){
    pyrUp(DownUp, DownUp, Size(DownUp.cols*2, DownUp.rows*2));
    GpuMat a = GpuMat(DownUp.size(), CV_32F, 20.0f);
    cuda::add(a, DownUp, DownUp);
  }

  Mat cpu_DownUp;
  Mat cpu_compare;

  // Problem : For whatever reason sending a GpuMat back to Mat results in an error saying it wasn't implented and that I should try to explicitly cast it...
  // GpuMat compare(Input) is an example where a GpuMat is set as a Mat (stuff processed on cpu).
  // Also, there is no option in GpuMat that I could find that let me do pixel operations.

  DownUp.download(cpu_DownUp);
  compare.download(cpu_compare);

  for (int x = 0; x < DownUp.rows; x++){
    for (int y = 0; y < DownUp.cols; y++){

      float a,b,c;
      a = cpu_DownUp.at<float>(x,y);
      b = cpu_compare.at<float>(x,y);

      if (a < b) {c = 1.0 - a/b;}
      else       {c = 1.0 - b/a;}

      Saliency.at<float>(x,y) = sqrt(c);

      if (x == 100 && y == 100){cout << "a = " << a << " b = " << b << " c = " << c << endl;}

    }
  }

}

/*

 for (int a = 0; a < DownUp.rows; a++){
      for (int b = 0; b < DownUp.cols; b++){
    float hold = DownUp.at<float> (a,b);
    DownUp.at<float>(a,b) = hold + 20;
      }
    }

 */