#include "opencv2/opencv.hpp"
#include "opencv2/videoio.hpp"
#include "opencv2/highgui.hpp"

#include <iostream>

const int FPS = 30;
bool isDiscardData = true;
int countDiscard = 0;
const int DISCARD_DURATION = 5;

int main() 
{ 
  cv::VideoCapture cap;
  cap.open(0);
  if (!cap.isOpened())
  {
    std::cerr << "[ERROR] Unable to open camera!" << std::endl;
    return -2;
  }
  //If Haard Cascade not found: error
  cv::CascadeClassifier faceDetector;
	if( !faceDetector.load("./haarcascade_frontalface_alt.xml"))
	{
	std::cerr << "[ERROR] Unable to load face cascade" << std::endl;
	return -1;
	};
  
  while (true)
	{
		if (isDiscardData)
		{
			countDiscard++;
			if (countDiscard == DISCARD_DURATION*FPS)
				isDiscardData = false;
		}
		else
		{
			// create a matrix to store the image from the cam
			cv::Mat frame;
			// wait for a new frame from camera and store it into 'frame'
			cap.read(frame);
			// check if we succeeded
			if (frame.empty())
			{
				std::cerr << "[ERROR] blank frame grabbed" << std::endl;
				break;
			}
						
			//Draw Rectangle around the face
			std::vector<cv::Rect> faceRectangles;
			faceDetector.detectMultiScale(frame, faceRectangles, 1.1, 3, 0,
			cv::Size(20, 20));
			cv::rectangle(frame, faceRectangles[0], cv::Scalar(0, 0, 255), 1, 1, 0);
			//Reduce to ROI
			cv::Rect foreheadROI;
			foreheadROI = faceRectangles[0];
			foreheadROI.height *= 0.5;
			
			cv::imshow("Your Face PLS", frame);
			if (cv::waitKey(1000.0/FPS) >= 0)
			break;
		}
	}
	return 0;
}