#include<opencv/cv.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <vector>
#include <stdio.h>

using namespace cv;
using namespace std;

int main(int argc, char* argv[])
{
    VideoCapture cap; // open the webcam for reading

    if ( !cap.open(0) )  // if not success, exit program
    {
        cout << "Cannot open webcam" << endl;
        return -1;
    }

    namedWindow("Original Video",CV_WINDOW_AUTOSIZE); //create a window called "Original Video"
    namedWindow("Object Detection",CV_WINDOW_AUTOSIZE); //create a window called "Object detection and changed colour"
//    double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get the width of frames of the video
//    double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get the height of frames of the video

    //Specifying the range of HSV.
    int hueLow = 0; //13
    int saturationLow = 110; // 160
    int valueLow = 110; //160

    int hueHigh = 21; //22
    int saturationHigh = 255;
    int valueHigh = 255;

    while(1)
    {
        Mat frame, convertedBGR;

        bool bSuccess = cap.read(frame); // read a new frame from video

        Mat hsvFrame = Mat::zeros(frame.rows, frame.cols, frame.type());

        cvtColor(frame,hsvFrame, CV_BGR2HSV); // Converting a frame to HSV color space

        if (!bSuccess) //if not success, break loop
        {
            cout << "Cannot read the frame from video file" << endl;
            break;
        }

        Mat onlyOrange = Mat::zeros(frame.rows, frame.cols, frame.type());
        // onlyOrange will have a binary image of 0s and 1s where 1s are orange colour.
        inRange(hsvFrame, Scalar(hueLow, saturationLow,valueLow), Scalar(hueHigh, saturationHigh, valueHigh), onlyOrange);
        cvtColor(onlyOrange, convertedBGR, CV_GRAY2BGR);
        // simply set all the white pixels (which are orange detected pixels) to blue.
        convertedBGR.setTo(Scalar(255, -1000, -1000), onlyOrange);

        std::vector<std::vector<cv::Point>> contours;
        findContours(onlyOrange, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);
        int biggestContourIdx = -1;
        float biggestContourArea = 0;
        Mat drawing = onlyOrange.clone();
        for( int i = 0; i< contours.size(); i++ )
        {
            cv::Scalar color = cv::Scalar(255, 0, 0);
            drawContours( drawing, contours, i, color, 1, 8, NULL, 0, cv::Point() );

            float ctArea= cv::contourArea(contours[i]);
            if(ctArea > biggestContourArea)
            {
                biggestContourArea = ctArea;
                biggestContourIdx = i;
            }
        }

        // if no contour found
        if(biggestContourIdx < 0)
        {
            continue;
        }

        cv::RotatedRect boundingBox = cv::minAreaRect(contours[biggestContourIdx]);
        cv::Point2f corners[4];
        boundingBox.points(corners);
        cv::line(drawing, corners[0], corners[1], cv::Scalar(255,0,0));
        cv::line(drawing, corners[1], corners[2], cv::Scalar(255,0,0));
        cv::line(drawing, corners[2], corners[3], cv::Scalar(255,0,0));
        cv::line(drawing, corners[3], corners[0], cv::Scalar(255,0,0));
        char diameter[100];
        sprintf(diameter, "Diameter: %f", (corners[0].x-corners[1].x));
        putText(drawing, diameter, Point2f(100,100), FONT_HERSHEY_PLAIN, 2, Scalar(255, 0,0), 2);
        cvtColor(drawing, drawing, CV_GRAY2BGR);

        imshow("Original Video", frame); //show the frame in ""Original Video"" window.
        imshow("Object Detection", frame + drawing + convertedBGR); //show the hsv frame in "object detection" window.

        if(waitKey(30) == 27) //wait for 'esc' key press for 30 ms. If 'esc' key is pressed, break loop
        {
            cout << "esc key is pressed by user" << endl;
            break;
        }
    }

    return 0;

}