/* 
 * Copyright (c) 2019 Stephane Lenclud
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 */

#include "cv-point-extractor.h"
#include "preview.h"
#include "tracker-easy.h"

#include "cv/numeric.hpp"
#include "compat/math.hpp"
#include <opencv2/imgproc/types_c.h>

#include <cmath>
#include <algorithm>
#include <cinttypes>
#include <memory>

#include <QDebug>

using namespace numeric_types;

namespace EasyTracker
{

    CvPointExtractor::CvPointExtractor() : s(KModuleName)
    {
    
    }


    void CvPointExtractor::extract_points(const cv::Mat& frame, cv::Mat* aPreview, std::vector<vec2>& aPoints)
    {

        // Contours detection
        std::vector<std::vector<cv::Point> > contours;
        cv::findContours(frame, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);
    
        // Workout which countours are valid points
        for (size_t i = 0; i < contours.size(); i++)
        {
            if (aPreview)
            {
                cv::drawContours(*aPreview, contours, i, CV_RGB(255, 0, 0), 2);
            }
        

            cv::Rect bBox;
            bBox = cv::boundingRect(contours[i]);

            float ratio = (float)bBox.width / (float)bBox.height;
            if (ratio > 1.0f)
                ratio = 1.0f / ratio;

       
            // Searching for a bBox almost square
            float minArea = s.min_point_size*s.min_point_size;
            float maxArea = s.max_point_size*s.max_point_size;
            if (bBox.width >= s.min_point_size
                && bBox.height >= s.min_point_size
                && bBox.width <= s.max_point_size
                && bBox.height <= s.max_point_size
                && bBox.area() >= minArea
                && bBox.area() <= maxArea
                /*&& ratio > 0.75 &&*/)
            {
                vec2 center;
                center[0] = bBox.x + bBox.width / 2;
                center[1] = bBox.y + bBox.height / 2;
                aPoints.push_back(vec2(center));

                if (aPreview)
                {
                    cv::rectangle(*aPreview, bBox, CV_RGB(0, 255, 0), 2);
                }
            }
        }

        // Keep the three points which are highest, i.e. with lowest Y coordinates
        // That's most usefull to discard noise from features below your cap/head.
        // Typically noise comming from zippers and metal parts on your clothing.
        // With a cap tracker it also successfully discards noise glasses.
        // However it may not work as good with a clip user wearing glasses.
        while (aPoints.size() > 3) // Until we have no more than three points
        {
            int maxY = 0;
            int index = -1;

            // Search for the point with highest Y coordinate
            for (size_t i = 0; i < aPoints.size(); i++)
            {
                if (aPoints[i][1] > maxY)
                {
                    maxY = aPoints[i][1];
                    index = i;
                }
            }

            // Discard it
            aPoints.erase(aPoints.begin() + index);
        }
    }

}