/*
Copyright (c) 2010-2016, Mathieu Labbe - IntRoLab - Universite de Sherbrooke
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the Universite de Sherbrooke nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <opencv2/core/core.hpp>
#include <opencv2/core/types_c.h>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <rtabmap/utilite/ULogger.h>
#include <rtabmap/utilite/UTimer.h>
#include <rtabmap/utilite/UConversion.h>
#include <rtabmap/utilite/UDirectory.h>
#include <rtabmap/utilite/UStl.h>
#include <rtabmap/utilite/UMath.h>
#include <opencv2/calib3d/calib3d.hpp>
#include "rtabmap/core/Features2d.h"
#include "rtabmap/core/EpipolarGeometry.h"
#include "rtabmap/core/VWDictionary.h"
#include "rtabmap/core/Odometry.h"
#include "rtabmap/utilite/UCv2Qt.h"

#include "rtabmap/gui/ImageView.h"
#include "rtabmap/gui/KeypointItem.h"
#include <QApplication>
#include <QGraphicsLineItem>
#include <QGraphicsPixmapItem>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QtCore/QTime>
#include <QtCore/QElapsedTimer>
#include <QGraphicsEffect>


using namespace rtabmap;

void showUsage()
{
	printf("\nUsage:\n"
			"rtabmap-epipolar_geometry image1.jpg image2.jpg\n");
	exit(1);
}

class MainWidget : public QWidget
{
public:
	MainWidget(const cv::Mat & image1,
			   const cv::Mat & image2,
			   const std::multimap<int, cv::KeyPoint> & words1,
			   const std::multimap<int, cv::KeyPoint> & words2,
			   const std::vector<uchar> & status)
	{
		view1_ = new ImageView(this);
		this->setLayout(new QHBoxLayout());
		this->layout()->setSpacing(0);
		this->layout()->setContentsMargins(0,0,0,0);
		this->layout()->addWidget(view1_);
		view1_->setSceneRect(QRectF(0,0,(float)image1.cols, (float)image1.rows));
		view1_->setLinesShown(true);
		view1_->setFeaturesShown(false);
		view1_->setImageDepthShown(true);

		view1_->setImage(uCvMat2QImage(image1));
		view1_->setImageDepth(image2);

		drawKeypoints(words1, words2, status);
	}
protected:
	virtual void showEvent(QShowEvent* event)
	{
		resizeEvent(0);
	}
private:
	void drawKeypoints(const std::multimap<int, cv::KeyPoint> & refWords, const std::multimap<int, cv::KeyPoint> & loopWords, const std::vector<uchar> & status)
	{
		UTimer timer;

		timer.start();
		QList<QPair<cv::Point2f, cv::Point2f> > uniqueCorrespondences;
		QList<bool> inliers;
		int j=0;
		for(std::multimap<int, cv::KeyPoint>::const_iterator i = refWords.begin(); i != refWords.end(); ++i )
		{
			int id = (*i).first;
			QColor color;
			if(uContains(loopWords, id))
			{
				// PINK = FOUND IN LOOP SIGNATURE
				color = Qt::magenta;
				//To draw lines... get only unique correspondences
				if(uValues(refWords, id).size() == 1 && uValues(loopWords, id).size() == 1)
				{
					uniqueCorrespondences.push_back(QPair<cv::Point2f, cv::Point2f>(i->second.pt, uValues(loopWords, id).begin()->pt));
					inliers.push_back(status[j++]);
				}
			}
			else if(refWords.count(id) > 1)
			{
				// YELLOW = NEW and multiple times
				color = Qt::yellow;
			}
			else
			{
				// GREEN = NEW
				color = Qt::green;
			}
			view1_->addFeature(id, i->second, 0, color);
		}
		ULOGGER_DEBUG("source time = %f s", timer.ticks());

		// Draw lines between corresponding features...
		UASSERT(uniqueCorrespondences.size() == inliers.size());
		QList<bool>::iterator jter = inliers.begin();
		for(QList<QPair<cv::Point2f, cv::Point2f> >::iterator iter = uniqueCorrespondences.begin();
			iter!=uniqueCorrespondences.end();
			++iter)
		{
			view1_->addLine(
					iter->first.x,
					iter->first.y,
					iter->second.x,
					iter->second.y,
					*jter?Qt::cyan:Qt::red);
			++jter;
		}
		view1_->update();
	}

private:
	ImageView * view1_;
};

std::multimap<int, cv::KeyPoint> aggregate(const std::list<int> & wordIds, const std::vector<cv::KeyPoint> & keypoints)
{
	std::multimap<int, cv::KeyPoint> words;
	std::vector<cv::KeyPoint>::const_iterator kpIter = keypoints.begin();
	for(std::list<int>::const_iterator iter=wordIds.begin(); iter!=wordIds.end(); ++iter)
	{
		words.insert(std::pair<int, cv::KeyPoint >(*iter, *kpIter));
		++kpIter;
	}
	return words;
}



int main(int argc, char** argv)
{
	ULogger::setType(ULogger::kTypeConsole);
	ULogger::setLevel(ULogger::kInfo);

	cv::Mat image1;
    cv::Mat image2;
	if(argc == 3)
	{
		image1 = cv::imread(argv[1], cv::IMREAD_GRAYSCALE);
		image2 = cv::imread(argv[2], cv::IMREAD_GRAYSCALE);
	}
	else
	{
		showUsage();
	}

	QElapsedTimer timer;
	timer.start();

	// Extract words
   VWDictionary dictionary;
   ParametersMap param;
   param.insert(ParametersPair(Parameters::kSURFExtended(), "true"));
   param.insert(ParametersPair(Parameters::kSURFHessianThreshold(), "100"));
   SURF detector(param);
   std::vector<cv::KeyPoint> kpts1 = detector.generateKeypoints(image1);
   std::vector<cv::KeyPoint> kpts2 = detector.generateKeypoints(image2);
   cv::Mat descriptors1 = detector.generateDescriptors(image1, kpts1);
   cv::Mat descriptors2 = detector.generateDescriptors(image2, kpts2);
   UINFO("detect/extract features = %d ms", timer.elapsed());

   timer.start();
   std::list<int> wordIds1 = dictionary.addNewWords(descriptors1, 1);
   dictionary.update();
   std::list<int> wordIds2 = dictionary.addNewWords(descriptors2, 2);
   UINFO("quantization to words = %d ms", timer.elapsed());

   std::multimap<int, cv::KeyPoint> words1 = aggregate(wordIds1, kpts1);
   std::multimap<int, cv::KeyPoint> words2 = aggregate(wordIds2, kpts2);

   // Find pairs
   timer.start();
   std::list<std::pair<int, std::pair<cv::KeyPoint, cv::KeyPoint> > > pairs;
   EpipolarGeometry::findPairsUnique(words1, words2, pairs);
   UINFO("find pairs = %d ms", timer.elapsed());

   // Find fundamental matrix
   timer.start();
   std::vector<uchar> status;
   cv::Mat fundamentalMatrix = EpipolarGeometry::findFFromWords(pairs, status);
   UINFO("inliers = %d/%d", uSum(status), pairs.size());
   UINFO("find F = %d ms", timer.elapsed());
   if(!fundamentalMatrix.empty())
   {
	   int i = 0;
	   int goodCount = 0;
	   for(std::list<std::pair<int, std::pair<cv::KeyPoint, cv::KeyPoint> > >::iterator iter=pairs.begin(); iter!=pairs.end(); ++iter)
		{
			if(status[i])
			{
				// the output of the correspondences can be easily copied in MatLab
				if(goodCount==0)
				{
					printf("x=[%f %f %d]; xp=[%f %f %d];\n",
							iter->second.first.pt.x,
							iter->second.first.pt.y,
							iter->first,
							iter->second.second.pt.x,
							iter->second.second.pt.y,
							iter->first);
				}
				else
				{
					printf("x=[x;[%f %f %d]]; xp=[xp;[%f %f %d]];\n",
							iter->second.first.pt.x,
							iter->second.first.pt.y,
							iter->first,
							iter->second.second.pt.x,
							iter->second.second.pt.y,
							iter->first);
				}
				++goodCount;
			}
			++i;
		}

		// Show the fundamental matrix
		std::cout << "F=" << fundamentalMatrix << std::endl;

		// Intrinsic parameters K of the camera (guest... non-calibrated camera)
		cv::Mat k = cv::Mat::zeros(3,3,CV_64FC1);
		k.at<double>(0,0) = image1.cols; // focal x
		k.at<double>(1,1) = image1.rows; // focal y
		k.at<double>(2,2) = 1;
		k.at<double>(0,2) = image1.cols/2; // center x in pixels
		k.at<double>(1,2) = image1.rows/2; // center y in pixels

		// Use essential matrix E=K'*F*K

		cv::Mat e = k.t()*fundamentalMatrix*k;

		//remove K from points xe = inv(K)*x
		cv::Mat x1(2, goodCount, CV_64FC1);
		cv::Mat x2(2, goodCount, CV_64FC1);
		i=0;
		int j=0;
		cv::Mat invK = k.inv();
		for(std::list<std::pair<int, std::pair<cv::KeyPoint, cv::KeyPoint> > >::iterator iter=pairs.begin(); iter!=pairs.end(); ++iter)
		{
			if(status[i])
			{
				cv::Mat tmp(3,1,CV_64FC1);
				tmp.at<double>(0,0) = iter->second.first.pt.x;
				tmp.at<double>(1,0) = iter->second.first.pt.y;
				tmp.at<double>(2,0) = 1;
				tmp = invK*tmp;
				x1.at<double>(0,j) = tmp.at<double>(0,0);
				x1.at<double>(1,j) = tmp.at<double>(1,0);
				tmp.at<double>(0,0) = iter->second.second.pt.x;
				tmp.at<double>(1,0) = iter->second.second.pt.y;
				tmp.at<double>(2,0) = 1;
				tmp = invK*tmp;
				x2.at<double>(0,j) = tmp.at<double>(0,0);
				x2.at<double>(1,j) = tmp.at<double>(1,0);
				UDEBUG("i=%d j=%d, x1=[%f,%f] x2=[%f,%f]", i, j, x1.at<double>(0,j), x1.at<double>(1,j), x2.at<double>(0,j), x2.at<double>(1,j));
				++j;
			}
			++i;
		}

		std::cout<<"K=" << k << std::endl;
		timer.start();
		//std::cout<<"e=" << e << std::endl;
		cv::Mat p = EpipolarGeometry::findPFromE(e, x1, x2);
		cv::Mat p0 = cv::Mat::zeros(3, 4, CV_64FC1);
		p0.at<double>(0,0) = 1;
		p0.at<double>(1,1) = 1;
		p0.at<double>(2,2) = 1;
		UINFO("find P from F = %d ms", timer.elapsed());

		std::cout<<"P=" << p << std::endl;

		//find 4D homogeneous points
		cv::Mat x4d;
		timer.start();
		cv::triangulatePoints(p0, p, x1, x2, x4d);
		UINFO("find X (triangulate) = %d ms", timer.elapsed());

		//Show 4D points
		for(int i=0; i<x4d.cols; ++i)
		{
			x4d.at<double>(0,i) = x4d.at<double>(0,i)/x4d.at<double>(3,i);
			x4d.at<double>(1,i) = x4d.at<double>(1,i)/x4d.at<double>(3,i);
			x4d.at<double>(2,i) = x4d.at<double>(2,i)/x4d.at<double>(3,i);
			x4d.at<double>(3,i) = x4d.at<double>(3,i)/x4d.at<double>(3,i);
			if(i==0)
			{
				printf("X=[%f;%f;%f;%f];\n",
					x4d.at<double>(0,i),
					x4d.at<double>(1,i),
					x4d.at<double>(2,i),
					x4d.at<double>(3,i));
			}
			else
			{
				printf("X=[X [%f;%f;%f;%f]];\n",
					x4d.at<double>(0,i),
					x4d.at<double>(1,i),
					x4d.at<double>(2,i),
					x4d.at<double>(3,i));
			}
		}

		//Show rotation/translation of the second camera
		cv::Mat r;
		cv::Mat t;
		EpipolarGeometry::findRTFromP(p, r, t);
		std::cout<< "R=" << r << std::endl;
		std::cout<< "t=" << t << std::endl;

		//GUI
		QApplication app(argc, argv);
		MainWidget mainWidget(image1, image2, words1, words2, status);
		mainWidget.show();
		app.exec();
	}
	else
	{
		UINFO("Fundamental matrix not found...");
	}

    return 0;
}
