/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2023, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/gui/CDisplayWindow3D.h>
#include <mrpt/math/ransac.h>
#include <mrpt/opengl/CGridPlaneXY.h>
#include <mrpt/opengl/CPointCloud.h>
#include <mrpt/opengl/CTexturedPlane.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/poses/CPose3D.h>
#include <mrpt/random.h>
#include <mrpt/system/CTicTac.h>

#include <iostream>

using namespace mrpt;
using namespace mrpt::gui;
using namespace mrpt::math;
using namespace mrpt::random;
using namespace mrpt::poses;
using namespace mrpt::system;
using namespace std;

void ransac3Dplane_fit(
	const CMatrixDouble& allData, const std::vector<size_t>& useIndices,
	vector<CMatrixDouble>& fitModels)
{
	ASSERT_(useIndices.size() == 3);

	TPoint3D p1(
		allData(0, useIndices[0]), allData(1, useIndices[0]),
		allData(2, useIndices[0]));
	TPoint3D p2(
		allData(0, useIndices[1]), allData(1, useIndices[1]),
		allData(2, useIndices[1]));
	TPoint3D p3(
		allData(0, useIndices[2]), allData(1, useIndices[2]),
		allData(2, useIndices[2]));

	try
	{
		TPlane plane(p1, p2, p3);
		fitModels.resize(1);
		CMatrixDouble& M = fitModels[0];

		M.setSize(1, 4);
		for (size_t i = 0; i < 4; i++)
			M(0, i) = plane.coefs[i];
	}
	catch (exception&)
	{
		fitModels.clear();
		return;
	}
}

void ransac3Dplane_distance(
	const CMatrixDouble& allData, const vector<CMatrixDouble>& testModels,
	const double distanceThreshold, unsigned int& out_bestModelIndex,
	std::vector<size_t>& out_inlierIndices)
{
	ASSERT_(testModels.size() == 1);
	out_bestModelIndex = 0;
	const CMatrixDouble& M = testModels[0];

	ASSERT_(M.rows() == 1 && M.cols() == 4);

	TPlane plane;
	plane.coefs[0] = M(0, 0);
	plane.coefs[1] = M(0, 1);
	plane.coefs[2] = M(0, 2);
	plane.coefs[3] = M(0, 3);

	const size_t N = allData.cols();
	out_inlierIndices.clear();
	out_inlierIndices.reserve(100);
	for (size_t i = 0; i < N; i++)
	{
		const double d = plane.distance(
			TPoint3D(allData(0, i), allData(1, i), allData(2, i)));
		if (d < distanceThreshold) out_inlierIndices.push_back(i);
	}
}

/** Return "true" if the selected points are a degenerate (invalid) case.
 */
bool ransac3Dplane_degenerate(
	const CMatrixDouble& allData, const std::vector<size_t>& useIndices)
{
	return false;
}

// ------------------------------------------------------
//				TestRANSAC
// ------------------------------------------------------
void TestRANSAC()
{
	getRandomGenerator().randomize();

	// Generate random points:
	// ------------------------------------
	const size_t N_plane = 300;
	const size_t N_noise = 100;

	const double PLANE_EQ[4] = {1, -1, 1, -2};

	CMatrixDouble data(3, N_plane + N_noise);
	for (size_t i = 0; i < N_plane; i++)
	{
		const double xx = getRandomGenerator().drawUniform(-3, 3);
		const double yy = getRandomGenerator().drawUniform(-3, 3);
		const double zz =
			-(PLANE_EQ[3] + PLANE_EQ[0] * xx + PLANE_EQ[1] * yy) / PLANE_EQ[2];
		data(0, i) = xx;
		data(1, i) = yy;
		data(2, i) = zz;
	}

	for (size_t i = 0; i < N_noise; i++)
	{
		data(0, i + N_plane) = getRandomGenerator().drawUniform(-4, 4);
		data(1, i + N_plane) = getRandomGenerator().drawUniform(-4, 4);
		data(2, i + N_plane) = getRandomGenerator().drawUniform(-4, 4);
	}

	// Run RANSAC
	// ------------------------------------
	CMatrixDouble best_model;
	std::vector<size_t> best_inliers;
	const double DIST_THRESHOLD = 0.05;

	CTicTac tictac;
	const size_t TIMES = 100;

	math::RANSAC myransac;
	for (size_t iters = 0; iters < TIMES; iters++)
	{
		myransac.setVerbosityLevel(
			iters == 0 ? mrpt::system::LVL_DEBUG : mrpt::system::LVL_INFO);

		myransac.execute(
			data, ransac3Dplane_fit, ransac3Dplane_distance,
			ransac3Dplane_degenerate, DIST_THRESHOLD,
			3,	// Minimum set of points
			best_inliers, best_model);
	}

	cout << "Computation time: " << tictac.Tac() * 1000.0 / TIMES << " ms"
		 << endl;

	ASSERT_(best_model.rows() == 1 && best_model.cols() == 4);

	cout << "RANSAC finished: Best model: " << best_model << endl;
	//	cout << "Best inliers: " << best_inliers << endl;

	TPlane plane(
		best_model(0, 0), best_model(0, 1), best_model(0, 2), best_model(0, 3));

	// Show GUI
	// --------------------------
	mrpt::gui::CDisplayWindow3D win("Set of points", 500, 500);
	opengl::Scene::Ptr scene = opengl::Scene::Create();

	scene->insert(opengl::CGridPlaneXY::Create(-20, 20, -20, 20, 0, 1));
	scene->insert(opengl::stock_objects::CornerXYZ());

	opengl::CPointCloud::Ptr points = opengl::CPointCloud::Create();
	points->setColor(0, 0, 1);
	points->setPointSize(3);
	points->enableColorFromZ();

	{
		std::vector<double> xs, ys, zs;

		data.extractRow(0, xs);
		data.extractRow(1, ys);
		data.extractRow(2, zs);
		points->setAllPoints(xs, ys, zs);
	}

	scene->insert(points);

	opengl::CTexturedPlane::Ptr glPlane =
		opengl::CTexturedPlane::Create(-4, 4, -4, 4);

	glPlane->setColor_u8(mrpt::img::TColor(0xff, 0x00, 0x00, 0x80));  // RGBA

	TPose3D glPlanePose;
	plane.getAsPose3D(glPlanePose);
	glPlane->setPose(glPlanePose);

	scene->insert(glPlane);

	win.get3DSceneAndLock() = scene;
	win.unlockAccess3DScene();
	win.forceRepaint();

	win.waitForKey();
}

// ------------------------------------------------------
//						MAIN
// ------------------------------------------------------
int main()
{
	try
	{
		TestRANSAC();
		return 0;
	}
	catch (const std::exception& e)
	{
		std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
		return -1;
	}
}
