#include <QApplication>
#include <QDebug>
#include <QFrame>
#include <QVBoxLayout>
#include <QWidget>
#include <QTimer>

#include <Qt3DRender/QCamera>
#include <Qt3DRender/QCameraLens>
#include <Qt3DRender/QRenderSettings>
#include <Qt3DRender/QPickingSettings>
#include <Qt3DExtras/Qt3DWindow>
#include <Qt3DExtras/QOrbitCameraController>
#include <Qt3DExtras/QDiffuseSpecularMaterial>
#include <Qt3DExtras/QSphereMesh>
#include <Qt3DRender/QScreenRayCaster>

Qt3DCore::QEntity* createSphereMesh()
{
	auto sphereMat = new Qt3DExtras::QDiffuseSpecularMaterial;
	sphereMat->setDiffuse(QColor(Qt::blue));

	auto mesh = new Qt3DExtras::QSphereMesh();
	mesh->setRadius(1);

	auto meshEntity = new Qt3DCore::QEntity;
	meshEntity->addComponent(mesh);
	meshEntity->addComponent(sphereMat);

	return meshEntity;
}

Qt3DRender::QScreenRayCaster* sm_rayCaster = nullptr;
QMetaObject::Connection sm_rayCasterConnection;

void recreateRayCaster(Qt3DCore::QEntity* rootEntity)
{
	if (!sm_rayCaster) {
		sm_rayCaster = new Qt3DRender::QScreenRayCaster(rootEntity);
		sm_rayCaster->setRunMode(Qt3DRender::QAbstractRayCaster::SingleShot);
		sm_rayCaster->setFilterMode(Qt3DRender::QAbstractRayCaster::DiscardAnyMatchingLayers);
		rootEntity->addComponent(sm_rayCaster);
		sm_rayCasterConnection = QObject::connect(sm_rayCaster, &Qt3DRender::QScreenRayCaster::hitsChanged, [&](const Qt3DRender::QAbstractRayCaster::Hits& hits) {
			for (auto& hit : hits)
				qDebug() << "Hit data" << hit.entity()->objectName() << hit.worldIntersection() << hit.distance() << hit.type();
			});
	}
	else {
		QObject::disconnect(sm_rayCasterConnection);
		rootEntity->removeComponent(sm_rayCaster);
		sm_rayCaster->setParent(Q_NODE_NULLPTR);
		sm_rayCaster->deleteLater();
		sm_rayCaster = nullptr;
	}
}

int main(int argc, char* argv[])
{
	QApplication a(argc, argv);

	auto view = new Qt3DExtras::Qt3DWindow();
	auto renderSettings = view->renderSettings();
	renderSettings->setRenderPolicy(Qt3DRender::QRenderSettings::Always);
	auto pickSettings = view->renderSettings()->pickingSettings();
	pickSettings->setPickMethod(Qt3DRender::QPickingSettings::PrimitivePicking);
	pickSettings->setWorldSpaceTolerance(0.1f);

	auto rootEntity = new Qt3DCore::QEntity();
	view->setRootEntity(rootEntity);

	auto camera = view->camera();
	camera->lens()->setPerspectiveProjection(45.0f, 1., 0.1f, 10000.0f);
	camera->setPosition(QVector3D(0, 0, 5));
	camera->setUpVector(QVector3D(0, 1, 0));
	camera->setViewCenter(QVector3D(0, 0, 0));

	auto camController = new Qt3DExtras::QOrbitCameraController(rootEntity);
	camController->setCamera(camera);

	recreateRayCaster(rootEntity);

	auto sphereEntity = createSphereMesh();
	sphereEntity->setParent(rootEntity);

	auto container = QWidget::createWindowContainer(view);
	QFrame frame;
	frame.setLayout(new QVBoxLayout);
	frame.layout()->addWidget(container);
	frame.resize(QSize(400, 300));

	QTimer::singleShot(100, [&]() {
		camera->viewAll();
	});

	QTimer timer;
	QObject::connect(&timer, &QTimer::timeout, [&]() {
		if (sm_rayCaster) {
			sm_rayCaster->trigger(container->mapFromGlobal(QCursor::pos()));
			qDebug() << "Trigger Raycaster";
		}
		QTimer::singleShot(250, [&]() {
			recreateRayCaster(rootEntity);
		});
	});
	timer.start(500);

	frame.show();
	return a.exec();
}