/*
    This file is part of Mitsuba, a physically based rendering system.

    Copyright (c) 2007-2012 by Wenzel Jakob and others.

    Mitsuba is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.

    Mitsuba is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

// Mitsuba's "Assert" macro conflicts with Xerces' XSerializeEngine::Assert(...).
// This becomes a problem when using a PCH which contains mitsuba/core/logger.h
#if defined(Assert)
# undef Assert
#endif
#include <xercesc/parsers/SAXParser.hpp>
#include "glwidget.h"
#include "sceneloader.h"
#include <mitsuba/render/scenehandler.h>
#include <mitsuba/core/fresolver.h>
#include <mitsuba/core/fstream.h>
#include <boost/algorithm/string.hpp>

XERCES_CPP_NAMESPACE_USE

SceneLoader::SceneLoader(FileResolver *resolver, const fs::path &filename,
	const std::map<std::string, std::string, SimpleStringOrdering> &parameters)
	: Thread("load"), m_resolver(resolver), m_filename(fromFsPath(filename)),
	  m_parameters(parameters) {
	m_wait = new WaitFlag();
	m_versionError = false;
}

SceneLoader::~SceneLoader() {
}

void SceneLoader::run() {
	Thread::getThread()->setFileResolver(m_resolver);
	SAXParser* parser = new SAXParser();
	QFileInfo fileInfo(m_filename);
	QString suffix = fileInfo.suffix().toLower();

	SceneHandler *handler = new SceneHandler(parser, m_parameters);
	m_result = new SceneContext();
	try {
		QSettings settings;
		m_result->srgb = settings.value("preview_sRGB", true).toBool();
		m_result->gamma = (Float) settings.value("preview_gamma", 2.2).toDouble();
		m_result->reinhardKey = (Float) settings.value("preview_reinhardKey", 0.18).toDouble();
		m_result->reinhardBurn = (Float) settings.value("preview_reinhardBurn", -10.0).toDouble();
		m_result->exposure = (Float) settings.value("preview_exposure", 0).toDouble();
		m_result->shadowMapResolution = settings.value("preview_shadowMapResolution", 256).toInt();
		m_result->clamping = (Float) settings.value("preview_clamping", 0.1f).toDouble();
		m_result->previewMethod = (EPreviewMethod) settings.value("preview_method", EOpenGL).toInt();
		if (m_result->previewMethod != EOpenGL && m_result->previewMethod != EDisabled)
			m_result->previewMethod = EOpenGL;
		m_result->toneMappingMethod = (EToneMappingMethod) settings.value("preview_toneMappingMethod", EGamma).toInt();
		m_result->diffuseSources = settings.value("preview_diffuseSources", true).toBool();
		m_result->diffuseReceivers = settings.value("preview_diffuseReceivers", false).toBool();

		if (suffix == "exr" || suffix == "png"  || suffix == "jpg" || suffix == "jpeg" ||
		    suffix == "hdr" || suffix == "rgbe" || suffix == "pfm") {
			/* This is an image, not a scene */
			ref<FileStream> fs = new FileStream(toFsPath(m_filename), FileStream::EReadOnly);
			ref<Bitmap> bitmap = new Bitmap(Bitmap::EAuto, fs);
			bitmap = bitmap->convert(Bitmap::ERGBA, Bitmap::EFloat32);

			m_result->mode = ERender;
			m_result->framebuffer = bitmap;
			m_result->fileName = m_filename;
			m_result->shortName = fileInfo.fileName();
			m_result->scrollOffset = Vector2i(0, 0);
			m_result->pathLength = 2;
		} else {
			fs::path schemaPath = m_resolver->resolveAbsolute("data/schema/scene.xsd");

			/* Check against the 'scene.xsd' XML Schema */
			parser->setDoSchema(true);
			parser->setValidationSchemaFullChecking(true);
			parser->setValidationScheme(SAXParser::Val_Always);
			parser->setExternalNoNamespaceSchemaLocation(schemaPath.c_str());
			#if !defined(__OSX__)
				/// Not supported on OSX
				parser->setCalculateSrcOfs(true);
			#endif

			/* Set the SAX handler */
			parser->setDoNamespaces(true);
			parser->setDocumentHandler(handler);
			parser->setErrorHandler(handler);

			fs::path
				filename = toFsPath(m_filename),
				filePath = fs::absolute(filename).parent_path(),
				baseName = filename.stem();

			SLog(EInfo, "Parsing scene description from \"%s\" ..", filename.string().c_str());

			if (!fs::exists(filename))
				SLog(EError, "Unable to load scene \"%s\": file not found!",
					filename.string().c_str());

			try {
				parser->parse(filename.c_str());
			} catch (const VersionException &ex) {
				m_versionError = true;
				m_version = ex.getVersion();
				throw;
			}

			ref<Scene> scene = handler->getScene();

			scene->setSourceFile(filename);
			scene->setDestinationFile(filePath / baseName);
			scene->initialize();

			if (scene->getIntegrator() == NULL)
				SLog(EError, "Unable to load scene: no integrator found!");
			if (scene->getSensor() == NULL)
				SLog(EError, "Unable to load scene: no sensor found!");
			if (scene->getSensor()->getFilm() == NULL)
				SLog(EError, "Unable to load scene: no film found!");
			if (scene->getEmitters().size() == 0)
				SLog(EError, "Unable to load scene: no light sources found!");
			Vector2i size = scene->getFilm()->getCropSize();
			Sensor *sensor = scene->getSensor();

			/* Also generate a DOM representation for the Qt-based GUI */
			QFile file(m_filename);
			if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
				Log(EError, "Unable to open the file \"%s\"", filename.string().c_str());
			QString errorMsg;
			int line, column;
			if (!m_result->doc.setContent(&file, &errorMsg, &line, &column))
				SLog(EError, "Unable to parse file: error %s at line %i, colum %i",
					qPrintable(errorMsg), line, column);

			m_result->scene = scene;
			m_result->sceneResID = Scheduler::getInstance()->registerResource(scene);
			m_result->renderJob = NULL;
			m_result->movementScale = scene->getBSphere().radius / 2000.0f;
			m_result->mode = EPreview;
			m_result->framebuffer = new Bitmap(Bitmap::ERGBA, Bitmap::EFloat32, size);
			m_result->framebuffer->clear();
			m_result->fileName = m_filename;
			m_result->shortName = fileInfo.fileName();
			if (sensor->getClass()->derivesFrom(MTS_CLASS(PerspectiveCamera))) {
				m_result->up = static_cast<PerspectiveCamera *>(sensor)->getInverseViewTransform(
					sensor->getShutterOpen() + 0.5f * sensor->getShutterOpenTime())(Vector(0, 1, 0));
			} else {
				m_result->up = Vector(0.0f);
			}
			m_result->scrollOffset = Vector2i(0, 0);
			m_result->originalSize = m_result->scene->getFilm()->getCropSize();
			m_result->pathLength = m_result->detectPathLength();
			m_result->showKDTree = false;
			m_result->shownKDTreeLevel = 0;
		}
	} catch (const std::exception &e) {
		m_error = e.what();
		delete m_result;
		m_result = NULL;
	} catch (...) {
		cout << "Don't know what" << endl;
		m_error = "An unknown type of error occurred!";
		delete m_result;
		m_result = NULL;
	}
	m_wait->set(true);
	delete parser;
	delete handler;
}