/*
 * Stellarium
 * Copyright (C) 2006 Fabien Chereau
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "StelTextureMgr.hpp"
#include "StelFileMgr.hpp"
#include "StelUtils.hpp"
#include "StelPainter.hpp"

#include <QHttp>
#include <QFileInfo>
#include <QFile>
#include <QDebug>
#include <QThread>
#include <QSettings>
#include <QGLFormat>
#include <cstdlib>


StelTextureMgr::StelTextureMgr()
{
}

StelTextureMgr::~StelTextureMgr()
{
}

void StelTextureMgr::init()
{
	StelPainter::makeMainGLContextCurrent();
	isNoPowerOfTwoAllowed = QGLFormat::openGLVersionFlags().testFlag(QGLFormat::OpenGL_Version_2_0) || QGLFormat::openGLVersionFlags().testFlag(QGLFormat::OpenGL_ES_Version_2_0);
}


StelTextureSP StelTextureMgr::createTexture(const QString& afilename, const StelTexture::StelTextureParams& params)
{
	if (afilename.isEmpty())
		return StelTextureSP();

	StelTextureSP tex = StelTextureSP(new StelTexture());
	try
	{
		tex->fullPath = StelFileMgr::findFile(afilename);
	}
	catch (std::runtime_error er)
	{
#ifdef USE_OPENGL_ES2
		// Allow to replace the texures by compressed .pvr versions using GPU decompression.
		// This saves memory and increases rendering speed.
		if (!afilename.endsWith(".pvr"))
		{
			QString pvrVersion = afilename;
			pvrVersion.replace(".png", ".pvr");
			return createTexture(pvrVersion, params);
		}
#endif
		qWarning() << "WARNING : Can't find texture file " << afilename << ": " << er.what() << endl;
		tex->errorOccured = true;
		return StelTextureSP();
	}

	StelPainter::makeMainGLContextCurrent();
	if (tex->fullPath.endsWith(".pvr"))
	{
		// Load compressed textures using Qt wrapper.
		tex->loadParams = params;
		tex->downloaded = true;

		tex->id = StelPainter::glContext->bindTexture(tex->fullPath);
		// For some reasons only LINEAR seems to work
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, tex->loadParams.wrapMode);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, tex->loadParams.wrapMode);
		return tex;
	}
	else
	{
		tex->qImage = QImage(tex->fullPath);
		if (tex->qImage.isNull())
			return StelTextureSP();
		tex->loadParams = params;
		tex->downloaded = true;

		if (tex->glLoad())
			return tex;
		else
			return StelTextureSP();
	}
}


StelTextureSP StelTextureMgr::createTextureThread(const QString& url, const StelTexture::StelTextureParams& params, const QString& fileExtension, bool lazyLoading)
{
	if (url.isEmpty())
		return StelTextureSP();

	StelTextureSP tex = StelTextureSP(new StelTexture());
	tex->loadParams = params;
	if (!url.startsWith("http://"))
	{
		// Assume a local file
		try
		{
			tex->fullPath = StelFileMgr::findFile(url);
		}
		catch (std::runtime_error e)
		{
			try
			{
				tex->fullPath = StelFileMgr::findFile("textures/" + url);
			}
			catch (std::runtime_error er)
			{
				qWarning() << "WARNING : Can't find texture file " << url << ": " << er.what() << endl;
				tex->errorOccured = true;
				return StelTextureSP();
			}
		}
		tex->downloaded = true;
	}
	else
	{
		tex->fullPath = url;
		if (fileExtension.isEmpty())
		{
			const int idx = url.lastIndexOf('.');
			if (idx!=-1)
				tex->fileExtension = url.right(url.size()-idx-1);
		}
	}
	if (!fileExtension.isEmpty())
		tex->fileExtension = fileExtension;
	if (!lazyLoading)
	{
		StelPainter::makeMainGLContextCurrent();
		tex->bind();
	}
	return tex;
}