/*
 * Copyright (C) 2003 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 "StelCore.hpp"
#include "StelNavigator.hpp"
#include "StelProjector.hpp"
#include "StelProjectorClasses.hpp"
#include "StelToneReproducer.hpp"
#include "StelSkyDrawer.hpp"
#include "StelApp.hpp"
#include "StelUtils.hpp"
#include "StelGeodesicGrid.hpp"
#include "StelMovementMgr.hpp"
#include "StelModuleMgr.hpp"
#include "StelPainter.hpp"

#include <QtOpenGL>
#include <QSettings>
#include <QDebug>
#include <QMetaEnum>

/*************************************************************************
 Constructor
*************************************************************************/
StelCore::StelCore() : navigation(NULL), movementMgr(NULL), geodesicGrid(NULL), currentProjectionType(ProjectionStereographic)
{
	toneConverter = new StelToneReproducer();

	QSettings* conf = StelApp::getInstance().getSettings();
	// Create and initialize the default projector params
	QString tmpstr = conf->value("projection/viewport").toString();
	currentProjectorParams.maskType = StelProjector::stringToMaskType(tmpstr);
	const int viewport_width = conf->value("projection/viewport_width", currentProjectorParams.viewportXywh[2]).toInt();
	const int viewport_height = conf->value("projection/viewport_height", currentProjectorParams.viewportXywh[3]).toInt();
	const int viewport_x = conf->value("projection/viewport_x", 0).toInt();
	const int viewport_y = conf->value("projection/viewport_y", 0).toInt();
	currentProjectorParams.viewportXywh.set(viewport_x,viewport_y,viewport_width,viewport_height);

	const float viewportCenterX = conf->value("projection/viewport_center_x",0.5f*viewport_width).toFloat();
	const float viewportCenterY = conf->value("projection/viewport_center_y",0.5f*viewport_height).toFloat();
	currentProjectorParams.viewportCenter.set(viewportCenterX, viewportCenterY);
	currentProjectorParams.viewportFovDiameter = conf->value("projection/viewport_fov_diameter", qMin(viewport_width,viewport_height)).toFloat();
	currentProjectorParams.flipHorz = conf->value("projection/flip_horz",false).toBool();
	currentProjectorParams.flipVert = conf->value("projection/flip_vert",false).toBool();

	currentProjectorParams.gravityLabels = conf->value("viewing/flag_gravity_labels").toBool();
}


/*************************************************************************
 Destructor
*************************************************************************/
StelCore::~StelCore()
{
	delete navigation; navigation=NULL;
	delete toneConverter; toneConverter=NULL;
	delete geodesicGrid; geodesicGrid=NULL;
	delete skyDrawer; skyDrawer=NULL;
}

/*************************************************************************
 Load core data and initialize with default values
*************************************************************************/
void StelCore::init()
{
	QSettings* conf = StelApp::getInstance().getSettings();

	// StelNavigator
	navigation = new StelNavigator();
	navigation->init();

	movementMgr = new StelMovementMgr(this);
	movementMgr->init();
	currentProjectorParams.fov = movementMgr->getInitFov();
	StelApp::getInstance().getModuleMgr().registerModule(movementMgr);

	QString tmpstr = conf->value("projection/type", "stereographic").toString();
	setCurrentProjectionTypeKey(tmpstr);

	skyDrawer = new StelSkyDrawer(this);
	skyDrawer->init();
}


// Get the shared instance of StelGeodesicGrid.
// The returned instance is garanteed to allow for at least maxLevel levels
const StelGeodesicGrid* StelCore::getGeodesicGrid(int maxLevel) const
{
	if (geodesicGrid==NULL)
	{
		geodesicGrid = new StelGeodesicGrid(maxLevel);
	}
	else if (maxLevel>geodesicGrid->getMaxLevel())
	{
		delete geodesicGrid;
		geodesicGrid = new StelGeodesicGrid(maxLevel);
	}
	return geodesicGrid;
}

StelProjectorP StelCore::getProjection2d() const
{
	StelProjectorP prj(new StelProjector2d());
	prj->init(currentProjectorParams);
	return prj;
}

// Get an instance of projector using the current display parameters from Navigation, StelMovementMgr
// and using the given modelview matrix
StelProjectorP StelCore::getProjection(const Mat4d& modelViewMat, ProjectionType projType) const
{
	if (projType==1000)
		projType = currentProjectionType;

	StelProjectorP prj;
	switch (projType)
	{
		case ProjectionPerspective:
			prj = StelProjectorP(new StelProjectorPerspective(modelViewMat));
			break;
		case ProjectionEqualArea:
			prj = StelProjectorP(new StelProjectorEqualArea(modelViewMat));
			break;
		case ProjectionStereographic:
			prj = StelProjectorP(new StelProjectorStereographic(modelViewMat));
			break;
		case ProjectionFisheye:
			prj = StelProjectorP(new StelProjectorFisheye(modelViewMat));
			break;
		case ProjectionHammer:
			prj = StelProjectorP(new StelProjectorHammer(modelViewMat));
			break;
		case ProjectionCylinder:
			prj = StelProjectorP(new StelProjectorCylinder(modelViewMat));
			break;
		case ProjectionMercator:
			prj = StelProjectorP(new StelProjectorMercator(modelViewMat));
			break;
		case ProjectionOrthographic:
			prj = StelProjectorP(new StelProjectorOrthographic(modelViewMat));
			break;
		default:
			qWarning() << "Unknown projection type: " << (int)(projType) << "using ProjectionStereographic instead";
			prj = StelProjectorP(new StelProjectorStereographic(modelViewMat));
			Q_ASSERT(0);
	}
	prj->init(currentProjectorParams);
	return prj;
}

// Get an instance of projector using the current display parameters from Navigation, StelMovementMgr
StelProjectorP StelCore::getProjection(FrameType frameType, ProjectionType projType) const
{
	switch (frameType)
	{
		case FrameAltAz:
			return getProjection(navigation->getAltAzModelViewMat(), projType);
		case FrameHeliocentricEcliptic:
			return getProjection(navigation->getHeliocentricEclipticModelViewMat(), projType);
		case FrameObservercentricEcliptic:
			return getProjection(navigation->getObservercentricEclipticModelViewMat(), projType);
		case FrameEquinoxEqu:
			return getProjection(navigation->getEquinoxEquModelViewMat(), projType);
		case FrameJ2000:
			return getProjection(navigation->getJ2000ModelViewMat(), projType);
		case FrameGalactic:
			 return getProjection(navigation->getGalacticModelViewMat(), projType);
		default:
			qDebug() << "Unknown reference frame type: " << (int)frameType << ".";
	}
	Q_ASSERT(0);
	return getProjection2d();
}

// Handle the resizing of the window
void StelCore::windowHasBeenResized(float x, float y, float width, float height)
{
	// Maximize display when resized since it invalidates previous options anyway
	currentProjectorParams.viewportXywh.set(x, y, width, height);
	currentProjectorParams.viewportCenter.set(x+0.5*width, y+0.5*height);
	currentProjectorParams.viewportFovDiameter = qMin(width,height);
}

/*************************************************************************
 Update all the objects in function of the time
*************************************************************************/
void StelCore::update(double deltaTime)
{
	// Update the position of observation and time and recompute planet positions etc...
	navigation->updateTime(deltaTime);

	// Transform matrices between coordinates systems
	navigation->updateTransformMatrices();

	// Update direction of vision/Zoom level
	movementMgr->updateMotion(deltaTime);

	currentProjectorParams.fov = movementMgr->getCurrentFov();

	skyDrawer->update(deltaTime);
}


/*************************************************************************
 Execute all the pre-drawing functions
*************************************************************************/
void StelCore::preDraw()
{
	// Init openGL viewing with fov, screen size and clip planes
	currentProjectorParams.zNear = 0.000001;
	currentProjectorParams.zFar = 50.;

	skyDrawer->preDraw();

	// Clear areas not redrawn by main viewport (i.e. fisheye square viewport)
	StelPainter sPainter(getProjection2d());
	glClearColor(0,0,0,0);
	glClear(GL_COLOR_BUFFER_BIT);
}


/*************************************************************************
 Update core state after drawing modules
*************************************************************************/
void StelCore::postDraw()
{
	StelPainter sPainter(getProjection(StelCore::FrameJ2000));
	sPainter.drawViewportShape();
}

void StelCore::setCurrentProjectionType(ProjectionType type)
{
	currentProjectionType=type;
	const double savedFov = currentProjectorParams.fov;
	currentProjectorParams.fov = 0.0001;	// Avoid crash
	double newMaxFov = getProjection(Mat4d::identity())->getMaxFov();
	movementMgr->setMaxFov(newMaxFov);
	currentProjectorParams.fov = qMin(newMaxFov, savedFov);
}

//! Set the current projection type to use
void StelCore::setCurrentProjectionTypeKey(QString key)
{
	const QMetaEnum& en = metaObject()->enumerator(metaObject()->indexOfEnumerator("ProjectionType"));
	ProjectionType newType = (ProjectionType)en.keyToValue(key.toAscii().data());
	if (newType<0)
	{
		qWarning() << "Unknown projection type: " << key << "setting \"ProjectionStereographic\" instead";
		newType = ProjectionStereographic;
	}
	setCurrentProjectionType(newType);
}

//! Get the current Mapping used by the Projection
QString StelCore::getCurrentProjectionTypeKey(void) const
{
	return metaObject()->enumerator(metaObject()->indexOfEnumerator("ProjectionType")).key(currentProjectionType);
}

//! Get the list of all the available projections
QStringList StelCore::getAllProjectionTypeKeys() const
{
	const QMetaEnum& en = metaObject()->enumerator(metaObject()->indexOfEnumerator("ProjectionType"));
	QStringList l;
	for (int i=0;i<en.keyCount();++i)
		l << en.key(i);
	return l;
}

//! Get the translated projection name from its TypeKey for the current locale
QString StelCore::projectionTypeKeyToNameI18n(const QString& key) const
{
	const QMetaEnum& en = metaObject()->enumerator(metaObject()->indexOfEnumerator("ProjectionType"));
	QString s(getProjection(StelCore::FrameJ2000, (ProjectionType)en.keysToValue(key.toAscii()))->getNameI18());
	return s;
}

//! Get the projection TypeKey from its translated name for the current locale
QString StelCore::projectionNameI18nToTypeKey(const QString& nameI18n) const
{
	const QMetaEnum& en = metaObject()->enumerator(metaObject()->indexOfEnumerator("ProjectionType"));
	for (int i=0;i<en.keyCount();++i)
	{
		if (getProjection(StelCore::FrameJ2000, (ProjectionType)i)->getNameI18()==nameI18n)
			return en.valueToKey(i);
	}
	// Unknown translated name
	Q_ASSERT(0);
	return en.valueToKey(ProjectionStereographic);
}