#include <iostream>
#include <osg/Geometry>
#include <osg/MatrixTransform>
#include <osg/Geode>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgGA/TrackballManipulator>
#include <osgGA/StateSetManipulator>
#include <osgUtil/SmoothingVisitor>
#include <osg/io_utils>

#include <osgAnimation/MorphGeometry>
#include <osgAnimation/BasicAnimationManager>

#include <osgDB/ReadFile>
#include <osgDB/WriteFile>

osgAnimation::Animation* animation;
osgAnimation::BasicAnimationManager* bam;

// Mouse/Keyboard event handler
class PickHandler : public osgGA::GUIEventHandler {
public: 

    PickHandler() {}        
    ~PickHandler() {}
    
    bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa);
};

bool PickHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa)
{
    switch(ea.getEventType())
    {
        case(osgGA::GUIEventAdapter::PUSH):
        {
            osgViewer::View* view = dynamic_cast<osgViewer::View*>(&aa);
			// do smth with mouse. disabled for now.
            return false;
        }    

        case(osgGA::GUIEventAdapter::KEYDOWN):
        {
			
            if (ea.getKey()=='a')
            {        
				// Play animation
				bam->playAnimation(animation);
            }
            return false;
        }    
        default:
            return false;
    }
}

// Geometry loader
struct GeometryFinder : public osg::NodeVisitor
{
    osg::ref_ptr<osg::Geometry> _geom;
    GeometryFinder() : osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {}
    void apply(osg::Geode& geode) 
    {
        if (_geom.valid())
            return;
        for (unsigned int i = 0; i < geode.getNumDrawables(); i++) 
        {
            osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode.getDrawable(i));
            if (geom) {
                _geom = geom;
                return;
            }
        }
    }
};

// Geometry loader
osg::Geometry* getShape(const std::string& name)
{
    osg::Node* shape0 = osgDB::readNodeFile(name);
    GeometryFinder finder;
    shape0->accept(finder);
    return finder._geom.get();
}

int main (int argc, char* argv[])
{
    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer(arguments);

	animation = new osgAnimation::Animation;
    osgAnimation::FloatLinearChannel* channel0 = new osgAnimation::FloatLinearChannel;
    channel0->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(0,0.0));
    channel0->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(1,1.0));
    channel0->setTargetName("MorphNodeCallback");
    channel0->setName("0");

    osgAnimation::FloatLinearChannel* channel1 = new osgAnimation::FloatLinearChannel;
    channel1->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(0,1.0));
    channel1->getOrCreateSampler()->getOrCreateKeyframeContainer()->push_back(osgAnimation::FloatKeyframe(1,0.0));
    channel1->setTargetName("MorphNodeCallback");
    channel1->setName("1");

    animation->addChannel(channel0);
    animation->addChannel(channel1);
    animation->setName("Morph");
    animation->computeDuration();
    //animation->setPlaymode(osgAnimation::Animation::PPONG);
	animation->setPlaymode(osgAnimation::Animation::ONCE);	// Just play it once...

	bam = new osgAnimation::BasicAnimationManager;
    bam->registerAnimation(animation);


	// Create 2 geometries...
	// Is this really needed? We only want to modify the position of a vertex in a drawable...
	
	// State A (Just a simple quad for now)	 
	osg::Geometry* geom0 = new osg::Geometry;
	osg::Vec3Array* verts0 = new osg::Vec3Array;
	osg::Vec4Array* colors0 = new osg::Vec4Array;

	geom0->setName("StateA");

	double x = 0, y = 0, w = 10, h = 15;
	verts0->push_back(osg::Vec3(x + w,	0, y + h));	// top right
	verts0->push_back(osg::Vec3(x,		0, y + h));	// top left
	verts0->push_back(osg::Vec3(x,		0, y));	// bottom left			
	verts0->push_back(osg::Vec3(x + w,	0, y));	// bottom right
		
	colors0->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors0->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors0->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors0->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));

	geom0->setVertexArray(verts0);
	geom0->setColorArray(colors0);
	geom0->setColorBinding(osg::Geometry::BIND_PER_VERTEX);	
	geom0->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));


	// State B
	osg::Geometry* geom1 = new osg::Geometry;
	osg::Vec3Array* verts1 = new osg::Vec3Array;
	osg::Vec4Array* colors1 = new osg::Vec4Array;

	geom0->setName("StateB");

	x = 50; y = 0; w = 20; h = 30;
	verts1->push_back(osg::Vec3(x + w,	0, y + h));	// top right
	verts1->push_back(osg::Vec3(x,		0, y + h));	// top left
	verts1->push_back(osg::Vec3(x,		0, y));	// bottom left			
	verts1->push_back(osg::Vec3(x + w,	0, y));	// bottom right
		
	colors1->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors1->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors1->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));
	colors1->push_back(osg::Vec4 (1.0f, 0.0f, 0.0f, 1.0f));

	geom1->setVertexArray(verts1);
	geom1->setColorArray(colors1);
	geom1->setColorBinding(osg::Geometry::BIND_PER_VERTEX);	
	geom1->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));


/*
	// Using osg data sets to morph from shape0 to shape1
	// this works...

    osg::Geometry* geom0 = getShape("morphtarget_shape0.osg");
    if (!geom0) {
        std::cerr << "can't read morphtarget_shape0.osg" << std::endl;
        return 0;
    }

    osg::Geometry* geom1 = getShape("morphtarget_shape1.osg");
    if (!geom1) {
        std::cerr << "can't read morphtarget_shape1.osg" << std::endl;
        return 0;
    }
*/

    // initialize with the first shape
    osgAnimation::MorphGeometry* morph = new osgAnimation::MorphGeometry(*geom0);
    morph->addMorphTarget(geom0);
    morph->addMorphTarget(geom1);
	


    osg::Group* scene = new osg::Group;
	scene->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
    scene->addUpdateCallback(bam);
    
    osg::Geode* geode = new osg::Geode;
    geode->addDrawable(morph);
    geode->addUpdateCallback(new osgAnimation::UpdateMorph("MorphNodeCallback"));
    scene->addChild(geode);



	// Viewer settings
    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());
    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
	viewer.setCameraManipulator(new osgGA::TrackballManipulator());	
	viewer.addEventHandler(new PickHandler());	// press a to start animation

    // let's run !
    viewer.setSceneData( scene );
	viewer.setUpViewInWindow(40, 40, 1024, 768, 0);
    viewer.realize();
    
    while (!viewer.done())
    {
        viewer.frame();
    }

    //osgDB::writeNodeFile(*scene, "morph_scene.osg");

    return 0;
}