/*
    SWWViewer

    An OpenSceneGraph viewer for pyVolution SWW files.
    copyright (C) 2004 Geoscience Australia
*/

#include <osg/Group>
#include <osg/Material>
#include <osg/MatrixTransform>
#include <osg/Notify>
#include <osg/PositionAttitudeTransform>
#include <osg/StateAttribute>

#include <project.h>
#include <SWWReader.h>
#include <bedslope.h>
#include <customtrackball.h>
#include <customviewer.h>
#include <hud.h>
#include <keyboardeventhandler.h>
#include <spotlight.h>
#include <watersurface.h>


// prototypes
osg::Transform* createSky(float radius, char* filename);
extern const char* version();


int main( int argc, char **argv )
{

    // use an ArgumentParser object to manage the program arguments
    osg::ArgumentParser arguments(&argc,argv);

    // set up the usage document
    std::string appname = arguments.getApplicationName();
    arguments.getApplicationUsage()->setDescription( appname );
    arguments.getApplicationUsage()->setCommandLineUsage("swollen [options] swwfile ...");
    arguments.getApplicationUsage()->addCommandLineOption("-help","Display this information");
    arguments.getApplicationUsage()->addCommandLineOption("-scale <float>","Vertical scale factor");
    arguments.getApplicationUsage()->addCommandLineOption("-tps <rate>","Timesteps per second");
    arguments.getApplicationUsage()->addCommandLineOption("-hmin <float>","Height below which transparency is set to zero");    
    arguments.getApplicationUsage()->addCommandLineOption("-hmax <float>","Height above which transparency is set to alphamax");       
    arguments.getApplicationUsage()->addCommandLineOption("-alphamin <float>","Transparency value at hmin");    
    arguments.getApplicationUsage()->addCommandLineOption("-alphamax <float>","Maximum transparency clamp value");
    arguments.getApplicationUsage()->addCommandLineOption("-nosky","Omit background sky");
    arguments.getApplicationUsage()->addCommandLineOption("-texture <file>","Image to use for bedslope topography");
    arguments.getApplicationUsage()->addCommandLineOption("-version","Revision number and creation (not compile) date");

    // construct the viewer.
    CustomViewer viewer(arguments);

    // set up with sensible default event handlers
    viewer.setUpViewer( osgProducer::Viewer::STANDARD_SETTINGS );
    viewer.setClearColor( osg::Vec4(DEF_BACKGROUND_COLOUR) );
    viewer.getCamera(0)->getRenderSurface()->setWindowRectangle(200,100,800,600);
    viewer.getCullSettings().setComputeNearFarMode( osg::CullSettings::COMPUTE_NEAR_FAR_USING_PRIMITIVES );


    // get details on keyboard and mouse bindings used by the viewer
    viewer.getUsage(*arguments.getApplicationUsage());

    // if user requested help, write it out to cout
    if( arguments.read("-help") )
    {
        arguments.getApplicationUsage()->write(std::cout);
        return 1;
    }

    // same for version info
    if( arguments.read("-version") )
    {
	std::cout << version() << std::endl;
        return 1;
    }



    // load sww file specified as final argument on command line (static bedslope
    // geometry only, per timestep height field geometry is done in loop below)
    int lastarg = arguments.argc()-1;
    std::string swwfile = arguments.argv()[lastarg];
    arguments.remove(lastarg);
    if( swwfile.substr(swwfile.size()-4,4).find(".sww",0) == -1 )  // ensure filename ends in .sww
    {
        std::cout << "Require last argument be an .sww file ... quitting" << std::endl;
        return 1; 
    }
    SWWReader *sww = new SWWReader(swwfile);
    if (sww->isValid() == false)
    {
        std::cout << "Unable to load " << swwfile << " ... is this really an .sww file?" << std::endl;
        return 1;
    }


    // default arguments and command line parameters
    float tps;
    if( !arguments.read("-tps",tps) || tps <= 0.0 ) tps = DEF_TPS;
    float vscale;
    if( !arguments.read("-scale",vscale) ) vscale = 1.0;

    std::string bedslopetexture;
    if( arguments.read("-texture",bedslopetexture) ) sww->setBedslopeTexture( bedslopetexture );

    float tmpfloat;
    if( arguments.read("-hmin",tmpfloat) ) sww->setHeightMin( tmpfloat );  
    if( arguments.read("-hmax",tmpfloat) ) sww->setHeightMax( tmpfloat );      
    if( arguments.read("-alphamin",tmpfloat) ) sww->setAlphaMin( tmpfloat );   
    if( arguments.read("-alphamax",tmpfloat) ) sww->setAlphaMax( tmpfloat );
        

    // root node
    osg::Group* rootnode = new osg::Group;

    // transform
    osg::PositionAttitudeTransform* model = new osg::PositionAttitudeTransform;
    model->setName("position_attitude_transform");

    // enscapsulates OpenGL state
    osg::StateSet* rootStateSet = new osg::StateSet;

    // Bedslope geometry
    BedSlope* bedslope = new BedSlope(sww);

    // Water geometry
    WaterSurface* water = new WaterSurface(sww);

    // Heads Up Display (text overlay)
    HeadsUpDisplay* hud = new HeadsUpDisplay();
    hud->setTitle("pyVolution SWW Viewer");


    // Lighting
    SpotLight* spotlight = new SpotLight(rootStateSet);
    spotlight->setPosition( osg::Vec3(0,1,0) );  // z is up
    spotlight->setSpotAngle( 45.0 );


    // scenegraph hierarchy
    rootnode->setStateSet(rootStateSet);
    rootnode->addChild( hud->get() );
    rootnode->addChild( spotlight->get() );
    rootnode->addChild(model);
    model->addChild( bedslope->get() );
    model->addChild( water->get() );


    // allow vertical scaling from command line parameter
    model->setScale( osg::Vec3(1.0, 1.0, vscale) );

    // surrounding sky sphere
    if( !arguments.read("-nosky") )
      rootnode->addChild( createSky(10.0, "sky_small.jpg") ); 


    // add model to viewer.
    viewer.setSceneData(rootnode);
 
    // any option left unread are converted into errors to write out later.
    arguments.reportRemainingOptionsAsUnrecognized();
 
    // report any errors if they have occured when parsing the program aguments.
    if (arguments.errors())
    {
        arguments.writeErrorMessages(std::cout);
        return 1;
    }

    // register additional event handler
    KeyboardEventHandler* event_handler = new KeyboardEventHandler(sww->getNumberOfTimesteps(), tps);
    viewer.getEventHandlerList().push_front(event_handler);

 
    // create the windows and run the threads.
    viewer.realize();


    // initial camera position
    CustomTrackballManipulator* trackball = viewer.getTrackball();
    trackball->setNode( model );
    trackball->setAutoComputeHomePosition( false );
    trackball->setHomePosition(
        osg::Vec3d(0,1,0),    // location
        osg::Vec3d(0,0,0),     // target
        osg::Vec3d(0,0,1) );   // up vector
    trackball->moveToHome();
    trackball->disable();


    CustomTerrainManipulator* terrainmanipulator = viewer.getTerrainManipulator();
    terrainmanipulator->setNode( rootnode );
    terrainmanipulator->setAutoComputeHomePosition( false );
    terrainmanipulator->setHomePosition(
        osg::Vec3d(0,-3,0),    // camera location
        osg::Vec3d(0,0,0),     // camera target
        osg::Vec3d(0,0,1) );   // camera up vector
    terrainmanipulator->moveToHome();
    terrainmanipulator->enable();


    unsigned int timestep = 0;
    while( !viewer.done() )
    {
    
        // wait for all cull and draw threads to complete.
        viewer.sync();

        // current time
        double time = viewer.getFrameStamp()->getReferenceTime();

        // advance sww frame?
        event_handler->setTime( time );
        if( event_handler->timestepChanged() )
        {
            timestep = event_handler->getTimestep();
            water->setTimeStep(timestep);
            hud->setTime( sww->getTime(timestep) );
        }

	// light position manipulator
	if( trackball->isEnabled() )
	{
	    //osg::Matrixd matrix = trackball->getInverseMatrix();
	   osg::Matrixd matrix = trackball->getMatrix();
	   osg::Vec3d position = matrix.getTrans();
	   //std::cout << "trackball position x: " << position. << std::endl;
	   spotlight->setPosition( position );
	}


        // events
        if( event_handler->toggleWireframe() )
            water->toggleWireframe();

	// click-mouse movement can change either camera view or scene light position
        if( event_handler->toggleManipulatorMode() )
	{
	    if( trackball->isEnabled() )
	    {
		trackball->disable();
		terrainmanipulator->enable();
	    }
	    else
	    {
		trackball->enable();
		terrainmanipulator->disable();
	    }
	}
	

       // update the scene by traversing with the update visitor 
        viewer.update();
         
        // fire off the cull and draw traversals of the scene.
        viewer.frame();
    }
    
    // wait for all cull and draw threads to complete before exit.
    viewer.sync();

    return 0;
}