/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This application is open source and may be redistributed and/or modified
 * freely and without restriction, both in commercial and non commercial applications,
 * as long as this copyright notice is maintained.
 *
 * This application 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.
*/

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

#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>

#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgGA/KeySwitchMatrixManipulator>
#include <osgGA/StateSetManipulator>
#include <osgGA/AnimationPathManipulator>
#include <osgGA/TerrainManipulator>

#include <iostream>



int main(int argc, char** argv)
{
    // use an ArgumentParser object to manage the program arguments.
    osg::ArgumentParser arguments(&argc,argv);

    arguments.getApplicationUsage()->setApplicationName(arguments.getApplicationName());
    arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+
            " is an example of conversion of fixed function pipeline to GLSL");
    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");

    osgViewer::Viewer viewer(arguments);



    unsigned int helpType = 0;
    if ((helpType = arguments.readHelpType()))
    {
        arguments.getApplicationUsage()->write(std::cout, helpType);
        return 1;
    }

    // report any errors if they have occurred when parsing the program arguments.
    if (arguments.errors())
    {
        arguments.writeErrorMessages(std::cout);
        return 1;
    }

    if (arguments.argc()<=1)
    {
        arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
        return 1;
    }

    // set up the camera manipulators.
    {
        osg::ref_ptr<osgGA::KeySwitchMatrixManipulator> keyswitchManipulator = new osgGA::KeySwitchMatrixManipulator;

        keyswitchManipulator->addMatrixManipulator( '1', "Trackball", new osgGA::TrackballManipulator() );
        keyswitchManipulator->addMatrixManipulator( '2', "Flight", new osgGA::FlightManipulator() );
        keyswitchManipulator->addMatrixManipulator( '3', "Drive", new osgGA::DriveManipulator() );
        keyswitchManipulator->addMatrixManipulator( '4', "Terrain", new osgGA::TerrainManipulator() );

        std::string pathfile;
        char keyForAnimationPath = '5';
        while (arguments.read("-p",pathfile))
        {
            osgGA::AnimationPathManipulator* apm = new osgGA::AnimationPathManipulator(pathfile);
            if (apm || !apm->valid())
            {
                unsigned int num = keyswitchManipulator->getNumMatrixManipulators();
                keyswitchManipulator->addMatrixManipulator( keyForAnimationPath, "Path", apm );
                keyswitchManipulator->selectMatrixManipulator(num);
                ++keyForAnimationPath;
            }
        }

        viewer.setCameraManipulator( keyswitchManipulator.get() );
    }

    // add the state manipulator
    viewer.addEventHandler( new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );

    // add the thread model handler
    viewer.addEventHandler(new osgViewer::ThreadingHandler);

    // add the window size toggle handler
    viewer.addEventHandler(new osgViewer::WindowSizeHandler);

    // add the stats handler
    viewer.addEventHandler(new osgViewer::StatsHandler);

    // add the help handler
    viewer.addEventHandler(new osgViewer::HelpHandler(arguments.getApplicationUsage()));

    // add the record camera path handler
    viewer.addEventHandler(new osgViewer::RecordCameraPathHandler);

    // add the LOD Scale handler
    viewer.addEventHandler(new osgViewer::LODScaleHandler);

    // add the screen capture handler
    viewer.addEventHandler(new osgViewer::ScreenCaptureHandler);

    osg::ref_ptr<osg::Program> uberProgram = new osg::Program;
    std::string shaderFilename;
    while(arguments.read("--shader", shaderFilename))
    {
        osg::ref_ptr<osg::Shader> shader = osgDB::readRefShaderFile(shaderFilename);
        if (shader.valid()) uberProgram->addShader(shader.get());
    }

    std::string outputFilename;
    if (arguments.read("-o", outputFilename)) {}

    // load the data
    osg::ref_ptr<osg::Node> loadedModel = osgDB::readRefNodeFiles(arguments);
    if (!loadedModel)
    {
        std::cout << arguments.getApplicationName() <<": No data loaded" << std::endl;
        return 1;
    }

    osg::ref_ptr<osg::StateSet> rootStateSet = viewer.getCamera()->getStateSet();

    // run the shadergen on the loaded scene graph, and assign the uber shader
    osgUtil::ShaderGenVisitor shadergen;

    if (uberProgram->getNumShaders()>0)
    {
        rootStateSet->setAttribute(uberProgram.get());
        rootStateSet->addUniform(new osg::Uniform("diffuseMap", 0));

        shadergen.remapStateSet(rootStateSet.get());
    }
    else
    {
        shadergen.assignUberProgram(rootStateSet.get());
    }

    loadedModel->accept(shadergen);

    if (!outputFilename.empty())
    {
        osgDB::writeNodeFile(*loadedModel, outputFilename);
        osgDB::writeObjectFile(*(viewer.getCamera()->getStateSet()),"rootStateSet.osgt");
        return 0;
    }


    // any option left unread are converted into errors to write out later.
    arguments.reportRemainingOptionsAsUnrecognized();

    // report any errors if they have occurred when parsing the program arguments.
    if (arguments.errors())
    {
        arguments.writeErrorMessages(std::cout);
        return 1;
    }

    viewer.setSceneData( loadedModel.get() );

    viewer.realize();

    return viewer.run();

}