/*
  SWWViewer

  An OpenSceneGraph viewer for pyVolution SWW files.
  copyright (C) 2004-2005 Geoscience Australia
*/

#include <iostream>
#include <fstream>

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

#include <animation.h>
#include <project.h>
#include <SWWReader.h>
#include <bedslope.h>
#include <hud.h>
#include <keyboardeventhandler.h>
#include <directionallight.h>
#include <state.h>
#include <watersurface.h>
#include <customviewer.h>
#include <customargumentparser.h>

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


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

   // use an ArgumentParser object to manage the program arguments.
   // this custom version detects if the last argument is a macro file
   // and modifies the argument list accordingly so the following code works ...
   CustomArgumentParser 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 0-1>", "Transparency value at hmin");
   arguments.getApplicationUsage()->addCommandLineOption("-alphamax <float 0-1>", "Maximum transparency clamp value");
   arguments.getApplicationUsage()->addCommandLineOption("-lightpos <float>,<float>,<float>", "x,y,z of bedslope directional light (z is up, default is overhead)");
   arguments.getApplicationUsage()->addCommandLineOption("-movie <dirname>", "Save numbered images to named directory and quit");
   arguments.getApplicationUsage()->addCommandLineOption("-loop", "Repeated (looped) playback of .swm files");
   arguments.getApplicationUsage()->addCommandLineOption("-nosky", "Omit background sky");
   arguments.getApplicationUsage()->addCommandLineOption("-cullangle <float angle 0-90>", "Cull triangles steeper than this value");
   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(200,300,400,300);
   viewer.getCullSettings().setComputeNearFarMode( osg::CullSettings::COMPUTE_NEAR_FAR_USING_PRIMITIVES );


   // animation
   StateList statelist;
   bool playbackmode;
   bool recordingmode = false;
   bool savemovie = false;
   bool loop = false;
   unsigned int playback_index = 0;
   std::string moviedir;
   Animation animation;

   if( arguments.isSWM() )
   {
      playbackmode = true;
      statelist.read( arguments.getFilename() );
      if( arguments.read("-movie",moviedir) ) 
      {
         savemovie = true;  // flag to store frames and quit ...
         animation.setDirectory( moviedir );
         animation.setViewer( viewer );
      }
      if( arguments.read("-loop") ) 
         loop = true;
   }
   else
   {
      playbackmode = false;
      savemovie = false;
      loop = true;  // playback in none macro mode should loop (otherwise you don't get a chance to save)
   }


   // 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.read("--help") || arguments.read("-h") )
   {
      arguments.getApplicationUsage()->write(std::cout);
      return 1;
   }


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


   // last argument is either an sww file or an swm macro recording
   int lastarg = arguments.argc()-1;
   std::string swwfile = arguments.argv()[lastarg];
   arguments.remove(lastarg);
   if( osgDB::getLowerCaseFileExtension(swwfile) != std::string("sww") )
   {
      std::cout << "Require last argument be an .sww/.swm 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;
   }


   // need swollen binary directory which contains resource images
   char *ptr;
   if( (ptr = getenv( "SWOLLEN_BINDIR" )) )
      sww->setSwollenDir( std::string(ptr) );
   else if( osgDB::getFilePath(argv[0]) == "" )
      sww->setSwollenDir( std::string(".") );
   else
      sww->setSwollenDir( osgDB::getFilePath(argv[0]) );
   std::cout << sww->getSwollenDir() << std::endl;


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

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

   // 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");
   if( arguments.isSWM() )
      hud->setMode("playback");


   // Lighting
   DirectionalLight* light = new DirectionalLight(rootStateSet);
   light->setPosition( osg::Vec3(1,1,1) );  // z is up

   std::string lightposstr;
   while (arguments.read("-lightpos",lightposstr))
   {
      float x, y, z;
      int count = sscanf( lightposstr.c_str(), "%f,%f,%f", &x, &y, &z );
      if( count == 3 ) light->setPosition( osg::Vec3(x,y,z) );  // z is up
      else osg::notify(osg::WARN) << "Invalid bedslope light position \"" << lightposstr << "\"" << std::endl;
   }



   // scenegraph hierarchy
   rootnode->setStateSet(rootStateSet);
   rootnode->addChild( hud->get() );
   rootnode->addChild( light->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, sww->getSwollenDir() + std::string("/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
   CustomTerrainManipulator* terrainmanipulator = viewer.getTerrainManipulator();
   terrainmanipulator->setNode( model );
   terrainmanipulator->setAutoComputeHomePosition( false );
   terrainmanipulator->setHomePosition(
      osg::Vec3d(0,-3,3),    // camera location
      osg::Vec3d(0,0,0),     // camera target
      osg::Vec3d(0,1,1) );   // camera up vector
   terrainmanipulator->moveToHome();
   terrainmanipulator->enable();

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

      // user hits 'escape' to exit
      if( viewer.done() )
         done = true;


      if( !playbackmode )
      {

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

         event_handler->setTime( time );
         timestep = event_handler->getTimestep();
         water->setTimeStep(timestep);
         hud->setTime( sww->getTime(timestep) );


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

         // '1' key starts/stops recording of view/position/setting info
         if( event_handler->toggleRecording() )
         {
            switch( recordingmode )
            {
               case false : 
                  recordingmode = true; 
                  hud->setMode("recording");
                  break;
               case true : 
                  recordingmode = false; 
                  hud->setMode("");
                  break;
            }
         }


         // '2' key starts playback of recorded frames
         if( event_handler->togglePlayback() && statelist.size() > 0 )
         {
            recordingmode = false;
            playbackmode = true; 
            hud->setMode("playback");
            event_handler->setPaused( true );
            playback_index = 0;
         }

         if( recordingmode )
         {
            State state = State();
            state.setTimestep( event_handler->getTimestep() );
            state.setCulling( sww->getCulling() );
            state.setWireframe( water->getWireframe() );
            state.setMatrix( viewer.getViewMatrix() );
            statelist.push_back( state );
         }
      }

      else

      {
         // might need to save image from previous pass ...
         if( savemovie )
            animation.saveImage( playback_index );

         // in playback mode
         State state = statelist.at( playback_index );
         water->setTimeStep( state.getTimestep() );
         water->setWireframe( state.getWireframe() );
         water->setCulling( state.getCulling() );
         hud->setTime( sww->getTime(state.getTimestep()) );

         // loop playback
         playback_index ++;
         if( playback_index == statelist.size() )
         {
            if( loop )
               playback_index = 0;
            else
               done = true;
         }

         // '2' key stops playback of recorded frames
         if( event_handler->togglePlayback() )
         {
            playbackmode = false; 
            hud->setMode("");
            event_handler->setPaused( true );
         }

         viewer.setView( state.getMatrix() );
      }


      // '3' key causes compiled animation to be saved to disk
      if( event_handler->toggleSave() )
      {
         std::fstream f;
         f.open( "movie.swm", std::fstream::out );
         if( f.is_open() )
         {
            f << "# SWM 1.0 START" << std::endl;
            arguments.write( f );
            statelist.write( f );
            f << "# SWM END" << std::endl;
            f.close();
         }
         std::cout << "Wrote macro file movie.swm" << std::endl;
      }

      // scene-graph updates
      bedslope->update();
      hud->update();
      water->update();

      // 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;
}