/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2008 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library 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 
 * OpenSceneGraph Public License for more details.
*/

#include "Exception.h"
#include "TerrainTile.h"
#include "Group.h"
#include "Layer.h"

#include <osgDB/Options>
#include <osgTerrain/GeometryTechnique>
#include <osgTerrain/Terrain>

using namespace ive;

void TerrainTile::write(DataOutputStream* out)
{
    // Write Terrain's identification.
    out->writeInt(IVETERRAINTILE);
    // If the osg class is inherited by any other class we should also write this to file.
    osg::Group*  group = dynamic_cast<osg::Group*>(this);
    if(group)
        ((ive::Group*)(group))->write(out);
    else
        out_THROW_EXCEPTION("Terrain::write(): Could not cast this osgTerrain::Terrain to an osg::Group.");

    if (out->getVersion() >= VERSION_0044)
    {
        out->writeInt(getBlendingPolicy());
    }

    if (out->getVersion() >= VERSION_0026)
    {
        out->writeInt(getTileID().level);
        out->writeInt(getTileID().x);
        out->writeInt(getTileID().y);
    }

    if (out->getVersion() >= VERSION_0023)
    {
        out->writeLocator(getLocator());
        out->writeLayer(getElevationLayer());

        out->writeUInt(getNumColorLayers());
        for(unsigned int i=0; i<getNumColorLayers(); ++i)
        {
            out->writeLayer(getColorLayer(i));
        }
    }
    else
    {
        LayerHelper helper;

        helper.writeLocator(out, getLocator());

        helper.writeLayer(out, getElevationLayer());

        out->writeUInt(getNumColorLayers());

        for(unsigned int i=0; i<getNumColorLayers(); ++i)
        {
            helper.writeLayer(out, getColorLayer(i));
        }
    }
        
    writeTerrainTechnique(out, getTerrainTechnique());
    
}

void TerrainTile::read(DataInputStream* in)
{
    // Peek on Terrain's identification.
    int id = in->peekInt();
    if (id != IVETERRAINTILE) in_THROW_EXCEPTION("TerrainTile::read(): Expected Terrain identification.");

    // Read Terrain's identification.
    id = in->readInt();
    // If the osg class is inherited by any other class we should also read this from file.
    osg::Group*  group = dynamic_cast<osg::Group*>(this);
    if(group)
        ((ive::Group*)(group))->read(in);
    else
        in_THROW_EXCEPTION("Terrain::read(): Could not cast this osgTerrain::Terrain to an osg::Group.");

    if (in->getVersion() >= VERSION_0044)
    {
        setBlendingPolicy(static_cast<osgTerrain::TerrainTile::BlendingPolicy>(in->readInt()));
    }

    if (in->getVersion() >= VERSION_0026)
    {
    
        int level = in->readInt();
        int x = in->readInt();
        int y = in->readInt();
        setTileID(osgTerrain::TileID(level,x,y));

        // OSG_NOTICE<<"Read TileID("<<level<<", "<<x<<", "<<y<<")"<<std::endl;
    }

    if (in->getVersion() >= VERSION_0023)
    {
        setLocator(in->readLocator());
        setElevationLayer(in->readLayer());
        unsigned int numColorLayers = in->readUInt();
        for(unsigned int i=0; i<numColorLayers; ++i)
        {
            setColorLayer(i, in->readLayer());
        }        
    }
    else
    {
        LayerHelper helper;

        setLocator(helper.readLocator(in));

        setElevationLayer(helper.readLayer(in));

        unsigned int numColorLayers = in->readUInt();
        for(unsigned int i=0; i<numColorLayers; ++i)
        {
            setColorLayer(i, helper.readLayer(in));
        }
    }
        
    setTerrainTechnique(readTerrainTechnique(in));

    if (in->getOptions())
    {
        osg::ref_ptr<osg::Node> node;
        if (in->getOptions()->getTerrain().lock(node))
        {
            setTerrain(node->asTerrain());
        }
    }

    if (osgTerrain::TerrainTile::getTileLoadedCallback().valid()) 
        osgTerrain::TerrainTile::getTileLoadedCallback()->loaded(this, in->getOptions());
}

void TerrainTile::writeTerrainTechnique(DataOutputStream* out, osgTerrain::TerrainTechnique* technique)
{
    if (dynamic_cast<osgTerrain::GeometryTechnique*>(technique))
    {
        out->writeBool(true);
        out->writeInt(IVEGEOMETRYTECHNIQUE);
    }
    else
    {
        out->writeBool(false);
    }
}

osgTerrain::TerrainTechnique* TerrainTile::readTerrainTechnique(DataInputStream* in)
{
    bool hasTechnique = in->readBool();
    if (!hasTechnique) return 0;

    int id = in->readInt();
    if (id==IVEGEOMETRYTECHNIQUE)
    {
        return new osgTerrain::GeometryTechnique;
    }
    else
    {
        return 0;
    }
}
