/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 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.
*/
//osgManipulator - Copyright (C) 2007 Fugro-Jason B.V.

#ifndef OSGMANIPULATOR_DRAGGER
#define OSGMANIPULATOR_DRAGGER 1

#include <osgManipulator/Selection>

#include <osg/BoundingSphere>
#include <osgUtil/SceneView>
#include <osgUtil/IntersectVisitor>
#include <osgGA/GUIEventAdapter>
#include <osgGA/GUIActionAdapter>

namespace osgManipulator
{

class CommandManager;
class CompositeDragger;

class OSGMANIPULATOR_EXPORT PointerInfo
{
    public:

        PointerInfo();

        PointerInfo(const PointerInfo& rhs):
            _hitList(rhs._hitList),
            _nearPoint(rhs._nearPoint),
            _farPoint(rhs._farPoint),
            _eyeDir(rhs._eyeDir)
        {
            _hitIter = _hitList.begin();
        }

        void reset()
        {
            _hitList.clear();
            _hitIter = _hitList.begin();
            setCamera(0);                
        }


        bool completed() const { return _hitIter==_hitList.end(); }

        void next() 
        {
            if (!completed()) ++_hitIter;
        }

        typedef std::pair<osg::NodePath, osg::Vec3> NodePathIntersectionPair;
        typedef std::list< NodePathIntersectionPair> IntersectionList;


        osg::Vec3 getLocalIntersectPoint() const { return _hitIter->second; }


        
        void setNearFarPoints (osg::Vec3 nearPoint, osg::Vec3 farPoint) {
            _nearPoint = nearPoint;
            _farPoint=farPoint;
            _eyeDir = farPoint - nearPoint;
        }
        
        const osg::Vec3& getEyeDir() const {return _eyeDir;}
        
        void getNearFarPoints( osg::Vec3& nearPoint, osg::Vec3& farPoint) const {
            nearPoint = _nearPoint;
            farPoint = _farPoint;
        }

        bool contains(const osg::Node* node) const;

        void setCamera(osg::Camera* camera)
        {
            
            if (camera)
            {
                _MVPW = camera->getViewMatrix() * camera->getProjectionMatrix();
                if (camera->getViewport()) _MVPW.postMult(camera->getViewport()->computeWindowMatrix());
                _inverseMVPW.invert(_MVPW);
                osg::Vec3 eye, center, up;
                camera->getViewMatrix().getLookAt(eye, center, up);
                _eyeDir = eye - center;

            }
            else
            {
                _MVPW.makeIdentity();
                _inverseMVPW.makeIdentity();
                _eyeDir = osg::Vec3(0,0,1);
            }

        }

        void addIntersection(const osg::NodePath& nodePath, const osg::Vec3& intersectionPoint)
        {
            bool needToResetHitIter = _hitList.empty();
            _hitList.push_back(NodePathIntersectionPair(nodePath, intersectionPoint));
            if (needToResetHitIter) _hitIter = _hitList.begin();
        }

        void setMousePosition(float pixel_x, float pixel_y)
        {   
            projectWindowXYIntoObject(osg::Vec2(pixel_x, pixel_y), _nearPoint, _farPoint);
        }
    protected:
        bool projectWindowXYIntoObject(const osg::Vec2& windowCoord, osg::Vec3& nearPoint, osg::Vec3& farPoint) const;

    public:
        IntersectionList _hitList;
        IntersectionList::const_iterator _hitIter;

    protected:
       
        osg::Vec3 _nearPoint,_farPoint;
        osg::Vec3 _eyeDir;

        osg::Matrix _MVPW;
        osg::Matrix _inverseMVPW;

};

/**
 * Base class for draggers. Concrete draggers implement the pick event handler
 * and generate motion commands (translate, rotate, ...) and sends these 
 * command to the CommandManager. The CommandManager dispatches the commands 
 * to all the Selections that are connected to the Dragger that generates the
 * commands.
 */
class OSGMANIPULATOR_EXPORT Dragger : public Selection
{
    public:

        /** Set/Get the CommandManager. Draggers use CommandManager to dispatch commands. */
        virtual void setCommandManager(CommandManager* cm) { _commandManager = cm; }
        CommandManager* getCommandManager() { return _commandManager; }
        const CommandManager* getCommandManager() const { return _commandManager; }

        /**
         * Set/Get parent dragger. For simple draggers parent points to itself.
         * For composite draggers parent points to the parent dragger that uses
         * this dragger.
         */
        virtual void setParentDragger(Dragger* parent) { _parentDragger = parent; }
        Dragger* getParentDragger() { return _parentDragger; }
        const Dragger* getParentDragger() const { return _parentDragger; }

        /** Returns 0 if this Dragger is not a CompositeDragger. */
        virtual const CompositeDragger* getComposite() const { return 0; }

        /** Returns 0 if this Dragger is not a CompositeDragger. */
        virtual CompositeDragger* getComposite() { return 0; }


        virtual bool handle(const PointerInfo&, const osgGA::GUIEventAdapter&, osgGA::GUIActionAdapter&) { return false; }

    protected:

        Dragger();
        virtual ~Dragger();
        
        CommandManager* _commandManager;

        Dragger*  _parentDragger;
       
};


/**
 * CompositeDragger allows to create complex draggers that are composed of a 
 * hierarchy of Draggers.
 */
class OSGMANIPULATOR_EXPORT CompositeDragger : public Dragger
{
    public:

        typedef std::vector< osg::ref_ptr<Dragger> > DraggerList;
        
        virtual const CompositeDragger* getComposite() const { return this; }
        virtual CompositeDragger* getComposite() { return this; }

        virtual void setCommandManager(CommandManager* cm);

        virtual void setParentDragger(Dragger* parent);

        virtual bool handle(const PointerInfo& pi, const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        // Composite-specific methods below
        virtual bool addDragger(Dragger* dragger);
        virtual bool removeDragger(Dragger* dragger);
        unsigned int getNumDraggers() const { return _draggerList.size(); }
        Dragger* getDragger(unsigned int i) { return _draggerList[i].get(); }
        const Dragger* getDragger(unsigned int i) const { return _draggerList[i].get(); }
        bool containsDragger(const Dragger* dragger) const;
        DraggerList::iterator findDragger(const Dragger* dragger);

    protected:

        CompositeDragger() {}
        virtual ~CompositeDragger() {}
        
        DraggerList _draggerList;
};

/**
 * Culls the drawable all the time. Used by draggers to have invisible geometry
 * around lines and points so that they can be picked. For example, a dragger
 * could have a line with an invisible cylinder around it to enable picking on 
 * that line.
 */
void OSGMANIPULATOR_EXPORT setDrawableToAlwaysCull(osg::Drawable& drawable);

/**
 * Convenience function for setting the material color on a node.
 */
void OSGMANIPULATOR_EXPORT setMaterialColor(const osg::Vec4& color, osg::Node& node);

}

#endif