/*  -*-c++-*- 
 *  Copyright (C) 2008 Cedric Pinson <cedric.pinson@plopbyte.net>
 *
 * 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.
 * 
 * Authors:
 *         Cedric Pinson <cedric.pinson@plopbyte.net>
 *         Michael Platings <mplatings@pixelpower.com>
 */

#ifndef OSGANIMATION_BONE_H
#define OSGANIMATION_BONE_H

#include <osg/Transform>
#include <osg/Quat>
#include <osg/Vec3>
#include <osg/Node>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/io_utils>
#include <osg/NodeVisitor>
#include <osgAnimation/Export>
#include <osgAnimation/Target>
#include <osgAnimation/Sampler>
#include <osgAnimation/Channel>
#include <osgAnimation/Keyframe>
#include <osgAnimation/UpdateCallback>
#include <osgAnimation/Animation>
#include <osgAnimation/AnimationManagerBase>
#include <osgAnimation/VertexInfluence>

namespace osgAnimation 
{

    // A bone can't have more than one parent Bone, so sharing a part of Bone's hierarchy
    // has not sense. You can share the entire hierarchie but not only a part of
    class OSGANIMATION_EXPORT Bone : public osg::Transform
    {
    public:
        typedef osg::ref_ptr<Bone> PointerType;
        typedef std::map<std::string, PointerType > BoneMap;
        typedef osg::Matrix MatrixType;

        META_Node(osgAnimation, Bone);
        Bone(const Bone& b, const osg::CopyOp& copyop= osg::CopyOp::SHALLOW_COPY);
        Bone(const std::string& name = "");

        void setDefaultUpdateCallback(const std::string& name = "");

        struct BoneMapVisitor : public osg::NodeVisitor
        {
            BoneMap _map;
            BoneMapVisitor(): osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {}

            META_NodeVisitor("osgAnimation","BoneMapVisitor")

            void apply(osg::Node&) { return; }
            void apply(osg::Transform& node)
            {
                Bone* bone = dynamic_cast<Bone*>(&node);
                if (bone) 
                {
                    _map[bone->getName()] = bone;
                    traverse(node);
                }
            }
        };

        struct FindNearestParentAnimationManager : public osg::NodeVisitor
        {
            osg::ref_ptr<osgAnimation::AnimationManagerBase> _manager;
            FindNearestParentAnimationManager() : osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_PARENTS) {}
            void apply(osg::Node& node)
            {
                if (_manager.valid())
                    return;
                osg::NodeCallback* callback = node.getUpdateCallback();
                while (callback) 
                {
                    _manager = dynamic_cast<osgAnimation::AnimationManagerBase*>(callback);
                    if (_manager.valid())
                        return;
                    callback = callback->getNestedCallback();
                }
                traverse(node);
            }
        };


        class OSGANIMATION_EXPORT UpdateBone : public AnimationUpdateCallback <osg::NodeCallback>
        {
        protected:
            osg::ref_ptr<osgAnimation::Vec3Target> _position;
            osg::ref_ptr<osgAnimation::QuatTarget> _quaternion;
            osg::ref_ptr<osgAnimation::Vec3Target> _scale;
    
        public:
            META_Object(osgAnimation, UpdateBone);
            UpdateBone(const UpdateBone& apc,const osg::CopyOp& copyop);

            UpdateBone(const std::string& name = "") : AnimationUpdateCallback <osg::NodeCallback>(name)
            {
                setName(name);
                _quaternion = new osgAnimation::QuatTarget;
                _position = new osgAnimation::Vec3Target;
                _scale = new osgAnimation::Vec3Target;
            }

            void update(osgAnimation::Bone& bone)
            {
                bone.setTranslation(_position->getValue());
                bone.setRotation(_quaternion->getValue());
                bone.setScale(_scale->getValue());
                bone.dirtyBound();
            }

            bool needLink() const
            {
                // the idea is to return true if nothing is linked
                return !((_position->getCount() + _quaternion->getCount() + _scale->getCount()) > 3);
            }

            bool link(osgAnimation::Channel* channel)
            {
                if (channel->getName().find("quaternion") != std::string::npos)
                {
                    return channel->setTarget(_quaternion.get());
                }
                else if (channel->getName().find("position") != std::string::npos)
                {
                    return channel->setTarget(_position.get());
                }
                else if (channel->getName().find("scale") != std::string::npos)
                {
                    return channel->setTarget(_scale.get());
                }
                else 
                {
                    osg::notify(osg::WARN) << "Channel " << channel->getName() << " does not contain a valid symbolic name for this class" << className() << std::endl;
                }
                return false;
            }

            /** Callback method called by the NodeVisitor when visiting a node.*/
            virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
            {
                if (nv && nv->getVisitorType() == osg::NodeVisitor::UPDATE_VISITOR) 
                {
                    Bone* b = dynamic_cast<Bone*>(node);
                    if (b && !_manager.valid()) 
                    {
                        FindNearestParentAnimationManager finder;

                        if (b->getParents().size() > 1) 
                        {
                            osg::notify(osg::WARN) << "A Bone should not have multi parent ( " << b->getName() << " ) has parents ";
                            osg::notify(osg::WARN) << "( " << b->getParents()[0]->getName();
                            for (int i = 1; i < (int)b->getParents().size(); i++)
                                osg::notify(osg::WARN) << ", " << b->getParents()[i]->getName();
                            osg::notify(osg::WARN) << ")" << std::endl;
                            return;
                        }
                        b->getParents()[0]->accept(finder);

                        if (!finder._manager.valid())
                        {
                            osg::notify(osg::WARN) << "Warning can't update Bone, path to parent AnimationManagerBase not found" << std::endl;
                            return;
                        }

                        _manager = finder._manager.get();
                    }

                    updateLink();
                    update(*b);
                }
                traverse(node,nv);
            }
        };

        virtual bool computeLocalToWorldMatrix(osg::Matrix& matrix,osg::NodeVisitor* nv) const;
        virtual bool computeWorldToLocalMatrix(osg::Matrix& matrix,osg::NodeVisitor* nv) const;

        Bone* getBoneParent();
        const Bone* getBoneParent() const;

        void setTranslation(const osg::Vec3& trans) { _position = trans;}
        void setRotation(const osg::Quat& quat) { _rotation = quat;}
        void setScale(const osg::Vec3& scale) { _scale = scale;}

        const osg::Vec3& getTranslation() const { return _position;}
        const osg::Quat& getRotation() const { return _rotation;}
        osg::Matrix getMatrixInBoneSpace() const { return (osg::Matrix(getRotation())) * osg::Matrix::translate(getTranslation()) * _bindInBoneSpace;}
        const osg::Matrix& getBindMatrixInBoneSpace() const { return _bindInBoneSpace; }
        const osg::Matrix& getMatrixInSkeletonSpace() const { return _boneInSkeletonSpace; }
        const osg::Matrix& getInvBindMatrixInSkeletonSpace() const { return _invBindInSkeletonSpace;}
        void setMatrixInSkeletonSpace(const osg::Matrix& matrix) { _boneInSkeletonSpace = matrix; }
        void setBindMatrixInBoneSpace(const osg::Matrix& matrix) 
        {
            _bindInBoneSpace = matrix;
            _needToRecomputeBindMatrix = true;
        }

        inline bool needToComputeBindMatrix() { return _needToRecomputeBindMatrix;}
        virtual void computeBindMatrix();

        void setNeedToComputeBindMatrix(bool state) { _needToRecomputeBindMatrix = state; }

        /** Add Node to Group.
         * If node is not NULL and is not contained in Group then increment its
         * reference count, add it to the child list and dirty the bounding
         * sphere to force it to recompute on next getBound() and return true for success.
         * Otherwise return false. Scene nodes can't be added as child nodes.
         */
        virtual bool addChild( Node *child );
        BoneMap getBoneMap();


    protected:

        osg::Vec3 _position;
        osg::Quat _rotation;
        osg::Vec3 _scale;


        // flag to recompute bind pose
        bool _needToRecomputeBindMatrix;

        // bind data
        osg::Matrix _bindInBoneSpace;
        osg::Matrix _invBindInSkeletonSpace;

        // bone updated
        osg::Matrix _boneInSkeletonSpace;
    
    };


    inline bool Bone::computeLocalToWorldMatrix(osg::Matrix& matrix,osg::NodeVisitor*) const
    {
        if (_referenceFrame==RELATIVE_RF) 
            matrix.preMult(getMatrixInBoneSpace());
        else 
            matrix = getMatrixInBoneSpace();
        return true;
    }


    inline bool Bone::computeWorldToLocalMatrix(osg::Matrix& matrix,osg::NodeVisitor*) const
    {
        if (_referenceFrame==RELATIVE_RF) 
            matrix.postMult(osg::Matrix::inverse(getMatrixInBoneSpace()));
        else
            matrix = osg::Matrix::inverse(getMatrixInBoneSpace());
        return true;
    }

}
#endif