#include "riggeometryosgaextension.hpp"

#include <osgAnimation/RigGeometry>

#include <osg/Drawable>
#include <osg/NodeVisitor>

#include <osgUtil/CullVisitor>

#include <components/debug/debuglog.hpp>
#include <components/resource/scenemanager.hpp>

namespace SceneUtil
{

    OsgaRigGeometry::OsgaRigGeometry()
        : osgAnimation::RigGeometry()
    {
        setDataVariance(osg::Object::STATIC);
    }

    OsgaRigGeometry::OsgaRigGeometry(const osgAnimation::RigGeometry& copy, const osg::CopyOp& copyop)
        : osgAnimation::RigGeometry(copy, copyop)
    {
        setDataVariance(osg::Object::STATIC);
    }

    OsgaRigGeometry::OsgaRigGeometry(const OsgaRigGeometry& copy, const osg::CopyOp& copyop)
        : osgAnimation::RigGeometry(copy, copyop)
    {
        setDataVariance(osg::Object::STATIC);
    }

    void OsgaRigGeometry::computeMatrixFromRootSkeleton(osg::MatrixList mtxList)
    {
        if (!_root.valid())
        {
            Log(Debug::Warning) << "Warning " << className()
                                << "::computeMatrixFromRootSkeleton if you have this message it means you miss to call "
                                   "buildTransformer(Skeleton* root), or your RigGeometry ("
                                << getName() << ") is not attached to a Skeleton subgraph";
            return;
        }
        osg::Matrix notRoot = _root->getMatrix();
        _matrixFromSkeletonToGeometry = mtxList[0] * osg::Matrix::inverse(notRoot);
        _invMatrixFromSkeletonToGeometry = osg::Matrix::inverse(_matrixFromSkeletonToGeometry);
        _needToComputeMatrix = false;
    }

    RigGeometryHolder::RigGeometryHolder()
        : mBackToOrigin(nullptr)
        , mLastFrameNumber(0)
        , mIsBodyPart(false)
    {
    }

    RigGeometryHolder::RigGeometryHolder(const RigGeometryHolder& copy, const osg::CopyOp& copyop)
        : Drawable(copy, copyop)
        , mBackToOrigin(copy.mBackToOrigin)
        , mLastFrameNumber(0)
        , mIsBodyPart(copy.mIsBodyPart)
    {
        setUseVertexBufferObjects(true);

        if (!copy.getSourceRigGeometry())
        {
            Log(Debug::Error) << "copy constructor of RigGeometryHolder partially failed (no source RigGeometry)";
            return;
        }

        osg::ref_ptr<OsgaRigGeometry> rigGeometry = new OsgaRigGeometry(*copy.getSourceRigGeometry(), copyop);
        setSourceRigGeometry(std::move(rigGeometry));
    }

    RigGeometryHolder::RigGeometryHolder(const osgAnimation::RigGeometry& copy, const osg::CopyOp& copyop)
        : mBackToOrigin(nullptr)
        , mLastFrameNumber(0)
        , mIsBodyPart(false)
    {
        setUseVertexBufferObjects(true);

        osg::ref_ptr<OsgaRigGeometry> rigGeometry = new OsgaRigGeometry(copy, copyop);
        setSourceRigGeometry(std::move(rigGeometry));
    }

    void RigGeometryHolder::setSourceRigGeometry(osg::ref_ptr<OsgaRigGeometry> sourceRigGeometry)
    {
        for (unsigned int i = 0; i < 2; ++i)
            mGeometry.at(i) = nullptr;

        mSourceRigGeometry = sourceRigGeometry;

        _boundingBox = mSourceRigGeometry->getComputeBoundingBoxCallback()->computeBound(*mSourceRigGeometry);
        _boundingSphere = osg::BoundingSphere(_boundingBox);

        for (unsigned int i = 0; i < 2; ++i)
        {
            const OsgaRigGeometry& from = *sourceRigGeometry;

            // DO NOT COPY AND PASTE THIS CODE. Cloning osg::Geometry without also cloning its contained Arrays is
            // generally unsafe. In this specific case the operation is safe under the following two assumptions:
            // - When Arrays are removed or replaced in the cloned geometry, the original Arrays in their place must
            // outlive the cloned geometry regardless. (ensured by mSourceRigGeometry, possibly also
            // RigGeometry._geometry)
            // - Arrays that we add or replace in the cloned geometry must be explicitely forbidden from reusing
            // BufferObjects of the original geometry.
            mGeometry.at(i) = new OsgaRigGeometry(from, osg::CopyOp::SHALLOW_COPY);
            mGeometry.at(i)->getOrCreateUserDataContainer()->addUserObject(
                new Resource::TemplateRef(mSourceRigGeometry));

            OsgaRigGeometry& to = *mGeometry.at(i);
            to.setSupportsDisplayList(false);
            to.setUseVertexBufferObjects(true);
            to.setCullingActive(false); // make sure to disable culling since that's handled by this class

            to.setDataVariance(osg::Object::STATIC);
            to.setNeedToComputeMatrix(true);

            // vertices and normals are modified every frame, so we need to deep copy them.
            // assign a dedicated VBO to make sure that modifications don't interfere with source geometry's VBO.
            osg::ref_ptr<osg::VertexBufferObject> vbo(new osg::VertexBufferObject);
            vbo->setUsage(GL_DYNAMIC_DRAW_ARB);

            osg::ref_ptr<osg::Array> vertexArray
                = static_cast<osg::Array*>(from.getVertexArray()->clone(osg::CopyOp::DEEP_COPY_ALL));
            if (vertexArray)
            {
                vertexArray->setVertexBufferObject(vbo);
                to.setVertexArray(vertexArray);
            }

            if (const osg::Array* normals = from.getNormalArray())
            {
                osg::ref_ptr<osg::Array> normalArray
                    = static_cast<osg::Array*>(normals->clone(osg::CopyOp::DEEP_COPY_ALL));
                if (normalArray)
                {
                    normalArray->setVertexBufferObject(vbo);
                    to.setNormalArray(normalArray, osg::Array::BIND_PER_VERTEX);
                }
            }

            if (const osg::Vec4Array* tangents = dynamic_cast<const osg::Vec4Array*>(from.getTexCoordArray(7)))
            {
                osg::ref_ptr<osg::Array> tangentArray
                    = static_cast<osg::Array*>(tangents->clone(osg::CopyOp::DEEP_COPY_ALL));
                tangentArray->setVertexBufferObject(vbo);
                to.setTexCoordArray(7, tangentArray, osg::Array::BIND_PER_VERTEX);
            }
        }
    }

    osg::ref_ptr<OsgaRigGeometry> RigGeometryHolder::getSourceRigGeometry() const
    {
        return mSourceRigGeometry;
    }

    void RigGeometryHolder::updateRigGeometry(OsgaRigGeometry* geom, osg::NodeVisitor* nv)
    {
        if (!geom)
            return;

        if (!geom->getSkeleton() && !this->getParents().empty())
        {
            osgAnimation::RigGeometry::FindNearestParentSkeleton finder;
            if (this->getParents().size() > 1)
                Log(Debug::Warning) << "A RigGeometry should not have multi parent ( " << geom->getName() << " )";
            this->getParents()[0]->accept(finder);

            if (!finder._root.valid())
            {
                Log(Debug::Warning) << "A RigGeometry did not find a parent skeleton for RigGeometry ( "
                                    << geom->getName() << " )";
                return;
            }
            geom->getRigTransformImplementation()->prepareData(*geom);
            geom->setSkeleton(finder._root.get());
        }

        if (!geom->getSkeleton())
            return;

        if (geom->getNeedToComputeMatrix())
        {
            osgAnimation::Skeleton* root = geom->getSkeleton();
            if (!root)
            {
                Log(Debug::Warning)
                    << "Warning: if you have this message it means you miss to call buildTransformer(Skeleton* root), "
                       "or your RigGeometry is not attached to a Skeleton subgraph";
                return;
            }
            osg::MatrixList mtxList
                = root->getWorldMatrices(root); // We always assume that RigGeometries have origin at their root
            geom->computeMatrixFromRootSkeleton(std::move(mtxList));

            if (mIsBodyPart && mBackToOrigin)
                updateBackToOriginTransform(geom);
        }

        if (geom->getSourceGeometry())
        {
            osg::Drawable::UpdateCallback* up
                = dynamic_cast<osg::Drawable::UpdateCallback*>(geom->getSourceGeometry()->getUpdateCallback());
            if (up)
            {
                up->update(nv, geom->getSourceGeometry());
            }
        }

        geom->update();
    }

    OsgaRigGeometry* RigGeometryHolder::getGeometry(int geometry)
    {
        return mGeometry.at(geometry).get();
    }

    void RigGeometryHolder::updateBackToOriginTransform(OsgaRigGeometry* geometry)
    {
        osgAnimation::Skeleton* skeleton = geometry->getSkeleton();
        if (skeleton)
        {
            osg::MatrixList mtxList = mBackToOrigin->getParents()[0]->getWorldMatrices(skeleton);
            osg::Matrix skeletonMatrix = skeleton->getMatrix();
            osg::Matrixf matrixFromSkeletonToGeometry = mtxList[0] * osg::Matrix::inverse(skeletonMatrix);
            osg::Matrixf invMatrixFromSkeletonToGeometry = osg::Matrix::inverse(matrixFromSkeletonToGeometry);
            mBackToOrigin->setMatrix(invMatrixFromSkeletonToGeometry);
        }
    }

    void RigGeometryHolder::accept(osg::NodeVisitor& nv)
    {
        if (!nv.validNodeMask(*this))
            return;

        nv.pushOntoNodePath(this);

        if (nv.getVisitorType() == osg::NodeVisitor::CULL_VISITOR && mSourceRigGeometry.get())
        {
            // The cull visitor won't be applied to the node itself,
            // but we want to use its state to render the child geometry.
            osg::StateSet* stateset = getStateSet();
            osgUtil::CullVisitor* cv = static_cast<osgUtil::CullVisitor*>(&nv);
            if (stateset)
                cv->pushStateSet(stateset);

            unsigned int traversalNumber = nv.getTraversalNumber();
            if (mLastFrameNumber == traversalNumber)
            {
                OsgaRigGeometry& geom = *getRigGeometryPerFrame(mLastFrameNumber);

                nv.pushOntoNodePath(&geom);
                nv.apply(geom);
                nv.popFromNodePath();
            }
            else
            {
                mLastFrameNumber = traversalNumber;

                OsgaRigGeometry& geom = *getRigGeometryPerFrame(mLastFrameNumber);

                if (mIsBodyPart)
                {
                    if (mBackToOrigin)
                        updateBackToOriginTransform(&geom);
                    else
                    {
                        osg::MatrixTransform* matrixTransform
                            = dynamic_cast<osg::MatrixTransform*>(this->getParents()[0]);
                        if (matrixTransform)
                        {
                            mBackToOrigin = matrixTransform;
                            updateBackToOriginTransform(&geom);
                        }
                    }
                }

                updateRigGeometry(&geom, &nv);

                nv.pushOntoNodePath(&geom);
                nv.apply(geom);
                nv.popFromNodePath();
            }

            if (stateset)
                cv->popStateSet();
        }
        else if (nv.getVisitorType() == osg::NodeVisitor::UPDATE_VISITOR)
        {
        }
        else
            nv.apply(*this);

        nv.popFromNodePath();
    }

    void RigGeometryHolder::accept(osg::PrimitiveFunctor& func) const
    {
        getRigGeometryPerFrame(mLastFrameNumber)->accept(func);
    }

    OsgaRigGeometry* RigGeometryHolder::getRigGeometryPerFrame(unsigned int frame) const
    {
        return mGeometry.at(frame % 2).get();
    }

}
