//-*****************************************************************************

//

// Copyright (c) 2013,

//  Sony Pictures Imageworks Inc. and

//  Industrial Light & Magic, a division of Lucasfilm Entertainment Company Ltd.

//

// All rights reserved.

//

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// modification, are permitted provided that the following conditions are

// met:

// *       Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

// *       Redistributions in binary form must reproduce the above

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// in the documentation and/or other materials provided with the

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//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

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//-*****************************************************************************

#include <Alembic/Ogawa/IGroup.h>

#include <Alembic/Ogawa/IArchive.h>

#include <Alembic/Ogawa/IStreams.h>

namespace Alembic {

namespace Ogawa {

namespace ALEMBIC_VERSION_NS {

class IGroup::PrivateData

{

public:

    PrivateData(IStreamsPtr iStreams)

    {

        numChildren = 0;

        pos = 0;

        streams = iStreams;

    }

    ~PrivateData() {}

    IStreamsPtr streams;

    std::vector<Alembic::Util::uint64_t> childVec;

    Alembic::Util::uint64_t numChildren;

    Alembic::Util::uint64_t pos;

};

IGroup::IGroup(IStreamsPtr iStreams,

               Alembic::Util::uint64_t iPos,

               bool iLight,

               std::size_t iThreadIndex) :

    mData(new IGroup::PrivateData(iStreams))

{

    // all done, we have no children, or our streams aren't good

    if (iPos == EMPTY_GROUP || !mData->streams || !mData->streams->isValid())

    {

        return;

    }

    mData->pos = iPos;

    mData->streams->read(iThreadIndex, iPos, 8, &mData->numChildren);

    // make sure we don't have a maliciously bad number of children

    if ( mData->numChildren > (mData->streams->getSize() / 8) ||

         mData->numChildren == 0 )

    {

        mData->numChildren = 0;

        return;

    }

    // 0 should NOT have been written, this groups should have been the

    // special EMPTY_GROUP instead

    // read all our child indices, unless we are light and have more than 8

    // children

    if (!iLight || mData->numChildren < 9)

    {

        mData->childVec.resize(mData->numChildren);

        mData->streams->read(iThreadIndex, iPos + 8, mData->numChildren * 8,

                             &(mData->childVec.front()));

    }

}

IGroup::~IGroup()

{

}

IGroupPtr IGroup::getGroup(Alembic::Util::uint64_t iIndex, bool iLight,

                           std::size_t iThreadIndex)

{

    IGroupPtr child;

    Alembic::Util::uint64_t childPos = EMPTY_DATA;

    if (isLight())

    {

        if (iIndex < mData->numChildren)

        {

            mData->streams->read(iThreadIndex, mData->pos + 8 * iIndex + 8, 8,

                                 &childPos);

        }

    }

    else if (isChildGroup(iIndex))

    {

        childPos = mData->childVec[iIndex];

    }

    // sanity check that we have a valid group, either an empty one

    // or a non data that has a decent value

    if (childPos == EMPTY_GROUP || ((childPos & EMPTY_DATA) == 0 &&

        childPos > 8 && childPos != mData->pos))

    {

        child.reset(new IGroup(mData->streams, childPos, iLight, iThreadIndex));

    }

    return child;

}

IDataPtr IGroup::getData(Alembic::Util::uint64_t iIndex,

                         std::size_t iThreadIndex)

{

    IDataPtr child;

    if (isLight())

    {

        if (iIndex < mData->numChildren)

        {

            Alembic::Util::uint64_t childPos = 0;

            mData->streams->read(iThreadIndex, mData->pos + 8 * iIndex + 8, 8,

                                 &childPos);

            // top bit should be set for data

            if ((childPos & EMPTY_DATA) != 0)

            {

                child.reset(new IData(mData->streams, childPos, iThreadIndex));

            }

        }

    }

    else if (isChildData(iIndex))

    {

        child.reset(new IData(mData->streams, mData->childVec[iIndex],

                              iThreadIndex));

    }

    return child;

}

Alembic::Util::uint64_t IGroup::getNumChildren() const

{

    return mData->numChildren;

}

bool IGroup::isChildGroup(Alembic::Util::uint64_t iIndex) const

{

    return (iIndex < mData->childVec.size() &&

            (mData->childVec[iIndex] & EMPTY_DATA) == 0);

}

bool IGroup::isChildData(Alembic::Util::uint64_t iIndex) const

{

    return (iIndex < mData->childVec.size() &&

            (mData->childVec[iIndex] & EMPTY_DATA) != 0);

}

bool IGroup::isEmptyChildGroup(Alembic::Util::uint64_t iIndex) const

{

    return (iIndex < mData->childVec.size() &&

            mData->childVec[iIndex] == EMPTY_GROUP);

}

bool IGroup::isEmptyChildData(Alembic::Util::uint64_t iIndex) const

{

    return (iIndex < mData->childVec.size() &&

        mData->childVec[iIndex] == EMPTY_DATA);

}

bool IGroup::isLight() const

{

    return mData->numChildren != 0 && mData->childVec.empty();

}

} // End namespace ALEMBIC_VERSION_NS

} // End namespace Ogawa

} // End namespace Alembic