#include "bag_attributeinfo.h"

#include "bag_private.h"

#include "bag_simplelayer.h"

#include "bag_simplelayerdescriptor.h"

#include <algorithm>

#include <array>

#include <H5Cpp.h>

namespace BAG {

//! Constructor.

/*!

\param dataset

    The BAG Dataset this layer belongs to.

\param descriptor

    The descriptor of this layer.

\param pH5dataSet

    The HDF5 DataSet that stores this layer.

*/

SimpleLayer::SimpleLayer(

    Dataset& dataset,

    SimpleLayerDescriptor& descriptor,

    std::unique_ptr<::H5::DataSet, DeleteH5dataSet> pH5dataSet)

    : Layer(dataset, descriptor)

    , m_pH5dataSet(std::move(pH5dataSet))

{

}

//! Create a new simple layer.

/*!

\param dataset

    The BAG Dataset this layer belongs to.

\param type

    The type of layer.

\param chunkSize

    The chunk size the HDF5 DataSet will use.

\param compressionLevel

    The compression level the HDF5 DataSet will use.

\return

    The new simple layer.

*/

std::shared_ptr<SimpleLayer> SimpleLayer::create(

    Dataset& dataset,

    LayerType type,

    uint32_t rows, uint32_t cols,

    uint64_t chunkSize,

    int compressionLevel)

{

    auto descriptor = SimpleLayerDescriptor::create(dataset, type, rows, cols, chunkSize, compressionLevel);

    auto h5dataSet = SimpleLayer::createH5dataSet(dataset, *descriptor);

    return std::make_shared<SimpleLayer>(dataset, *descriptor, std::move(h5dataSet));

}

//! Open an existing simple layer.

/*!

\param dataset

    The BAG Dataset this layer belongs to.

\param descriptor

    The descriptor of this layer.

\return

    The specified simple layer.

*/

std::shared_ptr<SimpleLayer> SimpleLayer::open(

    Dataset& dataset,

    SimpleLayerDescriptor& descriptor)

{

    const auto& h5file = dataset.getH5file();

    auto h5dataSet = std::unique_ptr<::H5::DataSet, DeleteH5dataSet>(

        new ::H5::DataSet{h5file.openDataSet(descriptor.getInternalPath())},

        DeleteH5dataSet{});

    // Configure the layer dimensions in the descriptor (we implicitally expect the layer

    // to be two-dimensional)

    hsize_t dims[2];

    h5dataSet->getSpace().getSimpleExtentDims(dims);

    descriptor.setDims(dims[0], dims[1]);

    // Read the min/max attribute values.

    const auto possibleMinMax = dataset.getMinMax(descriptor.getLayerType());

    if (std::get<0>(possibleMinMax))

        descriptor.setMinMax(std::get<1>(possibleMinMax),

            std::get<2>(possibleMinMax));

    return std::make_shared<SimpleLayer>(dataset, descriptor,std::move(h5dataSet));

}

//! Create the HDF5 DataSet.

/*!

\param dataset

    The BAG Dataset this layer belongs to.

\param descriptor

    The descriptor of this layer.

\return

    The new HDF5 DataSet.

*/

std::unique_ptr<::H5::DataSet, DeleteH5dataSet>

SimpleLayer::createH5dataSet(

    const Dataset& dataset,

    const SimpleLayerDescriptor& descriptor)

{

    uint32_t dim0 = 0, dim1 = 0;

    std::tie(dim0, dim1) = descriptor.getDims();

    const std::array<hsize_t, kRank> fileDims{dim0, dim1};

    ::H5::DataSpace h5dataSpace{kRank, fileDims.data(), fileDims.data()};

    ::H5::FloatType h5dataType;

    h5dataType.copy(::H5::PredType::NATIVE_FLOAT);

    h5dataType.setOrder(H5T_ORDER_LE);

    // Create the creation property list.

    const ::H5::DSetCreatPropList h5createPropList{};

    h5createPropList.setFillTime(H5D_FILL_TIME_ALLOC);

    constexpr float kFillValue = BAG_NULL_ELEVATION;

    h5createPropList.setFillValue(h5dataType, &kFillValue);

    // Use chunk size and compression level from the descriptor.

    const auto compressionLevel = descriptor.getCompressionLevel();

    const auto chunkSize = descriptor.getChunkSize();

    if (chunkSize > 0)

    {

        const std::array<hsize_t, kRank> chunkDims{chunkSize, chunkSize};

        h5createPropList.setChunk(kRank, chunkDims.data());

        if (compressionLevel > 0 && compressionLevel <= kMaxCompressionLevel)

            h5createPropList.setDeflate(compressionLevel);

    }

    else if (compressionLevel > 0)

        throw CompressionNeedsChunkingSet{};

    // Create the DataSet using the above.

    const auto& h5file = dataset.getH5file();

    auto pH5dataSet = std::unique_ptr<::H5::DataSet, DeleteH5dataSet>(

        new ::H5::DataSet{h5file.createDataSet(descriptor.getInternalPath(),

            h5dataType, h5dataSpace, h5createPropList)},

        DeleteH5dataSet{});

    // Create any attributes.

    const auto attInfo = getAttributeInfo(descriptor.getLayerType());

    const ::H5::DataSpace minElevDataSpace{};

    const auto minElevAtt = pH5dataSet->createAttribute(attInfo.minName,

        attInfo.h5type, minElevDataSpace);

    const ::H5::DataSpace maxElevDataSpace{};

    const auto maxElevAtt = pH5dataSet->createAttribute(attInfo.maxName,

        attInfo.h5type, maxElevDataSpace);

    // Set initial min/max values.

    constexpr float minElev = std::numeric_limits<float>::max();

    minElevAtt.write(attInfo.h5type, &minElev);

    constexpr float maxElev = std::numeric_limits<float>::lowest();

    maxElevAtt.write(attInfo.h5type, &maxElev);

    return pH5dataSet;

}

//! \copydoc Layer::read

UInt8Array SimpleLayer::readProxy(

    uint32_t rowStart,

    uint32_t columnStart,

    uint32_t rowEnd,

    uint32_t columnEnd) const

{

    // Query the file for the specified rows and columns.

    const auto h5fileDataSpace = m_pH5dataSet->getSpace();

    const auto rows = (rowEnd - rowStart) + 1;

    const auto columns = (columnEnd - columnStart) + 1;

    const std::array<hsize_t, kRank> count{rows, columns};

    const std::array<hsize_t, kRank> offset{rowStart, columnStart};

    h5fileDataSpace.selectHyperslab(H5S_SELECT_SET, count.data(), offset.data());

    // Initialize the output buffer.

    const auto bufferSize = this->getDescriptor()->getReadBufferSize(rows,

        columns);

    UInt8Array buffer{bufferSize};

    // Prepare the memory space.

    const ::H5::DataSpace h5memSpace{kRank, count.data(), count.data()};

    m_pH5dataSet->read(buffer.data(), H5Dget_type(m_pH5dataSet->getId()),

        h5memSpace, h5fileDataSpace);

    return buffer;

}

//! \copydoc Layer::writeAttributes

void SimpleLayer::writeAttributesProxy() const

{

    auto pDescriptor = this->getDescriptor();

    const auto attInfo = getAttributeInfo(pDescriptor->getLayerType());

    // Write any attributes, from the layer descriptor.

    // min value

    const auto minMax = pDescriptor->getMinMax();

    const auto minAtt = m_pH5dataSet->openAttribute(attInfo.minName);

    minAtt.write(attInfo.h5type, &std::get<0>(minMax));

    // max value

    const auto maxAtt = m_pH5dataSet->openAttribute(attInfo.maxName);

    maxAtt.write(attInfo.h5type, &std::get<1>(minMax));

}

//! \copydoc Layer::write

void SimpleLayer::writeProxy(

    uint32_t rowStart,

    uint32_t columnStart,

    uint32_t rowEnd,

    uint32_t columnEnd,

    const uint8_t* buffer)

{

    auto h5fileDataSpace = m_pH5dataSet->getSpace();

    // Make sure the area being written to does not exceed the file dimensions.

    std::array<hsize_t, kRank> fileDims{};

    h5fileDataSpace.getSimpleExtentDims(fileDims.data());

    if ((rowEnd >= fileDims[0]) || (columnEnd >= fileDims[1]))

        throw InvalidWriteSize{};

    const auto rows = (rowEnd - rowStart) + 1;

    const auto columns = (columnEnd - columnStart) + 1;

    const std::array<hsize_t, kRank> count{rows, columns};

    const std::array<hsize_t, kRank> offset{rowStart, columnStart};

    h5fileDataSpace.selectHyperslab(H5S_SELECT_SET, count.data(), offset.data());

    // Prepare the memory space.

    const ::H5::DataSpace h5memDataSpace{kRank, count.data(), count.data()};

    m_pH5dataSet->write(buffer, H5Dget_type(m_pH5dataSet->getId()),

        h5memDataSpace, h5fileDataSpace);

    // Update min/max attributes

    auto pDescriptor = this->getDescriptor();

    const auto attInfo = getAttributeInfo(pDescriptor->getLayerType());

    float min = 0.f, max = 0.f;

    if (attInfo.h5type == ::H5::PredType::NATIVE_FLOAT)

    {

        const auto* floatBuffer = reinterpret_cast<const float*>(buffer);

        const auto begin = floatBuffer;

        const auto end = floatBuffer + rows * columns;

        const auto mm = std::minmax_element(begin, end);

        min = *std::get<0>(mm);

        max = *std::get<1>(mm);

    }

    else if (attInfo.h5type == ::H5::PredType::NATIVE_UINT32)

    {

        const auto* uint32Buffer = reinterpret_cast<const uint32_t*>(buffer);

        const auto begin = uint32Buffer;

        const auto end = uint32Buffer + rows * columns;

        const auto mm = std::minmax_element(begin, end);

        min = static_cast<float>(*std::get<0>(mm));

        max = static_cast<float>(*std::get<1>(mm));

    }

    else

        throw UnsupportedAttributeType{};

    const float currentMin = std::get<0>(pDescriptor->getMinMax());

    const float currentMax = std::get<1>(pDescriptor->getMinMax());

    pDescriptor->setMinMax(std::min(currentMin, min), std::max(currentMax, max));

}

}   //namespace BAG