/******************************************************************************

*

 * Project:  GDAL

 * Purpose:  "as-features" step of "gdal pipeline"

 * Author:   Daniel Baston

 *

 ******************************************************************************

 * Copyright (c) 2025, ISciences, LLC

 *

 * SPDX-License-Identifier: MIT

 ****************************************************************************/

#include "gdalalg_raster_as_features.h"

#include "gdalalg_vector_pipeline.h"

#include "cpl_conv.h"

#include "gdal_priv.h"

#include "gdal_alg.h"

#include "ogrsf_frmts.h"

#include <cmath>

#include <limits>

#include <optional>

//! @cond Doxygen_Suppress

#ifndef _

#define _(x) (x)

#endif

GDALRasterAsFeaturesAlgorithm::GDALRasterAsFeaturesAlgorithm(

    bool standaloneStep)

    : GDALPipelineStepAlgorithm(

          NAME, DESCRIPTION, HELP_URL,

          ConstructorOptions()

              .SetStandaloneStep(standaloneStep)

              .SetAddUpsertArgument(false)

              .SetAddSkipErrorsArgument(false)

              .SetOutputFormatCreateCapability(GDAL_DCAP_CREATE))

{

    m_outputLayerName = "pixels";

    if (standaloneStep)

    {

        AddRasterInputArgs(false, false);

        AddVectorOutputArgs(false, false);

    }

    else

    {

        AddRasterHiddenInputDatasetArg();

        AddOutputLayerNameArg(/* hiddenForCLI = */ false,

                              /* shortNameOutputLayerAllowed = */ false);

    }

    AddBandArg(&m_bands);

    AddArg("geometry-type", 0, _("Geometry type"), &m_geomTypeName)

        .SetChoices("none", "point", "polygon")

        .SetDefault(m_geomTypeName);

    AddArg("skip-nodata", 0, _("Omit NoData pixels from the result"),

           &m_skipNoData);

    AddArg("include-xy", 0, _("Include fields for cell center coordinates"),

           &m_includeXY);

    AddArg("include-row-col", 0, _("Include columns for row and column"),

           &m_includeRowCol);

}

GDALRasterAsFeaturesAlgorithm::~GDALRasterAsFeaturesAlgorithm() = default;

GDALRasterAsFeaturesAlgorithmStandalone::

    ~GDALRasterAsFeaturesAlgorithmStandalone() = default;

struct RasterAsFeaturesOptions

{

    OGRwkbGeometryType geomType{wkbNone};

    bool includeXY{false};

    bool includeRowCol{false};

    bool skipNoData{false};

    std::vector<int> bands{};

    std::string outputLayerName{};

};

class GDALRasterAsFeaturesLayer final

    : public OGRLayer,

      public OGRGetNextFeatureThroughRaw<GDALRasterAsFeaturesLayer>

{

  public:

    static constexpr const char *ROW_FIELD = "ROW";

    static constexpr const char *COL_FIELD = "COL";

    static constexpr const char *X_FIELD = "CENTER_X";

    static constexpr const char *Y_FIELD = "CENTER_Y";

    DEFINE_GET_NEXT_FEATURE_THROUGH_RAW(GDALRasterAsFeaturesLayer)

    GDALRasterAsFeaturesLayer(GDALDataset &ds, RasterAsFeaturesOptions options)

        : m_ds(ds), m_it(GDALRasterBand::WindowIterator(

                        m_ds.GetRasterXSize(), m_ds.GetRasterYSize(),

                        m_ds.GetRasterXSize(), m_ds.GetRasterYSize(), 0, 0)),

          m_end(GDALRasterBand::WindowIterator(

              m_ds.GetRasterXSize(), m_ds.GetRasterYSize(),

              m_ds.GetRasterXSize(), m_ds.GetRasterYSize(), 1, 0)),

          m_includeXY(options.includeXY),

          m_includeRowCol(options.includeRowCol),

          m_excludeNoDataPixels(options.skipNoData)

    {

        // TODO: Handle Int64, UInt64

        m_ds.GetGeoTransform(m_gt);

        int nBands = m_ds.GetRasterCount();

        m_bands.resize(nBands);

        for (int i = 1; i <= nBands; i++)

        {

            m_bands[i - 1] = i;

        }

        // TODO: Handle per-band NoData values

        if (nBands > 0)

        {

            int hasNoData;

            double noData = m_ds.GetRasterBand(1)->GetNoDataValue(&hasNoData);

            if (hasNoData)

            {

                m_noData = noData;

            }

        }

        SetDescription(options.outputLayerName.c_str());

        m_defn = new OGRFeatureDefn(options.outputLayerName.c_str());

        if (options.geomType == wkbNone)

        {

            m_defn->SetGeomType(wkbNone);

        }

        else

        {

            m_defn->GetGeomFieldDefn(0)->SetType(options.geomType);

            m_defn->GetGeomFieldDefn(0)->SetSpatialRef(ds.GetSpatialRef());

        }

        m_defn->Reference();

        if (m_includeXY)

        {

            auto xField = std::make_unique<OGRFieldDefn>(X_FIELD, OFTReal);

            auto yField = std::make_unique<OGRFieldDefn>(Y_FIELD, OFTReal);

            m_defn->AddFieldDefn(std::move(xField));

            m_defn->AddFieldDefn(std::move(yField));

        }

        if (m_includeRowCol)

        {

            auto rowField =

                std::make_unique<OGRFieldDefn>(ROW_FIELD, OFTInteger);

            auto colField =

                std::make_unique<OGRFieldDefn>(COL_FIELD, OFTInteger);

            m_defn->AddFieldDefn(std::move(rowField));

            m_defn->AddFieldDefn(std::move(colField));

        }

        for (int band : m_bands)

        {

            CPLString fieldName = CPLSPrintf("BAND_%d", band);

            auto bandField =

                std::make_unique<OGRFieldDefn>(fieldName.c_str(), OFTReal);

            m_defn->AddFieldDefn(std::move(bandField));

            m_bandFields.push_back(m_defn->GetFieldIndex(fieldName));

        }

        GDALRasterAsFeaturesLayer::ResetReading();

    }

    ~GDALRasterAsFeaturesLayer() override;

    void ResetReading() override

    {

        if (m_ds.GetRasterCount() > 0)

        {

            GDALRasterBand *poFirstBand = m_ds.GetRasterBand(1);

            CPLAssert(poFirstBand);  // appease clang scan-build

            m_it = poFirstBand->IterateWindows().begin();

            m_end = poFirstBand->IterateWindows().end();

        }

    }

    int TestCapability(const char *pszCap) const override

    {

        return EQUAL(pszCap, OLCFastFeatureCount) &&

               m_poFilterGeom == nullptr && m_poAttrQuery == nullptr &&

               !m_excludeNoDataPixels;

    }

    GIntBig GetFeatureCount(int bForce) override

    {

        if (m_poFilterGeom == nullptr && m_poAttrQuery == nullptr &&

            !m_excludeNoDataPixels)

        {

            return static_cast<GIntBig>(m_ds.GetRasterXSize()) *

                   m_ds.GetRasterYSize();

        }

        return OGRLayer::GetFeatureCount(bForce);

    }

    OGRFeatureDefn *GetLayerDefn() const override

    {

        return m_defn;

    }

    OGRFeature *GetNextRawFeature()

    {

        if (m_row >= m_window.nYSize && !NextWindow())

        {

            return nullptr;

        }

        std::unique_ptr<OGRFeature> feature;

        while (m_row < m_window.nYSize)

        {

            const double *pSrcVal = reinterpret_cast<double *>(m_buf.data()) +

                                    (m_bands.size() * m_row * m_window.nXSize +

                                     m_col * m_bands.size());

            const bool emitFeature =

                !m_excludeNoDataPixels || !IsNoData(*pSrcVal);

            if (emitFeature)

            {

                feature.reset(OGRFeature::CreateFeature(m_defn));

                for (int fieldPos : m_bandFields)

                {

                    feature->SetField(fieldPos, *pSrcVal);

                    pSrcVal++;

                }

                const double line = m_window.nYOff + m_row;

                const double pixel = m_window.nXOff + m_col;

                if (m_includeRowCol)

                {

                    feature->SetField(ROW_FIELD, static_cast<GIntBig>(line));

                    feature->SetField(COL_FIELD, static_cast<GIntBig>(pixel));

                }

                if (m_includeXY)

                {

                    double x, y;

                    m_gt.Apply(pixel + 0.5, line + 0.5, &x, &y);

                    feature->SetField(X_FIELD, x);

                    feature->SetField(Y_FIELD, y);

                }

                std::unique_ptr<OGRGeometry> geom;

                const auto geomType = m_defn->GetGeomType();

                if (geomType == wkbPoint)

                {

                    double x, y;

                    m_gt.Apply(pixel + 0.5, line + 0.5, &x, &y);

                    geom = std::make_unique<OGRPoint>(x, y);

                    geom->assignSpatialReference(

                        m_defn->GetGeomFieldDefn(0)->GetSpatialRef());

                }

                else if (geomType == wkbPolygon)

                {

                    double x, y;

                    auto lr = std::make_unique<OGRLinearRing>();

                    m_gt.Apply(pixel, line, &x, &y);

                    lr->addPoint(x, y);

                    m_gt.Apply(pixel, line + 1, &x, &y);

                    lr->addPoint(x, y);

                    m_gt.Apply(pixel + 1, line + 1, &x, &y);

                    lr->addPoint(x, y);

                    m_gt.Apply(pixel + 1, line, &x, &y);

                    lr->addPoint(x, y);

                    m_gt.Apply(pixel, line, &x, &y);

                    lr->addPoint(x, y);

                    auto poly = std::make_unique<OGRPolygon>();

                    poly->addRing(std::move(lr));

                    geom = std::move(poly);

                    geom->assignSpatialReference(

                        m_defn->GetGeomFieldDefn(0)->GetSpatialRef());

                }

                feature->SetGeometry(std::move(geom));

            }

            m_col += 1;

            if (m_col >= m_window.nXSize)

            {

                m_col = 0;

                m_row++;

            }

            if (feature)

            {

                return feature.release();

            }

        }

        return nullptr;

    }

    CPL_DISALLOW_COPY_ASSIGN(GDALRasterAsFeaturesLayer)

  private:

    bool IsNoData(double x) const

    {

        if (!m_noData.has_value())

        {

            return false;

        }

        return m_noData.value() == x ||

               (std::isnan(m_noData.value()) && std::isnan(x));

    }

    bool NextWindow()

    {

        int nBandCount = static_cast<int>(m_bands.size());

        if (m_it == m_end)

        {

            return false;

        }

        if (m_ds.GetRasterXSize() == 0 || m_ds.GetRasterYSize() == 0)

        {

            return false;

        }

        m_window = *m_it;

        ++m_it;

        if (!m_bands.empty())

        {

            const auto nBufTypeSize = GDALGetDataTypeSizeBytes(m_bufType);

            if constexpr (sizeof(int) < sizeof(size_t))

            {

                if (m_window.nYSize > 0 &&

                    static_cast<size_t>(m_window.nXSize) >

                        std::numeric_limits<size_t>::max() / m_window.nYSize)

                {

                    CPLError(CE_Failure, CPLE_OutOfMemory,

                             "Failed to allocate buffer");

                    return false;

                }

            }

            const size_t nPixelCount =

                static_cast<size_t>(m_window.nXSize) * m_window.nYSize;

            if (static_cast<size_t>(nBandCount) * nBufTypeSize >

                std::numeric_limits<size_t>::max() / nPixelCount)

            {

                CPLError(CE_Failure, CPLE_OutOfMemory,

                         "Failed to allocate buffer");

                return false;

            }

            const size_t nBufSize = nPixelCount * nBandCount * nBufTypeSize;

            if (m_buf.size() < nBufSize)

            {

                try

                {

                    m_buf.resize(nBufSize);

                }

                catch (const std::exception &)

                {

                    CPLError(CE_Failure, CPLE_OutOfMemory,

                             "Failed to allocate buffer");

                    return false;

                }

            }

            const auto nPixelSpace =

                static_cast<GSpacing>(nBandCount) * nBufTypeSize;

            const auto eErr = m_ds.RasterIO(

                GF_Read, m_window.nXOff, m_window.nYOff, m_window.nXSize,

                m_window.nYSize, m_buf.data(), m_window.nXSize, m_window.nYSize,

                m_bufType, static_cast<int>(m_bands.size()), m_bands.data(),

                nPixelSpace, nPixelSpace * m_window.nXSize, nBufTypeSize,

                nullptr);

            if (eErr != CE_None)

            {

                CPLError(CE_Failure, CPLE_AppDefined,

                         "Failed to read raster data");

                return false;

            }

        }

        m_row = 0;

        m_col = 0;

        return true;

    }

    GDALDataset &m_ds;

    std::vector<GByte> m_buf{};

    const GDALDataType m_bufType = GDT_Float64;

    GDALGeoTransform m_gt{};

    std::optional<double> m_noData{std::nullopt};

    std::vector<int> m_bands{};

    std::vector<int> m_bandFields{};

    GDALRasterBand::WindowIterator m_it;

    GDALRasterBand::WindowIterator m_end;

    GDALRasterWindow m_window{};

    int m_row{0};

    int m_col{0};

    OGRFeatureDefn *m_defn{nullptr};

    bool m_includeXY;

    bool m_includeRowCol;

    bool m_excludeNoDataPixels;

};

GDALRasterAsFeaturesLayer::~GDALRasterAsFeaturesLayer()

{

    m_defn->Release();

}

bool GDALRasterAsFeaturesAlgorithm::RunStep(GDALPipelineStepRunContext &)

{

    auto poSrcDS = m_inputDataset[0].GetDatasetRef();

    RasterAsFeaturesOptions options;

    options.geomType = m_geomTypeName == "point"     ? wkbPoint

                       : m_geomTypeName == "polygon" ? wkbPolygon

                                                     : wkbNone;

    options.includeRowCol = m_includeRowCol;

    options.includeXY = m_includeXY;

    options.skipNoData = m_skipNoData;

    options.outputLayerName = m_outputLayerName;

    if (!m_bands.empty())

    {

        options.bands = std::move(m_bands);

    }

    auto poLayer =

        std::make_unique<GDALRasterAsFeaturesLayer>(*poSrcDS, options);

    auto poRetDS = std::make_unique<GDALVectorOutputDataset>();

    poRetDS->AddLayer(std::move(poLayer));

    m_outputDataset.Set(std::move(poRetDS));

    return true;

}

//! @endcond