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

*

 * Project:  GDAL

 * Purpose:  "gdal vector simplify-coverage" subcommand

 * Author:   Daniel Baston

 *

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

 * Copyright (c) 2025, ISciences LLC

 *

 * SPDX-License-Identifier: MIT

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

#include "gdalalg_vector_simplify_coverage.h"

#include "cpl_error.h"

#include "gdal_priv.h"

#include "gdalalg_vector_geom.h"

#include "ogr_geometry.h"

#include "ogr_geos.h"

#include "ogrsf_frmts.h"

#include <cinttypes>

#ifndef _

#define _(x) (x)

#endif

//! @cond Doxygen_Suppress

GDALVectorSimplifyCoverageAlgorithm::GDALVectorSimplifyCoverageAlgorithm(

    bool standaloneStep)

    : GDALVectorPipelineStepAlgorithm(NAME, DESCRIPTION, HELP_URL,

                                      standaloneStep)

{

    AddActiveLayerArg(&m_activeLayer);

    AddArg("tolerance", 0, _("Distance tolerance for simplification."),

           &m_opts.tolerance)

        .SetPositional()

        .SetRequired()

        .SetMinValueIncluded(0);

    AddArg("preserve-boundary", 0,

           _("Whether the exterior boundary should be preserved."),

           &m_opts.preserveBoundary);

}

#if defined HAVE_GEOS &&                                                       \

    (GEOS_VERSION_MAJOR > 3 ||                                                 \

     (GEOS_VERSION_MAJOR == 3 && GEOS_VERSION_MINOR >= 12))

class GDALVectorSimplifyCoverageOutputLayer final

    : public GDALGeosNonStreamingAlgorithmLayer

{

  public:

    GDALVectorSimplifyCoverageOutputLayer(

        OGRLayer &srcLayer, int geomFieldIndex,

        const GDALVectorSimplifyCoverageAlgorithm::Options &opts)

        : GDALGeosNonStreamingAlgorithmLayer(srcLayer, geomFieldIndex),

          m_opts(opts)

    {

    }

    ~GDALVectorSimplifyCoverageOutputLayer() override;

    const OGRFeatureDefn *GetLayerDefn() const override

    {

        return m_srcLayer.GetLayerDefn();

    }

    GIntBig GetFeatureCount(int bForce) override

    {

        if (!m_poAttrQuery && !m_poFilterGeom)

        {

            return m_srcLayer.GetFeatureCount(bForce);

        }

        return OGRLayer::GetFeatureCount(bForce);

    }

    int TestCapability(const char *pszCap) const override

    {

        if (EQUAL(pszCap, OLCFastFeatureCount))

        {

            return m_srcLayer.TestCapability(pszCap);

        }

        return false;

    }

    bool PolygonsOnly() const override

    {

        return true;

    }

    bool SkipEmpty() const override

    {

        return false;

    }

    bool ProcessGeos() override

    {

        // Perform coverage simplification

        GEOSGeometry *coll = GEOSGeom_createCollection_r(

            m_poGeosContext, GEOS_GEOMETRYCOLLECTION, m_apoGeosInputs.data(),

            static_cast<unsigned int>(m_apoGeosInputs.size()));

        if (coll == nullptr)

        {

            return false;

        }

        m_apoGeosInputs.clear();

        m_poGeosResultAsCollection = GEOSCoverageSimplifyVW_r(

            m_poGeosContext, coll, m_opts.tolerance, m_opts.preserveBoundary);

        GEOSGeom_destroy_r(m_poGeosContext, coll);

        return m_poGeosResultAsCollection != nullptr;

    }

  private:

    CPL_DISALLOW_COPY_ASSIGN(GDALVectorSimplifyCoverageOutputLayer)

    const GDALVectorSimplifyCoverageAlgorithm::Options &m_opts;

};

GDALVectorSimplifyCoverageOutputLayer::

    ~GDALVectorSimplifyCoverageOutputLayer() = default;

bool GDALVectorSimplifyCoverageAlgorithm::RunStep(

    GDALPipelineStepRunContext &ctxt)

{

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

    auto poDstDS = std::make_unique<GDALVectorNonStreamingAlgorithmDataset>();

    GDALVectorAlgorithmLayerProgressHelper progressHelper(ctxt);

    for (auto &&poSrcLayer : poSrcDS->GetLayers())

    {

        if (m_activeLayer.empty() ||

            m_activeLayer == poSrcLayer->GetDescription())

        {

            progressHelper.AddProcessedLayer(*poSrcLayer);

        }

        else

        {

            progressHelper.AddPassThroughLayer(*poSrcLayer);

        }

    }

    if (!progressHelper.HasProcessedLayers())

    {

        ReportError(CE_Failure, CPLE_AppDefined,

                    "Specified layer '%s' was not found",

                    m_activeLayer.c_str());

        return false;

    }

    for (auto [poSrcLayer, bProcessed, layerProgressFunc, layerProgressData] :

         progressHelper)

    {

        if (bProcessed)

        {

            constexpr int geomFieldIndex = 0;  // TODO: parametrize

            auto poLayer =

                std::make_unique<GDALVectorSimplifyCoverageOutputLayer>(

                    *poSrcLayer, geomFieldIndex, m_opts);

            if (!poDstDS->AddProcessedLayer(std::move(poLayer),

                                            layerProgressFunc,

                                            layerProgressData.get()))

            {

                return false;

            }

        }

        else

        {

            poDstDS->AddPassThroughLayer(*poSrcLayer);

        }

    }

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

    return true;

}

#else

bool GDALVectorSimplifyCoverageAlgorithm::RunStep(GDALPipelineStepRunContext &)

{

    ReportError(CE_Failure, CPLE_AppDefined,

                "%s requires GDAL to be built against version 3.12 or later of "

                "the GEOS library.",

                NAME);

    return false;

}

#endif  // HAVE_GEOS

GDALVectorSimplifyCoverageAlgorithmStandalone::

    ~GDALVectorSimplifyCoverageAlgorithmStandalone() = default;

//! @endcond