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

 *

 * Project:  GDAL

 * Purpose:  "gdal vector buffer"

 * Author:   Even Rouault <even dot rouault at spatialys.com>

 *

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

 * Copyright (c) 2025, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

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

#include "gdalalg_vector_buffer.h"

#include "gdal_priv.h"

#include "ogrsf_frmts.h"

//! @cond Doxygen_Suppress

#ifndef _

#define _(x) (x)

#endif

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

/*                     GDALVectorBufferAlgorithm()                      */

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

GDALVectorBufferAlgorithm::GDALVectorBufferAlgorithm(bool standaloneStep)

    : GDALVectorGeomAbstractAlgorithm(NAME, DESCRIPTION, HELP_URL,

                                      standaloneStep, m_opts)

{

    AddArg("distance", 0, _("Distance to which to extend the geometry."),

           &m_opts.m_distance)

        .SetPositional()

        .SetRequired();

    AddArg("endcap-style", 0, _("Endcap style."), &m_opts.m_endCapStyle)

        .SetChoices("round", "flat", "square")

        .SetDefault(m_opts.m_endCapStyle);

    AddArg("join-style", 0, _("Join style."), &m_opts.m_joinStyle)

        .SetChoices("round", "mitre", "bevel")

        .SetDefault(m_opts.m_joinStyle);

    AddArg("mitre-limit", 0,

           _("Mitre ratio limit (only affects mitered join style)."),

           &m_opts.m_mitreLimit)

        .SetDefault(m_opts.m_mitreLimit)

        .SetMinValueIncluded(0);

    AddArg("quadrant-segments", 0,

           _("Number of line segments used to approximate a quarter circle."),

           &m_opts.m_quadrantSegments)

        .SetDefault(m_opts.m_quadrantSegments)

        .SetMinValueIncluded(1);

    AddArg("side", 0,

           _("Sets whether the computed buffer should be single-sided or not."),

           &m_opts.m_side)

        .SetChoices("both", "left", "right")

        .SetDefault(m_opts.m_side);

}

#ifdef HAVE_GEOS

namespace

{

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

/*                    GDALVectorBufferAlgorithmLayer                    */

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

class GDALVectorBufferAlgorithmLayer final

    : public GDALVectorGeomOneToOneAlgorithmLayer<GDALVectorBufferAlgorithm>

{

  public:

    GDALVectorBufferAlgorithmLayer(

        OGRLayer &oSrcLayer, const GDALVectorBufferAlgorithm::Options &opts)

        : GDALVectorGeomOneToOneAlgorithmLayer<GDALVectorBufferAlgorithm>(

              oSrcLayer, opts),

          m_poFeatureDefn(oSrcLayer.GetLayerDefn()->Clone())

    {

        for (int i = 0; i < m_poFeatureDefn->GetGeomFieldCount(); ++i)

        {

            if (IsSelectedGeomField(i))

            {

                m_poFeatureDefn->GetGeomFieldDefn(i)->SetType(wkbMultiPolygon);

            }

        }

        m_aosBufferOptions.SetNameValue("ENDCAP_STYLE",

                                        opts.m_endCapStyle.c_str());

        m_aosBufferOptions.SetNameValue("JOIN_STYLE", opts.m_joinStyle.c_str());

        m_aosBufferOptions.SetNameValue("MITRE_LIMIT",

                                        CPLSPrintf("%.17g", opts.m_mitreLimit));

        m_aosBufferOptions.SetNameValue(

            "QUADRANT_SEGMENTS", CPLSPrintf("%d", opts.m_quadrantSegments));

        m_aosBufferOptions.SetNameValue("SINGLE_SIDED",

                                        m_opts.m_side != "both" ? "YES" : "NO");

    }

    const OGRFeatureDefn *GetLayerDefn() const override

    {

        return m_poFeatureDefn.get();

    }

  protected:

    using GDALVectorGeomOneToOneAlgorithmLayer::TranslateFeature;

    std::unique_ptr<OGRFeature>

    TranslateFeature(std::unique_ptr<OGRFeature> poSrcFeature) const override;

  private:

    CPLStringList m_aosBufferOptions{};

    const OGRFeatureDefnRefCountedPtr m_poFeatureDefn;

    CPL_DISALLOW_COPY_ASSIGN(GDALVectorBufferAlgorithmLayer)

};

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

/*                          TranslateFeature()                          */

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

std::unique_ptr<OGRFeature> GDALVectorBufferAlgorithmLayer::TranslateFeature(

    std::unique_ptr<OGRFeature> poSrcFeature) const

{

    const int nGeomFieldCount = m_poFeatureDefn->GetGeomFieldCount();

    for (int i = 0; i < nGeomFieldCount; ++i)

    {

        if (IsSelectedGeomField(i))

        {

            if (auto poGeom = std::unique_ptr<OGRGeometry>(

                    poSrcFeature->StealGeometry(i)))

            {

                poGeom.reset(poGeom->BufferEx(m_opts.m_distance,

                                              m_aosBufferOptions.List()));

                if (poGeom)

                {

                    const auto poGeomFieldDefn =

                        m_poFeatureDefn->GetGeomFieldDefn(i);

                    poGeom = OGRGeometryFactory::forceTo(

                        std::move(poGeom), poGeomFieldDefn->GetType());

                    if (poGeom)

                    {

                        poGeom->assignSpatialReference(

                            poGeomFieldDefn->GetSpatialRef());

                        poSrcFeature->SetGeomField(i, std::move(poGeom));

                    }

                }

            }

        }

    }

    poSrcFeature->SetFDefnUnsafe(m_poFeatureDefn.get());

    return poSrcFeature;

}

}  // namespace

#endif  // HAVE_GEOS

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

/*             GDALVectorBufferAlgorithm::CreateAlgLayer()              */

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

std::unique_ptr<OGRLayerWithTranslateFeature>

GDALVectorBufferAlgorithm::CreateAlgLayer([[maybe_unused]] OGRLayer &srcLayer)

{

#ifdef HAVE_GEOS

    return std::make_unique<GDALVectorBufferAlgorithmLayer>(srcLayer, m_opts);

#else

    CPLAssert(false);

    return nullptr;

#endif

}

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

/*                 GDALVectorBufferAlgorithm::RunStep()                 */

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

bool GDALVectorBufferAlgorithm::RunStep(GDALPipelineStepRunContext &ctxt)

{

#ifdef HAVE_GEOS

    if (m_opts.m_side == "right")

        m_opts.m_distance = -m_opts.m_distance;

    return GDALVectorGeomAbstractAlgorithm::RunStep(ctxt);

#else

    (void)ctxt;

    ReportError(CE_Failure, CPLE_NotSupported,

                "This algorithm is only supported for builds against GEOS");

    return false;

#endif

}

GDALVectorBufferAlgorithmStandalone::~GDALVectorBufferAlgorithmStandalone() =

    default;

//! @endcond