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

 *

 * Project:  GDAL

 * Purpose:  gdal "raster overview add" subcommand

 * 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_raster_overview.h"

#include "gdalalg_raster_overview_add.h"

#include "cpl_string.h"

#include "gdal_priv.h"

//! @cond Doxygen_Suppress

#ifndef _

#define _(x) (x)

#endif

bool GDALRasterOverviewAlgorithm::RunStep(GDALPipelineStepRunContext &)

{

    CPLError(CE_Failure, CPLE_AppDefined,

             "The Run() method should not be called directly on the \"gdal "

             "raster overview\" program.");

    return false;

}

GDALRasterOverviewAlgorithmStandalone::

    ~GDALRasterOverviewAlgorithmStandalone() = default;

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

/*                   GDALRasterOverviewAlgorithmAdd()                   */

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

GDALRasterOverviewAlgorithmAdd::GDALRasterOverviewAlgorithmAdd(

    bool standaloneStep)

    : GDALRasterPipelineStepAlgorithm(NAME, DESCRIPTION, HELP_URL,

                                      ConstructorOptions()

                                          .SetStandaloneStep(standaloneStep)

                                          .SetAddDefaultArguments(false))

{

    if (standaloneStep)

        AddProgressArg();

    AddOpenOptionsArg(&m_openOptions);

    auto &datasetArg =

        AddInputDatasetArg(

            &m_inputDataset, GDAL_OF_RASTER | GDAL_OF_UPDATE,

            /* positionalAndRequired = */ standaloneStep,

            _("Dataset (to be updated in-place, unless --external)"))

            .AddAlias("dataset")

            .SetMaxCount(1);

    if (!standaloneStep)

    {

        datasetArg.SetPositional();

        datasetArg.SetHidden();

    }

    constexpr const char *OVERVIEW_SRC_LEVELS_MUTEX = "overview-src-levels";

    auto &overviewSrcArg =

        AddArg("overview-src", 0, _("Source overview dataset"),

               &m_overviewSources, GDAL_OF_RASTER)

            .SetMutualExclusionGroup(OVERVIEW_SRC_LEVELS_MUTEX);

    SetAutoCompleteFunctionForFilename(overviewSrcArg, GDAL_OF_RASTER);

    if (standaloneStep)

    {

        AddArg("external", 0, _("Add external overviews"), &m_readOnly)

            .AddHiddenAlias("ro")

            .AddHiddenAlias(GDAL_ARG_NAME_READ_ONLY);

    }

    AddArg("resampling", 'r', _("Resampling method"), &m_resampling)

        .SetChoices("nearest", "average", "cubic", "cubicspline", "lanczos",

                    "bilinear", "gauss", "average_magphase", "rms", "mode")

        .SetHiddenChoices("near", "none");

    AddArg("levels", 0, _("Levels / decimation factors"), &m_levels)

        .SetMinValueIncluded(2)

        .SetMutualExclusionGroup(OVERVIEW_SRC_LEVELS_MUTEX);

    AddArg("min-size", 0,

           _("Maximum width or height of the smallest overview level."),

           &m_minSize)

        .SetMinValueIncluded(1);

    if (standaloneStep)

    {

        auto &ovrCreationOptionArg =

            AddArg(GDAL_ARG_NAME_CREATION_OPTION, 0,

                   _("Overview creation option"), &m_creationOptions)

                .AddAlias("co")

                .SetMetaVar("<KEY>=<VALUE>")

                .SetPackedValuesAllowed(false);

        ovrCreationOptionArg.AddValidationAction(

            [this, &ovrCreationOptionArg]()

            { return ParseAndValidateKeyValue(ovrCreationOptionArg); });

        ovrCreationOptionArg.SetAutoCompleteFunction(

            [this](const std::string &currentValue)

            {

                std::vector<std::string> oRet;

                const std::string osDSName = m_inputDataset.size() == 1

                                                 ? m_inputDataset[0].GetName()

                                                 : std::string();

                const std::string osExt = CPLGetExtensionSafe(osDSName.c_str());

                if (!osExt.empty())

                {

                    std::set<std::string> oVisitedExtensions;

                    auto poDM = GetGDALDriverManager();

                    for (int i = 0; i < poDM->GetDriverCount(); ++i)

                    {

                        auto poDriver = poDM->GetDriver(i);

                        if (poDriver->GetMetadataItem(GDAL_DCAP_RASTER))

                        {

                            const char *pszExtensions =

                                poDriver->GetMetadataItem(GDAL_DMD_EXTENSIONS);

                            if (pszExtensions)

                            {

                                const CPLStringList aosExts(

                                    CSLTokenizeString2(pszExtensions, " ", 0));

                                for (const char *pszExt : cpl::Iterate(aosExts))

                                {

                                    if (EQUAL(pszExt, osExt.c_str()) &&

                                        !cpl::contains(oVisitedExtensions,

                                                       pszExt))

                                    {

                                        oVisitedExtensions.insert(pszExt);

                                        if (AddOptionsSuggestions(

                                                poDriver->GetMetadataItem(

                                                    GDAL_DMD_OVERVIEW_CREATIONOPTIONLIST),

                                                GDAL_OF_RASTER, currentValue,

                                                oRet))

                                        {

                                            return oRet;

                                        }

                                        break;

                                    }

                                }

                            }

                        }

                    }

                }

                return oRet;

            });

    }

}

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

/*              GDALRasterOverviewAlgorithmAdd::RunStep()               */

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

bool GDALRasterOverviewAlgorithmAdd::RunStep(GDALPipelineStepRunContext &ctxt)

{

    GDALProgressFunc pfnProgress = ctxt.m_pfnProgress;

    void *pProgressData = ctxt.m_pProgressData;

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

    CPLAssert(poDS);

    CPLStringList aosOptions(m_creationOptions);

    if (m_readOnly)

    {

        auto poDriver = poDS->GetDriver();

        if (poDriver)

        {

            const char *pszOptionList =

                poDriver->GetMetadataItem(GDAL_DMD_OVERVIEW_CREATIONOPTIONLIST);

            if (pszOptionList)

            {

                if (strstr(pszOptionList, "<Value>EXTERNAL</Value>") == nullptr)

                {

                    ReportError(CE_Failure, CPLE_NotSupported,

                                "Driver %s does not support external overviews",

                                poDriver->GetDescription());

                    return false;

                }

                else if (aosOptions.FetchNameValue("LOCATION") == nullptr)

                {

                    aosOptions.SetNameValue("LOCATION", "EXTERNAL");

                }

            }

        }

    }

    std::string resampling = m_resampling;

    if (resampling.empty() && poDS->GetRasterCount() > 0)

    {

        auto poBand = poDS->GetRasterBand(1);

        if (poBand->GetOverviewCount() > 0)

        {

            const char *pszResampling =

                poBand->GetOverview(0)->GetMetadataItem("RESAMPLING");

            if (pszResampling)

            {

                resampling = pszResampling;

                CPLDebug("GDAL",

                         "Reusing resampling method %s from existing "

                         "overview",

                         pszResampling);

            }

        }

    }

    if (resampling.empty())

        resampling = "nearest";

    if (!m_overviewSources.empty())

    {

        std::vector<GDALDataset *> apoDS;

        for (auto &val : m_overviewSources)

        {

            CPLAssert(val.GetDatasetRef());

            apoDS.push_back(val.GetDatasetRef());

        }

        return poDS->AddOverviews(apoDS, pfnProgress, pProgressData, nullptr) ==

               CE_None;

    }

    std::vector<int> levels = m_levels;

    // If no levels are specified, reuse the potentially existing ones.

    if (levels.empty() && poDS->GetRasterCount() > 0)

    {

        auto poBand = poDS->GetRasterBand(1);

        const int nExistingCount = poBand->GetOverviewCount();

        if (nExistingCount > 0)

        {

            for (int iOvr = 0; iOvr < nExistingCount; ++iOvr)

            {

                auto poOverview = poBand->GetOverview(iOvr);

                if (poOverview)

                {

                    const int nOvFactor = GDALComputeOvFactor(

                        poOverview->GetXSize(), poBand->GetXSize(),

                        poOverview->GetYSize(), poBand->GetYSize());

                    levels.push_back(nOvFactor);

                }

            }

        }

    }

    if (levels.empty())

    {

        const int nXSize = poDS->GetRasterXSize();

        const int nYSize = poDS->GetRasterYSize();

        int nOvrFactor = 1;

        while (DIV_ROUND_UP(nXSize, nOvrFactor) > m_minSize ||

               DIV_ROUND_UP(nYSize, nOvrFactor) > m_minSize)

        {

            nOvrFactor *= 2;

            levels.push_back(nOvrFactor);

        }

    }

    if (!m_standaloneStep && !levels.empty())

    {

        auto poVRTDriver = GetGDALDriverManager()->GetDriverByName("VRT");

        if (!poVRTDriver)

        {

            ReportError(CE_Failure, CPLE_AppDefined,

                        "VRT driver not available");

            return false;

        }

        auto poVRTDS = std::unique_ptr<GDALDataset>(poVRTDriver->CreateCopy(

            "", poDS, false, nullptr, nullptr, nullptr));

        bool bRet = poVRTDS != nullptr;

        if (bRet)

        {

            aosOptions.SetNameValue("VIRTUAL", "YES");

            bRet = GDALBuildOverviewsEx(

                       GDALDataset::ToHandle(poVRTDS.get()), resampling.c_str(),

                       static_cast<int>(levels.size()), levels.data(), 0,

                       nullptr, nullptr, nullptr, aosOptions.List()) == CE_None;

            if (bRet)

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

        }

        return bRet;

    }

    else

    {

        const auto ret =

            levels.empty() ||

            GDALBuildOverviewsEx(

                GDALDataset::ToHandle(poDS), resampling.c_str(),

                static_cast<int>(levels.size()), levels.data(), 0, nullptr,

                pfnProgress, pProgressData, aosOptions.List()) == CE_None;

        if (ret)

            m_outputDataset.Set(poDS);

        return ret;

    }

}

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

/*              GDALRasterOverviewAlgorithmAdd::RunImpl()               */

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

bool GDALRasterOverviewAlgorithmAdd::RunImpl(GDALProgressFunc pfnProgress,

                                             void *pProgressData)

{

    GDALPipelineStepRunContext stepCtxt;

    stepCtxt.m_pfnProgress = pfnProgress;

    stepCtxt.m_pProgressData = pProgressData;

    return RunStep(stepCtxt);

}

GDALRasterOverviewAlgorithmAddStandalone::

    ~GDALRasterOverviewAlgorithmAddStandalone() = default;

//! @endcond