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

 *

 * Project:  WMS Client Driver

 * Purpose:  Definition of GDALWMSMetaDataset class

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

 *

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

 * Copyright (c) 2011-2013, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

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

#include "wmsmetadataset.h"

#include "gdal_openinfo.h"

int VersionStringToInt(const char *version);

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

/*                         GDALWMSMetaDataset()                         */

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

GDALWMSMetaDataset::GDALWMSMetaDataset() = default;

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

/*                        ~GDALWMSMetaDataset()                         */

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

GDALWMSMetaDataset::~GDALWMSMetaDataset()

{

    CSLDestroy(papszSubDatasets);

}

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

/*                           AddSubDataset()                            */

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

void GDALWMSMetaDataset::AddSubDataset(const char *pszName, const char *pszDesc)

{

    char szName[80];

    int nCount = CSLCount(papszSubDatasets) / 2;

    snprintf(szName, sizeof(szName), "SUBDATASET_%d_NAME", nCount + 1);

    papszSubDatasets = CSLSetNameValue(papszSubDatasets, szName, pszName);

    snprintf(szName, sizeof(szName), "SUBDATASET_%d_DESC", nCount + 1);

    papszSubDatasets = CSLSetNameValue(papszSubDatasets, szName, pszDesc);

}

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

/*                      DownloadGetCapabilities()                       */

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

GDALDataset *

GDALWMSMetaDataset::DownloadGetCapabilities(GDALOpenInfo *poOpenInfo)

{

    const char *pszURL = poOpenInfo->pszFilename;

    if (STARTS_WITH_CI(pszURL, "WMS:"))

        pszURL += 4;

    CPLString osFormat = CPLURLGetValue(pszURL, "FORMAT");

    CPLString osTransparent = CPLURLGetValue(pszURL, "TRANSPARENT");

    CPLString osVersion = CPLURLGetValue(pszURL, "VERSION");

    CPLString osPreferredSRS = CPLURLGetValue(pszURL, "SRS");

    if (osPreferredSRS.empty())

        osPreferredSRS = CPLURLGetValue(pszURL, "CRS");

    if (osVersion.empty())

        osVersion = "1.1.1";

    CPLString osURL(pszURL);

    osURL = CPLURLAddKVP(osURL, "SERVICE", "WMS");

    osURL = CPLURLAddKVP(osURL, "VERSION", osVersion);

    osURL = CPLURLAddKVP(osURL, "REQUEST", "GetCapabilities");

    /* Remove all other keywords */

    osURL = CPLURLAddKVP(osURL, "LAYERS", nullptr);

    osURL = CPLURLAddKVP(osURL, "SRS", nullptr);

    osURL = CPLURLAddKVP(osURL, "CRS", nullptr);

    osURL = CPLURLAddKVP(osURL, "BBOX", nullptr);

    osURL = CPLURLAddKVP(osURL, "FORMAT", nullptr);

    osURL = CPLURLAddKVP(osURL, "TRANSPARENT", nullptr);

    osURL = CPLURLAddKVP(osURL, "STYLES", nullptr);

    osURL = CPLURLAddKVP(osURL, "WIDTH", nullptr);

    osURL = CPLURLAddKVP(osURL, "HEIGHT", nullptr);

    CPLHTTPResult *psResult = CPLHTTPFetch(osURL, nullptr);

    if (psResult == nullptr)

    {

        return nullptr;

    }

    if (psResult->nStatus != 0 || psResult->pszErrBuf != nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined,

                 "Error returned by server : %s (%d)",

                 (psResult->pszErrBuf) ? psResult->pszErrBuf : "unknown",

                 psResult->nStatus);

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    if (psResult->pabyData == nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined,

                 "Empty content returned by server");

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    CPLXMLNode *psXML =

        CPLParseXMLString(reinterpret_cast<const char *>(psResult->pabyData));

    if (psXML == nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",

                 psResult->pabyData);

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    GDALDataset *poRet =

        AnalyzeGetCapabilities(psXML, osFormat, osTransparent, osPreferredSRS);

    CPLHTTPDestroyResult(psResult);

    CPLDestroyXMLNode(psXML);

    return poRet;

}

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

/*                       DownloadGetTileService()                       */

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

GDALDataset *

GDALWMSMetaDataset::DownloadGetTileService(GDALOpenInfo *poOpenInfo)

{

    const char *pszURL = poOpenInfo->pszFilename;

    if (STARTS_WITH_CI(pszURL, "WMS:"))

        pszURL += 4;

    CPLString osURL(pszURL);

    osURL = CPLURLAddKVP(osURL, "SERVICE", "WMS");

    osURL = CPLURLAddKVP(osURL, "REQUEST", "GetTileService");

    /* Remove all other keywords */

    osURL = CPLURLAddKVP(osURL, "VERSION", nullptr);

    osURL = CPLURLAddKVP(osURL, "LAYERS", nullptr);

    osURL = CPLURLAddKVP(osURL, "SRS", nullptr);

    osURL = CPLURLAddKVP(osURL, "CRS", nullptr);

    osURL = CPLURLAddKVP(osURL, "BBOX", nullptr);

    osURL = CPLURLAddKVP(osURL, "FORMAT", nullptr);

    osURL = CPLURLAddKVP(osURL, "TRANSPARENT", nullptr);

    osURL = CPLURLAddKVP(osURL, "STYLES", nullptr);

    osURL = CPLURLAddKVP(osURL, "WIDTH", nullptr);

    osURL = CPLURLAddKVP(osURL, "HEIGHT", nullptr);

    CPLHTTPResult *psResult = CPLHTTPFetch(osURL, nullptr);

    if (psResult == nullptr)

    {

        return nullptr;

    }

    if (psResult->nStatus != 0 || psResult->pszErrBuf != nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined,

                 "Error returned by server : %s (%d)",

                 (psResult->pszErrBuf) ? psResult->pszErrBuf : "unknown",

                 psResult->nStatus);

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    if (psResult->pabyData == nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined,

                 "Empty content returned by server");

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    CPLXMLNode *psXML =

        CPLParseXMLString(reinterpret_cast<const char *>(psResult->pabyData));

    if (psXML == nullptr)

    {

        CPLError(CE_Failure, CPLE_AppDefined, "Invalid XML content : %s",

                 psResult->pabyData);

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    GDALDataset *poRet = AnalyzeGetTileService(psXML, poOpenInfo);

    CPLHTTPDestroyResult(psResult);

    CPLDestroyXMLNode(psXML);

    return poRet;

}

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

/*                       GetMetadataDomainList()                        */

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

char **GDALWMSMetaDataset::GetMetadataDomainList()

{

    return BuildMetadataDomainList(GDALPamDataset::GetMetadataDomainList(),

                                   TRUE, "SUBDATASETS", nullptr);

}

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

/*                            GetMetadata()                             */

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

CSLConstList GDALWMSMetaDataset::GetMetadata(const char *pszDomain)

{

    if (pszDomain != nullptr && EQUAL(pszDomain, "SUBDATASETS"))

        return papszSubDatasets;

    return GDALPamDataset::GetMetadata(pszDomain);

}

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

/*                           AddSubDataset()                            */

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

void GDALWMSMetaDataset::AddSubDataset(

    const char *pszLayerName, const char *pszTitle,

    CPL_UNUSED const char *pszAbstract, const char *pszSRS, const char *pszMinX,

    const char *pszMinY, const char *pszMaxX, const char *pszMaxY,

    const std::string &osFormat, const std::string &osTransparent)

{

    CPLString osSubdatasetName = "WMS:";

    osSubdatasetName += osGetURL;

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "SERVICE", "WMS");

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "VERSION", osVersion);

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "REQUEST", "GetMap");

    char *pszEscapedLayerName = CPLEscapeString(pszLayerName, -1, CPLES_URL);

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "LAYERS", pszEscapedLayerName);

    CPLFree(pszEscapedLayerName);

    if (VersionStringToInt(osVersion.c_str()) >= VersionStringToInt("1.3.0"))

    {

        osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "CRS", pszSRS);

    }

    else

        osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "SRS", pszSRS);

    osSubdatasetName = CPLURLAddKVP(

        osSubdatasetName, "BBOX",

        CPLSPrintf("%s,%s,%s,%s", pszMinX, pszMinY, pszMaxX, pszMaxY));

    if (!osFormat.empty())

        osSubdatasetName =

            CPLURLAddKVP(osSubdatasetName, "FORMAT", osFormat.c_str());

    if (!osTransparent.empty())

        osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "TRANSPARENT",

                                        osTransparent.c_str());

    if (pszTitle)

    {

        if (!osXMLEncoding.empty() && osXMLEncoding != "utf-8" &&

            osXMLEncoding != "UTF-8")

        {

            char *pszRecodedTitle =

                CPLRecode(pszTitle, osXMLEncoding.c_str(), CPL_ENC_UTF8);

            if (pszRecodedTitle)

                AddSubDataset(osSubdatasetName, pszRecodedTitle);

            else

                AddSubDataset(osSubdatasetName, pszTitle);

            CPLFree(pszRecodedTitle);

        }

        else

        {

            AddSubDataset(osSubdatasetName, pszTitle);

        }

    }

    else

    {

        AddSubDataset(osSubdatasetName, pszLayerName);

    }

}

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

/*                         AddWMSCSubDataset()                          */

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

void GDALWMSMetaDataset::AddWMSCSubDataset(WMSCTileSetDesc &oWMSCTileSetDesc,

                                           const char *pszTitle,

                                           const CPLString &osTransparent)

{

    CPLString osSubdatasetName = "WMS:";

    osSubdatasetName += osGetURL;

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "SERVICE", "WMS");

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "VERSION", osVersion);

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "REQUEST", "GetMap");

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "LAYERS", oWMSCTileSetDesc.osLayers);

    if (VersionStringToInt(osVersion.c_str()) >= VersionStringToInt("1.3.0"))

        osSubdatasetName =

            CPLURLAddKVP(osSubdatasetName, "CRS", oWMSCTileSetDesc.osSRS);

    else

        osSubdatasetName =

            CPLURLAddKVP(osSubdatasetName, "SRS", oWMSCTileSetDesc.osSRS);

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "BBOX",

                     CPLSPrintf("%s,%s,%s,%s", oWMSCTileSetDesc.osMinX.c_str(),

                                oWMSCTileSetDesc.osMinY.c_str(),

                                oWMSCTileSetDesc.osMaxX.c_str(),

                                oWMSCTileSetDesc.osMaxY.c_str()));

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "FORMAT", oWMSCTileSetDesc.osFormat);

    if (!osTransparent.empty())

        osSubdatasetName =

            CPLURLAddKVP(osSubdatasetName, "TRANSPARENT", osTransparent);

    if (oWMSCTileSetDesc.nTileWidth != oWMSCTileSetDesc.nTileHeight)

        CPLDebug("WMS", "Weird: nTileWidth != nTileHeight for %s",

                 oWMSCTileSetDesc.osLayers.c_str());

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "TILESIZE",

                     CPLSPrintf("%d", oWMSCTileSetDesc.nTileWidth));

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "OVERVIEWCOUNT",

                     CPLSPrintf("%d", oWMSCTileSetDesc.nResolutions - 1));

    osSubdatasetName =

        CPLURLAddKVP(osSubdatasetName, "MINRESOLUTION",

                     CPLSPrintf("%.16f", oWMSCTileSetDesc.dfMinResolution));

    osSubdatasetName = CPLURLAddKVP(osSubdatasetName, "TILED", "true");

    if (pszTitle)

    {

        if (!osXMLEncoding.empty() && osXMLEncoding != "utf-8" &&

            osXMLEncoding != "UTF-8")

        {

            char *pszRecodedTitle =

                CPLRecode(pszTitle, osXMLEncoding.c_str(), CPL_ENC_UTF8);

            if (pszRecodedTitle)

                AddSubDataset(osSubdatasetName, pszRecodedTitle);

            else

                AddSubDataset(osSubdatasetName, pszTitle);

            CPLFree(pszRecodedTitle);

        }

        else

        {

            AddSubDataset(osSubdatasetName, pszTitle);

        }

    }

    else

    {

        AddSubDataset(osSubdatasetName, oWMSCTileSetDesc.osLayers);

    }

}

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

/*                            ExploreLayer()                            */

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

void GDALWMSMetaDataset::ExploreLayer(CPLXMLNode *psXML,

                                      const CPLString &osFormat,

                                      const CPLString &osTransparent,

                                      const CPLString &osPreferredSRS,

                                      const char *pszSRS, const char *pszMinX,

                                      const char *pszMinY, const char *pszMaxX,

                                      const char *pszMaxY)

{

    const char *pszName = CPLGetXMLValue(psXML, "Name", nullptr);

    const char *pszTitle = CPLGetXMLValue(psXML, "Title", nullptr);

    const char *pszAbstract = CPLGetXMLValue(psXML, "Abstract", nullptr);

    CPLXMLNode *psSRS = nullptr;

    const char *pszSRSLocal = nullptr;

    const char *pszMinXLocal = nullptr;

    const char *pszMinYLocal = nullptr;

    const char *pszMaxXLocal = nullptr;

    const char *pszMaxYLocal = nullptr;

    const bool bIsWMS130 =

        VersionStringToInt(osVersion.c_str()) >= VersionStringToInt("1.3.0");

    const auto GetCRS = [bIsWMS130](const CPLXMLNode *psNode)

    {

        const char *pszVal =

            CPLGetXMLValue(psNode, bIsWMS130 ? "CRS" : "SRS", nullptr);

        if (!pszVal && !bIsWMS130)

        {

            // Some WMS servers have a non-conformant WMS 1.1.1 implementation

            // that use "CRS" instead of "SRS"

            // like https://mapy.geoportal.gov.pl/wss/service/PZGIK/BDOO/WMS/aktualne?service=wms&request=getcapabilities

            pszVal = CPLGetXMLValue(psNode, "CRS", nullptr);

            if (pszVal)

            {

                static bool bWarned = false;

                if (!bWarned)

                {

                    bWarned = true;

                    CPLError(CE_Warning, CPLE_AppDefined,

                             "WMS server uses non-standard CRS attribute for "

                             "WMS 1.1.0. Things might mis-behave. Perhaps try "

                             "using VERSION=1.3.0");

                }

            }

        }

        return pszVal;

    };

    /* Use local bounding box if available, otherwise use the one */

    /* that comes from an upper layer */

    /* such as in http://neowms.sci.gsfc.nasa.gov/wms/wms */

    CPLXMLNode *psIter = psXML->psChild;

    while (psIter != nullptr)

    {

        if (psIter->eType == CXT_Element &&

            strcmp(psIter->pszValue, "BoundingBox") == 0)

        {

            psSRS = psIter;

            pszSRSLocal = GetCRS(psSRS);

            if (osPreferredSRS.empty() || pszSRSLocal == nullptr)

                break;

            if (EQUAL(osPreferredSRS, pszSRSLocal))

                break;

            psSRS = nullptr;

            pszSRSLocal = nullptr;

        }

        psIter = psIter->psNext;

    }

    if (psSRS == nullptr)

    {

        psSRS = CPLGetXMLNode(psXML, "LatLonBoundingBox");

        pszSRSLocal = GetCRS(psSRS);

        if (pszSRSLocal == nullptr)

            pszSRSLocal = "EPSG:4326";

    }

    if (pszSRSLocal != nullptr && psSRS != nullptr)

    {

        pszMinXLocal = CPLGetXMLValue(psSRS, "minx", nullptr);

        pszMinYLocal = CPLGetXMLValue(psSRS, "miny", nullptr);

        pszMaxXLocal = CPLGetXMLValue(psSRS, "maxx", nullptr);

        pszMaxYLocal = CPLGetXMLValue(psSRS, "maxy", nullptr);

        if (pszMinXLocal && pszMinYLocal && pszMaxXLocal && pszMaxYLocal)

        {

            pszSRS = pszSRSLocal;

            pszMinX = pszMinXLocal;

            pszMinY = pszMinYLocal;

            pszMaxX = pszMaxXLocal;

            pszMaxY = pszMaxYLocal;

        }

    }

    if (pszName != nullptr && pszSRS && pszMinX && pszMinY && pszMaxX &&

        pszMaxY)

    {

        CPLString osLocalTransparent(osTransparent);

        if (osLocalTransparent.empty())

        {

            const char *pszOpaque = CPLGetXMLValue(psXML, "opaque", "0");

            if (EQUAL(pszOpaque, "1"))

                osLocalTransparent = "FALSE";

        }

        WMSCKeyType oWMSCKey(pszName, pszSRS);

        std::map<WMSCKeyType, WMSCTileSetDesc>::iterator oIter =

            osMapWMSCTileSet.find(oWMSCKey);

        if (oIter != osMapWMSCTileSet.end())

        {

            AddWMSCSubDataset(oIter->second, pszTitle, osLocalTransparent);

        }

        else

        {

            AddSubDataset(pszName, pszTitle, pszAbstract, pszSRS, pszMinX,

                          pszMinY, pszMaxX, pszMaxY, osFormat,

                          osLocalTransparent);

        }

    }

    psIter = psXML->psChild;

    for (; psIter != nullptr; psIter = psIter->psNext)

    {

        if (psIter->eType == CXT_Element)

        {

            if (EQUAL(psIter->pszValue, "Layer"))

                ExploreLayer(psIter, osFormat, osTransparent, osPreferredSRS,

                             pszSRS, pszMinX, pszMinY, pszMaxX, pszMaxY);

        }

    }

}

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

/*                         ParseWMSCTileSets()                          */

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

void GDALWMSMetaDataset::ParseWMSCTileSets(CPLXMLNode *psXML)

{

    CPLXMLNode *psIter = psXML->psChild;

    for (; psIter; psIter = psIter->psNext)

    {

        if (psIter->eType == CXT_Element && EQUAL(psIter->pszValue, "TileSet"))

        {

            const char *pszSRS = CPLGetXMLValue(psIter, "SRS", nullptr);

            if (pszSRS == nullptr)

                continue;

            CPLXMLNode *psBoundingBox = CPLGetXMLNode(psIter, "BoundingBox");

            if (psBoundingBox == nullptr)

                continue;

            const char *pszMinX =

                CPLGetXMLValue(psBoundingBox, "minx", nullptr);

            const char *pszMinY =

                CPLGetXMLValue(psBoundingBox, "miny", nullptr);

            const char *pszMaxX =

                CPLGetXMLValue(psBoundingBox, "maxx", nullptr);

            const char *pszMaxY =

                CPLGetXMLValue(psBoundingBox, "maxy", nullptr);

            if (pszMinX == nullptr || pszMinY == nullptr ||

                pszMaxX == nullptr || pszMaxY == nullptr)

                continue;

            double dfMinX = CPLAtofM(pszMinX);

            double dfMinY = CPLAtofM(pszMinY);

            double dfMaxX = CPLAtofM(pszMaxX);

            double dfMaxY = CPLAtofM(pszMaxY);

            if (dfMaxY <= dfMinY || dfMaxX <= dfMinX)

                continue;

            const char *pszFormat = CPLGetXMLValue(psIter, "Format", nullptr);

            if (pszFormat == nullptr)

                continue;

            if (strstr(pszFormat, "kml"))

                continue;

            const char *pszTileWidth = CPLGetXMLValue(psIter, "Width", nullptr);

            const char *pszTileHeight =

                CPLGetXMLValue(psIter, "Height", nullptr);

            if (pszTileWidth == nullptr || pszTileHeight == nullptr)

                continue;

            int nTileWidth = atoi(pszTileWidth);

            int nTileHeight = atoi(pszTileHeight);

            if (nTileWidth < 128 || nTileHeight < 128)

                continue;

            const char *pszLayers = CPLGetXMLValue(psIter, "Layers", nullptr);

            if (pszLayers == nullptr)

                continue;

            const char *pszResolutions =

                CPLGetXMLValue(psIter, "Resolutions", nullptr);

            if (pszResolutions == nullptr)

                continue;

            char **papszTokens =

                CSLTokenizeStringComplex(pszResolutions, " ", 0, 0);

            double dfMinResolution = 0;

            int i;

            for (i = 0; papszTokens && papszTokens[i]; i++)

            {

                double dfResolution = CPLAtofM(papszTokens[i]);

                if (i == 0 || dfResolution < dfMinResolution)

                    dfMinResolution = dfResolution;

            }

            CSLDestroy(papszTokens);

            int nResolutions = i;

            if (nResolutions == 0)

                continue;

            const char *pszStyles = CPLGetXMLValue(psIter, "Styles", "");

            /* http://demo.opengeo.org/geoserver/gwc/service/wms?tiled=TRUE&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetCapabilities

             */

            /* has different variations of formats for the same (formats, SRS)

             * tuple, so just */

            /* keep the first one which is a png format */

            WMSCKeyType oWMSCKey(pszLayers, pszSRS);

            std::map<WMSCKeyType, WMSCTileSetDesc>::iterator oIter =

                osMapWMSCTileSet.find(oWMSCKey);

            if (oIter != osMapWMSCTileSet.end())

                continue;

            WMSCTileSetDesc oWMSCTileSet;

            oWMSCTileSet.osLayers = pszLayers;

            oWMSCTileSet.osSRS = pszSRS;

            oWMSCTileSet.osMinX = pszMinX;

            oWMSCTileSet.osMinY = pszMinY;

            oWMSCTileSet.osMaxX = pszMaxX;

            oWMSCTileSet.osMaxY = pszMaxY;

            oWMSCTileSet.dfMinX = dfMinX;

            oWMSCTileSet.dfMinY = dfMinY;

            oWMSCTileSet.dfMaxX = dfMaxX;

            oWMSCTileSet.dfMaxY = dfMaxY;

            oWMSCTileSet.nResolutions = nResolutions;

            oWMSCTileSet.dfMinResolution = dfMinResolution;

            oWMSCTileSet.osFormat = pszFormat;

            oWMSCTileSet.osStyle = pszStyles;

            oWMSCTileSet.nTileWidth = nTileWidth;

            oWMSCTileSet.nTileHeight = nTileHeight;

            osMapWMSCTileSet[oWMSCKey] = std::move(oWMSCTileSet);

        }

    }

}

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

/*                       AnalyzeGetCapabilities()                       */

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

GDALDataset *GDALWMSMetaDataset::AnalyzeGetCapabilities(

    CPLXMLNode *psXML, const std::string &osFormat,

    const std::string &osTransparent, const std::string &osPreferredSRS)

{

    const char *pszEncoding = nullptr;

    if (psXML->eType == CXT_Element && strcmp(psXML->pszValue, "?xml") == 0)

        pszEncoding = CPLGetXMLValue(psXML, "encoding", nullptr);

    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=WMT_MS_Capabilities");

    if (psRoot == nullptr)

        psRoot = CPLGetXMLNode(psXML, "=WMS_Capabilities");

    if (psRoot == nullptr)

        return nullptr;

    CPLXMLNode *psCapability = CPLGetXMLNode(psRoot, "Capability");

    if (psCapability == nullptr)

        return nullptr;

    CPLXMLNode *psOnlineResource = CPLGetXMLNode(

        psCapability, "Request.GetMap.DCPType.HTTP.Get.OnlineResource");

    if (psOnlineResource == nullptr)

        return nullptr;

    const char *pszGetURL =

        CPLGetXMLValue(psOnlineResource, "xlink:href", nullptr);

    if (pszGetURL == nullptr)

        return nullptr;

    CPLXMLNode *psLayer = CPLGetXMLNode(psCapability, "Layer");

    if (psLayer == nullptr)

        return nullptr;

    CPLXMLNode *psVendorSpecificCapabilities =

        CPLGetXMLNode(psCapability, "VendorSpecificCapabilities");

    GDALWMSMetaDataset *poDS = new GDALWMSMetaDataset();

    const char *pszVersion = CPLGetXMLValue(psRoot, "version", nullptr);

    if (pszVersion)

        poDS->osVersion = pszVersion;

    else

        poDS->osVersion = "1.1.1";

    poDS->osGetURL = pszGetURL;

    poDS->osXMLEncoding = pszEncoding ? pszEncoding : "";

    if (psVendorSpecificCapabilities)

        poDS->ParseWMSCTileSets(psVendorSpecificCapabilities);

    poDS->ExploreLayer(psLayer, osFormat, osTransparent, osPreferredSRS);

    return poDS;

}

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

/*                         AddTiledSubDataset()                         */

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

// tiledWMS only

void GDALWMSMetaDataset::AddTiledSubDataset(const char *pszTiledGroupName,

                                            const char *pszTitle,

                                            const char *const *papszChanges)

{

    CPLString osSubdatasetName =

        "<GDAL_WMS><Service name=\"TiledWMS\"><ServerUrl>";

    osSubdatasetName += osGetURL;

    osSubdatasetName += "</ServerUrl><TiledGroupName>";

    osSubdatasetName += pszTiledGroupName;

    osSubdatasetName += "</TiledGroupName>";

    for (int i = 0; papszChanges != nullptr && papszChanges[i] != nullptr; i++)

    {

        char *key = nullptr;

        const char *value = CPLParseNameValue(papszChanges[i], &key);

        if (value != nullptr && key != nullptr)

            osSubdatasetName +=

                CPLSPrintf("<Change key=\"${%s}\">%s</Change>", key, value);

        CPLFree(key);

    }

    osSubdatasetName += "</Service></GDAL_WMS>";

    if (pszTitle)

    {

        if (!osXMLEncoding.empty() && osXMLEncoding != "utf-8" &&

            osXMLEncoding != "UTF-8")

        {

            char *pszRecodedTitle =

                CPLRecode(pszTitle, osXMLEncoding.c_str(), CPL_ENC_UTF8);

            if (pszRecodedTitle)

                AddSubDataset(osSubdatasetName, pszRecodedTitle);

            else

                AddSubDataset(osSubdatasetName, pszTitle);

            CPLFree(pszRecodedTitle);

        }

        else

        {

            AddSubDataset(osSubdatasetName, pszTitle);

        }

    }

    else

    {

        AddSubDataset(osSubdatasetName, pszTiledGroupName);

    }

}

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

/*                    AnalyzeGetTileServiceRecurse()                    */

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

// tiledWMS only

void GDALWMSMetaDataset::AnalyzeGetTileServiceRecurse(CPLXMLNode *psXML,

                                                      GDALOpenInfo *poOpenInfo)

{

    // Only list tiled groups that contain the string in the open option

    // TiledGroupName, if given

    char **papszLocalOpenOptions =

        poOpenInfo ? poOpenInfo->papszOpenOptions : nullptr;

    CPLString osMatch(

        CSLFetchNameValueDef(papszLocalOpenOptions, "TiledGroupName", ""));

    osMatch.toupper();

    // Also pass the change patterns, if provided

    char **papszChanges =

        CSLFetchNameValueMultiple(papszLocalOpenOptions, "Change");

    CPLXMLNode *psIter = psXML->psChild;

    for (; psIter != nullptr; psIter = psIter->psNext)

    {

        if (psIter->eType == CXT_Element &&

            EQUAL(psIter->pszValue, "TiledGroup"))

        {

            const char *pszName = CPLGetXMLValue(psIter, "Name", nullptr);

            if (pszName)

            {

                const char *pszTitle = CPLGetXMLValue(psIter, "Title", nullptr);

                if (osMatch.empty())

                {

                    AddTiledSubDataset(pszName, pszTitle, papszChanges);

                }

                else

                {

                    CPLString osNameUpper(pszName);

                    osNameUpper.toupper();

                    if (std::string::npos != osNameUpper.find(osMatch))

                        AddTiledSubDataset(pszName, pszTitle, papszChanges);

                }

            }

        }

        else if (psIter->eType == CXT_Element &&

                 EQUAL(psIter->pszValue, "TiledGroups"))

        {

            AnalyzeGetTileServiceRecurse(psIter, poOpenInfo);

        }

    }

    CPLFree(papszChanges);

}

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

/*                       AnalyzeGetTileService()                        */

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

// tiledWMS only

GDALDataset *GDALWMSMetaDataset::AnalyzeGetTileService(CPLXMLNode *psXML,

                                                       GDALOpenInfo *poOpenInfo)

{

    const char *pszEncoding = nullptr;

    if (psXML->eType == CXT_Element && strcmp(psXML->pszValue, "?xml") == 0)

        pszEncoding = CPLGetXMLValue(psXML, "encoding", nullptr);

    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=WMS_Tile_Service");

    if (psRoot == nullptr)

        return nullptr;

    CPLXMLNode *psTiledPatterns = CPLGetXMLNode(psRoot, "TiledPatterns");

    if (psTiledPatterns == nullptr)

        return nullptr;

    const char *pszURL =

        CPLGetXMLValue(psTiledPatterns, "OnlineResource.xlink:href", nullptr);

    if (pszURL == nullptr)

        return nullptr;

    GDALWMSMetaDataset *poDS = new GDALWMSMetaDataset();

    poDS->osGetURL = pszURL;

    poDS->osXMLEncoding = pszEncoding ? pszEncoding : "";

    poDS->AnalyzeGetTileServiceRecurse(psTiledPatterns, poOpenInfo);

    return poDS;

}

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

/*                       AnalyzeTileMapService()                        */

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

GDALDataset *GDALWMSMetaDataset::AnalyzeTileMapService(CPLXMLNode *psXML)

{

    CPLXMLNode *psRoot = CPLGetXMLNode(psXML, "=TileMapService");

    if (psRoot == nullptr)

        return nullptr;

    CPLXMLNode *psTileMaps = CPLGetXMLNode(psRoot, "TileMaps");

    if (psTileMaps == nullptr)

        return nullptr;

    GDALWMSMetaDataset *poDS = new GDALWMSMetaDataset();

    CPLXMLNode *psIter = psTileMaps->psChild;

    for (; psIter != nullptr; psIter = psIter->psNext)

    {

        if (psIter->eType == CXT_Element && EQUAL(psIter->pszValue, "TileMap"))

        {

            const char *pszHref = CPLGetXMLValue(psIter, "href", nullptr);

            const char *pszTitle = CPLGetXMLValue(psIter, "title", nullptr);

            if (pszHref && pszTitle)

            {

                CPLString osHref(pszHref);

                const char *pszDup100 = strstr(pszHref, "1.0.0/1.0.0/");

                if (pszDup100)

                {

                    osHref.resize(pszDup100 - pszHref);

                    osHref += pszDup100 + strlen("1.0.0/");

                }

                poDS->AddSubDataset(osHref, pszTitle);

            }

        }

    }

    return poDS;

}