/******************************************************************************
 *
 * Project:  WCS Client Driver
 * Purpose:  Implementation of Dataset class for WCS 1.1.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2006, Frank Warmerdam
 * Copyright (c) 2008-2013, Even Rouault <even dot rouault at spatialys.com>
 * Copyright (c) 2017, Ari Jolma
 * Copyright (c) 2017, Finnish Environment Institute
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_string.h"
#include "cpl_minixml.h"
#include "cpl_http.h"
#include "gmlutils.h"
#include "gdal_frmts.h"
#include "gdal_pam.h"
#include "ogr_spatialref.h"
#include "gmlcoverage.h"

#include <algorithm>

#include "wcsdataset.h"
#include "wcsutils.h"

using namespace WCSUtils;

/************************************************************************/
/*                         GetExtent()                                  */
/*                                                                      */
/************************************************************************/

std::vector<double> WCSDataset110::GetExtent(int nXOff, int nYOff, int nXSize,
                                             int nYSize,
                                             CPL_UNUSED int nBufXSize,
                                             CPL_UNUSED int nBufYSize)
{
    std::vector<double> extent;

    // outer edges of outer pixels.
    extent.push_back(adfGeoTransform[0] + (nXOff)*adfGeoTransform[1]);
    extent.push_back(adfGeoTransform[3] +
                     (nYOff + nYSize) * adfGeoTransform[5]);
    extent.push_back(adfGeoTransform[0] +
                     (nXOff + nXSize) * adfGeoTransform[1]);
    extent.push_back(adfGeoTransform[3] + (nYOff)*adfGeoTransform[5]);

    bool no_shrink = CPLGetXMLBoolean(psService, "OuterExtents");

    // WCS 1.1 extents are centers of outer pixels.
    if (!no_shrink)
    {
        extent[2] -= adfGeoTransform[1] * 0.5;
        extent[0] += adfGeoTransform[1] * 0.5;
        extent[1] -= adfGeoTransform[5] * 0.5;
        extent[3] += adfGeoTransform[5] * 0.5;
    }

    double dfXStep, dfYStep;

    if (!no_shrink)
    {
        dfXStep = (nXSize / (double)nBufXSize) * adfGeoTransform[1];
        dfYStep = (nYSize / (double)nBufYSize) * adfGeoTransform[5];
        // Carefully adjust bounds for pixel centered values at new
        // sampling density.
        if (nBufXSize != nXSize || nBufYSize != nYSize)
        {
            dfXStep = (nXSize / (double)nBufXSize) * adfGeoTransform[1];
            dfYStep = (nYSize / (double)nBufYSize) * adfGeoTransform[5];

            extent[0] =
                nXOff * adfGeoTransform[1] + adfGeoTransform[0] + dfXStep * 0.5;
            extent[2] = extent[0] + (nBufXSize - 1) * dfXStep;

            extent[3] =
                nYOff * adfGeoTransform[5] + adfGeoTransform[3] + dfYStep * 0.5;
            extent[1] = extent[3] + (nBufYSize - 1) * dfYStep;
        }
    }
    else
    {
        double adjust =
            CPLAtof(CPLGetXMLValue(psService, "BufSizeAdjust", "0.0"));
        dfXStep = (nXSize / ((double)nBufXSize + adjust)) * adfGeoTransform[1];
        dfYStep = (nYSize / ((double)nBufYSize + adjust)) * adfGeoTransform[5];
    }

    extent.push_back(dfXStep);
    extent.push_back(dfYStep);

    return extent;
}

/************************************************************************/
/*                        GetCoverageRequest()                          */
/*                                                                      */
/************************************************************************/

std::string WCSDataset110::GetCoverageRequest(bool scaled, int /* nBufXSize */,
                                              int /* nBufYSize */,
                                              const std::vector<double> &extent,
                                              const std::string &osBandList)
{
    CPLString osRequest;

    /* -------------------------------------------------------------------- */
    /*      URL encode strings that could have questionable characters.     */
    /* -------------------------------------------------------------------- */
    CPLString osCoverage = CPLGetXMLValue(psService, "CoverageName", "");

    char *pszEncoded = CPLEscapeString(osCoverage, -1, CPLES_URL);
    osCoverage = pszEncoded;
    CPLFree(pszEncoded);

    CPLString osFormat = CPLGetXMLValue(psService, "PreferredFormat", "");

    pszEncoded = CPLEscapeString(osFormat, -1, CPLES_URL);
    osFormat = pszEncoded;
    CPLFree(pszEncoded);

    CPLString osRangeSubset = CPLGetXMLValue(psService, "FieldName", "");

    // todo: MapServer seems to require interpolation

    CPLString interpolation = CPLGetXMLValue(psService, "Interpolation", "");
    if (interpolation == "")
    {
        // old undocumented key for interpolation in service
        interpolation = CPLGetXMLValue(psService, "Resample", "");
    }
    if (interpolation != "")
    {
        osRangeSubset += ":" + interpolation;
    }

    if (osBandList != "")
    {
        if (osBandIdentifier != "")
        {
            osRangeSubset += CPLString().Printf(
                "[%s[%s]]", osBandIdentifier.c_str(), osBandList.c_str());
        }
    }

    osRangeSubset = "&RangeSubset=" + URLEncode(osRangeSubset);

    double bbox_0 = extent[0],  // min X
        bbox_1 = extent[1],     // min Y
        bbox_2 = extent[2],     // max X
        bbox_3 = extent[3];     // max Y

    if (axis_order_swap)
    {
        bbox_0 = extent[1];  // min Y
        bbox_1 = extent[0];  // min X
        bbox_2 = extent[3];  // max Y
        bbox_3 = extent[2];  // max X
    }
    std::string request = CPLGetXMLValue(psService, "ServiceURL", "");
    request = CPLURLAddKVP(request.c_str(), "SERVICE", "WCS");
    request += CPLString().Printf(
        "&VERSION=%s&REQUEST=GetCoverage&IDENTIFIER=%s"
        "&FORMAT=%s&BOUNDINGBOX=%.15g,%.15g,%.15g,%.15g,%s%s",
        CPLGetXMLValue(psService, "Version", ""), osCoverage.c_str(),
        osFormat.c_str(), bbox_0, bbox_1, bbox_2, bbox_3, osCRS.c_str(),
        osRangeSubset.c_str());
    double origin_1 = extent[0],  // min X
        origin_2 = extent[3],     // max Y
        offset_1 = extent[4],     // dX
        offset_2 = extent[5];     // dY

    if (axis_order_swap)
    {
        origin_1 = extent[3];  // max Y
        origin_2 = extent[0];  // min X
        offset_1 = extent[5];  // dY
        offset_2 = extent[4];  // dX
    }
    CPLString offsets;
    if (CPLGetXMLBoolean(psService, "OffsetsPositive"))
    {
        offset_1 = fabs(offset_1);
        offset_2 = fabs(offset_2);
    }
    if (EQUAL(CPLGetXMLValue(psService, "NrOffsets", "4"), "2"))
    {
        offsets = CPLString().Printf("%.15g,%.15g", offset_1, offset_2);
    }
    else
    {
        if (axis_order_swap)
        {
            // Only tested with GeoServer but this is the correct offset(?)
            offsets = CPLString().Printf("0,%.15g,%.15g,0", offset_2, offset_1);
        }
        else
        {
            offsets = CPLString().Printf("%.15g,0,0,%.15g", offset_1, offset_2);
        }
    }
    bool do_not_include =
        CPLGetXMLBoolean(psService, "GridCRSOptional") && !scaled;
    if (!do_not_include)
    {
        request += CPLString().Printf(
            "&GridBaseCRS=%s"
            "&GridCS=urn:ogc:def:cs:OGC:0.0:Grid2dSquareCS"
            "&GridType=urn:ogc:def:method:WCS:1.1:2dGridIn2dCrs"
            "&GridOrigin=%.15g,%.15g"
            "&GridOffsets=%s",
            osCRS.c_str(), origin_1, origin_2, offsets.c_str());
    }
    CPLString extra = CPLGetXMLValue(psService, "Parameters", "");
    if (extra != "")
    {
        std::vector<std::string> pairs = Split(extra.c_str(), "&");
        for (unsigned int i = 0; i < pairs.size(); ++i)
        {
            std::vector<std::string> pair = Split(pairs[i].c_str(), "=");
            request =
                CPLURLAddKVP(request.c_str(), pair[0].c_str(), pair[1].c_str());
        }
    }
    extra = CPLGetXMLValue(psService, "GetCoverageExtra", "");
    if (extra != "")
    {
        std::vector<std::string> pairs = Split(extra.c_str(), "&");
        for (unsigned int i = 0; i < pairs.size(); ++i)
        {
            std::vector<std::string> pair = Split(pairs[i].c_str(), "=");
            request =
                CPLURLAddKVP(request.c_str(), pair[0].c_str(), pair[1].c_str());
        }
    }
    CPLDebug("WCS", "Requesting %s", request.c_str());
    return request;
}

/************************************************************************/
/*                        DescribeCoverageRequest()                     */
/*                                                                      */
/************************************************************************/

std::string WCSDataset110::DescribeCoverageRequest()
{
    std::string request = CPLGetXMLValue(psService, "ServiceURL", "");
    request = CPLURLAddKVP(request.c_str(), "SERVICE", "WCS");
    request = CPLURLAddKVP(request.c_str(), "REQUEST", "DescribeCoverage");
    request = CPLURLAddKVP(request.c_str(), "VERSION",
                           CPLGetXMLValue(psService, "Version", "1.1.0"));
    request = CPLURLAddKVP(request.c_str(), "IDENTIFIERS",
                           CPLGetXMLValue(psService, "CoverageName", ""));
    CPLString extra = CPLGetXMLValue(psService, "Parameters", "");
    if (extra != "")
    {
        std::vector<std::string> pairs = Split(extra.c_str(), "&");
        for (unsigned int i = 0; i < pairs.size(); ++i)
        {
            std::vector<std::string> pair = Split(pairs[i].c_str(), "=");
            request =
                CPLURLAddKVP(request.c_str(), pair[0].c_str(), pair[1].c_str());
        }
    }
    extra = CPLGetXMLValue(psService, "DescribeCoverageExtra", "");
    if (extra != "")
    {
        std::vector<std::string> pairs = Split(extra.c_str(), "&");
        for (unsigned int i = 0; i < pairs.size(); ++i)
        {
            std::vector<std::string> pair = Split(pairs[i].c_str(), "=");
            request =
                CPLURLAddKVP(request.c_str(), pair[0].c_str(), pair[1].c_str());
        }
    }
    return request;
}

/************************************************************************/
/*                         CoverageOffering()                           */
/*                                                                      */
/************************************************************************/

CPLXMLNode *WCSDataset110::CoverageOffering(CPLXMLNode *psDC)
{
    return CPLGetXMLNode(psDC, "=CoverageDescriptions.CoverageDescription");
}

/************************************************************************/
/*                          ExtractGridInfo()                           */
/*                                                                      */
/*      Collect info about grid from describe coverage for WCS 1.1.     */
/*                                                                      */
/************************************************************************/

bool WCSDataset110::ExtractGridInfo()

{
    CPLXMLNode *psCO = CPLGetXMLNode(psService, "CoverageDescription");

    if (psCO == nullptr)
        return false;

    /* -------------------------------------------------------------------- */
    /*      We need to strip off name spaces so it is easier to             */
    /*      searchfor plain gml names.                                      */
    /* -------------------------------------------------------------------- */
    CPLStripXMLNamespace(psCO, nullptr, TRUE);

    /* -------------------------------------------------------------------- */
    /*      Verify we have a SpatialDomain and GridCRS.                     */
    /* -------------------------------------------------------------------- */
    CPLXMLNode *psSD = CPLGetXMLNode(psCO, "Domain.SpatialDomain");
    CPLXMLNode *psGCRS = CPLGetXMLNode(psSD, "GridCRS");

    if (psSD == nullptr || psGCRS == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unable to find GridCRS in CoverageDescription,\n"
                 "unable to process WCS Coverage.");
        return false;
    }

    /* -------------------------------------------------------------------- */
    /*      Establish our coordinate system.                                */
    /*   This is needed before geometry since we may have axis order swap.  */
    /* -------------------------------------------------------------------- */
    CPLString crs = ParseCRS(psGCRS);

    if (crs.empty())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unable to find GridCRS.GridBaseCRS");
        return false;
    }

    // SetCRS should fail only if the CRS is really unknown to GDAL
    if (!SetCRS(crs, true))
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unable to interpret GridBaseCRS '%s'.", crs.c_str());
        return false;
    }

    /* -------------------------------------------------------------------- */
    /*      Collect size, origin, and offsets for SetGeometry()             */
    /*                                                                      */
    /*      Extract Geotransform from GridCRS.                              */
    /*                                                                      */
    /* -------------------------------------------------------------------- */
    const char *pszGridType = CPLGetXMLValue(
        psGCRS, "GridType", "urn:ogc:def:method:WCS::2dSimpleGrid");
    bool swap =
        axis_order_swap && !CPLGetXMLBoolean(psService, "NoGridAxisSwap");
    std::vector<double> origin =
        Flist(Split(CPLGetXMLValue(psGCRS, "GridOrigin", ""), " ", swap));

    std::vector<std::string> offset_1 =
        Split(CPLGetXMLValue(psGCRS, "GridOffsets", ""), " ");
    std::vector<std::string> offset_2;
    size_t n = offset_1.size();
    if (n % 2 != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "GridOffsets has incorrect amount of coefficients.\n"
                 "Unable to process WCS coverage.");
        return false;
    }
    for (unsigned int i = 0; i < n / 2; ++i)
    {
        CPLString s = offset_1.back();
        offset_1.erase(offset_1.end() - 1);
#if defined(__GNUC__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnull-dereference"
#endif
        offset_2.insert(offset_2.begin(), s);
#if defined(__GNUC__)
#pragma GCC diagnostic pop
#endif
    }
    std::vector<std::vector<double>> offsets;
    if (swap)
    {
        offsets.push_back(Flist(offset_2));
        offsets.push_back(Flist(offset_1));
    }
    else
    {
        offsets.push_back(Flist(offset_1));
        offsets.push_back(Flist(offset_2));
    }

    if (strstr(pszGridType, ":2dGridIn2dCrs") ||
        strstr(pszGridType, ":2dGridin2dCrs"))
    {
        if (!(offset_1.size() == 2 && origin.size() == 2))
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "2dGridIn2dCrs does not have expected GridOrigin or\n"
                     "GridOffsets values - unable to process WCS coverage.");
            return false;
        }
    }

    else if (strstr(pszGridType, ":2dGridIn3dCrs"))
    {
        if (!(offset_1.size() == 3 && origin.size() == 3))
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "2dGridIn3dCrs does not have expected GridOrigin or\n"
                     "GridOffsets values - unable to process WCS coverage.");
            return false;
        }
    }

    else if (strstr(pszGridType, ":2dSimpleGrid"))
    {
        if (!(offset_1.size() == 1 && origin.size() == 2))
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "2dSimpleGrid does not have expected GridOrigin or\n"
                     "GridOffsets values - unable to process WCS coverage.");
            return false;
        }
    }

    else
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Unrecognized GridCRS.GridType value '%s',\n"
                 "unable to process WCS coverage.",
                 pszGridType);
        return false;
    }

    /* -------------------------------------------------------------------- */
    /*      Search for an ImageCRS for raster size.                         */
    /* -------------------------------------------------------------------- */
    std::vector<int> size;
    CPLXMLNode *psNode;

    for (psNode = psSD->psChild; psNode != nullptr && size.size() == 0;
         psNode = psNode->psNext)
    {
        if (psNode->eType != CXT_Element ||
            !EQUAL(psNode->pszValue, "BoundingBox"))
            continue;

        CPLString osBBCRS = ParseCRS(psNode);
        if (strstr(osBBCRS, ":imageCRS"))
        {
            std::vector<std::string> bbox = ParseBoundingBox(psNode);
            if (bbox.size() >= 2)
            {
                std::vector<int> low = Ilist(Split(bbox[0].c_str(), " "), 0, 2);
                std::vector<int> high =
                    Ilist(Split(bbox[1].c_str(), " "), 0, 2);
                if (low[0] == 0 && low[1] == 0)
                {
                    size.push_back(high[0]);
                    size.push_back(high[1]);
                }
            }
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Otherwise we search for a bounding box in our coordinate        */
    /*      system and derive the size from that.                           */
    /* -------------------------------------------------------------------- */
    for (psNode = psSD->psChild; psNode != nullptr && size.size() == 0;
         psNode = psNode->psNext)
    {
        if (psNode->eType != CXT_Element ||
            !EQUAL(psNode->pszValue, "BoundingBox"))
            continue;

        CPLString osBBCRS = ParseCRS(psNode);
        if (osBBCRS == osCRS)
        {
            std::vector<std::string> bbox = ParseBoundingBox(psNode);
            bool not_rot =
                (offsets[0].size() == 1 && offsets[1].size() == 1) ||
                ((swap && offsets[0][0] == 0.0 && offsets[1][1] == 0.0) ||
                 (!swap && offsets[0][1] == 0.0 && offsets[1][0] == 0.0));
            if (bbox.size() >= 2 && not_rot)
            {
                std::vector<double> low =
                    Flist(Split(bbox[0].c_str(), " ", axis_order_swap), 0, 2);
                std::vector<double> high =
                    Flist(Split(bbox[1].c_str(), " ", axis_order_swap), 0, 2);
                double c1 = offsets[0][0];
                double c2 =
                    offsets[1].size() == 1 ? offsets[1][0] : offsets[1][1];
                size.push_back((int)((high[0] - low[0]) / c1 + 1.01));
                size.push_back((int)((high[1] - low[1]) / fabs(c2) + 1.01));
            }
        }
    }

    if (size.size() < 2)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Could not determine the size of the grid.");
        return false;
    }

    SetGeometry(size, origin, offsets);

    /* -------------------------------------------------------------------- */
    /*      Do we have a coordinate system override?                        */
    /* -------------------------------------------------------------------- */
    const char *pszProjOverride = CPLGetXMLValue(psService, "SRS", nullptr);

    if (pszProjOverride)
    {
        if (m_oSRS.SetFromUserInput(
                pszProjOverride,
                OGRSpatialReference::SET_FROM_USER_INPUT_LIMITATIONS_get()) !=
            OGRERR_NONE)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "<SRS> element contents not parsable:\n%s",
                     pszProjOverride);
            return false;
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Pick a format type if we don't already have one selected.       */
    /*                                                                      */
    /*      We will prefer anything that sounds like TIFF, otherwise        */
    /*      falling back to the first supported format.  Should we          */
    /*      consider preferring the nativeFormat if available?              */
    /* -------------------------------------------------------------------- */
    if (CPLGetXMLValue(psService, "PreferredFormat", nullptr) == nullptr)
    {
        CPLString osPreferredFormat;

        for (psNode = psCO->psChild; psNode != nullptr; psNode = psNode->psNext)
        {
            if (psNode->eType == CXT_Element &&
                EQUAL(psNode->pszValue, "SupportedFormat") && psNode->psChild &&
                psNode->psChild->eType == CXT_Text)
            {
                if (osPreferredFormat.empty())
                    osPreferredFormat = psNode->psChild->pszValue;

                if (strstr(psNode->psChild->pszValue, "tiff") != nullptr ||
                    strstr(psNode->psChild->pszValue, "TIFF") != nullptr ||
                    strstr(psNode->psChild->pszValue, "Tiff") != nullptr)
                {
                    osPreferredFormat = psNode->psChild->pszValue;
                    break;
                }
            }
        }

        if (!osPreferredFormat.empty())
        {
            bServiceDirty = true;
            CPLCreateXMLElementAndValue(psService, "PreferredFormat",
                                        osPreferredFormat);
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Try to identify a nodata value.  For now we only support the    */
    /*      singleValue mechanism.                                          */
    /* -------------------------------------------------------------------- */
    if (CPLGetXMLValue(psService, "NoDataValue", nullptr) == nullptr)
    {
        const char *pszSV =
            CPLGetXMLValue(psCO, "Range.Field.NullValue", nullptr);

        if (pszSV != nullptr && (CPLAtof(pszSV) != 0.0 || *pszSV == DIGIT_ZERO))
        {
            bServiceDirty = true;
            CPLCreateXMLElementAndValue(psService, "NoDataValue", pszSV);
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Grab the field name, if possible.                               */
    /* -------------------------------------------------------------------- */
    if (CPLGetXMLValue(psService, "FieldName", nullptr) == nullptr)
    {
        CPLString osFieldName =
            CPLGetXMLValue(psCO, "Range.Field.Identifier", "");

        if (!osFieldName.empty())
        {
            bServiceDirty = true;
            CPLCreateXMLElementAndValue(psService, "FieldName", osFieldName);
        }
        else
        {
            CPLError(
                CE_Failure, CPLE_AppDefined,
                "Unable to find required Identifier name %s for Range Field.",
                osCRS.c_str());
            return false;
        }
    }

    /* -------------------------------------------------------------------- */
    /*      Do we have a "Band" axis?  If so try to grab the bandcount      */
    /*      and data type from it.                                          */
    /* -------------------------------------------------------------------- */
    osBandIdentifier = CPLGetXMLValue(psService, "BandIdentifier", "");
    CPLXMLNode *psAxis =
        CPLGetXMLNode(psService, "CoverageDescription.Range.Field.Axis");

    if (osBandIdentifier.empty() &&
        (EQUAL(CPLGetXMLValue(psAxis, "Identifier", ""), "Band") ||
         EQUAL(CPLGetXMLValue(psAxis, "Identifier", ""), "Bands")) &&
        CPLGetXMLNode(psAxis, "AvailableKeys") != nullptr)
    {
        osBandIdentifier = CPLGetXMLValue(psAxis, "Identifier", "");

        // verify keys are ascending starting at 1
        CPLXMLNode *psValues = CPLGetXMLNode(psAxis, "AvailableKeys");
        CPLXMLNode *psSV;
        int iBand;

        for (psSV = psValues->psChild, iBand = 1; psSV != nullptr;
             psSV = psSV->psNext, iBand++)
        {
            if (psSV->eType != CXT_Element || !EQUAL(psSV->pszValue, "Key") ||
                psSV->psChild == nullptr || psSV->psChild->eType != CXT_Text ||
                atoi(psSV->psChild->pszValue) != iBand)
            {
                osBandIdentifier = "";
                break;
            }
        }

        if (!osBandIdentifier.empty())
        {
            if (CPLGetXMLValue(psService, "BandIdentifier", nullptr) == nullptr)
            {
                bServiceDirty = true;
                CPLSetXMLValue(psService, "BandIdentifier",
                               osBandIdentifier.c_str());
            }

            if (CPLGetXMLValue(psService, "BandCount", nullptr) == nullptr)
            {
                bServiceDirty = true;
                CPLSetXMLValue(psService, "BandCount",
                               CPLString().Printf("%d", iBand - 1));
            }
        }

        // Is this an ESRI server returning a GDAL recognised data type?
        CPLString osDataType = CPLGetXMLValue(psAxis, "DataType", "");
        if (GDALGetDataTypeByName(osDataType) != GDT_Unknown &&
            CPLGetXMLValue(psService, "BandType", nullptr) == nullptr)
        {
            bServiceDirty = true;
            CPLCreateXMLElementAndValue(psService, "BandType", osDataType);
        }
    }

    return true;
}

/************************************************************************/
/*                      ParseCapabilities()                             */
/************************************************************************/

CPLErr WCSDataset110::ParseCapabilities(CPLXMLNode *Capabilities,
                                        const std::string &url)
{
    CPLStripXMLNamespace(Capabilities, nullptr, TRUE);

    // make sure this is a capabilities document
    if (strcmp(Capabilities->pszValue, "Capabilities") != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Error in capabilities document.\n");
        return CE_Failure;
    }

    char **metadata = nullptr;
    std::string path = "WCS_GLOBAL#";

    CPLString key = path + "version";
    metadata = CSLSetNameValue(metadata, key, Version());

    for (CPLXMLNode *node = Capabilities->psChild; node != nullptr;
         node = node->psNext)
    {
        const char *attr = node->pszValue;
        if (node->eType == CXT_Attribute && EQUAL(attr, "updateSequence"))
        {
            key = path + "updateSequence";
            CPLString value = CPLGetXMLValue(node, nullptr, "");
            metadata = CSLSetNameValue(metadata, key, value);
        }
    }

    // identification metadata
    std::string path2 = path;
    CPLXMLNode *service = AddSimpleMetaData(
        &metadata, Capabilities, path2, "ServiceIdentification",
        {"Title", "Abstract", "Fees", "AccessConstraints"});
    CPLString kw = GetKeywords(service, "Keywords", "Keyword");
    if (kw != "")
    {
        CPLString name = path + "Keywords";
        metadata = CSLSetNameValue(metadata, name, kw);
    }
    CPLString profiles = GetKeywords(service, "", "Profile");
    if (profiles != "")
    {
        CPLString name = path + "Profiles";
        metadata = CSLSetNameValue(metadata, name, profiles);
    }

    // provider metadata
    path2 = path;
    CPLXMLNode *provider = AddSimpleMetaData(
        &metadata, Capabilities, path2, "ServiceProvider", {"ProviderName"});
    if (provider)
    {
        CPLXMLNode *site = CPLGetXMLNode(provider, "ProviderSite");
        if (site)
        {
            std::string path3 = path2 + "ProviderSite";
            CPLString value =
                CPLGetXMLValue(CPLGetXMLNode(site, "href"), nullptr, "");
            metadata = CSLSetNameValue(metadata, path3.c_str(), value);
        }
        std::string path3 = std::move(path2);
        CPLXMLNode *contact =
            AddSimpleMetaData(&metadata, provider, path3, "ServiceContact",
                              {"IndividualName", "PositionName", "Role"});
        if (contact)
        {
            std::string path4 = std::move(path3);
            CPLXMLNode *info =
                AddSimpleMetaData(&metadata, contact, path4, "ContactInfo",
                                  {"HoursOfService", "ContactInstructions"});
            if (info)
            {
                std::string path5 = path4;
                std::string path6 = path4;
                AddSimpleMetaData(&metadata, info, path5, "Address",
                                  {"DeliveryPoint", "City",
                                   "AdministrativeArea", "PostalCode",
                                   "Country", "ElectronicMailAddress"});
                AddSimpleMetaData(&metadata, info, path6, "Phone",
                                  {"Voice", "Facsimile"});
                CPL_IGNORE_RET_VAL(path4);
            }
        }
    }

    // operations metadata
    CPLString DescribeCoverageURL = "";
    CPLXMLNode *service2 = CPLGetXMLNode(Capabilities, "OperationsMetadata");
    if (service2)
    {
        for (CPLXMLNode *operation = service2->psChild; operation != nullptr;
             operation = operation->psNext)
        {
            if (operation->eType != CXT_Element ||
                !EQUAL(operation->pszValue, "Operation"))
            {
                continue;
            }
            if (EQUAL(CPLGetXMLValue(CPLGetXMLNode(operation, "name"), nullptr,
                                     ""),
                      "DescribeCoverage"))
            {
                DescribeCoverageURL = CPLGetXMLValue(
                    CPLGetXMLNode(CPLSearchXMLNode(operation, "Get"), "href"),
                    nullptr, "");
            }
        }
    }
    // if DescribeCoverageURL looks wrong, we change it
    if (DescribeCoverageURL.find("localhost") != std::string::npos)
    {
        DescribeCoverageURL = URLRemoveKey(url.c_str(), "request");
    }

    // service metadata (in 2.0)
    CPLString ext = "ServiceMetadata";
    CPLString formats = GetKeywords(Capabilities, ext, "formatSupported");
    if (formats != "")
    {
        CPLString name = path + "formatSupported";
        metadata = CSLSetNameValue(metadata, name, formats);
    }
    // wcs:Extensions: interpolation, CRS, others?
    ext += ".Extension";
    CPLString interpolation =
        GetKeywords(Capabilities, ext, "interpolationSupported");
    if (interpolation == "")
    {
        interpolation =
            GetKeywords(Capabilities, ext + ".InterpolationMetadata",
                        "InterpolationSupported");
    }
    if (interpolation != "")
    {
        CPLString name = path + "InterpolationSupported";
        metadata = CSLSetNameValue(metadata, name, interpolation);
    }
    CPLString crs = GetKeywords(Capabilities, ext, "crsSupported");
    if (crs == "")
    {
        crs = GetKeywords(Capabilities, ext + ".CrsMetadata", "crsSupported");
    }
    if (crs != "")
    {
        CPLString name = path + "crsSupported";
        metadata = CSLSetNameValue(metadata, name, crs);
    }

    this->SetMetadata(metadata, "");
    CSLDestroy(metadata);
    metadata = nullptr;

    // contents metadata
    CPLXMLNode *contents = CPLGetXMLNode(Capabilities, "Contents");
    if (contents)
    {
        int index = 1;
        for (CPLXMLNode *summary = contents->psChild; summary != nullptr;
             summary = summary->psNext)
        {
            if (summary->eType != CXT_Element ||
                !EQUAL(summary->pszValue, "CoverageSummary"))
            {
                continue;
            }
            CPLString path3;
            path3.Printf("SUBDATASET_%d_", index);
            index += 1;

            // the name and description of the subdataset:
            // GDAL Data Model:
            // The value of the _NAME is a string that can be passed to
            // GDALOpen() to access the file.

            CPLString key2 = path3 + "NAME";

            CPLString name = DescribeCoverageURL;
            name = CPLURLAddKVP(name, "version", this->Version());

            CPLXMLNode *node = CPLGetXMLNode(summary, "CoverageId");
            std::string id;
            if (node)
            {
                id = CPLGetXMLValue(node, nullptr, "");
            }
            else
            {
                node = CPLGetXMLNode(summary, "Identifier");
                if (node)
                {
                    id = CPLGetXMLValue(node, nullptr, "");
                }
                else
                {
                    // todo: maybe not an error since CoverageSummary may be
                    // within CoverageSummary (07-067r5 Fig4)
                    CSLDestroy(metadata);
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Error in capabilities document.\n");
                    return CE_Failure;
                }
            }
            name = CPLURLAddKVP(name, "coverage", id.c_str());
            name = "WCS:" + name;
            metadata = CSLSetNameValue(metadata, key2, name);

            key2 = path3 + "DESC";

            node = CPLGetXMLNode(summary, "Title");
            if (node)
            {
                metadata = CSLSetNameValue(metadata, key2,
                                           CPLGetXMLValue(node, nullptr, ""));
            }
            else
            {
                metadata = CSLSetNameValue(metadata, key2, id.c_str());
            }

            // todo: compose global bounding box from WGS84BoundingBox and
            // BoundingBox

            // further subdataset (coverage) parameters are parsed in
            // ParseCoverageCapabilities
        }
    }
    this->SetMetadata(metadata, "SUBDATASETS");
    CSLDestroy(metadata);
    return CE_None;
}

void WCSDataset110::ParseCoverageCapabilities(CPLXMLNode *capabilities,
                                              const std::string &coverage,
                                              CPLXMLNode *metadata)
{
    CPLStripXMLNamespace(capabilities, nullptr, TRUE);
    CPLXMLNode *contents = CPLGetXMLNode(capabilities, "Contents");
    if (contents)
    {
        for (CPLXMLNode *summary = contents->psChild; summary != nullptr;
             summary = summary->psNext)
        {
            if (summary->eType != CXT_Element ||
                !EQUAL(summary->pszValue, "CoverageSummary"))
            {
                continue;
            }
            CPLXMLNode *node = CPLGetXMLNode(summary, "CoverageId");
            CPLString id;
            if (node)
            {
                id = CPLGetXMLValue(node, nullptr, "");
            }
            else
            {
                node = CPLGetXMLNode(summary, "Identifier");
                if (node)
                {
                    id = CPLGetXMLValue(node, nullptr, "");
                }
                else
                {
                    id = "";
                }
            }
            if (id != coverage)
            {
                continue;
            }

            // Description
            // todo: there could be Title and Abstract for each supported
            // language
            XMLCopyMetadata(summary, metadata, "Title");
            XMLCopyMetadata(summary, metadata, "Abstract");

            // 2.0.1 stuff
            XMLCopyMetadata(summary, metadata, "CoverageSubtype");

            // Keywords
            CPLString kw = GetKeywords(summary, "Keywords", "Keyword");
            CPLAddXMLAttributeAndValue(
                CPLCreateXMLElementAndValue(metadata, "MDI", kw), "key",
                "Keywords");

            // WCSContents
            const char *tags[] = {"SupportedCRS", "SupportedFormat",
                                  "OtherSource"};
            for (unsigned int i = 0; i < CPL_ARRAYSIZE(tags); i++)
            {
                kw = GetKeywords(summary, "", tags[i]);
                CPLAddXMLAttributeAndValue(
                    CPLCreateXMLElementAndValue(metadata, "MDI", kw), "key",
                    tags[i]);
            }

            // skipping WGS84BoundingBox, BoundingBox, Metadata, Extension
            // since those we'll get from coverage description
        }
    }
}
