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

 *

 * Project:  WCS Client Driver

 * Purpose:  Implementation of an HTTP fetching driver.

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

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

 * Copyright (c) 2007, Frank Warmerdam

 * Copyright (c) 2008-2013, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

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

#include "cpl_error_internal.h"

#include "cpl_string.h"

#include "cpl_http.h"

#include "gdal_frmts.h"

#include "gdal_pam.h"

static std::string SanitizeDispositionFilename(const std::string &osVal)

{

    std::string osRet(osVal);

    if (!osRet.empty() && osRet[0] == '"')

    {

        const auto nEnd = osRet.find('"', 1);

        if (nEnd != std::string::npos)

            return osRet.substr(1, nEnd - 1);

    }

    return osRet;

}

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

/*               HTTPFetchContentDispositionFilename()                 */

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

static std::string HTTPFetchContentDispositionFilename(char **papszHeaders)

{

    char **papszIter = papszHeaders;

    while (papszIter && *papszIter)

    {

        /* For multipart, we have in raw format, but without end-of-line

         * characters */

        if (STARTS_WITH(*papszIter,

                        "Content-Disposition: attachment; filename="))

        {

            return SanitizeDispositionFilename(*papszIter + 42);

        }

        /* For single part, the headers are in KEY=VAL format, but with e-o-l

         * ... */

        else if (STARTS_WITH(*papszIter,

                             "Content-Disposition=attachment; filename="))

        {

            char *pszVal = (*papszIter + 41);

            char *pszEOL = strchr(pszVal, '\r');

            if (pszEOL)

                *pszEOL = 0;

            pszEOL = strchr(pszVal, '\n');

            if (pszEOL)

                *pszEOL = 0;

            return SanitizeDispositionFilename(pszVal);

        }

        papszIter++;

    }

    return std::string();

}

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

/*                              HTTPOpen()                              */

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

static GDALDataset *HTTPOpen(GDALOpenInfo *poOpenInfo)

{

    if (poOpenInfo->nHeaderBytes != 0)

        return nullptr;

    if (!STARTS_WITH_CI(poOpenInfo->pszFilename, "http:") &&

        !STARTS_WITH_CI(poOpenInfo->pszFilename, "https:") &&

        !STARTS_WITH_CI(poOpenInfo->pszFilename, "ftp:"))

        return nullptr;

    /* -------------------------------------------------------------------- */

    /*      Fetch the result.                                               */

    /* -------------------------------------------------------------------- */

    CPLErrorReset();

    CPLHTTPResult *psResult = CPLHTTPFetch(poOpenInfo->pszFilename, nullptr);

    /* -------------------------------------------------------------------- */

    /*      Try to handle errors.                                           */

    /* -------------------------------------------------------------------- */

    if (psResult == nullptr || psResult->nDataLen == 0 ||

        CPLGetLastErrorNo() != 0)

    {

        CPLHTTPDestroyResult(psResult);

        return nullptr;

    }

    /* -------------------------------------------------------------------- */

    /*      Create a memory file from the result.                           */

    /* -------------------------------------------------------------------- */

    std::string osFilename =

        HTTPFetchContentDispositionFilename(psResult->papszHeaders);

    if (osFilename.empty())

    {

        osFilename = CPLGetFilename(poOpenInfo->pszFilename);

        /* If we have special characters, let's default to a fixed name */

        if (strchr(osFilename.c_str(), '?') || strchr(osFilename.c_str(), '&'))

            osFilename = "file.dat";

    }

    // If changing the _gdal_http_ marker, change jpgdataset.cpp that tests for it

    const CPLString osResultFilename = VSIMemGenerateHiddenFilename(

        std::string("_gdal_http_").append(osFilename).c_str());

    VSILFILE *fp = VSIFileFromMemBuffer(osResultFilename, psResult->pabyData,

                                        psResult->nDataLen, TRUE);

    if (fp == nullptr)

        return nullptr;

    VSIFCloseL(fp);

    /* -------------------------------------------------------------------- */

    /*      Steal the memory buffer from HTTP result before destroying      */

    /*      it.                                                             */

    /* -------------------------------------------------------------------- */

    psResult->pabyData = nullptr;

    psResult->nDataLen = 0;

    psResult->nDataAlloc = 0;

    CPLHTTPDestroyResult(psResult);

    CPLStringList aosOpenOptions;

    for (const char *pszStr :

         cpl::Iterate(const_cast<CSLConstList>(poOpenInfo->papszOpenOptions)))

    {

        if (STARTS_WITH_CI(pszStr, "NATIVE_DATA="))

        {

            // Avoid warning with "ogr2ogr out http://example.com/in.gpkg"

            aosOpenOptions.push_back(std::string("@").append(pszStr).c_str());

        }

        else

        {

            aosOpenOptions.push_back(pszStr);

        }

    }

    /* -------------------------------------------------------------------- */

    /*      Try opening this result as a gdaldataset.                       */

    /* -------------------------------------------------------------------- */

    /* suppress errors as not all drivers support /vsimem */

    GDALDataset *poDS;

    CPLErrorAccumulator oErrorAccumulator;

    {

        CPLErrorStateBackuper oBackuper(CPLQuietErrorHandler);

        auto oAccumulator = oErrorAccumulator.InstallForCurrentScope();

        CPL_IGNORE_RET_VAL(oAccumulator);

        poDS = GDALDataset::Open(

            osResultFilename, poOpenInfo->nOpenFlags & ~GDAL_OF_SHARED,

            poOpenInfo->papszAllowedDrivers, aosOpenOptions.List(), nullptr);

    }

    // Re-emit silenced errors if open was successful

    if (poDS)

    {

        oErrorAccumulator.ReplayErrors();

    }

    // The JP2OpenJPEG driver may need to reopen the file, hence this special

    // behavior

    if (poDS != nullptr && poDS->GetDriver() != nullptr &&

        EQUAL(poDS->GetDriver()->GetDescription(), "JP2OpenJPEG"))

    {

        poDS->MarkSuppressOnClose();

        return poDS;

    }

    /* -------------------------------------------------------------------- */

    /*      If opening it in memory didn't work, perhaps we need to         */

    /*      write to a temp file on disk?                                   */

    /* -------------------------------------------------------------------- */

    if (poDS == nullptr)

    {

        CPLString osTempFilename;

#ifdef _WIN32

        const std::string osPath =

            CPLGetPathSafe(CPLGenerateTempFilenameSafe(NULL).c_str());

#else

        const std::string osPath = "/tmp";

#endif

        osTempFilename = CPLFormFilenameSafe(

            osPath.c_str(), CPLGetFilename(osResultFilename), nullptr);

        if (CPLCopyFile(osTempFilename, osResultFilename) != 0)

        {

            CPLError(CE_Failure, CPLE_OpenFailed,

                     "Failed to create temporary file:%s",

                     osTempFilename.c_str());

        }

        else

        {

            poDS = GDALDataset::Open(osTempFilename,

                                     poOpenInfo->nOpenFlags & ~GDAL_OF_SHARED,

                                     poOpenInfo->papszAllowedDrivers,

                                     aosOpenOptions.List(), nullptr);

            if (VSIUnlink(osTempFilename) != 0 && poDS != nullptr)

                poDS->MarkSuppressOnClose(); /* VSIUnlink() may not work on

                                                windows */

            if (poDS && strcmp(poDS->GetDescription(), osTempFilename) == 0)

                poDS->SetDescription(poOpenInfo->pszFilename);

        }

    }

    else if (strcmp(poDS->GetDescription(), osResultFilename) == 0)

        poDS->SetDescription(poOpenInfo->pszFilename);

    /* -------------------------------------------------------------------- */

    /*      Release our hold on the vsi memory file, though if it is        */

    /*      held open by a dataset it will continue to exist till that      */

    /*      lets it go.                                                     */

    /* -------------------------------------------------------------------- */

    VSIUnlink(osResultFilename);

    return poDS;

}

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

/*                         GDALRegister_HTTP()                          */

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

void GDALRegister_HTTP()

{

    if (GDALGetDriverByName("HTTP") != nullptr)

        return;

    GDALDriver *poDriver = new GDALDriver();

    poDriver->SetDescription("HTTP");

    poDriver->SetMetadataItem(GDAL_DCAP_RASTER, "YES");

    poDriver->SetMetadataItem(GDAL_DCAP_VECTOR, "YES");

    poDriver->SetMetadataItem(GDAL_DMD_LONGNAME, "HTTP Fetching Wrapper");

    poDriver->pfnOpen = HTTPOpen;

    GetGDALDriverManager()->RegisterDriver(poDriver);

}