/******************************************************************************
 *
 * 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>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "cpl_string.h"
#include "cpl_http.h"
#include "cpl_atomic_ops.h"
#include "gdal_frmts.h"
#include "gdal_pam.h"

/************************************************************************/
/*               HTTPFetchContentDispositionFilename()                 */
/************************************************************************/

static const char *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 *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 = (char *)(*papszIter + 41);
            char *pszEOL = strchr(pszVal, '\r');
            if (pszEOL)
                *pszEOL = 0;
            pszEOL = strchr(pszVal, '\n');
            if (pszEOL)
                *pszEOL = 0;
            return pszVal;
        }
        papszIter++;
    }
    return nullptr;
}

/************************************************************************/
/*                              HTTPOpen()                              */
/************************************************************************/

static GDALDataset *HTTPOpen(GDALOpenInfo *poOpenInfo)

{
    static volatile int nCounter = 0;

    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.                           */
    /* -------------------------------------------------------------------- */
    CPLString osResultFilename;

    int nNewCounter = CPLAtomicInc(&nCounter);

    const char *pszFilename =
        HTTPFetchContentDispositionFilename(psResult->papszHeaders);
    if (pszFilename == nullptr)
    {
        pszFilename = CPLGetFilename(poOpenInfo->pszFilename);
        /* If we have special characters, let's default to a fixed name */
        if (strchr(pszFilename, '?') || strchr(pszFilename, '&'))
            pszFilename = "file.dat";
    }

    osResultFilename.Printf("/vsimem/http_%d/%s", nNewCounter, pszFilename);

    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);

    /* -------------------------------------------------------------------- */
    /*      Try opening this result as a gdaldataset.                       */
    /* -------------------------------------------------------------------- */
    /* suppress errors as not all drivers support /vsimem */
    CPLPushErrorHandler(CPLQuietErrorHandler);
    GDALDataset *poDS = (GDALDataset *)GDALOpenEx(
        osResultFilename, poOpenInfo->nOpenFlags & ~GDAL_OF_SHARED,
        poOpenInfo->papszAllowedDrivers, poOpenInfo->papszOpenOptions, nullptr);
    CPLPopErrorHandler();

    // 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 char *pszPath = CPLGetPath(CPLGenerateTempFilename(NULL));
#else
        const char *pszPath = "/tmp";
#endif
        osTempFilename =
            CPLFormFilename(pszPath, 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 *)GDALOpenEx(
                osTempFilename, poOpenInfo->nOpenFlags & ~GDAL_OF_SHARED,
                poOpenInfo->papszAllowedDrivers, poOpenInfo->papszOpenOptions,
                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);
}
