/******************************************************************************
 * $Id: cpl_http.cpp 10646 2007-01-18 02:38:10Z warmerdam $
 *
 * Project:  WCS Client Driver
 * Purpose:  Implementation of Dataset and RasterBand classes for WCS.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2006, Frank Warmerdam
 *
 * 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_conv.h"
#include "cpl_http.h"

#ifdef HAVE_CURL
#  include <curl/curl.h>
#endif

CPL_CVSID("$Id: cpl_http.cpp 10646 2007-01-18 02:38:10Z warmerdam $");

/************************************************************************/
/*                            CPLWriteFct()                             */
/*                                                                      */
/*      Append incoming text to our collection buffer, reallocating     */
/*      it larger as needed.                                            */
/************************************************************************/

#ifdef HAVE_CURL
static size_t 
CPLWriteFct(void *buffer, size_t size, size_t nmemb, void *reqInfo)

{
    CPLHTTPResult *psResult = (CPLHTTPResult *) reqInfo;
    int  nNewSize;

    nNewSize = psResult->nDataLen + nmemb*size + 1;
    if( nNewSize > psResult->nDataAlloc )
    {
        psResult->nDataAlloc = (int) (nNewSize * 1.25 + 100);
        psResult->pabyData = (GByte *) VSIRealloc(psResult->pabyData,
                                                  psResult->nDataAlloc);
        if( psResult->pabyData == NULL )
        {
            psResult->pszErrBuf = CPLStrdup(CPLString().Printf("Out of memory allocating %s bytes for HTTP data buffer.", psResult->nDataAlloc));
            psResult->nDataAlloc = psResult->nDataLen = 0;

            return 0;
        }
    }

    memcpy( psResult->pabyData + psResult->nDataLen, buffer,
            nmemb * size );

    psResult->nDataLen += nmemb * size;
    psResult->pabyData[psResult->nDataLen] = 0;

    return nmemb;
}
#endif /* def HAVE_CURL */

/************************************************************************/
/*                           CPLHTTPFetch()                             */
/*                                                                      */
/*      Fetch a document from an url and return in a string.            */
/************************************************************************/

CPLHTTPResult *CPLHTTPFetch( const char *pszURL, char **papszOptions )

{
#ifndef HAVE_CURL
    CPLError( CE_Failure, CPLE_NotSupported,
              "GDAL/OGR not compiled with libcurl support, remote requests not supported." );
    return NULL;
#else
    CURL *http_handle;
    char szCurlErrBuf[CURL_ERROR_SIZE+1];
    CPLHTTPResult *psResult;

    CPLDebug( "HTTP", "Fetch(%s)", pszURL );

    psResult = (CPLHTTPResult *) CPLCalloc(1,sizeof(CPLHTTPResult));

    http_handle = curl_easy_init();

    curl_easy_setopt(http_handle, CURLOPT_URL, pszURL );

    /* Enable following redirections.  Requires libcurl 7.10.1 at least */
    curl_easy_setopt(http_handle, CURLOPT_FOLLOWLOCATION, 1 );
    curl_easy_setopt(http_handle, CURLOPT_MAXREDIRS, 10 );
    
    /* Set timeout.*/
    const char *pszTimeout = CSLFetchNameValue( papszOptions, "TIMEOUT" );
    if( pszTimeout != NULL )
        curl_easy_setopt(http_handle, CURLOPT_TIMEOUT, 
                         atoi(pszTimeout) );

    /* NOSIGNAL should be set to true for timeout to work in multithread
     * environments on Unix, requires libcurl 7.10 or more recent.
     * (this force avoiding the use of sgnal handlers)
     */
#ifdef CURLOPT_NOSIGNAL
    curl_easy_setopt(http_handle, CURLOPT_NOSIGNAL, 1 );
#endif

    curl_easy_setopt(http_handle, CURLOPT_WRITEDATA, psResult );
    curl_easy_setopt(http_handle, CURLOPT_WRITEFUNCTION, CPLWriteFct );

    szCurlErrBuf[0] = '\0';

    curl_easy_setopt(http_handle, CURLOPT_ERRORBUFFER, szCurlErrBuf );

    psResult->nStatus = (int) curl_easy_perform( http_handle );

/* -------------------------------------------------------------------- */
/*      Fetch content-type if possible.                                 */
/* -------------------------------------------------------------------- */
    CURLcode err;

    psResult->pszContentType = NULL;
    err = curl_easy_getinfo( http_handle, CURLINFO_CONTENT_TYPE, 
                             &(psResult->pszContentType) );
    if( psResult->pszContentType != NULL )
        psResult->pszContentType = CPLStrdup(psResult->pszContentType);

/* -------------------------------------------------------------------- */
/*      Have we encountered some sort of error?                         */
/* -------------------------------------------------------------------- */
    if( strlen(szCurlErrBuf) > 0 )
    {
        psResult->pszErrBuf = CPLStrdup(szCurlErrBuf);
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "%s", szCurlErrBuf );
    }

    curl_easy_cleanup( http_handle );

    return psResult;
#endif /* def HAVE_CURL */
}

/************************************************************************/
/*                           CPLHTTPEnabled()                           */
/************************************************************************/

int CPLHTTPEnabled()

{
#ifdef HAVE_CURL
    return TRUE;
#else
    return FALSE;
#endif
}

/************************************************************************/
/*                           CPLHTTPCleanup()                           */
/************************************************************************/

void CPLHTTPCleanup()

{
    /* nothing for now, but if we use the more complicated api later, 
       we will need to do cleanup, like mapserver maphttp.c does. */
}

/************************************************************************/
/*                        CPLHTTPDestroyResult()                        */
/************************************************************************/

void CPLHTTPDestroyResult( CPLHTTPResult *psResult )

{
    if( psResult )
    {
        CPLFree( psResult->pabyData );
        CPLFree( psResult->pszErrBuf );
        CPLFree( psResult->pszContentType );
        CPLFree( psResult );
    }
}