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

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

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

#include "curl_setup.h"

#include <curl/curl.h>

#include "curl_range.h"

#include "sendf.h"

#include "curlx/strparse.h"

/* Only include this function if one or more of FTP, FILE are enabled. */

#if !defined(CURL_DISABLE_FTP) || !defined(CURL_DISABLE_FILE)

 /*

  Check if this is a range download, and if so, set the internal variables

  properly.

 */

CURLcode Curl_range(struct Curl_easy *data)

{

  if(data->state.use_range && data->state.range) {

    curl_off_t from, to;

    bool first_num = TRUE;

    const char *p = data->state.range;

    if(curlx_str_number(&p, &from, CURL_OFF_T_MAX))

      first_num = FALSE;

    if(curlx_str_single(&p, '-'))

      /* no leading dash or after the first number is an error */

      return CURLE_RANGE_ERROR;

    if(curlx_str_number(&p, &to, CURL_OFF_T_MAX)) {

      /* no second number */

      /* X - */

      data->state.resume_from = from;

      DEBUGF(infof(data, "RANGE %" FMT_OFF_T " to end of file", from));

    }

    else if(!first_num) {

      /* -Y */

      if(!to)

        /* "-0" is just wrong */

        return CURLE_RANGE_ERROR;

      data->req.maxdownload = to;

      data->state.resume_from = -to;

      DEBUGF(infof(data, "RANGE the last %" FMT_OFF_T " bytes", to));

    }

    else {

      /* X-Y */

      curl_off_t totalsize;

      /* Ensure the range is sensible - to should follow from. */

      if(from > to)

        return CURLE_RANGE_ERROR;

      totalsize = to - from;

      if(totalsize == CURL_OFF_T_MAX)

        return CURLE_RANGE_ERROR;

      data->req.maxdownload = totalsize + 1; /* include last byte */

      data->state.resume_from = from;

      DEBUGF(infof(data, "RANGE from %" FMT_OFF_T

                   " getting %" FMT_OFF_T " bytes",

                   from, data->req.maxdownload));

    }

    DEBUGF(infof(data, "range-download from %" FMT_OFF_T

                 " to %" FMT_OFF_T ", totally %" FMT_OFF_T " bytes",

                 from, to, data->req.maxdownload));

  }

  else

    data->req.maxdownload = -1;

  return CURLE_OK;

}

#endif