/*

 * nohtml.c     -- (X)HTML helper functions

 *

 * Copyright (C) 2008 Mikael Berthe <mikael@lilotux.net>

 * Some portions come from the jabberd project, see below.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or (at

 * your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307

 * USA

 *

 *

 * Some parts come from libjabber/str.c:

 * Copyright (c) 1999-2002 Jabber.com, Inc.  All Rights Reserved.  Contact

 * information for Jabber.com, Inc. is available at http://www.jabber.com/.

 * Portions Copyright (c) 1998-1999 Jeremie Miller.

 */

#include <string.h>

#include <glib.h>

#include <config.h>

/*  html_strip(htmlbuf)

 * Remove html entities from htmlbuf and try to convert it to plain text.

 * The caller must g_free the string after use.

 * Code mostly derived from strunescape(), in libjabber.

 */

char *html_strip(const char *htmlbuf)

{

  int i, j=0;

  char *nohtml;

  if (!htmlbuf) return(NULL);

  nohtml = g_strdup(htmlbuf);

  if (!strchr(htmlbuf, '&') && !strchr(htmlbuf, '<'))

    return(nohtml);

  for (i = 0; i < (int)strlen(htmlbuf); i++) {

    if (htmlbuf[i] == '&') {

      if (!strncmp(&htmlbuf[i],"&",5)) {

        nohtml[j] = '&';

        i += 4;

      } else if (!strncmp(&htmlbuf[i],""", 6)) {

        nohtml[j] = '\"';

        i += 5;

      } else if (!strncmp(&htmlbuf[i],"'", 6)) {

        nohtml[j] = '\'';

        i += 5;

      } else if (!strncmp(&htmlbuf[i],"<", 4)) {

        nohtml[j] = '<';

        i += 3;

      } else if (!strncmp(&htmlbuf[i],">", 4)) {

        nohtml[j] = '>';

        i += 3;

      }

    } else if (!strncmp(&htmlbuf[i],"<br>", 4) ||

               !strncmp(&htmlbuf[i],"<br/>", 5)) {

      nohtml[j] = '\n';

      i += (htmlbuf[i+3] == '/' ? 4 : 3);

    } else if (htmlbuf[i] == '<') {

      /* Let's strip all unknown tags */

      j--;

      while (htmlbuf[++i] != '>');

    } else

      nohtml[j] = htmlbuf[i];

    j++;

  }

  nohtml[j] = '\0';

  return nohtml;

}

/*  html_escape(text)

 * Add (x)html entities to the text.

 * The caller must g_free the string after use.

 * Code mostly derived from strescape(), in libjabber.

 */

char *html_escape(const char *text)

{

  int i, j;

  int oldlen, newlen;

  char *html;

  if (!text) return(NULL);

  oldlen = newlen = strlen(text);

  for (i = 0; i < oldlen; i++) {

    switch(text[i])

    {

      case '&':

          newlen += 5;

          break;

      case '\'':

          newlen += 6;

          break;

          case '\"':

              newlen += 6;

          break;

      case '<':

          newlen += 4;

          break;

      case '>':

          newlen += 4;

          break;

      case '\n':

          newlen += 5;

    }

  }

  if (oldlen == newlen)

    return g_strdup(text);

  html = g_new0(char, newlen+1);

  for (i = j = 0; i < oldlen; i++) {

    switch(text[i])

    {

      case '&':

          memcpy(&html[j], "&", 5);

          j += 5;

          break;

      case '\'':

          memcpy(&html[j], "'", 6);

          j += 6;

          break;

      case '\"':

          memcpy(&html[j], """, 6);

          j += 6;

          break;

      case '<':

          memcpy(&html[j], "<", 4);

          j += 4;

          break;

      case '>':

          memcpy(&html[j], ">", 4);

          j += 4;

          break;

      case '\n':

          memcpy(&html[j], "<br/>", 5);

          j += 5;

          break;

      default:

          html[j++] = text[i];

    }

  }

  return html;

}

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