/*-------------------------------------------------------------------------
 * Copyright (c) 2000-2002 Kenneth W. Sodemann (stuffle@charter.net)
 *-------------------------------------------------------------------------
 * gstr_utils
 *
 * Synopsis:
 *   A collection of utilities for working with GStrings
 *
 * $Id: gstr_utils.c,v 1.1 2003/03/09 20:59:11 stuffle Exp $
 *
 * 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
 * Free Software Foundation, Inc.
 * 59 Temple Place, Suite 330 
 * Boston, MA  02111-1307  USA 
 *-------------------------------------------------------------------------
 */
#include <assert.h>
#include <ctype.h>
#include <glib.h>

GString*
g_string_strip (GString  *str)
{
   gint new_len = str->len;
 
   assert (str);
 
   while (new_len > 0 && isspace (str->str[new_len - 1]))
      {
      new_len--;
      }
 
   if (new_len != str->len)
      {
      return g_string_truncate (str, new_len);
      }
 
   return str;
}
 
 
void
g_string_delete_char (GString *str, gint pos)
{
   GString  *tmp;
 
   assert (pos < str->len);
 
   /*
    * Create a tmp string containing all of the characters after the
    * one to delete.
    *
    * 'pos' doubles as the number of chars before the position to be
    * deleted (since c strings are 0 indexed), so truncating the string
    * to that length, then reattaching the tmp string will do the trick.
    */
   tmp = g_string_new (str->str + pos + 1);
   str = g_string_truncate (str, pos);
   str = g_string_append (str, tmp->str);
 
   g_string_free (tmp, TRUE);
}

void
g_string_insert_char (GString *str, gchar chr, gint pos)
{
   GString  *tmp;
 
   assert (pos <= str->len);
 
   /*
    * We are doing the insert before the given position, so copy the
    * characters at that position and beyond to a temp string, truncate
    * the original string to that length, then paste in the new char,
    * and reattach the end of the string.
    */
   tmp = g_string_new (str->str + pos);
   str = g_string_truncate (str, pos);
   str = g_string_append_c (str, chr);
   str = g_string_append (str, tmp->str);
 
   g_string_free (tmp, TRUE);
}
 
 
void
g_string_insert_str (GString *str1, gchar *str2, gint pos)
{
   GString  *tmp;
 
   assert (pos <= str1->len);
 
   tmp = g_string_new (str1->str + pos);
   str1 = g_string_truncate (str1, pos);
   str1 = g_string_append (str1, str2);
   str1 = g_string_append (str1, tmp->str);
 
   g_string_free (tmp, TRUE);
}
 
 
void
g_string_escape_char (GString *str, gchar chr)
{
   gint  i;                                                                      
   for (i = str->len - 1; i >= 0; --i)
      {
      if (str->str[i] == chr)
         {
         g_string_insert_char (str, '\\', i);
         }
      }
}
 
 
void
g_string_prepare_db_instr (GString *str)
{
   str = g_string_strip (str);
 
   if (str->len)
      {
      g_string_escape_char (str, '\\');
      g_string_escape_char (str, '\'');
      g_string_insert_char (str, '\'', 0);
      g_string_insert_char (str, '\'', str->len);
      }
   else
      {
      str = g_string_assign (str, "NULL");
      }
}                                                                               


void
g_string_prepare_html (GString *str)
{
   gboolean  prev_space = FALSE;
   gint      i = 0;

   while (i < str->len)
      {
      switch (str->str[i])
         {
         case '&':
            g_string_insert_str (str, "amp;", i + 1);
            i += 5;
            prev_space = FALSE;
            break;

         case '<':
            str->str[i] = '&';
            g_string_insert_str (str, "lt;", i + 1);
            i += 4;
            prev_space = FALSE;
            break;

         case '>':
            str->str[i] = '&';
            g_string_insert_str (str, "gt;", i + 1);
            i += 4;
            prev_space = FALSE;
            break;

         case '"':
            str->str[i] = '&';
            g_string_insert_str (str, "quot;", i + 1);
            i += 6;
            prev_space = FALSE;
            break;

         case '\n':
            str->str[i] = '<';
            g_string_insert_str (str, "br>\n", i + 1);
            i += 5;
            prev_space = FALSE;
            break;

         case ' ':
            if (prev_space)
               {
               str->str[i] = '&';
               g_string_insert_str (str, "nbsp;", i + 1);
               i += 5; /* xtra char added outside if */
               }
            i += 1;
            prev_space = TRUE;
            break;

         default:
            prev_space = FALSE;
            i += 1;
         } /* switch */
      } /* while */
}