/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2021 ircd-hybrid development team
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file match.c
 * \brief Functions to match/compare strings.
 * \version $Id$
 */

#include "match.h"


#define ToLower(c) (ToLowerTab[(unsigned char)(c)])

static const unsigned char ToLowerTab[] =
{
  0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xa,
  0xb, 0xc, 0xd, 0xe, 0xf, 0x10, 0x11, 0x12, 0x13, 0x14,
  0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
  0x1e, 0x1f,
  ' ', '!', '"', '#', '$', '%', '&', 0x27, '(', ')',
  '*', '+', ',', '-', '.', '/',
  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
  ':', ';', '<', '=', '>', '?',
  '@', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
  'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
  't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~',
  '_',
  '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
  'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
  't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '|', '}', '~',
  0x7f,
  0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
  0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
  0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
  0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9,
  0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
  0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9,
  0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
  0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9,
  0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
  0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9,
  0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
  0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
  0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
  0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9,
  0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};

/*! \brief Check a string against a mask.
 * This test checks using traditional IRC wildcards only: '*' means
 * match zero or more characters of any type; '?' means match exactly
 * one character of any type.  A backslash escapes the next character
 * so that a wildcard may be matched exactly.
 * param mask Wildcard-containing mask.
 * param name String to check against \a mask.
 * return Zero if \a mask matches \a name, non-zero if no match.
 */
int
match(const char *mask, const char *name)
{
  const char *m = mask, *n = name;
  const char *m_tmp = mask, *n_tmp = name;
  unsigned int star = 0;

  while (1)
  {
    switch (*m)
    {
      case '\0':
        if (*n == '\0')
          return 0;
  backtrack:
        if (m_tmp == mask)
          return 1;

        m = m_tmp;
        n = ++n_tmp;

        if (*n == '\0')
          return 1;
        break;
      case '\\':
        ++m;

        /* allow escaping to force capitalization */
        if (*m++ != *n++)
          goto backtrack;
        break;
      case '*':
      case '?':
        for (star = 0; ; ++m)
        {
          if (*m == '*')
            star = 1;
          else if (*m == '?')
          {
            if (*n++ == '\0')
              goto backtrack;
          }
          else
            break;
        }

        if (star)
        {
          if (*m == '\0')
            return 0;
          else if (*m == '\\')
          {
            m_tmp = ++m;

            if (*m == '\0')
              return 1;
            for (n_tmp = n; *n && *n != *m; ++n)
              ;
          }
          else
          {
            m_tmp = m;
            for (n_tmp = n; *n && (ToLower(*n) != ToLower(*m)); ++n)
              ;
          }
        }
        /* and fall through */
      default:
        if (*n == '\0')
          return *m != '\0';
        if (ToLower(*m) != ToLower(*n))
          goto backtrack;
        ++m;
        ++n;
        break;
    }
  }

  return 1;
}