// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id: m_cheat.c 8 2005-07-23 16:44:57Z fraggle $
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
//
// 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.
//
// $Log$
// Revision 1.2  2005/07/23 16:44:55  fraggle
// Update copyright to GNU GPL
//
// Revision 1.1.1.1  2005/07/23 16:20:31  fraggle
// Initial import
//
//
// DESCRIPTION:
//	Cheat sequence checking.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: m_cheat.c 8 2005-07-23 16:44:57Z fraggle $";

#include "m_cheat.h"

//
// CHEAT SEQUENCE PACKAGE
//

static int		firsttime = 1;
static unsigned char	cheat_xlate_table[256];


//
// Called in st_stuff module, which handles the input.
// Returns a 1 if the cheat was successful, 0 if failed.
//
int
cht_CheckCheat
( cheatseq_t*	cht,
  char		key )
{
    int i;
    int rc = 0;

    if (firsttime)
    {
	firsttime = 0;
	for (i=0;i<256;i++) cheat_xlate_table[i] = SCRAMBLE(i);
    }

    if (!cht->p)
	cht->p = cht->sequence; // initialize if first time

    if (*cht->p == 0)
	*(cht->p++) = key;
    else if
	(cheat_xlate_table[(unsigned char)key] == *cht->p) cht->p++;
    else
	cht->p = cht->sequence;

    if (*cht->p == 1)
	cht->p++;
    else if (*cht->p == 0xff) // end of sequence character
    {
	cht->p = cht->sequence;
	rc = 1;
    }

    return rc;
}

void
cht_GetParam
( cheatseq_t*	cht,
  char*		buffer )
{

    unsigned char *p, c;

    p = cht->sequence;
    while (*(p++) != 1);
    
    do
    {
	c = *p;
	*(buffer++) = c;
	*(p++) = 0;
    }
    while (c && *p!=0xff );

    if (*p==0xff)
	*buffer = 0;

}