/************************************************************************
 *   Unreal Internet Relay Chat Daemon, src/fdlist.c
 *   Copyright (C) Mika Nystrom
 *
 *   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 1, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* $Id$ */

#include "struct.h"
#include "common.h"
#include "sys.h"
#include "h.h"
#include "config.h"
#include "fdlist.h"
#include "proto.h"
#include <string.h>

extern fdlist default_fdlist;
extern fdlist busycli_fdlist;
extern fdlist serv_fdlist;
extern fdlist oper_fdlist;

#define FDLIST_DEBUG

void addto_fdlist(int fd, fdlist * listp)
{
	int  index;
#ifdef FDLIST_DEBUG
	int i;
#endif

	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
	if ((fd < 0) || (fd >= MAXCONNECTIONS))
	{
		sendto_realops("[BUG] trying to add fd #%d to %p (%p/%p/%p/%p), range is 0..%d",
			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
			MAXCONNECTIONS);
		ircd_log(LOG_ERROR, "[BUG] trying to add fd #%d to %p (%p/%p/%p/%p), range is 0..%d",
			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
			MAXCONNECTIONS);
		return;
	}

#ifdef FDLIST_DEBUG
	for (i = listp->last_entry; i; i--)
	{
		if (listp->entry[i] == fd)
		{
			char buf[2048];
			ircsprintf(buf, "[BUG] addto_fdlist() called for duplicate entry! fd=%d, fdlist=%p, client=%s (%p/%p/%p/%p)",
				fd, listp, local[fd] ? local[fd]->name : "<null>", &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist);
			sendto_realops("%s", buf);
			ircd_log(LOG_ERROR, "%s", buf);
			return;
		}
	}
#endif

	if ((index = ++listp->last_entry) >= MAXCONNECTIONS)
	{
		/*
		 * list too big.. must exit 
		 */
		--listp->last_entry;
		ircd_log(LOG_ERROR, "fdlist.c list too big, must exit...");
		abort();
	}
	else
		listp->entry[index] = fd;
	return;
}

void delfrom_fdlist(int fd, fdlist * listp)
{
	int  i;
#ifdef FDLIST_DEBUG
	int cnt = 0;
#endif

	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
	if ((fd < 0) || (fd >= MAXCONNECTIONS))
	{
		sendto_realops("[BUG] trying to remove fd #%d to %p (%p/%p/%p/%p), range is 0..%d",
			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
			MAXCONNECTIONS);
		ircd_log(LOG_ERROR, "[BUG] trying to remove fd #%d to %p (%p/%p/%p/%p), range is 0..%d",
			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
			MAXCONNECTIONS);
		return;
	}

#ifdef FDLIST_DEBUG
	for (i = listp->last_entry; i; i--)
	{
		if (listp->entry[i] == fd)
			cnt++;
	}
	if (cnt > 1)
	{
		char buf[2048];
		ircsprintf(buf, "[BUG] delfrom_fdlist() called, duplicate entries detected! fd=%d, fdlist=%p, client=%s (%p/%p/%p/%p)",
			fd, listp, local[fd] ? local[fd]->name : "<null>", &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist);
		sendto_realops("%s", buf);
		ircd_log(LOG_ERROR, "%s", buf);
		return;
	}
#endif


	for (i = listp->last_entry; i; i--)
	{
		if (listp->entry[i] == fd)
			break;
	}
	if (!i)
		return;		/*
				 * could not find it! 
				 */
	/*
	 * swap with last_entry 
	 */
	if (i == listp->last_entry)
	{
		listp->entry[i] = 0;
		listp->last_entry--;
		return;
	}
	else
	{
		listp->entry[i] = listp->entry[listp->last_entry];
		listp->entry[listp->last_entry] = 0;
		listp->last_entry--;
		return;
	}
}

void init_fdlist(fdlist * listp)
{
	listp->last_entry = 0;
	memset((char *)listp->entry, '\0', sizeof(listp->entry));
	return;
}