/*
 * IRC - Internet Relay Chat, ircd/m_clearmode.c
 * Copyright (C) 1990 Jarkko Oikarinen and
 *                    University of Oulu, Computing Center
 * Copyright (C) 2000 Kevin L. Mitchell <klmitch@mit.edu>
 *
 * See file AUTHORS in IRC package for additional names of
 * the programmers.
 *
 * 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: m_clearmode.c 1023 2005-03-23 18:33:08Z r33d $
 */

/*
 * m_functions execute protocol messages on this server:
 *
 *    cptr    is always NON-NULL, pointing to a *LOCAL* client
 *            structure (with an open socket connected!). This
 *            identifies the physical socket where the message
 *            originated (or which caused the m_function to be
 *            executed--some m_functions may call others...).
 *
 *    sptr    is the source of the message, defined by the
 *            prefix part of the message if present. If not
 *            or prefix not found, then sptr==cptr.
 *
 *            (!IsServer(cptr)) => (cptr == sptr), because
 *            prefixes are taken *only* from servers...
 *
 *            (IsServer(cptr))
 *                    (sptr == cptr) => the message didn't
 *                    have the prefix.
 *
 *                    (sptr != cptr && IsServer(sptr) means
 *                    the prefix specified servername. (?)
 *
 *                    (sptr != cptr && !IsServer(sptr) means
 *                    that message originated from a remote
 *                    user (not local).
 *
 *            combining
 *
 *            (!IsServer(sptr)) means that, sptr can safely
 *            taken as defining the target structure of the
 *            message in this server.
 *
 *    *Always* true (if 'parse' and others are working correct):
 *
 *    1)      sptr->from == cptr  (note: cptr->from == cptr)
 *
 *    2)      MyConnect(sptr) <=> sptr == cptr (e.g. sptr
 *            *cannot* be a local connection, unless it's
 *            actually cptr!). [MyConnect(x) should probably
 *            be defined as (x == x->from) --msa ]
 *
 *    parc    number of variable parameter strings (if zero,
 *            parv is allowed to be NULL)
 *
 *    parv    a NULL terminated list of parameter pointers,
 *
 *                    parv[0], sender (prefix string), if not present
 *                            this points to an empty string.
 *                    parv[1]...parv[parc-1]
 *                            pointers to additional parameters
 *                    parv[parc] == NULL, *always*
 *
 *            note:   it is guaranteed that parv[0]..parv[parc-1] are all
 *                    non-NULL pointers.
 */
#include "config.h"

#include "client.h"
#include "channel.h"
#include "hash.h"
#include "ircd.h"
#include "ircd_alloc.h"
#include "ircd_features.h"
#include "ircd_log.h"
#include "ircd_reply.h"
#include "ircd_string.h"
#include "list.h"
#include "msg.h"
#include "numeric.h"
#include "numnicks.h"
#include "s_conf.h"
#include "send.h"
#include "support.h"
#include "supported.h"

#include <assert.h>

/*
 * do_clearmode(struct Client *cptr, struct Client *sptr,
 *		struct Channel *chptr, char *control)
 *
 * This is the function that actually clears the channel modes.
 */
static int
do_clearmode(struct Client *cptr, struct Client *sptr, struct Channel *chptr,
	     char *control)
{
  static int flags[] = {
    MODE_CHANOP,	'o',
    MODE_HALFOP,	'h',
    MODE_VOICE,		'v',
    MODE_PRIVATE,	'p',
    MODE_SECRET,	's',
    MODE_MODERATED,	'm',
    MODE_TOPICLIMIT,	't',
    MODE_INVITEONLY,	'i',
    MODE_NOPRIVMSGS,	'n',
    MODE_KEY,		'k',
    MODE_BAN,		'b',
    MODE_EXCEPT,        'e',
    MODE_LIMIT,		'l',
    MODE_REGONLY,	'r',
    MODE_NOCOLOUR,	'c',
    MODE_STRIP,		'S',
    MODE_NOCTCP,	'C',
    MODE_ACCONLY,	'M',
    MODE_NONOTICE,	'N',
    MODE_OPERONLY,	'O',
    MODE_ADMINONLY,	'a',
    MODE_NOQUITPARTS,	'Q',
    MODE_SSLONLY,	'Z',
    MODE_NOAMSG,	'T',
    MODE_NOLISTMODES,	'L',
    0x0, 0x0
  };
  int *flag_p;
  unsigned int del_mode = 0;
  char control_buf[20];
  int control_buf_i = 0;
  struct ModeBuf mbuf;
  struct SLink *link, *next;
  struct Membership *member;

  /* Ok, so what are we supposed to get rid of? */
  for (; *control; control++) {
    for (flag_p = flags; flag_p[0]; flag_p += 2)
      if (*control == flag_p[1]) {
	del_mode |= flag_p[0];
	break;
      }
  }

  if (!del_mode)
    return 0; /* nothing to remove; ho hum. */

  modebuf_init(&mbuf, sptr, cptr, chptr,
	       (MODEBUF_DEST_CHANNEL | /* Send MODE to channel */
		MODEBUF_DEST_OPMODE  | /* Treat it like an OPMODE */
		MODEBUF_DEST_HACK4));  /* Generate a HACK(4) notice */

  modebuf_mode(&mbuf, MODE_DEL | (del_mode & chptr->mode.mode));
  chptr->mode.mode &= ~del_mode; /* and of course actually delete them */

  /* If we're removing invite, remove all the invites */
  if (del_mode & MODE_INVITEONLY)
    mode_invite_clear(chptr);

  /*
   * If we're removing the key, note that; note that we can't clear
   * the key until after modebuf_* are done with it
   */
  if (del_mode & MODE_KEY && *chptr->mode.key)
    modebuf_mode_string(&mbuf, MODE_DEL | MODE_KEY, chptr->mode.key, 0);

  /* If we're removing the limit, note that and clear the limit */
  if (del_mode & MODE_LIMIT && chptr->mode.limit) {
    modebuf_mode_uint(&mbuf, MODE_DEL | MODE_LIMIT, chptr->mode.limit);
    chptr->mode.limit = 0; /* not referenced, so safe */
  }

  /*
   * Go through and mark the bans for deletion; note that we can't
   * free them until after modebuf_* are done with them
   */
  if (del_mode & MODE_BAN) {
    for (link = chptr->banlist; link; link = next) {
      next = link->next;

      modebuf_mode_string(&mbuf, MODE_DEL | MODE_BAN, /* delete ban */
			  link->value.ban.banstr, 1);

      MyFree(link->value.ban.who); /* free up who string */
      free_link(link); /* and of course the link itself */
    }

    chptr->banlist = 0;
  }

  /*
   * Go through and mark the except for deletion; note that we can't
   * free them until after modebuf_* are done with them
   */
  if (del_mode & MODE_EXCEPT) {
    for (link = chptr->exceptlist; link; link = next) {
      next = link->next;

      modebuf_mode_string(&mbuf, MODE_DEL | MODE_EXCEPT, /* delete except */
                          link->value.except.exceptstr, 1);

      MyFree(link->value.except.who); /* free up who string */
      free_link(link); /* and of course the link itself */
    }

    chptr->exceptlist = 0;
  }

  /* Deal with users on the channel */
  if (del_mode & (MODE_BAN | MODE_EXCEPT | MODE_HALFOP | MODE_CHANOP | MODE_VOICE))
    for (member = chptr->members; member; member = member->next_member) {
      if (IsZombie(member)) /* we ignore zombies */
	continue;

      if (del_mode & MODE_BAN) /* If we cleared bans, clear the valid flags */
	ClearBanValid(member);

      if (del_mode & MODE_EXCEPT) /* If we cleared excepts, clear the valid flags */
        ClearExceptValid(member);

      /* Drop channel operator status */
      if (IsChanOp(member) && del_mode & MODE_CHANOP) {
	modebuf_mode_client(&mbuf, MODE_DEL | MODE_CHANOP, member->user);
	member->status &= ~CHFL_CHANOP;
      }

      /* Drop halfop status */
      if (IsHalfOp(member) && del_mode & MODE_HALFOP) {
	modebuf_mode_client(&mbuf, MODE_DEL | MODE_HALFOP, member->user);
	member->status &= ~CHFL_HALFOP;
      }

      /* Drop voice */
      if (HasVoice(member) && del_mode & MODE_VOICE) {
	modebuf_mode_client(&mbuf, MODE_DEL | MODE_VOICE, member->user);
	member->status &= ~CHFL_VOICE;
      }
    }

  /* And flush the modes to the channel */
  modebuf_flush(&mbuf);

  /* Finally, we can clear the key... */
  if (del_mode & MODE_KEY)
    chptr->mode.key[0] = '\0';

  /* Ok, build control string again */
  for (flag_p = flags; flag_p[0]; flag_p += 2)
    if (del_mode & flag_p[0])
      control_buf[control_buf_i++] = flag_p[1];

  control_buf[control_buf_i] = '\0';

  /* Log it... */
  log_write(LS_OPERMODE, L_INFO, LOG_NOSNOTICE, "%#C CLEARMODE %H %s", sptr,
	    chptr, control_buf);

  /* Then send it */
  if (!IsLocalChannel(chptr->chname))
    sendcmdto_serv_butone(sptr, CMD_CLEARMODE, cptr, "%H %s", chptr,
			  control_buf);

  return 0;
}

/*
 * ms_clearmode - server message handler
 *
 * parv[0] = Send prefix
 * parv[1] = Channel name
 * parv[2] = Control string
 */
int
ms_clearmode(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
{
  struct Channel *chptr;

  if (parc < 3)
    return need_more_params(sptr, "CLEARMODE");

  if (!IsPrivileged(sptr)) {
    protocol_violation(sptr, "No privileges on source for CLEARMODE, desync?");
    return send_reply(sptr, ERR_NOPRIVILEGES);
  }

  if (!IsChannelName(parv[1]) || !(chptr = FindChannel(parv[1])))
    return send_reply(sptr, ERR_NOSUCHCHANNEL, parv[1]);

  return do_clearmode(cptr, sptr, chptr, parv[2]);
}

/*
 * mo_clearmode - oper message handler
 *
 * parv[0] = Send prefix
 * parv[1] = Channel name
 * parv[2] = Control string
 */
int
mo_clearmode(struct Client* cptr, struct Client* sptr, int parc, char* parv[])
{
  struct Channel *chptr;
  char *control = clearchanmodes; /* default control string (supported.h) */
  char *chname, *qreason;
  struct Membership *tmp;
  int force = 0;

  if (!feature_bool(FEAT_CONFIG_OPERCMDS))
    return send_reply(sptr, ERR_DISABLED, "CLEARMODE");

  if (parc < 2)
    return need_more_params(sptr, "CLEARMODE");

  if (parc > 2)
    control = parv[2];

  chname = parv[1];
  if (*chname == '!') {
    chname++;
    if (!HasPriv(sptr, IsLocalChannel(chname) ? PRIV_FORCE_LOCAL_OPMODE : PRIV_FORCE_OPMODE))
      return send_reply(sptr, ERR_NOPRIVILEGES);
    force = 1;
  }

  if (!HasPriv(sptr,
	       IsLocalChannel(chname) ? PRIV_LOCAL_OPMODE : PRIV_OPMODE))
    return send_reply(sptr, ERR_NOPRIVILEGES);

  if (!(chptr = FindChannel(chname)))
    return send_reply(sptr, ERR_NOSUCHCHANNEL, chname);

  if (!force) {
    if ((qreason = find_quarantine(chptr->chname)))
      return send_reply(sptr, ERR_QUARANTINED, chptr->chname, qreason);

    for (tmp = chptr->members; tmp; tmp = tmp->next_member)
      if (IsService(cli_user(tmp->user)->server) && IsChannelService(tmp->user)) {
	/* Impersonate the abuser */
	sendwallto_group_butone(&me, WALL_DESYNCH, NULL,
				"Failed CLEARMODE for registered channel %s by %s",
				chptr->chname, cli_name(sptr));
	return send_reply(sptr, ERR_QUARANTINED, chptr->chname,
			  "This channel is registered.");
      }
  }
    
  return do_clearmode(cptr, sptr, chptr, control);
}