/*
 *  ircd-ratbox: A slightly useful ircd.
 *  m_invite.c: Invites the user to join a channel.
 *
 *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
 *  Copyright (C) 1996-2002 Hybrid Development Team
 *  Copyright (C) 2002-2005 ircd-ratbox 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 */

#include "stdinc.h"
#include "common.h"
#include "channel.h"
#include "client.h"
#include "hash.h"
#include "match.h"
#include "ircd.h"
#include "numeric.h"
#include "send.h"
#include "s_conf.h"
#include "s_serv.h"
#include "msg.h"
#include "parse.h"
#include "modules.h"
#include "packet.h"
#include "tgchange.h"

static int m_invite(struct Client *, struct Client *, int, const char **);

struct Message invite_msgtab = {
    "INVITE", 0, 0, 0, MFLG_SLOW,
    {mg_unreg, {m_invite, 3}, {m_invite, 3}, mg_ignore, mg_ignore, {m_invite, 3}}
};
mapi_clist_av1 invite_clist[] = { &invite_msgtab, NULL };
DECLARE_MODULE_AV1(invite, NULL, NULL, invite_clist, NULL, NULL, "$Revision: 3438 $");

static void add_invite(struct Channel *, struct Client *);

/* m_invite()
 *      parv[1] - user to invite
 *      parv[2] - channel name
 */
static int
m_invite(struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
    struct Client *target_p;
    struct Channel *chptr;
    struct membership *msptr;
    int store_invite = 0;

    if(MyClient(source_p) && !IsFloodDone(source_p))
        flood_endgrace(source_p);

    if(MyClient(source_p))
        target_p = find_named_person(parv[1]);
    else
        target_p = find_person(parv[1]);
    if(target_p == NULL) {
        if(!MyClient(source_p) && IsDigit(parv[1][0]))
            sendto_one_numeric(source_p, ERR_NOSUCHNICK,
                               "* :Target left IRC. Failed to invite to %s",
                               parv[2]);
        else
            sendto_one_numeric(source_p, ERR_NOSUCHNICK,
                               form_str(ERR_NOSUCHNICK),
                               parv[1]);
        return 0;
    }

    if(check_channel_name(parv[2]) == 0) {
        sendto_one_numeric(source_p, ERR_BADCHANNAME,
                           form_str(ERR_BADCHANNAME),
                           parv[2]);
        return 0;
    }

    if(!IsChannelName(parv[2])) {
        if(MyClient(source_p))
            sendto_one_numeric(source_p, ERR_NOSUCHCHANNEL,
                               form_str(ERR_NOSUCHCHANNEL), parv[2]);
        return 0;
    }

    /* Do not send local channel invites to users if they are not on the
     * same server as the person sending the INVITE message.
     */
    if(parv[2][0] == '&' && !MyConnect(target_p)) {
        sendto_one(source_p, form_str(ERR_USERNOTONSERV),
                   me.name, source_p->name, target_p->name);
        return 0;
    }

    if(((MyConnect(source_p) && !IsExemptResv(source_p)) ||
        (MyConnect(target_p) && !IsExemptResv(target_p))) &&
       hash_find_resv(parv[2])) {
        sendto_one_numeric(source_p, ERR_BADCHANNAME,
                           form_str(ERR_BADCHANNAME),
                           parv[2]);
        return 0;
    }

    if((chptr = find_channel(parv[2])) == NULL) {
        sendto_one_numeric(source_p, ERR_NOSUCHCHANNEL,
                           form_str(ERR_NOSUCHCHANNEL), parv[2]);
        return 0;
    }

    msptr = find_channel_membership(chptr, source_p);
    if(MyClient(source_p) && (msptr == NULL)) {
        sendto_one_numeric(source_p, ERR_NOTONCHANNEL,
                           form_str(ERR_NOTONCHANNEL), parv[2]);
        return 0;
    }

    if(IsMember(target_p, chptr)) {
        sendto_one_numeric(source_p, ERR_USERONCHANNEL,
                           form_str(ERR_USERONCHANNEL),
                           target_p->name, parv[2]);
        return 0;
    }

    /* unconditionally require ops, unless the channel is +g */
    /* treat remote clients as chanops */
    if(MyClient(source_p) && !is_any_op(msptr) &&
       !(chptr->mode.mode & MODE_FREEINVITE)) {
        if(IsOverride(source_p)) {
            sendto_wallops_flags(UMODE_WALLOP, &me,
                                 "%s is overriding INVITE [%s] on [%s]",
                                 get_oper_name(source_p), target_p->name, chptr->chname);
            sendto_server(NULL, chptr, NOCAPS, NOCAPS,
                          ":%s WALLOPS :%s is overriding INVITE [%s] on [%s]",
                          me.name, get_oper_name(source_p), target_p->name, chptr->chname);
        } else {
            sendto_one(source_p, form_str(ERR_CHANOPRIVSNEEDED),
                       me.name, source_p->name, parv[2]);
            return 0;
        }
    }

    if (IsSetNoInvite(target_p)) {
        sendto_one_numeric(source_p, ERR_NOINVITE,
                           form_str(ERR_NOINVITE),
                           target_p->name);
        return 0;
    }

    /* store invites when they could affect the ability to join
     * for +l/+j just check if the mode is set, this varies over time
     */
    if(chptr->mode.mode & MODE_INVITEONLY ||
       (chptr->mode.mode & MODE_REGONLY && EmptyString(target_p->user->suser)) ||
       chptr->mode.limit || chptr->mode.join_num)
        store_invite = 1;

    if(MyConnect(source_p)) {
        if (ConfigFileEntry.target_change && !IsOper(source_p) &&
            !find_allowing_channel(source_p, target_p) &&
            !add_target(source_p, target_p)) {
            sendto_one(source_p, form_str(ERR_TARGCHANGE),
                       me.name, source_p->name, target_p->name);
            return 0;
        }
        sendto_one(source_p, form_str(RPL_INVITING),
                   me.name, source_p->name,
                   target_p->name, parv[2]);
        if(target_p->user->away)
            sendto_one_numeric(source_p, RPL_AWAY, form_str(RPL_AWAY),
                               target_p->name, target_p->user->away);
    }
    /* invite timestamp */
    else if(parc > 3 && !EmptyString(parv[3])) {
        /* this should never be less than */
        if(atol(parv[3]) > chptr->channelts)
            return 0;
    }

    if(MyConnect(target_p)) {
        if(!IsOper(source_p) && (IsSetCallerId(target_p) ||
                                 (IsSetRegOnlyMsg(target_p) && !source_p->user->suser[0])) &&
           !accept_message(source_p, target_p)) {
            if (IsSetRegOnlyMsg(target_p) && !source_p->user->suser[0]) {
                sendto_one_numeric(source_p, ERR_NONONREG,
                                   form_str(ERR_NONONREG),
                                   target_p->name);
                return 0;
            } else {
                /* instead of sending RPL_UMODEGMSG,
                 * just let the invite through
                 */
                if((target_p->localClient->last_caller_id_time +
                    ConfigFileEntry.caller_id_wait) >= rb_current_time()) {
                    sendto_one_numeric(source_p, ERR_TARGUMODEG,
                                       form_str(ERR_TARGUMODEG),
                                       target_p->name);
                    return 0;
                }
                target_p->localClient->last_caller_id_time = rb_current_time();
            }
        }
        add_reply_target(target_p, source_p);
        sendto_one(target_p, ":%s!%s@%s INVITE %s :%s",
                   source_p->name, source_p->username, source_p->host,
                   target_p->name, chptr->chname);

        if(store_invite)
            add_invite(chptr, target_p);
    } else if(target_p->from != client_p) {
        sendto_one_prefix(target_p, source_p, "INVITE", "%s %lu",
                          chptr->chname, (unsigned long) chptr->channelts);
    }

    return 0;
}

/* add_invite()
 *
 * input	- channel to add invite to, client to add
 * output	-
 * side effects - client is added to invite list.
 */
static void
add_invite(struct Channel *chptr, struct Client *who)
{
    rb_dlink_node *ptr;

    /* already invited? */
    RB_DLINK_FOREACH(ptr, who->user->invited.head) {
        if(ptr->data == chptr)
            return;
    }

    /* ok, if their invite list is too long, remove the tail */
    if((int)rb_dlink_list_length(&who->user->invited) >=
       ConfigChannel.max_chans_per_user) {
        ptr = who->user->invited.tail;
        del_invite(ptr->data, who);
    }

    /* add user to channel invite list */
    rb_dlinkAddAlloc(who, &chptr->invites);

    /* add channel to user invite list */
    rb_dlinkAddAlloc(chptr, &who->user->invited);
}


