/*
 * charybdis: an advanced Internet Relay Chat Daemon(ircd).
 * tgchange.c - code for restricting private messages
 *
 * Copyright (C) 2004-2005 Lee Hardy <lee@leeh.co.uk>
 * Copyright (C) 2005-2010 Jilles Tjoelker <jilles@stack.nl>
 * Copyright (C) 2004-2005 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 "tgchange.h"
#include "channel.h"
#include "client.h"
#include "s_stats.h"
#include "hash.h"
#include "s_newconf.h"

static int add_hashed_target(struct Client *source_p, uint32_t hashv);

struct Channel *
find_allowing_channel(struct Client *source_p, struct Client *target_p)
{
    rb_dlink_node *ptr;
    struct membership *msptr;

    RB_DLINK_FOREACH(ptr, source_p->user->channel.head) {
        msptr = ptr->data;
        if (is_chanop_voiced(msptr) && IsMember(target_p, msptr->chptr))
            return msptr->chptr;
    }
    return NULL;
}

int
add_target(struct Client *source_p, struct Client *target_p)
{
    uint32_t hashv;

    /* can msg themselves or services without using any target slots */
    if(source_p == target_p || IsService(target_p))
        return 1;

    /* special condition for those who have had PRIVMSG crippled to allow them
     * to talk to IRCops still.
     *
     * XXX: is this controversial?
     */
    if(source_p->localClient->target_last > rb_current_time() && IsOper(target_p))
        return 1;

    hashv = fnv_hash_upper((const unsigned char *)use_id(target_p), 32);
    return add_hashed_target(source_p, hashv);
}

int
add_channel_target(struct Client *source_p, struct Channel *chptr)
{
    uint32_t hashv;

    hashv = fnv_hash_upper((const unsigned char *)chptr->chname, 32);
    return add_hashed_target(source_p, hashv);
}

static int
add_hashed_target(struct Client *source_p, uint32_t hashv)
{
    int i, j;
    uint32_t *targets;

    targets = source_p->localClient->targets;

    /* check for existing target, and move it to the head */
    for(i = 0; i < TGCHANGE_NUM + TGCHANGE_REPLY; i++) {
        if(targets[i] == hashv) {
            for(j = i; j > 0; j--)
                targets[j] = targets[j - 1];
            targets[0] = hashv;
            return 1;
        }
    }

    if(source_p->localClient->targets_free < TGCHANGE_NUM) {
        /* first message after connect, we may only start clearing
         * slots after this message --anfl
         */
        if(!IsTGChange(source_p)) {
            SetTGChange(source_p);
            source_p->localClient->target_last = rb_current_time();
        }
        /* clear as many targets as we can */
        else if((i = (rb_current_time() - source_p->localClient->target_last) / 60)) {
            if(i + source_p->localClient->targets_free > TGCHANGE_NUM)
                source_p->localClient->targets_free = TGCHANGE_NUM;
            else
                source_p->localClient->targets_free += i;

            source_p->localClient->target_last = rb_current_time();
        }
        /* cant clear any, full target list */
        else if(source_p->localClient->targets_free == 0) {
            ServerStats.is_tgch++;
            add_tgchange(source_p->sockhost);
            return 0;
        }
    }
    /* no targets in use, reset their target_last so that they cant
     * abuse a long idle to get targets back more quickly
     */
    else {
        source_p->localClient->target_last = rb_current_time();
        SetTGChange(source_p);
    }

    for(i = TGCHANGE_NUM + TGCHANGE_REPLY - 1; i > 0; i--)
        targets[i] = targets[i - 1];
    targets[0] = hashv;
    source_p->localClient->targets_free--;
    return 1;
}

void
add_reply_target(struct Client *source_p, struct Client *target_p)
{
    int i, j;
    uint32_t hashv;
    uint32_t *targets;

    /* can msg themselves or services without using any target slots */
    if(source_p == target_p || IsService(target_p))
        return;

    hashv = fnv_hash_upper((const unsigned char *)use_id(target_p), 32);
    targets = source_p->localClient->targets;

    /* check for existing target, and move it to the first reply slot
     * if it is in a reply slot
     */
    for(i = 0; i < TGCHANGE_NUM + TGCHANGE_REPLY; i++) {
        if(targets[i] == hashv) {
            if(i > TGCHANGE_NUM) {
                for(j = i; j > TGCHANGE_NUM; j--)
                    targets[j] = targets[j - 1];
                targets[TGCHANGE_NUM] = hashv;
            }
            return;
        }
    }
    for(i = TGCHANGE_NUM + TGCHANGE_REPLY - 1; i > TGCHANGE_NUM; i--)
        targets[i] = targets[i - 1];
    targets[TGCHANGE_NUM] = hashv;
}