/*
 * ircd-ratbox: an advanced Internet Relay Chat Daemon(ircd).
 * monitor.c - Code for server-side notify lists
 *
 * Copyright (C) 2005 Lee Hardy <lee -at- leeh.co.uk>
 * Copyright (C) 2005 ircd-ratbox development team
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * 1.Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * 2.Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 3.The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: monitor.c 3520 2007-06-30 22:15:35Z jilles $
 */
#include "stdinc.h"
#include "client.h"
#include "monitor.h"
#include "hash.h"
#include "numeric.h"

static struct monitor *monitorTable[MONITOR_HASH_SIZE];
BlockHeap *monitor_heap;

static void cleanup_monitor(void *unused);

void
init_monitor(void)
{
	monitor_heap = BlockHeapCreate(sizeof(struct monitor), MONITOR_HEAP_SIZE);
	eventAddIsh("cleanup_monitor", cleanup_monitor, NULL, 3600);
}

static inline unsigned int
hash_monitor_nick(const char *name)
{
	return fnv_hash_upper((const unsigned char *) name, MONITOR_HASH_BITS);
}

struct monitor *
find_monitor(const char *name, int add)
{
	struct monitor *monptr;

	unsigned int hashv = hash_monitor_nick(name);

	for(monptr = monitorTable[hashv]; monptr; monptr = monptr->hnext)
	{
		if(!irccmp(monptr->name, name))
			return monptr;
	}

	if(add)
	{
		monptr = BlockHeapAlloc(monitor_heap);
		strlcpy(monptr->name, name, sizeof(monptr->name));

		monptr->hnext = monitorTable[hashv];
		monitorTable[hashv] = monptr;

		return monptr;
	}

	return NULL;
}

/* monitor_signon()
 *
 * inputs	- client who has just connected
 * outputs	-
 * side effects	- notifies any clients monitoring this nickname that it has
 * 		  connected to the network
 */
void
monitor_signon(struct Client *client_p)
{
	char buf[USERHOST_REPLYLEN];
	struct monitor *monptr = find_monitor(client_p->name, 0);

	/* noones watching this nick */
	if(monptr == NULL)
		return;

	rb_snprintf(buf, sizeof(buf), "%s!%s@%s",
		    client_p->name, client_p->username, client_p->host);

	sendto_monitor(monptr, form_str(RPL_MONONLINE), me.name, "*", buf);
}

/* monitor_signoff()
 *
 * inputs	- client who is exiting
 * outputs	-
 * side effects	- notifies any clients monitoring this nickname that it has
 * 		  left the network
 */
void
monitor_signoff(struct Client *client_p)
{
	struct monitor *monptr = find_monitor(client_p->name, 0);

	/* noones watching this nick */
	if(monptr == NULL)
		return;

	sendto_monitor(monptr, form_str(RPL_MONOFFLINE), me.name, "*",
			client_p->name);
}

void
clear_monitor(struct Client *client_p)
{
	struct monitor *monptr;
	rb_dlink_node *ptr, *rb_free(;

	RB_DLINK_FOREACH_SAFE(ptr, rb_free(, client_p->localClient->monitor_list.head)
	{
		monptr = ptr->data;

		/* we leave the actual entry around with no users, itll be
		 * cleaned up periodically by cleanup_monitor() --anfl
		 */
		rb_dlinkFindDestroy(client_p, &monptr->users);
		free_rb_dlink_node(ptr);
	}

	client_p->localClient->monitor_list.head = client_p->localClient->monitor_list.tail = NULL;
	client_p->localClient->monitor_list.length = 0;
}

static void
cleanup_monitor(void *unused)
{
	struct monitor *last_ptr = NULL;
	struct monitor *rb_free(, *ptr;
	int i;

	for(i = 0; i < MONITOR_HASH_SIZE; i++)
	{
		last_ptr = NULL;
		for(ptr = monitorTable[i]; ptr; ptr = rb_free()
		{
			rb_free( = ptr->hnext;

			if(!rb_dlink_list_length(&ptr->users))
			{
				if(last_ptr)
					last_ptr->hnext = rb_free(;
				else
					monitorTable[i] = rb_free(;

				BlockHeapFree(monitor_heap, ptr);
			}
			else
				last_ptr = ptr;
		}
	}
}