/*
** Zabbix
** Copyright (C) 2001-2021 Zabbix SIA
**
** 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/

#include "common.h"
#include "db.h"
#include "log.h"
#include "events.h"
#include "discovery.h"

static DB_RESULT	discovery_get_dhost_by_value(zbx_uint64_t dcheckid, const char *value)
{
	DB_RESULT	result;
	char		*value_esc;

	value_esc = DBdyn_escape_field("dservices", "value", value);

	result = DBselect(
			"select dh.dhostid,dh.status,dh.lastup,dh.lastdown"
			" from dhosts dh,dservices ds"
			" where ds.dhostid=dh.dhostid"
				" and ds.dcheckid=" ZBX_FS_UI64
				" and ds.value" ZBX_SQL_STRCMP
			" order by dh.dhostid",
			dcheckid, ZBX_SQL_STRVAL_EQ(value_esc));

	zbx_free(value_esc);

	return result;
}

static DB_RESULT	discovery_get_dhost_by_ip_port(zbx_uint64_t druleid, const char *ip, int port)
{
	DB_RESULT	result;
	char		*ip_esc;

	ip_esc = DBdyn_escape_field("dservices", "ip", ip);

	result = DBselect(
			"select dh.dhostid,dh.status,dh.lastup,dh.lastdown"
			" from dhosts dh,dservices ds"
			" where ds.dhostid=dh.dhostid"
				" and dh.druleid=" ZBX_FS_UI64
				" and ds.ip" ZBX_SQL_STRCMP
				" and ds.port=%d"
			" order by dh.dhostid",
			druleid, ZBX_SQL_STRVAL_EQ(ip_esc), port);

	zbx_free(ip_esc);

	return result;
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_separate_host                                          *
 *                                                                            *
 * Purpose: separate multiple-IP hosts                                        *
 *                                                                            *
 * Parameters: host ip address                                                *
 *                                                                            *
 ******************************************************************************/
static void	discovery_separate_host(DB_DRULE *drule, DB_DHOST *dhost, const char *ip)
{
	const char	*__function_name = "discovery_separate_host";

	DB_RESULT	result;
	DB_ROW		row;
	char		*ip_esc, *sql = NULL;
	zbx_uint64_t	dhostid;

	zabbix_log(LOG_LEVEL_DEBUG, "In %s() ip:'%s'", __function_name, ip);

	ip_esc = DBdyn_escape_field("dservices", "ip", ip);

	sql = zbx_dsprintf(sql,
			"select dserviceid"
			" from dservices"
			" where dhostid=" ZBX_FS_UI64
				" and ip" ZBX_SQL_STRCMP,
			dhost->dhostid, ZBX_SQL_STRVAL_NE(ip_esc));

	result = DBselectN(sql, 1);

	if (NULL != (row = DBfetch(result)))
	{
		dhostid = DBget_maxid("dhosts");

		DBexecute("insert into dhosts (dhostid,druleid)"
				" values (" ZBX_FS_UI64 "," ZBX_FS_UI64 ")",
				dhostid, drule->druleid);

		DBexecute("update dservices"
				" set dhostid=" ZBX_FS_UI64
				" where dhostid=" ZBX_FS_UI64
					" and ip" ZBX_SQL_STRCMP,
				dhostid, dhost->dhostid, ZBX_SQL_STRVAL_EQ(ip_esc));

		dhost->dhostid = dhostid;
		dhost->status = DOBJECT_STATUS_DOWN;
		dhost->lastup = 0;
		dhost->lastdown = 0;
	}
	DBfree_result(result);

	zbx_free(sql);
	zbx_free(ip_esc);

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_register_host                                          *
 *                                                                            *
 * Purpose: register host if one does not exist                               *
 *                                                                            *
 * Parameters: host ip address                                                *
 *                                                                            *
 ******************************************************************************/
static void	discovery_register_host(DB_DRULE *drule, zbx_uint64_t dcheckid, DB_DHOST *dhost,
		const char *ip, int port, int status, const char *value)
{
	const char	*__function_name = "discovery_register_host";

	DB_RESULT	result;
	DB_ROW		row;
	int		match_value = 0;

	zabbix_log(LOG_LEVEL_DEBUG, "In %s() ip:'%s' status:%d value:'%s'",
			__function_name, ip, status, value);

	if (drule->unique_dcheckid == dcheckid)
	{
		result = discovery_get_dhost_by_value(dcheckid, value);

		if (NULL == (row = DBfetch(result)))
		{
			DBfree_result(result);

			result = discovery_get_dhost_by_ip_port(drule->druleid, ip, port);
			row = DBfetch(result);
		}
		else
			match_value = 1;

	}
	else
	{
		result = discovery_get_dhost_by_ip_port(drule->druleid, ip, port);
		row = DBfetch(result);
	}

	if (NULL == row)
	{
		if (DOBJECT_STATUS_UP == status)	/* add host only if service is up */
		{
			zabbix_log(LOG_LEVEL_DEBUG, "new host discovered at %s", ip);

			dhost->dhostid = DBget_maxid("dhosts");
			dhost->status = DOBJECT_STATUS_DOWN;
			dhost->lastup = 0;
			dhost->lastdown = 0;

			DBexecute("insert into dhosts (dhostid,druleid)"
					" values (" ZBX_FS_UI64 "," ZBX_FS_UI64 ")",
					dhost->dhostid, drule->druleid);
		}
	}
	else
	{
		zabbix_log(LOG_LEVEL_DEBUG, "host at %s is already in database", ip);

		ZBX_STR2UINT64(dhost->dhostid, row[0]);
		dhost->status = atoi(row[1]);
		dhost->lastup = atoi(row[2]);
		dhost->lastdown = atoi(row[3]);

		if (0 == match_value)
			discovery_separate_host(drule, dhost, ip);
	}
	DBfree_result(result);

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_register_service                                       *
 *                                                                            *
 * Purpose: register service if one does not exist                            *
 *                                                                            *
 * Parameters: host ip address                                                *
 *                                                                            *
 ******************************************************************************/
static void	discovery_register_service(zbx_uint64_t dcheckid, DB_DHOST *dhost, DB_DSERVICE *dservice,
		const char *ip, const char *dns, int port, int status)
{
	const char	*__function_name = "discovery_register_service";

	DB_RESULT	result;
	DB_ROW		row;
	char		*ip_esc, *dns_esc;

	zbx_uint64_t	dhostid;

	zabbix_log(LOG_LEVEL_DEBUG, "In %s() ip:'%s' port:%d", __function_name, ip, port);

	ip_esc = DBdyn_escape_field("dservices", "ip", ip);

	result = DBselect(
			"select dserviceid,dhostid,status,lastup,lastdown,value,dns"
			" from dservices"
			" where dcheckid=" ZBX_FS_UI64
				" and ip" ZBX_SQL_STRCMP
				" and port=%d",
			dcheckid, ZBX_SQL_STRVAL_EQ(ip_esc), port);

	if (NULL == (row = DBfetch(result)))
	{
		if (DOBJECT_STATUS_UP == status)	/* add host only if service is up */
		{
			zabbix_log(LOG_LEVEL_DEBUG, "new service discovered on port %d", port);

			dservice->dserviceid = DBget_maxid("dservices");
			dservice->status = DOBJECT_STATUS_DOWN;
			dservice->value = zbx_strdup(dservice->value, "");

			dns_esc = DBdyn_escape_field("dservices", "dns", dns);

			DBexecute("insert into dservices (dserviceid,dhostid,dcheckid,ip,dns,port,status)"
					" values (" ZBX_FS_UI64 "," ZBX_FS_UI64 "," ZBX_FS_UI64 ",'%s','%s',%d,%d)",
					dservice->dserviceid, dhost->dhostid, dcheckid, ip_esc, dns_esc, port,
					dservice->status);

			zbx_free(dns_esc);
		}
	}
	else
	{
		zabbix_log(LOG_LEVEL_DEBUG, "service is already in database");

		ZBX_STR2UINT64(dservice->dserviceid, row[0]);
		ZBX_STR2UINT64(dhostid, row[1]);
		dservice->status = atoi(row[2]);
		dservice->lastup = atoi(row[3]);
		dservice->lastdown = atoi(row[4]);
		dservice->value = zbx_strdup(dservice->value, row[5]);

		if (dhostid != dhost->dhostid)
		{
			DBexecute("update dservices"
					" set dhostid=" ZBX_FS_UI64
					" where dhostid=" ZBX_FS_UI64,
					dhost->dhostid, dhostid);

			DBexecute("delete from dhosts"
					" where dhostid=" ZBX_FS_UI64,
					dhostid);
		}

		if (0 != strcmp(row[6], dns))
		{
			dns_esc = DBdyn_escape_field("dservices", "dns", dns);

			DBexecute("update dservices"
					" set dns='%s'"
					" where dserviceid=" ZBX_FS_UI64,
					dns_esc, dservice->dserviceid);

			zbx_free(dns_esc);
		}
	}
	DBfree_result(result);

	zbx_free(ip_esc);

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_dservice                                        *
 *                                                                            *
 * Purpose: update discovered service details                                 *
 *                                                                            *
 ******************************************************************************/
static void	discovery_update_dservice(zbx_uint64_t dserviceid, int status, int lastup, int lastdown,
		const char *value)
{
	char	*value_esc;

	value_esc = DBdyn_escape_field("dservices", "value", value);

	DBexecute("update dservices set status=%d,lastup=%d,lastdown=%d,value='%s' where dserviceid=" ZBX_FS_UI64,
			status, lastup, lastdown, value_esc, dserviceid);

	zbx_free(value_esc);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_dservice_value                                  *
 *                                                                            *
 * Purpose: update discovered service details                                 *
 *                                                                            *
 ******************************************************************************/
static void	discovery_update_dservice_value(zbx_uint64_t dserviceid, const char *value)
{
	char	*value_esc;

	value_esc = DBdyn_escape_field("dservices", "value", value);

	DBexecute("update dservices set value='%s' where dserviceid=" ZBX_FS_UI64, value_esc, dserviceid);

	zbx_free(value_esc);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_dhost                                           *
 *                                                                            *
 * Purpose: update discovered host details                                    *
 *                                                                            *
 ******************************************************************************/
static void	discovery_update_dhost(const DB_DHOST *dhost)
{
	DBexecute("update dhosts set status=%d,lastup=%d,lastdown=%d where dhostid=" ZBX_FS_UI64,
			dhost->status, dhost->lastup, dhost->lastdown, dhost->dhostid);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_service_status                                  *
 *                                                                            *
 * Purpose: process and update the new service status                         *
 *                                                                            *
 ******************************************************************************/
static void	discovery_update_service_status(DB_DHOST *dhost, const DB_DSERVICE *dservice, int service_status,
		const char *value, int now)
{
	const char	*__function_name = "discovery_update_service_status";

	zbx_timespec_t	ts;

	zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);

	ts.sec = now;
	ts.ns = 0;

	if (DOBJECT_STATUS_UP == service_status)
	{
		if (DOBJECT_STATUS_DOWN == dservice->status || 0 == dservice->lastup)
		{
			discovery_update_dservice(dservice->dserviceid, service_status, now, 0, value);
			zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DSERVICE, dservice->dserviceid, &ts,
					DOBJECT_STATUS_DISCOVER, NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0, NULL);

			if (DOBJECT_STATUS_DOWN == dhost->status)
			{
				/* Service went UP, but host status is DOWN. Update host status. */

				dhost->status = DOBJECT_STATUS_UP;
				dhost->lastup = now;
				dhost->lastdown = 0;

				discovery_update_dhost(dhost);
				zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DHOST, dhost->dhostid, &ts,
						DOBJECT_STATUS_DISCOVER, NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0,
						NULL);
			}
		}
		else if (0 != strcmp(dservice->value, value))
		{
			discovery_update_dservice_value(dservice->dserviceid, value);
		}
	}
	else	/* DOBJECT_STATUS_DOWN */
	{
		if (DOBJECT_STATUS_UP == dservice->status || 0 == dservice->lastdown)
		{
			discovery_update_dservice(dservice->dserviceid, service_status, 0, now, dservice->value);
			zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DSERVICE, dservice->dserviceid, &ts,
					DOBJECT_STATUS_LOST, NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0, NULL);

			/* service went DOWN, no need to update host status here as other services may be UP */
		}
	}
	zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DSERVICE, dservice->dserviceid, &ts, service_status,
			NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0, NULL);

	zbx_process_events(NULL, NULL);
	zbx_clean_events();

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_host_status                                     *
 *                                                                            *
 * Purpose: update new host status                                            *
 *                                                                            *
 ******************************************************************************/
static void	discovery_update_host_status(DB_DHOST *dhost, int status, int now)
{
	zbx_timespec_t	ts;

	ts.sec = now;
	ts.ns = 0;

	/* update host status */
	if (DOBJECT_STATUS_UP == status)
	{
		if (DOBJECT_STATUS_DOWN == dhost->status || 0 == dhost->lastup)
		{
			dhost->status = status;
			dhost->lastdown = 0;
			dhost->lastup = now;

			discovery_update_dhost(dhost);
			zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DHOST, dhost->dhostid, &ts,
					DOBJECT_STATUS_DISCOVER, NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0, NULL);
		}
	}
	else	/* DOBJECT_STATUS_DOWN */
	{
		if (DOBJECT_STATUS_UP == dhost->status || 0 == dhost->lastdown)
		{
			dhost->status = status;
			dhost->lastdown = now;
			dhost->lastup = 0;

			discovery_update_dhost(dhost);
			zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DHOST, dhost->dhostid, &ts,
					DOBJECT_STATUS_LOST, NULL, NULL, NULL, 0, 0, NULL, 0, NULL, 0, NULL);
		}
	}
	zbx_add_event(EVENT_SOURCE_DISCOVERY, EVENT_OBJECT_DHOST, dhost->dhostid, &ts, status, NULL, NULL, NULL, 0, 0,
			NULL, 0, NULL, 0, NULL);

	zbx_process_events(NULL, NULL);
	zbx_clean_events();
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_host                                            *
 *                                                                            *
 * Purpose: process new host status                                           *
 *                                                                            *
 * Parameters: host - host info                                               *
 *                                                                            *
 ******************************************************************************/
void	discovery_update_host(DB_DHOST *dhost, int status, int now)
{
	const char	*__function_name = "discovery_update_host";

	zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);

	if (0 != dhost->dhostid)
		discovery_update_host_status(dhost, status, now);

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

/******************************************************************************
 *                                                                            *
 * Function: discovery_update_service                                         *
 *                                                                            *
 * Purpose: process new service status                                        *
 *                                                                            *
 * Parameters: service - service info                                         *
 *                                                                            *
 ******************************************************************************/
void	discovery_update_service(DB_DRULE *drule, zbx_uint64_t dcheckid, DB_DHOST *dhost, const char *ip,
		const char *dns, int port, int status, const char *value, int now)
{
	const char	*__function_name = "discovery_update_service";

	DB_DSERVICE	dservice;

	zabbix_log(LOG_LEVEL_DEBUG, "In %s() ip:'%s' dns:'%s' port:%d status:%d value:'%s'",
			__function_name, ip, dns, port, status, value);

	memset(&dservice, 0, sizeof(dservice));

	/* register host if is not registered yet */
	if (0 == dhost->dhostid)
		discovery_register_host(drule, dcheckid, dhost, ip, port, status, value);

	/* register service if is not registered yet */
	if (0 != dhost->dhostid)
		discovery_register_service(dcheckid, dhost, &dservice, ip, dns, port, status);

	/* service was not registered because we do not add down service */
	if (0 != dservice.dserviceid)
		discovery_update_service_status(dhost, &dservice, status, value, now);

	zbx_free(dservice.value);

	zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}
