/*
 * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
 * (C) 2010 by On-Waves
 * All Rights Reserved
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
#include <snmp_mtp.h>
#include <osmocore/talloc.h>

static void add_pdu_var(netsnmp_pdu *pdu, const char *mib_name, int id, const char *value)
{
	oid oid_name[MAX_OID_LEN];
	size_t name_length;

	char buf[4096];
	buf[4095] = '\0';
	snprintf(buf, sizeof(buf)-1, "%s.%d", mib_name, id);

	name_length = MAX_OID_LEN;
	if (snmp_parse_oid(buf, oid_name, &name_length) == NULL) {
		snmp_perror(buf);
		return;
	}

	if (snmp_add_var(pdu, oid_name, name_length, '=', value)) {
		snmp_perror(buf);
		return;
	}
}

static void send_pdu(netsnmp_session *ss, netsnmp_pdu *pdu)
{
	int status;
	netsnmp_pdu *response;

	status = snmp_synch_response(ss, pdu, &response);
	if (status == STAT_ERROR) {
		snmp_sess_perror("set failed", ss);
	} else if (status == STAT_TIMEOUT) {
		fprintf(stderr, "Timeout for SNMP.\n");
	}

	if (response)
		snmp_free_pdu(response);
}

void snmp_mtp_start_c7_datalink(struct snmp_mtp_session *session, int link_id)
{
	netsnmp_pdu *pdu;
	pdu = snmp_pdu_create(SNMP_MSG_SET);

	add_pdu_var(pdu, "PTI-NexusWareC7-MIB::nwc7DatalinkCommand", link_id, "nwc7DatalinkCmdPowerOn");
	add_pdu_var(pdu, "PTI-NexusWareC7-MIB::nwc7Mtp2Active", link_id, "true");
	send_pdu(session->ss, pdu);
}

void snmp_mtp_stop_c7_datalink(struct snmp_mtp_session *session, int link_id)
{
	netsnmp_pdu *pdu;
	pdu = snmp_pdu_create(SNMP_MSG_SET);

	add_pdu_var(pdu, "PTI-NexusWareC7-MIB::nwc7Mtp2Active", link_id, "false");
	send_pdu(session->ss, pdu);
}

struct snmp_mtp_session *snmp_mtp_session_create(char *host)
{
	struct snmp_mtp_session *session = talloc_zero(NULL, struct snmp_mtp_session);
	if (!session)
		return NULL;

	init_snmp("cellmgr_ng");
	snmp_sess_init(&session->session);
	session->session.peername = host;
	session->session.version = SNMP_VERSION_1;
	session->session.community = (unsigned char *) "private";
	session->session.community_len = strlen((const char *) session->session.community);

	session->ss = snmp_open(&session->session);
	if (!session->ss) {
		snmp_perror("create failure");
		snmp_log(LOG_ERR, "Could not connect to the remote.\n");
		talloc_free(session);
		return NULL;
	}

	return session;
}

void snmp_mtp_deactivate(struct snmp_mtp_session *session, int index)
{
	snmp_mtp_stop_c7_datalink(session, index);
}

void snmp_mtp_activate(struct snmp_mtp_session *session, int index)
{
	snmp_mtp_start_c7_datalink(session, index);
}