/*
 * In this module we implement our UAC functionality of sending BYE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <syslog.h>
#include "../libsip/parse.h"
#include "../libsip/resp_ident.h"
#include "../libsip/out_msg.h"
#include "call.h"

extern struct call *find_call_by_sip_id();

extern struct in_addr sip_bind_ip;
extern unsigned sip_bind_port;
extern unsigned max_forwards;

fill_bye_out_msg(msg, call)
	struct sip_msg_out *msg;
	struct call *call;
{
	char strbuf[80];
	int rc;

	rc = start_request_out_msg_urilen(msg, "BYE", call->from_uri,
					  call->from_uri_len);
	if (rc < 0)
		return rc;
	sprintf(strbuf, "SIP/2.0/UDP %s:%u",
		inet_ntoa(sip_bind_ip), sip_bind_port);
	rc = out_msg_add_header(msg, "Via", strbuf);
	if (rc < 0)
		return rc;
	rc = out_msg_add_header(msg, "From", call->invite_to);
	if (rc < 0)
		return rc;
	rc = out_msg_add_header(msg, "To", call->invite_from);
	if (rc < 0)
		return rc;
	rc = out_msg_add_header(msg, "Call-ID", call->sip_call_id);
	if (rc < 0)
		return rc;
	rc = out_msg_add_header(msg, "CSeq", "1 BYE");
	if (rc < 0)
		return rc;
	sprintf(strbuf, "%u", max_forwards);
	rc = out_msg_add_header(msg, "Max-Forwards", strbuf);
	if (rc < 0)
		return rc;
	out_msg_finish(msg);
	return 0;
}

void
initiate_bye(call)
	struct call *call;
{
	struct sip_msg_out msg;
	int rc;

	rc = fill_bye_out_msg(&msg, call);
	if (rc < 0) {
		syslog(LOG_ERR, "outgoing BYE request msg length exceeded");
		call->sip_state = SIP_STATE_MSG_SIZE_ERR;
		/* TODO: transition from TEARDOWN to DEAD_SIP */
		return;
	}
	sip_tx_packet(&msg, &call->udp_sin);
	call->sip_state = SIP_STATE_BYE_SENT;
	call->sip_tx_count = 1;
}

void
process_sip_response(msg, sin)
	struct sip_pkt_rx *msg;
	struct sockaddr_in *sin;
{
	struct sip_resp_ident rid;
	struct call *call;
	int rc;

	rc = sip_resp_extract_ident(msg, &rid);
	if (rc < 0) {
		syslog(LOG_ERR, "SIP %03u response: bad or missing %s header",
			msg->status_code, rid.error_field);
		return;
	}
	call = find_call_by_sip_id(rid.call_id);
	if (!call) {
		syslog(LOG_ERR, "SIP %03u response: unmatched Call-ID",
			msg->status_code);
		return;
	}
	if (rid.cseq_num != 1 || strcmp(rid.cseq_method, "BYE")) {
		syslog(LOG_ERR,
			"UAC received %03u response with unknown CSeq %u %.32s",
			msg->status_code, rid.cseq_num, rid.cseq_method);
		return;
	}
	if (msg->status_code < 200)
		return;
	if (call->sip_state == SIP_STATE_BYE_SENT)
		call->sip_state = SIP_STATE_ENDED;
}