/*
 * UAS for sip-manual-out.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "../libsip/parse.h"
#include "../libsip/uas_basic.h"
#include "../libsip/out_msg.h"

extern char call_id[];

static void
bye_correct_call(req, ess, sin)
	struct sip_pkt_rx *req;
	struct uas_parse_hdrs *ess;
	struct sockaddr_in *sin;
{
	struct sip_msg_out resp;
	int rc;

	printf("Received BYE for our call, responding with 200\n");
	start_response_out_msg(&resp, "200 OK");
	rc = add_resp_basic_headers(&resp, ess, req->req_method);
	if (rc < 0) {
		fprintf(stderr, "sending 200 response: msg length exceeded\n");
		return;
	}
	out_msg_finish(&resp);
	sip_tx_packet(&resp, sin);
}

static void
bye_unknown_call(req, ess, sin)
	struct sip_pkt_rx *req;
	struct uas_parse_hdrs *ess;
	struct sockaddr_in *sin;
{
	struct sip_msg_out resp;
	int rc;

	printf("Received BYE for unknown call, responding with 481\n");
	start_response_out_msg(&resp, "481 Call-ID not found");
	rc = add_resp_basic_headers(&resp, ess, req->req_method);
	if (rc < 0) {
		fprintf(stderr, "sending 481 response: msg length exceeded\n");
		return;
	}
	out_msg_finish(&resp);
	sip_tx_packet(&resp, sin);
}

static void
handle_bye(req, ess, sin)
	struct sip_pkt_rx *req;
	struct uas_parse_hdrs *ess;
	struct sockaddr_in *sin;
{
	if (!strcmp(ess->call_id, call_id))
		bye_correct_call(req, ess, sin);
	else
		bye_unknown_call(req, ess, sin);
}

static void
unsupported_method(req, ess, sin)
	struct sip_pkt_rx *req;
	struct uas_parse_hdrs *ess;
	struct sockaddr_in *sin;
{
	struct sip_msg_out resp;
	int rc;

	printf("SIP %.16s request: unsupported method\n", req->req_method);
	start_response_out_msg(&resp, "501 Method not supported");
	rc = add_resp_basic_headers(&resp, ess, req->req_method);
	if (rc < 0) {
too_long:	fprintf(stderr,
			"sending 501 error: response length exceeded\n");
		return;
	}
	rc = out_msg_add_header(&resp, "Allow", "BYE");
	if (rc < 0)
		goto too_long;
	out_msg_finish(&resp);
	sip_tx_packet(&resp, sin);
}

void
process_sip_request(msg, sin)
	struct sip_pkt_rx *msg;
	struct sockaddr_in *sin;
{
	struct uas_parse_hdrs ess;
	int rc;

	rc = uas_get_basic_headers(msg, &ess);
	if (rc < 0) {
		printf("SIP %.16s request: bad or missing %s header\n",
			msg->req_method, ess.error_field);
		return;
	}
	/* dispatch by method */
	if (!strcmp(msg->req_method, "BYE"))
		handle_bye(msg, &ess, sin);
	else if (!strcmp(msg->req_method, "ACK"))
		printf("Received unexpected ACK, swallowing it\n");
	else
		unsupported_method(msg, &ess, sin);
}