/* osmo-cc-sip-endpoint main
 *
 * (C) 2020 by Andreas Eversberg <jolly@eversberg.eu>
 * All Rights Reserved
 *
 * 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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include "../libdebug/debug.h"
#include "../liboptions/options.h"
#include "sip.h"

sip_endpoint_t *sip_ep = NULL;
int num_kanal = 1;

int sofia_debug = 0;
int send_no_ringing_after_progress = 0;
int receive_no_ringing_after_progress = 0;
const char *name = "sip";
const char *user_agent = "osmo-cc-sip-endpoint";
const char *local_user = NULL;
const char *local_peer = NULL;
const char *remote_user = NULL;
const char *remote_peer = NULL;
const char *asserted_id = NULL;
int local_register = 0;
int remote_register = 0;
int remote_nat_sip = 0;
int remote_nat_rtp = 0;
const char *register_user = NULL;
const char *register_peer = NULL;
int local_auth = 0;
int remote_auth = 0;
const char *auth_user = NULL;
const char *auth_password = NULL;
const char *auth_realm = NULL;
const char *public_ip = NULL;
const char *stun_server = NULL;
int register_interval = 600;
int options_interval = 60;
int stun_interval = 60;
int expires = 0;
#define MAX_CC_ARGS 1024
static int cc_argc = 0;
static const char *cc_argv[MAX_CC_ARGS];

static void print_usage(const char *app)
{
	printf("Usage: %s --local [<user>@]<address> --remote [<user>@]<address> [<options>]\n", app);
}

static void print_help()
{
	/*      -                                                                             - */
	printf(" -h --help\n");
	printf("        This help\n");
	printf(" --config [~/]<path to config file>\n");
	printf("        Give a config file to use. If it starts with '~/', path is at home dir.\n");
	printf("        Each line in config file is one option, '-' or '--' must not be given!\n");
	debug_print_help();
	printf(" -D --sofia-debug <level>\n");
	printf("        A level of 0 is off, a level of 9 is full debugging. (default = %d)\n", sofia_debug);
	printf("    --send-ner\n");
	printf("        Do not send extra ringing response (180), after progress response (183)\n");
	printf("        was sent.\n");
	printf("    --receive-ner\n");
	printf("        Do not expect to receive extra ringing response (180), after progress\n");
	printf("        response (183) was received.\n");
	printf(" -n --name <interface name>\n");
	printf("        Give name of this interface. It will be sent in each call towards\n");
	printf("        remote interface. (default = '%s')\n", name);
	printf(" -l --local [<user>@]<address>\n");
	printf("        Give local SIP peer. It will be used for local URI.\n");
	printf("        If user is not given, the caller ID is used as user.\n");
	printf(" -r --remote [<user>@]<address>\n");
	printf("        Give remote SIP peer. It will be used for remote URI.\n");
	printf("        If user is not given, the dialed number is used as user.\n");
	printf(" -a --asserted-id <user>\n");
	printf("        The asserted ID is used to idenitfy the actual SIP user, if the local\n");
	printf("        and remote user in their URI are replaced by caller ID and dialed\n");
	printf("        number. To send caller ID, you must not specify user at local SIP peer.\n");
	printf("        To send dialed number, you must not specify user at remote SIP peer.\n");
	printf(" -R --register <user>@<address>\n");
	printf("        Give user and address to register at a remote SIP registrar.\n");
	printf("    --local-register\n");
	printf("        Define, if the remote must register to us, so that we know the remote\n");
	printf("        address.\n");
	printf("    --remote-register\n");
	printf("        Define, if we must register to a registrar.\n");
	printf("        If '--register' was given, but not any of '--local-register' or\n");
	printf("        '--remote-register', remote registration automatically used.\n");
	printf("    --remote-nat-sip\n");
	printf("        Ignore the address+port from the SIP contact. Use the address+port from\n");
	printf("        where the SIP massasge was sent.\n");
	printf("    --remote-nat-rtp\n");
	printf("        Ignore the RTP address from the SDP message. Use the RTP address from\n");
	printf("        the remote peer. (untested!)\n");
	printf(" -A --auth <user> <password> <realm>\n");
	printf("        Define, if we must perform authentication.\n");
	printf("        Realm can be set to anything. It is relevant for local authentication.\n");
	printf("    --local-auth\n");
	printf("        Define, if the remote must authenticate when calling (or registering)\n");
	printf("        to us.\n");
	printf("    --remote-auth\n");
	printf("        Define, if we must authenticate when calling (or registering) towards\n");
	printf("        remote.\n");
	printf("        If '--auth' was given, but not any of '--local-auth' or\n");
	printf("        '--remote-auth', remote authentication automatically used.\n");
	printf(" -P --public-ip <ip>\n");
	printf("        If our local IP is changed by NAT, give the actual public IP.\n");
	printf(" -S --stun-server <address>\n");
	printf("        Instead of dynamic public IP, a STUN server can be given.\n");
	printf("    --register-interval <seconds> (default = %d seconds)\n", register_interval);
	printf("    --options-interval <seconds> (default = %d seconds)\n", options_interval);
	printf("    --stun-interval <seconds> (default = %d seconds)\n", stun_interval);
	printf("    --expires <seconds> | 0 (default = %d seconds)\n", expires);
	printf("        Alter intervals, if needed.\n");
	printf(" -U --user-endpoint <string>\n");
	printf("        Any string that is used as user agent. (default = '%s')\n", user_agent);
	printf(" -C --cc \"<osmo-cc arg>\" [--cc ...]\n");
	printf("        Pass arguments to Osmo-CC endpoint. Use '-cc help' for description.\n");
}

#define OPT_SEND_NER	256
#define OPT_RECEIVE_NER	257
#define OPT_LOCAL_REG	258
#define OPT_REMOTE_REG	259
#define OPT_REMOTE_SIP	260
#define OPT_REMOTE_RTP	261
#define OPT_LOCAL_AUTH	262
#define OPT_REMOTE_AUTH	263
#define OPT_REG_INTER	264
#define OPT_OPT_INTER	265
#define OPT_STUN_INTER	266
#define OPT_EXPIRES	267

static void add_options(void)
{
	option_add('h', "help", 0);
	option_add('v', "verbose", 1);
	option_add('D', "sofia-debug", 1);
	option_add(OPT_SEND_NER, "send-ner", 0);
	option_add(OPT_RECEIVE_NER, "receive-ner", 0);
	option_add('n', "name", 1);
	option_add('l', "local", 1);
	option_add('r', "remote", 1);
	option_add('a', "asserted-id", 1);
	option_add('R', "register", 1);
	option_add(OPT_LOCAL_REG, "local-register", 0);
	option_add(OPT_REMOTE_REG, "remote-register", 0);
	option_add(OPT_REMOTE_SIP, "remote-nat-sip", 0);
	option_add(OPT_REMOTE_RTP, "remote-nat-rtp", 0);
	option_add('A', "auth", 3);
	option_add(OPT_LOCAL_AUTH, "local-auth", 0);
	option_add(OPT_REMOTE_AUTH, "remote-auth", 0);
	option_add('P', "public-ip", 1);
	option_add('S', "stun-server", 1);
	option_add(OPT_REG_INTER, "register-interval", 1);
	option_add(OPT_OPT_INTER, "options-interval", 1);
	option_add(OPT_STUN_INTER, "stun-interval", 1);
	option_add(OPT_EXPIRES, "expires", 1);
	option_add('U', "user-agent", 1);
	option_add('C', "cc", 1);
}

static int handle_options(int short_option, int argi, char **argv)
{
	const char *p;
	int rc;

	switch (short_option) {
	case 'h':
		print_usage(argv[0]);
		print_help();
		return 0;
	case 'v':
		if (!strcasecmp(argv[argi], "list")) {
	                debug_list_cat();
			return 0;
		}
		rc = parse_debug_opt(argv[argi]);
		if (rc < 0) {
			fprintf(stderr, "Failed to parse debug option, please use -h for help.\n");
			return rc;
		}
		break;
	case 'D':
		sofia_debug = atoi(argv[argi]);
		break;
	case OPT_SEND_NER:
		send_no_ringing_after_progress = 1;
		break;
	case OPT_RECEIVE_NER:
		receive_no_ringing_after_progress = 1;
		break;
	case 'n':
		name = options_strdup(argv[argi]);
		break;
	case 'l':
		if ((p = strchr(argv[argi], '@'))) {
			local_user = options_strdup(argv[argi]);
			*strchr(local_user, '@') = '\0';
			local_peer = options_strdup(p + 1);
		} else
			local_peer = options_strdup(argv[argi]);
		break;
	case 'r':
		if ((p = strchr(argv[argi], '@'))) {
			remote_user = options_strdup(argv[argi]);
			*strchr(remote_user, '@') = '\0';
			remote_peer = options_strdup(p + 1);
		} else
			remote_peer = options_strdup(argv[argi]);
		break;
	case 'a':
		asserted_id = options_strdup(argv[argi]);
		break;
	case 'R':
		if ((p = strchr(argv[argi], '@'))) {
			register_user = options_strdup(argv[argi]);
			*strchr(register_user, '@') = '\0';
			register_peer = options_strdup(p + 1);
		} else {
			fprintf(stderr, "Missing '@' sign in given registrar!\n");
			return -EINVAL;
		}
		break;
	case OPT_LOCAL_REG:
		local_register = 1;
		break;
	case OPT_REMOTE_REG:
		remote_register = 1;
		break;
	case OPT_REMOTE_SIP:
		remote_nat_sip = 1;
		break;
	case OPT_REMOTE_RTP:
		remote_nat_rtp = 1;
		break;
	case 'A':
		auth_user = options_strdup(argv[argi]);
		auth_password = options_strdup(argv[argi + 1]);
		auth_realm = options_strdup(argv[argi + 2]);
		break;
	case OPT_LOCAL_AUTH:
		local_auth = 1;
		break;
	case OPT_REMOTE_AUTH:
		remote_auth = 1;
		break;
	case 'P':
		public_ip = options_strdup(argv[argi]);
		break;
	case 'S':
		stun_server = options_strdup(argv[argi]);
		break;
	case OPT_REG_INTER:
		register_interval = atoi(argv[argi]);
		break;
	case OPT_OPT_INTER:
		options_interval = atoi(argv[argi]);
		break;
	case OPT_STUN_INTER:
		stun_interval = atoi(argv[argi]);
		break;
	case OPT_EXPIRES:
		expires = atoi(argv[argi]);
		break;
	case 'U':
		user_agent = options_strdup(argv[argi]);
		break;
	case 'C':
		if (!strcasecmp(argv[argi], "help")) {
			osmo_cc_help();
			return 0;
		}
		if (cc_argc == MAX_CC_ARGS) {
			fprintf(stderr, "Too many osmo-cc args!\n");
			break;
		}
		cc_argv[cc_argc++] = options_strdup(argv[argi]);
		break;
	default:
		return -EINVAL;
	}
	return 1;
}

static int quit = 0;
void sighandler(int sigset)
{
	if (sigset == SIGHUP || sigset == SIGPIPE)
		return;

	fprintf(stderr, "\nSignal %d received.\n", sigset);

	quit = 1;
}

int main(int argc, char *argv[])
{
	int argi, rc;

	cc_argv[cc_argc++] = options_strdup("remote auto");

        /* handle options / config file */
	add_options();
	rc = options_config_file(argc, argv, "~/.osmocom/sip/sip.conf", handle_options);
	if (rc < 0)
		return 0;
	argi = options_command_line(argc, argv, handle_options);
	if (argi <= 0)
		return argi;

	sip_init(sofia_debug);

	/* complete remote register and authentication flag */
	if (register_peer && !local_register && !remote_register)
		remote_register = 1;
	if (auth_user && !local_auth && !remote_auth)
		remote_auth = 1;

	if (!local_peer) {
		PDEBUG(DSIP, DEBUG_ERROR, "You must specify local SIP peer!\n");
		goto error;
	}

	if (!remote_peer && !local_register) {
		PDEBUG(DSIP, DEBUG_ERROR, "You must specify remote SIP peer!\n");
		goto error;
	}

	if (!auth_user && local_auth) {
		PDEBUG(DSIP, DEBUG_ERROR, "You must specify authentication parameters!\n");
		goto error;
	}

	if (!cc_argc || !!strncasecmp(cc_argv[0], "help", 4)) {
		sip_ep = sip_endpoint_create(user_agent, send_no_ringing_after_progress, receive_no_ringing_after_progress, name, local_user, local_peer, remote_user, remote_peer, asserted_id, local_register, remote_register, remote_nat_sip, remote_nat_rtp, register_user, register_peer, local_auth, remote_auth, auth_user, auth_password, auth_realm, public_ip, stun_server, register_interval, options_interval, stun_interval, expires);
		if (!sip_ep) {
			PDEBUG(DSIP, DEBUG_ERROR, "SIP initializing failed!\n");
			goto error;
		}
	}

	rc = osmo_cc_new(&sip_ep->cc_ep, OSMO_CC_VERSION, name, OSMO_CC_LOCATION_BEYOND_INTERWORKING, cc_message, NULL, sip_ep, cc_argc, cc_argv);
	if (rc)
		goto error;

	signal(SIGINT, sighandler);
	signal(SIGHUP, sighandler);
	signal(SIGTERM, sighandler);
	signal(SIGPIPE, sighandler);

	while (!quit) {
		int w;
		process_timer();
		sip_handle(sip_ep);
		do {
			w = 0;
			w |= osmo_cc_handle();
		} while (w);
		usleep(1000);
	}

	signal(SIGINT, SIG_DFL);
	signal(SIGTSTP, SIG_DFL);
	signal(SIGHUP, SIG_DFL);
	signal(SIGTERM, SIG_DFL);
	signal(SIGPIPE, SIG_DFL);

error:
	if (sip_ep) {
		osmo_cc_delete(&sip_ep->cc_ep);
		sip_endpoint_destroy(sip_ep);
	}

	sip_exit();

	options_free();

	return 0;
}