/*
 * (C) 2022 by Harald Welte <laforge@osmocom.org>
 * (C) 2021 by Andreas Eversberg <andreas@eversberg.eu>
 * 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 <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include <unistd.h>
#include <errno.h>
#include <osmocom/core/msgb.h>

#include <osmocom/core/application.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/stats.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/socket.h>

#include <osmocom/ctrl/control_vty.h>

#include <osmocom/vty/telnet_interface.h>
#include <osmocom/vty/logging.h>
#include <osmocom/vty/ports.h>
#include <osmocom/vty/command.h>
#include <osmocom/vty/stats.h>
#include <osmocom/vty/misc.h>
#include <osmocom/vty/cpu_sched_vty.h>

#include <osmocom/abis/e1_input.h>

#include <osmocom/abis/abis.h>

#include "v5x_internal.h"
#include "v5x_protocol.h"
#include "layer1.h"
#include "v5x_l1_fsm.h"
#include "lapv5.h"
#include "v5x_le_ctrl_fsm.h"
#include "v5x_le_port_fsm.h"
#include "v5x_le_pstn_fsm.h"
#include "v52_le_lcp_fsm.h"
#include "v52_le_bcc_fsm.h"
#include "v52_le_pp_fsm.h"
#include "v5x_le_management.h"
#include "v5le_vty.h"
#include "logging.h"

#define _GNU_SOURCE
#include <getopt.h>

void *tall_v5le_ctx = NULL;
struct v5x_instance *v5i = NULL;

static int daemonize = 0;

const char *v5le_copyright =
	"Copyright (C) 2022 by Harald Welte & Andreas Eversberg\r\n"
	"License AGPLv3+: GNU AGPL version 3 or later <http://gnu.org/licenses/agpl-3.0.html>\r\n"
	"This is free software: you are free to change and redistribute it.\r\n"
	"There is NO WARRANTY, to the extent permitted by law.\r\n";

static char *config_file = "osmo-v5-le.cfg";

static void print_help()
{
	printf("Some useful options:\n");
	printf(" -h --help is printing this text.\n");
	printf(" -c --config-file filename The config file to use.\n");
	printf(" -s --disable-color\n");
	printf(" -D --daemonize Fork the process into a background daemon\n");
	printf(" -V --version Print the version number\n");

	printf("\nVTY reference generation:\n");
	printf("    --vty-ref-mode MODE		VTY reference generation mode (e.g. 'expert').\n");
	printf("    --vty-ref-xml		Generate the VTY reference XML output and exit.\n");
}

static void handle_long_options(const char *prog_name, const int long_option)
{
	static int vty_ref_mode = VTY_REF_GEN_MODE_DEFAULT;

	switch (long_option) {
	case 1:
		vty_ref_mode = get_string_value(vty_ref_gen_mode_names, optarg);
		if (vty_ref_mode < 0) {
			fprintf(stderr, "%s: Unknown VTY reference generation "
				"mode '%s'\n", prog_name, optarg);
			exit(2);
		}
		break;
	case 2:
		fprintf(stderr, "Generating the VTY reference in mode '%s' (%s)\n",
			get_value_string(vty_ref_gen_mode_names, vty_ref_mode),
			get_value_string(vty_ref_gen_mode_desc, vty_ref_mode));
		vty_dump_xml_ref_mode(stdout, (enum vty_ref_gen_mode) vty_ref_mode);
		exit(0);
	default:
		fprintf(stderr, "%s: error parsing cmdline options\n", prog_name);
		exit(2);
	}
}

static void handle_options(int argc, char **argv)
{
	while (1) {
		int option_index = 0, c;
		static int long_option = 0;
		static struct option long_options[] = {
			{"help", 0, 0, 'h'},
			{"config-file", 1, 0, 'c'},
			{"daemonize", 0, 0, 'D'},
			{"version", 0, 0, 'V'},
			{"disable-color", 0, 0, 's'},
			{"vty-ref-mode", 1, &long_option, 1},
			{"vty-ref-xml", 0, &long_option, 2},
			{0, 0, 0, 0},
		};

		c = getopt_long(argc, argv, "hc:sVD", long_options, &option_index);

		if (c == -1)
			break;

		switch(c) {
		case 'h':
			print_help();
			exit(0);
			break;
		case 0:
			handle_long_options(argv[0], long_option);
			break;
		case 'c':
			config_file = talloc_strdup(tall_v5le_ctx, optarg);
			break;
		case 's':
			log_set_use_color(osmo_stderr_target, 0);
			break;
		case 'V':
			print_version(1);
			exit(0);
			break;
		case 'D':
			daemonize = 1;
			break;
		default:
			/* ignore */
			break;
		};
	}
	if (argc > optind) {
		fprintf(stderr, "Unsupported positional arguments on command line\n");
		exit(2);
	}
}

static int quit = 0;

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

	fprintf(stderr, "Signal received: %d\n", sigset);

	quit = 1;
}

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

	tall_v5le_ctx = talloc_named_const(NULL, 1, "v5le");
	vty_info.tall_ctx = tall_v5le_ctx;

	msgb_talloc_ctx_init(tall_v5le_ctx, 0);

	osmo_init_ignore_signals();
	osmo_init_logging2(tall_v5le_ctx, &log_info);
	libosmo_abis_init(tall_v5le_ctx);

	vty_info.copyright = v5le_copyright;

	vty_init(&vty_info);
	logging_vty_add_cmds();
	osmo_talloc_vty_add_cmds();
	osmo_stats_vty_add_cmds();
	v5le_vty_init();
	ctrl_vty_init(tall_v5le_ctx);
	e1inp_vty_init();
	osmo_cpu_sched_vty_init(tall_v5le_ctx);

	handle_options(argc, argv);

	rate_ctr_init(tall_v5le_ctx);
	osmo_stats_init(tall_v5le_ctx);

	/* global inits of protocols */
	v5x_l1_init();
	v5x_le_ctrl_init();
	v5x_le_port_init();
	v5x_le_pstn_init();
	v52_le_lcp_init();
	v52_le_bcc_init();
	v52_le_pp_init();
	v5x_le_mgmt_init();

	/* create v5x instance */
	v5i = v5x_instance_alloc(tall_v5le_ctx);
	if (!v5i)
		return -ENOMEM;

	rc = vty_read_config_file(config_file, NULL);
	if (rc < 0) {
		fprintf(stderr, "Failed to read config file '%s'.\n", config_file);
		return rc;
	}

	rc = e1_init();
	OSMO_ASSERT(rc == 0);

	/* start telnet after reading config for vty_get_bind_addr() */
	rc = telnet_init_dynif(tall_v5le_ctx, NULL,
			       vty_get_bind_addr(), OSMO_VTY_PORT_MGW);
	if (rc < 0)
		return rc;

	/* start DL */
	if (!llist_empty(&v5i->interfaces)) {
		struct v5x_interface *v5if;
		v5if = (struct v5x_interface *)v5i->interfaces.next;
		if (v5if->control.li)
			lapv5_dl_est_req(v5if->control.li, V5X_DLADDR_CTRL);
		if (v5if->pstn.li)
			lapv5_dl_est_req(v5if->pstn.li, V5X_DLADDR_PSTN);
		if (v5if->lcp.li)
			lapv5_dl_est_req(v5if->lcp.li, V52_DLADDR_LCP);
		if (v5if->bcc.li)
			lapv5_dl_est_req(v5if->bcc.li, V52_DLADDR_BCC);
		if (v5if->protection.li[0])
			lapv5_dl_est_req(v5if->protection.li[0], V52_DLADDR_PROTECTION);
		if (v5if->protection.li[1])
			lapv5_dl_est_req(v5if->protection.li[1], V52_DLADDR_PROTECTION);
	}

	/* initialisation */
	srand(time(NULL));

	if (daemonize) {
		rc = osmo_daemonize();
		if (rc < 0) {
			perror("Error during daemonize");
			exit(1);
		}
	}

	/* catch signals */
	signal(SIGINT, sighandler);
	signal(SIGHUP, sighandler);
	signal(SIGTERM, sighandler);
	signal(SIGPIPE, sighandler);

	/* main loop */
	while (!quit) {
		osmo_select_main(0);
	}

	/* reset signals */
	signal(SIGINT, SIG_DFL);
	signal(SIGHUP, SIG_DFL);
	signal(SIGTERM, SIG_DFL);
	signal(SIGPIPE, SIG_DFL);

	/* destroy the universe */
	v5x_instance_free(v5i);

	return 0;
}