/* osmo-isdntap VTY interface */
/* (C) 2022 by Harald Welte <laforge@osmocom.org>
 * 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 2 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/>.
 *
 */

#define _GNU_SOURCE	/* struct ucred */
#include <sys/socket.h>

#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <errno.h>

#include <osmocom/core/linuxlist.h>
#include <osmocom/core/gsmtap.h>
#include <osmocom/core/gsmtap_util.h>

#include <osmocom/vty/command.h>
#include <osmocom/vty/buffer.h>
#include <osmocom/vty/vty.h>
#include <osmocom/vty/logging.h>
#include <osmocom/vty/stats.h>
#include <osmocom/vty/telnet_interface.h>
#include <osmocom/vty/misc.h>
#include <osmocom/vty/tdef_vty.h>

#include "isdntap.h"

static struct isdntap_instance *vty_itd;

static struct cmd_node isdntap_node = {
	(enum node_type) ISDNTAP_NODE,
	"%s(config-isdntap)# ",
	1,
};

static struct cmd_node line_node = {
	(enum node_type) LINE_NODE,
	"%s(config-isdntap-line)# ",
	1,
};

static void vty_dump_line(struct vty *vty, const struct isdntap_line *line)
{
	vty_out(vty, "Line %s%s", line->name, VTY_NEWLINE);
	if (1) {
		vty_out(vty, " Driver: DAHDI, span_name=%s, span_type=%s, span_no=%d, "
			"basechan=%d, channels=%d%s",
			line->drvdata.dahdi.name, line->drvdata.dahdi.spantype,
			line->drvdata.dahdi.spanno, line->drvdata.dahdi.basechan,
			line->drvdata.dahdi.channels, VTY_NEWLINE);
	}

	//vty_out_rate_ctr_group(vty, " ", line->ctrs);
}

DEFUN(show_line, show_line_cmd, "show line",
	SHOW_STR "Display information about an E1 Line\n")
{
	struct isdntap_line *line;

	llist_for_each_entry(line, &vty_itd->lines, list) {
		vty_dump_line(vty, line);
	}

	return CMD_SUCCESS;
}

DEFUN(cfg_isdntap, cfg_isdntap_cmd, "isdntap",
	"isdntap Daemon specific configuration\n")
{
	vty->node = ISDNTAP_NODE;

	return CMD_SUCCESS;
}

DEFUN(cfg_itd_gsmtap_remote_host, cfg_itd_gsmtap_remote_host_cmd, "gsmtap remote-host " VTY_IPV46_CMD,
	"GSMTAP configuration\n"
	"Remote host to which signaling shall be sent in GSMTAP format\n" IP_STR IPV6_STR)
{
	osmo_talloc_replace_string(vty_itd, &vty_itd->cfg.gsmtap.remote_host, argv[0]);

	if (vty_itd->gti)
		gsmtap_source_free(vty_itd->gti);

	vty_itd->gti = gsmtap_source_init(vty_itd->cfg.gsmtap.remote_host, GSMTAP_UDP_PORT, 0);

	return CMD_SUCCESS;
}

DEFUN(cfg_itd_output_path, cfg_itd_output_path_cmd, "output-path PATH",
	"Path of output directory for B-Channel recordings\n"
	"Path of output directory for B-Channel recordings\n")
{
	osmo_talloc_replace_string(vty_itd, &vty_itd->cfg.output_path, argv[0]);

	return CMD_SUCCESS;
}

DEFUN(cfg_itd_line_dahdi, cfg_itd_line_dahdi_cmd, "line NAME dahdi SPAN_NAME",
	"Configure an ISDNtap E1 line\n"
	"E1 Line (Span) Name\n"
	"Use the DAHDI Driver\n"
	"DAHDI span name of the line\n")
{
	const char *name = argv[0];
	const char *span_name = argv[1];
	struct isdntap_line *line;
	int rc;

	if (!osmo_identifier_valid(name)) {
		vty_out(vty, "%% Sorry, '%s' is not a valid identifier%s", name, VTY_NEWLINE);
		return CMD_WARNING;
	}

	line = isdntap_line_find(vty_itd, name);
	if (line) {
		if (strcmp(line->drvdata.dahdi.name, span_name)) {
			/* span name has changed */
			/* close old line / span name */
			line->driver->line_close(line);
			osmo_talloc_replace_string(line, &line->drvdata.dahdi.name, span_name);
			/* open new span name */
			rc = line->driver->line_open(line);
			if (rc < 0) {
				vty_out(vty, "%% Could not open line%s", VTY_NEWLINE);
				isdntap_line_free(line);
				/* should we try to re-open the old one? better fail fast... */
				exit(23);
			}
		}
	} else {
		line = isdntap_line_new(vty_itd, name);
		if (!line) {
			vty_out(vty, "%% Could not create line%s", VTY_NEWLINE);
			return CMD_WARNING;
		}
		line->driver = &dahdi_driver;
		line->drvdata.dahdi.name = talloc_strdup(line, span_name);

		rc = line->driver->line_open(line);
		if (rc < 0) {
			vty_out(vty, "%% Could not open line%s", VTY_NEWLINE);
			isdntap_line_free(line);
			return CMD_WARNING;
		}
	}

	vty->index = line;
	vty->node = LINE_NODE;
	return CMD_SUCCESS;
}

DEFUN(cfg_line_role, cfg_line_role_cmd, "local-role (network|user)",
	"Local role of the ISDN line\n"
	"Local end implements NETWORK role\n"
	"Local end implements USER role\n")
{
	struct isdntap_line *line = vty->index;

	if (!strcmp(argv[0], "network"))
		line->local_side_is_network = true;
	else
		line->local_side_is_network = false;

	return CMD_SUCCESS;
}

#if 0
DEFUN(cfg_e1d_if_usb_serial, cfg_e1d_if_usb_serial_cmd,
	"usb-serial SERNO",
	"Configure the USB serial number of an E1 interface device\n"
	"iSerial string\n")
{
	struct e1_intf *intf = vty->index;

	if (intf->drv != E1_DRIVER_USB)
		return CMD_WARNING;

	osmo_talloc_replace_string(intf, &intf->usb.serial_str, argv[0]);
	return CMD_SUCCESS;
}

DEFUN(cfg_e1d_if_line_mode, cfg_e1d_if_line_mode_cmd,
	"mode (channelized|superchannel|e1oip)",
	"Configure the mode of the E1 line\n"
	"Channelized (64kBps timeslot) mode\n"
	"Superchannel (1xHDLC over 31x64kBps) mode\n")
{
	struct e1_line *line = vty->index;
	enum e1_line_mode new_mode = get_string_value(e1_line_mode_names, argv[0]);
	if (line->mode != new_mode) {
		/* FIXME: clean up any old state */
		line->mode = new_mode;
	}
	return CMD_SUCCESS;
}
#endif

static int config_write_line(struct vty *vty, struct isdntap_line *line)
{
	vty_out(vty, " line %s dahdi %s%s", line->name, line->drvdata.dahdi.name, VTY_NEWLINE);
	//vty_out(vty, "  mode %s%s", get_value_string(e1_line_mode_names, line->mode), VTY_NEWLINE);
	vty_out(vty, "  local-role %s%s", line->local_side_is_network ? "network" : "user", VTY_NEWLINE);

	return 0;
}

static int config_write_isdntap(struct vty *vty)
{
	struct isdntap_line *line;

	vty_out(vty, "isdntap%s", VTY_NEWLINE);
	vty_out(vty, " output-path %s%s", vty_itd->cfg.output_path, VTY_NEWLINE);
	if (vty_itd->cfg.gsmtap.remote_host)
		vty_out(vty, " gsmtap remote-host %s%s", vty_itd->cfg.gsmtap.remote_host, VTY_NEWLINE);

	/* find all vpair interfaces */
	llist_for_each_entry(line, &vty_itd->lines, list) {
		config_write_line(vty, line);
	}

	return 0;
}

void isdntap_vty_init(struct isdntap_instance *itd)
{
	vty_itd = itd;
	install_element_ve(&show_line_cmd);

	install_node(&isdntap_node, config_write_isdntap);
	install_element(CONFIG_NODE, &cfg_isdntap_cmd);

	install_node(&line_node, NULL);
	install_element(ISDNTAP_NODE, &cfg_itd_output_path_cmd);
	install_element(ISDNTAP_NODE, &cfg_itd_gsmtap_remote_host_cmd);
	install_element(ISDNTAP_NODE, &cfg_itd_line_dahdi_cmd);
	install_element(LINE_NODE, &cfg_line_role_cmd);
}