/* MGCP client interface to quagga VTY */
/* (C) 2016 by sysmocom s.m.f.c. GmbH <info@sysmocom.de>
 * Based on OpenBSC interface to quagga VTY (libmsc/vty_interface_layer3.c)
 * (C) 2009 by Harald Welte <laforge@gnumonks.org>
 * (C) 2009-2011 by Holger Hans Peter Freyther
 * 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/>.
 *
 */

#include <inttypes.h>
#include <stdlib.h>
#include <talloc.h>

#include <osmocom/vty/vty.h>
#include <osmocom/vty/command.h>
#include <osmocom/vty/misc.h>
#include <osmocom/core/utils.h>

#include <osmocom/mgcp_client/mgcp_client.h>
#include <osmocom/mgcp_client/mgcp_client_internal.h>
#include <osmocom/mgcp_client/mgcp_client_pool_internal.h>

#define MGW_STR MGCP_CLIENT_MGW_STR

/* Only common (non-pooled) VTY connands will use this talloc context. All
 * pooled VTY commands will use the pool (global_mgcp_client_pool) as
 * talloc context. */
static void *global_mgcp_client_ctx = NULL;

/* MGCP Client configuration used with mgcp_client_vty_init(). (This pointer
 * points to user provided memory, so it cannot be used as talloc context.) */
static struct mgcp_client_conf *global_mgcp_client_conf = NULL;

/* Pointer to the MGCP pool that is managed by mgcp_client_pool_vty_init() */
static struct mgcp_client_pool *global_mgcp_client_pool = NULL;

struct mgcp_client_conf *get_mgcp_client_config(struct vty *vty)
{
	if (global_mgcp_client_pool && vty->node == global_mgcp_client_pool->vty_node->node)
		return vty->index;
	else
		return global_mgcp_client_conf;
}

DEFUN(cfg_mgw_local_ip, cfg_mgw_local_ip_cmd,
      "mgw local-ip " VTY_IPV46_CMD,
      MGW_STR "local bind to connect to MGW from\n"
      "local bind IPv4 address\n"
      "local bind IPv6 address\n")
{
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	osmo_talloc_replace_string(global_mgcp_client_ctx,
				   (char **)&conf->local_addr,
				   argv[0]);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_local_ip, cfg_mgcpgw_local_ip_cmd,
		 "mgcpgw local-ip A.B.C.D",
		 MGW_STR "local bind to connect to MGCP gateway with\n"
		 "local bind IP address\n")

DEFUN(cfg_mgw_local_port, cfg_mgw_local_port_cmd,
      "mgw local-port <0-65535>",
      MGW_STR "local port to connect to MGW from\n"
      "local bind port\n")
{
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	conf->local_port = atoi(argv[0]);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_local_port, cfg_mgcpgw_local_port_cmd,
		 "mgcpgw local-port <0-65535>",
		 MGW_STR "local bind to connect to MGCP gateway with\n"
		 "local bind port\n")

DEFUN(cfg_mgw_remote_ip, cfg_mgw_remote_ip_cmd,
      "mgw remote-ip " VTY_IPV46_CMD,
      MGW_STR "remote IP address to reach the MGW at\n"
      "remote IPv4 address\n"
      "remote IPv6 address\n")
{
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	osmo_talloc_replace_string(global_mgcp_client_ctx,
				   (char **)&conf->remote_addr, argv[0]);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_remote_ip, cfg_mgcpgw_remote_ip_cmd,
		 "mgcpgw remote-ip A.B.C.D",
		 MGW_STR "remote bind to connect to MGCP gateway with\n"
		 "remote bind IP address\n")

DEFUN(cfg_mgw_remote_port, cfg_mgw_remote_port_cmd,
      "mgw remote-port <0-65535>",
      MGW_STR "remote port to reach the MGW at\n"
      "remote port\n")
{
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	conf->remote_port = atoi(argv[0]);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_remote_port, cfg_mgcpgw_remote_port_cmd,
		 "mgcpgw remote-port <0-65535>",
		 MGW_STR "remote bind to connect to MGCP gateway with\n"
		 "remote bind port\n")

DEFUN_DEPRECATED(cfg_mgw_endpoint_range, cfg_mgw_endpoint_range_cmd,
      "mgw endpoint-range <1-65534> <1-65534>",
      MGW_STR "DEPRECATED: the endpoint range cannot be defined by the client\n"
      "-\n" "-\n")
{
	vty_out(vty, "Please do not use legacy config 'mgw endpoint-range'"
		" (the range can no longer be defined by the MGCP client)%s",
		VTY_NEWLINE);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_endpoint_range, cfg_mgcpgw_endpoint_range_cmd,
      "mgcpgw endpoint-range <1-65534> <1-65534>",
      MGW_STR "usable range of endpoint identifiers\n"
      "set first useable endpoint identifier\n"
      "set the last useable endpoint identifier\n")

#define BTS_START_STR "First UDP port allocated for the BTS side\n"
#define UDP_PORT_STR "UDP Port number\n"
DEFUN_DEPRECATED(cfg_mgw_rtp_bts_base_port,
      cfg_mgw_rtp_bts_base_port_cmd,
      "mgw bts-base <0-65534>",
      MGW_STR
      "DEPRECATED: there is no explicit BTS side in current osmo-mgw\n" "-\n")
{
	vty_out(vty, "Please do not use legacy config 'mgw bts-base'"
		" (there is no explicit BTS side in an MGW anymore)%s",
		VTY_NEWLINE);
	return CMD_SUCCESS;
}
ALIAS_DEPRECATED(cfg_mgw_rtp_bts_base_port,
      cfg_mgcpgw_rtp_bts_base_port_cmd,
      "mgcpgw bts-base <0-65534>",
      MGW_STR
      BTS_START_STR
      UDP_PORT_STR)

DEFUN(cfg_mgw_endpoint_domain_name,
      cfg_mgw_endpoint_domain_name_cmd,
      "mgw endpoint-domain NAME",
      MGW_STR "Set the domain name to send in MGCP messages, e.g. the part 'foo' in 'rtpbridge/*@foo'.\n"
      "Domain name, should be alphanumeric.\n")
{
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	if (osmo_strlcpy(conf->endpoint_domain_name, argv[0], sizeof(conf->endpoint_domain_name))
	    >= sizeof(conf->endpoint_domain_name)) {
		vty_out(vty, "%% Error: 'mgw endpoint-domain' name too long, max length is %zu: '%s'%s",
			sizeof(conf->endpoint_domain_name) - 1, argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	return CMD_SUCCESS;
}

DEFUN(cfg_mgw_reset_ep_name,
      cfg_mgw_reset_ep_name_cmd,
      "mgw reset-endpoint NAME",
      MGW_STR "Add an endpoint name that should be reset (DLCX) on connect to the reset-endpoint list,"
      "e.g. 'rtpbridge/*'\n"
      "Endpoint name, e.g. 'rtpbridge/*' or 'ds/e1-0/s-3/su16-4'.\n")
{
	int rc;
	struct reset_ep *reset_ep;
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	/* stop when the address is already in the list */
	llist_for_each_entry(reset_ep, &conf->reset_epnames, list) {
		if (strcmp(argv[0], reset_ep->name) == 0) {
			vty_out(vty, "%% duplicate endpoint name configured ('%s')%s", argv[0], VTY_NEWLINE);
			return CMD_WARNING;
		}
	}

	/* the domain name is not part of the actual endpoint name */
	if (strchr(argv[0], '@')) {
		vty_out(vty, "%% the endpoint name must be given without domain name ('%s')%s",
			argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	reset_ep = talloc_zero(global_mgcp_client_ctx, struct reset_ep);
	OSMO_ASSERT(reset_ep);

	rc = osmo_strlcpy(reset_ep->name, argv[0], sizeof(reset_ep->name));
	if (rc >= sizeof(reset_ep->name)) {
		vty_out(vty, "%% Error: 'mgw reset-endpoint' name too long, max length is %zu: '%s'%s",
			sizeof(reset_ep->name) - 1, argv[0], VTY_NEWLINE);
		talloc_free(reset_ep);
		return CMD_WARNING;
	}

	llist_add_tail(&reset_ep->list, &conf->reset_epnames);

	return CMD_SUCCESS;
}

DEFUN(cfg_mgw_no_reset_ep_name,
      cfg_mgw_no_reset_ep_name_cmd,
      "no mgw reset-endpoint NAME",
      MGW_STR "remove an endpoint name from the reset-endpoint list, e.g. 'rtpbridge/*'\n"
      "Endpoint name, e.g. 'rtpbridge/*' or 'ds/e1-0/s-3/su16-4'.\n")
{
	struct reset_ep *reset_ep;
	struct mgcp_client_conf *conf = get_mgcp_client_config(vty);

	llist_for_each_entry(reset_ep, &conf->reset_epnames, list) {
		if (strcmp(argv[0], reset_ep->name) == 0) {
			llist_del(&reset_ep->list);
			talloc_free(reset_ep);
			return CMD_SUCCESS;
		}
	}

	vty_out(vty, "%% no such endpoint name configured ('%s')%s", argv[0], VTY_NEWLINE);
	return CMD_WARNING;
}

static int config_write(struct vty *vty, const char *indent, struct mgcp_client_conf *conf)
{
	const char *addr;
	int port;
	struct reset_ep *reset_ep;

	addr = conf->local_addr;
	if (addr)
		vty_out(vty, "%smgw local-ip %s%s", indent, addr,
			VTY_NEWLINE);
	port = conf->local_port;
	if (port >= 0)
		vty_out(vty, "%smgw local-port %u%s", indent,
			(uint16_t)port, VTY_NEWLINE);

	addr = conf->remote_addr;
	if (addr)
		vty_out(vty, "%smgw remote-ip %s%s", indent, addr,
			VTY_NEWLINE);
	port = conf->remote_port;
	if (port >= 0)
		vty_out(vty, "%smgw remote-port %u%s", indent,
			(uint16_t)port, VTY_NEWLINE);

	if (conf->endpoint_domain_name[0])
		vty_out(vty, "%smgw endpoint-domain %s%s", indent,
			conf->endpoint_domain_name, VTY_NEWLINE);

	llist_for_each_entry(reset_ep, &conf->reset_epnames, list)
		vty_out(vty, "%smgw reset-endpoint %s%s", indent, reset_ep->name, VTY_NEWLINE);

	return CMD_SUCCESS;
}

/*! Write out MGCP client config to VTY.
 *  \param[in] vty VTY to which we should print.
 *  \param[in] string used for indentation (e.g. " ").
 *  \returns CMD_SUCCESS on success, CMD_WARNING on error */
int mgcp_client_config_write(struct vty *vty, const char *indent)
{
	return config_write(vty, indent, global_mgcp_client_conf);
}

static void vty_init_common(void *talloc_ctx, int node)
{
	global_mgcp_client_ctx = talloc_ctx;

	install_lib_element(node, &cfg_mgw_local_ip_cmd);
	install_lib_element(node, &cfg_mgw_local_port_cmd);
	install_lib_element(node, &cfg_mgw_remote_ip_cmd);
	install_lib_element(node, &cfg_mgw_remote_port_cmd);
	install_lib_element(node, &cfg_mgw_endpoint_range_cmd);
	install_lib_element(node, &cfg_mgw_rtp_bts_base_port_cmd);
	install_lib_element(node, &cfg_mgw_endpoint_domain_name_cmd);
	install_lib_element(node, &cfg_mgw_reset_ep_name_cmd);
	install_lib_element(node, &cfg_mgw_no_reset_ep_name_cmd);

	osmo_fsm_vty_add_cmds();
}

/*! Set up MGCP client VTY
 *  (called once at startup by the application process).
 *  \param[in] talloc_ctx talloc context to be used by the VTY for allocating memory.
 *  \param[in] node identifier of the node on which the VTY commands should be installed.
 *  \param[in] conf user provided memory to to store the MGCP client configuration data. */
void mgcp_client_vty_init(void *talloc_ctx, int node, struct mgcp_client_conf *conf)
{
	global_mgcp_client_conf = conf;

	/* deprecated 'mgcpgw' commands */
	install_lib_element(node, &cfg_mgcpgw_local_ip_cmd);
	install_lib_element(node, &cfg_mgcpgw_local_port_cmd);
	install_lib_element(node, &cfg_mgcpgw_remote_ip_cmd);
	install_lib_element(node, &cfg_mgcpgw_remote_port_cmd);
	install_lib_element(node, &cfg_mgcpgw_endpoint_range_cmd);
	install_lib_element(node, &cfg_mgcpgw_rtp_bts_base_port_cmd);

	vty_init_common(talloc_ctx, node);
}

static int config_write_pool(struct vty *vty)
{
	struct mgcp_client_pool *pool = global_mgcp_client_pool;
	struct mgcp_client_pool_member *pool_member;
	unsigned int indent_buf_len = strlen(pool->vty_indent) + 1 + 1;
	char *indent = talloc_zero_size(vty, indent_buf_len);

	snprintf(indent, indent_buf_len, "%s ", pool->vty_indent);

	llist_for_each_entry(pool_member, &pool->pool, list) {
		vty_out(vty, "%smgw %u%s", pool->vty_indent, pool_member->nr, VTY_NEWLINE);
		config_write(vty, indent, &pool_member->conf);
	}

	talloc_free(indent);
	return CMD_SUCCESS;
}

/* Lookup the selected MGCP client config by its reference number */
static struct mgcp_client_pool_member *pool_member_by_nr(unsigned int nr)
{
	struct mgcp_client_pool_member *pool_member = NULL;
	struct mgcp_client_pool_member *pool_member_tmp;

	llist_for_each_entry(pool_member_tmp, &global_mgcp_client_pool->pool, list) {
		if (pool_member_tmp->nr == nr) {
			pool_member = pool_member_tmp;
			break;
		}
	}

	return pool_member;
}

DEFUN_ATTR(cfg_mgw,
	   cfg_mgw_cmd, "mgw <0-255>", "Select a MGCP client config to setup\n" "reference number", CMD_ATTR_IMMEDIATE)
{
	int nr = atoi(argv[0]);
	struct mgcp_client_pool_member *pool_member;

	pool_member = pool_member_by_nr(nr);
	if (!pool_member) {
		pool_member = talloc_zero(global_mgcp_client_pool, struct mgcp_client_pool_member);
		OSMO_ASSERT(pool_member);
		mgcp_client_conf_init(&pool_member->conf);
		pool_member->nr = nr;
		llist_add_tail(&pool_member->list, &global_mgcp_client_pool->pool);
	}

	vty->index = &pool_member->conf;
	vty->index_sub = NULL;
	vty->node = global_mgcp_client_pool->vty_node->node;

	return CMD_SUCCESS;
}

DEFUN_ATTR(cfg_no_mgw,
	   cfg_no_mgw_cmd,
	   "no mgw <0-255>", "Select a MGCP client config to remove\n" "reference number", CMD_ATTR_IMMEDIATE)
{
	int nr = atoi(argv[0]);
	struct mgcp_client_pool_member *pool_member;

	pool_member = pool_member_by_nr(nr);
	if (!pool_member) {
		vty_out(vty, "%% no such MGCP client configured ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	/* Make sure that there are no ongoing calls */
	if (pool_member->refcount > 0) {
		vty_out(vty, "%% MGCP client (MGW %u) is still serving ongoing calls -- can't remove it now!%s",
			pool_member->nr, VTY_NEWLINE);
		return CMD_WARNING;
	}

	llist_del(&pool_member->list);
	if (pool_member->client) {
		mgcp_client_disconnect(pool_member->client);
		talloc_free(pool_member->client);
	}
	talloc_free(pool_member);

	return CMD_SUCCESS;
}

DEFUN_ATTR(mgw_reconnect, mgw_reconnect_cmd,
	   "mgw <0-255> reconnect",
	   MGW_STR "reconfigure and reconnect MGCP client\n", CMD_ATTR_IMMEDIATE)
{
	int nr = atoi(argv[0]);
	struct mgcp_client_pool_member *pool_member = NULL;

	pool_member = pool_member_by_nr(nr);
	if (!pool_member) {
		vty_out(vty, "%% no such MGCP client configured ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	/* Make sure that there are no ongoing calls */
	if (pool_member->refcount > 0) {
		vty_out(vty, "%% MGCP client (MGW %u) is still serving ongoing calls -- can't reconnect it now!%s",
			pool_member->nr, VTY_NEWLINE);
		return CMD_WARNING;
	}

	/* Get rid of a possibly existing old MGCP client instance first */
	if (pool_member->client) {
		mgcp_client_disconnect(pool_member->client);
		talloc_free(pool_member->client);
	}

	/* Create a new MGCP client instance with the current config */
	pool_member->client = mgcp_client_init(pool_member, &pool_member->conf);
	if (!pool_member->client) {
		LOGP(DLMGCP, LOGL_ERROR, "(manual) MGW %u initalization failed\n", pool_member->nr);
		vty_out(vty, "%% MGCP client initalization failed ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	/* Set backpointer so that we can detect later that this MGCP client is managed by this pool. */
	pool_member->client->pool = global_mgcp_client_pool;

	/* Connect client */
	if (mgcp_client_connect(pool_member->client)) {
		LOGP(DLMGCP, LOGL_ERROR, "(manual) MGW %u connect failed at (%s:%u)\n",
		     pool_member->nr, pool_member->conf.remote_addr, pool_member->conf.remote_port);
		talloc_free(pool_member->client);
		pool_member->client = NULL;
		vty_out(vty, "%% MGCP client initalization failed ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	return CMD_SUCCESS;
}

DEFUN_ATTR(mgw_block, mgw_block_cmd,
	   "mgw <0-255> block",
	   MGW_STR "block MGCP client so that it won't be used for new calls\n", CMD_ATTR_IMMEDIATE)
{
	int nr = atoi(argv[0]);
	struct mgcp_client_pool_member *pool_member = NULL;

	pool_member = pool_member_by_nr(nr);
	if (!pool_member) {
		vty_out(vty, "%% no such MGCP client configured ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	pool_member->blocked = true;
	return CMD_SUCCESS;
}

DEFUN_ATTR(mgw_unblock, mgw_unblock_cmd,
	   "mgw <0-255> unblock",
	   MGW_STR "unblock MGCP client so that it will be available for new calls\n", CMD_ATTR_IMMEDIATE)
{
	int nr = atoi(argv[0]);
	struct mgcp_client_pool_member *pool_member = NULL;

	pool_member = pool_member_by_nr(nr);
	if (!pool_member) {
		vty_out(vty, "%% no such MGCP client configured ('%s')%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	pool_member->blocked = false;
	return CMD_SUCCESS;
}

DEFUN(mgw_show, mgw_snow_cmd, "show mgw-pool", SHOW_STR "Display information about the MGW-Pool\n")
{
	vty_out(vty, "%% MGW-Pool:%s", VTY_NEWLINE);
	struct mgcp_client_pool_member *pool_member;

	if (llist_empty(&global_mgcp_client_pool->pool) && global_mgcp_client_pool->mgcp_client_single) {
		vty_out(vty, "%%  (pool is empty, single MGCP client will be used)%s", VTY_NEWLINE);
		return CMD_SUCCESS;
	} else if (llist_empty(&global_mgcp_client_pool->pool)) {
		vty_out(vty, "%%  (pool is empty)%s", VTY_NEWLINE);
		return CMD_SUCCESS;
	}

	llist_for_each_entry(pool_member, &global_mgcp_client_pool->pool, list) {
		vty_out(vty, "%%  MGW %u%s", pool_member->nr, VTY_NEWLINE);
		vty_out(vty, "%%   mgcp-client:   %s%s", pool_member->client ? "connected" : "disconnected",
			VTY_NEWLINE);
		vty_out(vty, "%%   service:       %s%s", pool_member->blocked ? "blocked" : "unblocked", VTY_NEWLINE);
		vty_out(vty, "%%   ongoing calls: %u%s", pool_member->refcount, VTY_NEWLINE);
	}
	return CMD_SUCCESS;
}

/*! Set up MGCP client VTY (pooled)
 *  (called once at startup by the application process).
 *  \param[in] parent_node identifier of the parent node on which the mgw node appears.
 *  \param[in] mgw_node identifier that should be used with the newly installed MGW node.
 *  \param[in] indent indentation string to match the indentation in the VTY config
 *  \param[in] pool user provided memory to store the configured MGCP client (MGW) pool. */
void mgcp_client_pool_vty_init(int parent_node, int mgw_node, const char *indent, struct mgcp_client_pool *pool)
{
	/* Never allow this function to be called twice on the same pool */
	OSMO_ASSERT(!pool->vty_indent);
	OSMO_ASSERT(!pool->vty_node);

	pool->vty_indent = talloc_strdup(pool, indent);
	OSMO_ASSERT(pool->vty_indent);
	pool->vty_node = talloc_zero(pool, struct cmd_node);
	OSMO_ASSERT(pool->vty_node);
	pool->vty_node->node = mgw_node;
	pool->vty_node->vtysh = 1;
	pool->vty_node->prompt = talloc_strdup(pool->vty_node, "%s(config-mgw)# ");

	install_lib_element(parent_node, &cfg_mgw_cmd);
	install_lib_element(parent_node, &cfg_no_mgw_cmd);

	install_node(pool->vty_node, config_write_pool);
	vty_init_common(pool, mgw_node);

	install_lib_element(ENABLE_NODE, &mgw_reconnect_cmd);
	install_lib_element(ENABLE_NODE, &mgw_block_cmd);
	install_lib_element(ENABLE_NODE, &mgw_unblock_cmd);

	install_lib_element_ve(&mgw_snow_cmd);

	global_mgcp_client_pool = pool;
}