/* OpenBSC logging helper for the VTY */
/* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
 * (C) 2009-2014 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <stdlib.h>
#include <string.h>

#include "../../config.h"

#include <osmocom/core/talloc.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/strrb.h>
#include <osmocom/core/loggingrb.h>

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

#define LOG_STR "Configure logging sub-system\n"

extern const struct log_info *osmo_log_info;

static void _vty_output(struct log_target *tgt,
			unsigned int level, const char *line)
{
	struct vty *vty = tgt->tgt_vty.vty;
	vty_out(vty, "%s", line);
	/* This is an ugly hack, but there is no easy way... */
	if (strchr(line, '\n'))
		vty_out(vty, "\r");
}

struct log_target *log_target_create_vty(struct vty *vty)
{
	struct log_target *target;

	target = log_target_create();
	if (!target)
		return NULL;

	target->tgt_vty.vty = vty;
	target->output = _vty_output;
	return target;
}

DEFUN(enable_logging,
      enable_logging_cmd,
      "logging enable",
	LOGGING_STR
      "Enables logging to this vty\n")
{
	struct telnet_connection *conn;

	conn = (struct telnet_connection *) vty->priv;
	if (conn->dbg) {
		vty_out(vty, "Logging already enabled.%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	conn->dbg = log_target_create_vty(vty);
	if (!conn->dbg)
		return CMD_WARNING;

	log_add_target(conn->dbg);
	return CMD_SUCCESS;
}

struct log_target *osmo_log_vty2tgt(struct vty *vty)
{
	struct telnet_connection *conn;

	if (vty->node == CFG_LOG_NODE)
		return vty->index;


	conn = (struct telnet_connection *) vty->priv;
	if (!conn->dbg)
		vty_out(vty, "Logging was not enabled.%s", VTY_NEWLINE);

	return conn->dbg;
}

DEFUN(logging_fltr_all,
      logging_fltr_all_cmd,
      "logging filter all (0|1)",
	LOGGING_STR FILTER_STR
	"Do you want to log all messages?\n"
	"Only print messages matched by other filters\n"
	"Bypass filter and print all messages\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_set_all_filter(tgt, atoi(argv[0]));
	return CMD_SUCCESS;
}

DEFUN(logging_use_clr,
      logging_use_clr_cmd,
      "logging color (0|1)",
	LOGGING_STR "Configure color-printing for log messages\n"
      "Don't use color for printing messages\n"
      "Use color for printing messages\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_set_use_color(tgt, atoi(argv[0]));
	return CMD_SUCCESS;
}

DEFUN(logging_prnt_timestamp,
      logging_prnt_timestamp_cmd,
      "logging timestamp (0|1)",
	LOGGING_STR "Configure log message timestamping\n"
	"Don't prefix each log message\n"
	"Prefix each log message with current timestamp\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_set_print_timestamp(tgt, atoi(argv[0]));
	return CMD_SUCCESS;
}

DEFUN(logging_prnt_ext_timestamp,
      logging_prnt_ext_timestamp_cmd,
      "logging print extended-timestamp (0|1)",
	LOGGING_STR "Log output settings\n"
	"Configure log message timestamping\n"
	"Don't prefix each log message\n"
	"Prefix each log message with current timestamp with YYYYMMDDhhmmssnnn\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_set_print_extended_timestamp(tgt, atoi(argv[0]));
	return CMD_SUCCESS;
}

DEFUN(logging_prnt_cat,
      logging_prnt_cat_cmd,
      "logging print category (0|1)",
	LOGGING_STR "Log output settings\n"
	"Configure log message\n"
	"Don't prefix each log message\n"
	"Prefix each log message with category/subsystem name\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_set_print_category(tgt, atoi(argv[0]));
	return CMD_SUCCESS;
}

DEFUN(logging_level,
      logging_level_cmd,
      NULL, /* cmdstr is dynamically set in logging_vty_add_cmds(). */
      NULL) /* same thing for helpstr. */
{
	int category = log_parse_category(argv[0]);
	int level = log_parse_level(argv[1]);
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	if (level < 0) {
		vty_out(vty, "Invalid level `%s'%s", argv[1], VTY_NEWLINE);
		return CMD_WARNING;
	}

	/* Check for special case where we want to set global log level */
	if (!strcmp(argv[0], "all")) {
		log_set_log_level(tgt, level);
		return CMD_SUCCESS;
	}

	if (category < 0) {
		vty_out(vty, "Invalid category `%s'%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	tgt->categories[category].enabled = 1;
	tgt->categories[category].loglevel = level;

	return CMD_SUCCESS;
}

DEFUN(logging_set_category_mask,
      logging_set_category_mask_cmd,
      "logging set-log-mask MASK",
	LOGGING_STR
      "Set the logmask of this logging target\n"
      "The logmask to use\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	log_parse_category_mask(tgt, argv[0]);
	return CMD_SUCCESS;
}

ALIAS_DEPRECATED(logging_set_category_mask,
		 logging_set_category_mask_old_cmd,
		 "logging set log mask MASK",
		 LOGGING_STR
		 "Decide which categories to output.\n"
		 "Log commands\n" "Mask commands\n" "The logmask to use\n");


DEFUN(diable_logging,
      disable_logging_cmd,
      "logging disable",
	LOGGING_STR
      "Disables logging to this vty\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);
	struct telnet_connection *conn = (struct telnet_connection *) vty->priv;

	if (!tgt)
		return CMD_WARNING;

	log_del_target(tgt);
	talloc_free(tgt);
	conn->dbg = NULL;

	return CMD_SUCCESS;
}

static void vty_print_logtarget(struct vty *vty, const struct log_info *info,
				const struct log_target *tgt)
{
	unsigned int i;

	vty_out(vty, " Global Loglevel: %s%s",
		log_level_str(tgt->loglevel), VTY_NEWLINE);
	vty_out(vty, " Use color: %s, Print Timestamp: %s%s",
		tgt->use_color ? "On" : "Off",
		tgt->print_timestamp ? "On" : "Off", VTY_NEWLINE);

	vty_out(vty, " Log Level specific information:%s", VTY_NEWLINE);

	for (i = 0; i < info->num_cat; i++) {
		const struct log_category *cat = &tgt->categories[i];
		vty_out(vty, "  %-10s %-10s %-8s %s%s",
			info->cat[i].name+1, log_level_str(cat->loglevel),
			cat->enabled ? "Enabled" : "Disabled",
 			info->cat[i].description,
			VTY_NEWLINE);
	}

	vty_out(vty, " Log Filter 'ALL': %s%s",
		tgt->filter_map & LOG_FILTER_ALL ? "Enabled" : "Disabled",
		VTY_NEWLINE);

	/* print application specific filters */
	if (info->print_fn)
		info->print_fn(vty, info, tgt);
}

#define SHOW_LOG_STR "Show current logging configuration\n"

DEFUN(show_logging_vty,
	show_logging_vty_cmd,
	"show logging vty",
	SHOW_STR SHOW_LOG_STR
	"Show current logging configuration for this vty\n")
{
	struct log_target *tgt = osmo_log_vty2tgt(vty);

	if (!tgt)
		return CMD_WARNING;

	vty_print_logtarget(vty, osmo_log_info, tgt);

	return CMD_SUCCESS;
}

DEFUN(show_alarms,
	show_alarms_cmd,
	"show alarms",
	SHOW_STR SHOW_LOG_STR
	"Show the contents of the logging ringbuffer\n")
{
	int i, num_alarms;
	struct osmo_strrb *rb;
	struct log_target *tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
	if (!tgt) {
		vty_out(vty, "%% No alarms, run 'log alarms <2-32700>'%s",
			VTY_NEWLINE);
		return CMD_WARNING;
	}

	rb = tgt->tgt_rb.rb;
	num_alarms = osmo_strrb_elements(rb);

	vty_out(vty, "%% Showing %i alarms%s", num_alarms, VTY_NEWLINE);

	for (i = 0; i < num_alarms; i++)
		vty_out(vty, "%% %s%s", osmo_strrb_get_nth(rb, i),
			VTY_NEWLINE);

	return CMD_SUCCESS;
}

gDEFUN(cfg_description, cfg_description_cmd,
	"description .TEXT",
	"Save human-readable decription of the object\n"
	"Text until the end of the line\n")
{
	char **dptr = vty->index_sub;

	if (!dptr) {
		vty_out(vty, "vty->index_sub == NULL%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	if (*dptr)
		talloc_free(*dptr);
	*dptr = argv_concat(argv, argc, 0);
	if (!*dptr)
		return CMD_WARNING;

	return CMD_SUCCESS;
}

gDEFUN(cfg_no_description, cfg_no_description_cmd,
	"no description",
	NO_STR
	"Remove description of the object\n")
{
	char **dptr = vty->index_sub;

	if (!dptr) {
		vty_out(vty, "vty->index_sub == NULL%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	if (*dptr) {
		talloc_free(*dptr);
		*dptr = NULL;
	}

	return CMD_SUCCESS;
}

/* Support for configuration of log targets != the current vty */

struct cmd_node cfg_log_node = {
	CFG_LOG_NODE,
	"%s(config-log)# ",
	1
};

#ifdef HAVE_SYSLOG_H

#include <syslog.h>

static const int local_sysl_map[] = {
	[0] = LOG_LOCAL0,
	[1] = LOG_LOCAL1,
	[2] = LOG_LOCAL2,
	[3] = LOG_LOCAL3,
	[4] = LOG_LOCAL4,
	[5] = LOG_LOCAL5,
	[6] = LOG_LOCAL6,
	[7] = LOG_LOCAL7
};

/* From VTY core code */
extern struct host host;

static int _cfg_log_syslog(struct vty *vty, int facility)
{
	struct log_target *tgt;

	/* First delete the old syslog target, if any */
	tgt = log_target_find(LOG_TGT_TYPE_SYSLOG, NULL);
	if (tgt)
		log_target_destroy(tgt);

	tgt = log_target_create_syslog(host.app_info->name, 0, facility);
	if (!tgt) {
		vty_out(vty, "%% Unable to open syslog%s", VTY_NEWLINE);
		return CMD_WARNING;
	}
	log_add_target(tgt);

	vty->index = tgt;
	vty->node = CFG_LOG_NODE;

	return CMD_SUCCESS;
}

DEFUN(cfg_log_syslog_local, cfg_log_syslog_local_cmd,
      "log syslog local <0-7>",
	LOG_STR "Logging via syslog\n" "Syslog LOCAL facility\n"
	"Local facility number\n")
{
	int local = atoi(argv[0]);
	int facility = local_sysl_map[local];

	return _cfg_log_syslog(vty, facility);
}

static struct value_string sysl_level_names[] = {
	{ LOG_AUTHPRIV, "authpriv" },
	{ LOG_CRON, 	"cron" },
	{ LOG_DAEMON,	"daemon" },
	{ LOG_FTP,	"ftp" },
	{ LOG_LPR,	"lpr" },
	{ LOG_MAIL,	"mail" },
	{ LOG_NEWS,	"news" },
	{ LOG_USER,	"user" },
	{ LOG_UUCP,	"uucp" },
	/* only for value -> string conversion */
	{ LOG_LOCAL0,	"local 0" },
	{ LOG_LOCAL1,	"local 1" },
	{ LOG_LOCAL2,	"local 2" },
	{ LOG_LOCAL3,	"local 3" },
	{ LOG_LOCAL4,	"local 4" },
	{ LOG_LOCAL5,	"local 5" },
	{ LOG_LOCAL6,	"local 6" },
	{ LOG_LOCAL7,	"local 7" },
	{ 0, NULL }
};

DEFUN(cfg_log_syslog, cfg_log_syslog_cmd,
      "log syslog (authpriv|cron|daemon|ftp|lpr|mail|news|user|uucp)",
	LOG_STR "Logging via syslog\n"
	"Security/authorization messages facility\n"
	"Clock daemon (cron/at) facility\n"
	"General system daemon facility\n"
	"Ftp daemon facility\n"
	"Line printer facility\n"
	"Mail facility\n"
	"News facility\n"
	"Generic facility\n"
	"UUCP facility\n")
{
	int facility = get_string_value(sysl_level_names, argv[0]);

	return _cfg_log_syslog(vty, facility);
}

DEFUN(cfg_no_log_syslog, cfg_no_log_syslog_cmd,
	"no log syslog",
	NO_STR LOG_STR "Logging via syslog\n")
{
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_SYSLOG, NULL);
	if (!tgt) {
		vty_out(vty, "%% No syslog target found%s",
			VTY_NEWLINE);
		return CMD_WARNING;
	}

	log_target_destroy(tgt);

	return CMD_SUCCESS;
}
#endif /* HAVE_SYSLOG_H */

DEFUN(cfg_log_stderr, cfg_log_stderr_cmd,
	"log stderr",
	LOG_STR "Logging via STDERR of the process\n")
{
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_STDERR, NULL);
	if (!tgt) {
		tgt = log_target_create_stderr();
		if (!tgt) {
			vty_out(vty, "%% Unable to create stderr log%s",
				VTY_NEWLINE);
			return CMD_WARNING;
		}
		log_add_target(tgt);
	}

	vty->index = tgt;
	vty->node = CFG_LOG_NODE;

	return CMD_SUCCESS;
}

DEFUN(cfg_no_log_stderr, cfg_no_log_stderr_cmd,
	"no log stderr",
	NO_STR LOG_STR "Logging via STDERR of the process\n")
{
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_STDERR, NULL);
	if (!tgt) {
		vty_out(vty, "%% No stderr logging active%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	log_target_destroy(tgt);

	return CMD_SUCCESS;
}

DEFUN(cfg_log_file, cfg_log_file_cmd,
	"log file .FILENAME",
	LOG_STR "Logging to text file\n" "Filename\n")
{
	const char *fname = argv[0];
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_FILE, fname);
	if (!tgt) {
		tgt = log_target_create_file(fname);
		if (!tgt) {
			vty_out(vty, "%% Unable to create file `%s'%s",
				fname, VTY_NEWLINE);
			return CMD_WARNING;
		}
		log_add_target(tgt);
	}

	vty->index = tgt;
	vty->node = CFG_LOG_NODE;

	return CMD_SUCCESS;
}


DEFUN(cfg_no_log_file, cfg_no_log_file_cmd,
	"no log file .FILENAME",
	NO_STR LOG_STR "Logging to text file\n" "Filename\n")
{
	const char *fname = argv[0];
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_FILE, fname);
	if (!tgt) {
		vty_out(vty, "%% No such log file `%s'%s",
			fname, VTY_NEWLINE);
		return CMD_WARNING;
	}

	log_target_destroy(tgt);

	return CMD_SUCCESS;
}

DEFUN(cfg_log_alarms, cfg_log_alarms_cmd,
	"log alarms <2-32700>",
	LOG_STR "Logging alarms to osmo_strrb\n"
	"Maximum number of messages to log\n")
{
	struct log_target *tgt;
	unsigned int rbsize = atoi(argv[0]);

	tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
	if (tgt)
		log_target_destroy(tgt);

	tgt = log_target_create_rb(rbsize);
	if (!tgt) {
		vty_out(vty, "%% Unable to create osmo_strrb (size %u)%s",
			rbsize, VTY_NEWLINE);
		return CMD_WARNING;
	}
	log_add_target(tgt);

	vty->index = tgt;
	vty->node = CFG_LOG_NODE;

	return CMD_SUCCESS;
}

DEFUN(cfg_no_log_alarms, cfg_no_log_alarms_cmd,
	"no log alarms",
	NO_STR LOG_STR "Logging alarms to osmo_strrb\n")
{
	struct log_target *tgt;

	tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
	if (!tgt) {
		vty_out(vty, "%% No osmo_strrb target found%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	log_target_destroy(tgt);

	return CMD_SUCCESS;
}

static int config_write_log_single(struct vty *vty, struct log_target *tgt)
{
	int i;
	char level_lower[32];

	switch (tgt->type) {
	case LOG_TGT_TYPE_VTY:
		return 1;
		break;
	case LOG_TGT_TYPE_STDERR:
		vty_out(vty, "log stderr%s", VTY_NEWLINE);
		break;
	case LOG_TGT_TYPE_SYSLOG:
#ifdef HAVE_SYSLOG_H
		vty_out(vty, "log syslog %s%s",
			get_value_string(sysl_level_names,
					 tgt->tgt_syslog.facility),
			VTY_NEWLINE);
#endif
		break;
	case LOG_TGT_TYPE_FILE:
		vty_out(vty, "log file %s%s", tgt->tgt_file.fname, VTY_NEWLINE);
		break;
	case LOG_TGT_TYPE_STRRB:
		vty_out(vty, "log alarms %zu%s",
			log_target_rb_avail_size(tgt), VTY_NEWLINE);
		break;
	}

	vty_out(vty, "  logging filter all %u%s",
		tgt->filter_map & LOG_FILTER_ALL ? 1 : 0, VTY_NEWLINE);
	/* save filters outside of libosmocore, i.e. in app code */
	if (osmo_log_info->save_fn)
		osmo_log_info->save_fn(vty, osmo_log_info, tgt);

	vty_out(vty, "  logging color %u%s", tgt->use_color ? 1 : 0,
		VTY_NEWLINE);
	vty_out(vty, "  logging print category %d%s",
		tgt->print_category ? 1 : 0, VTY_NEWLINE);
	if (tgt->print_ext_timestamp)
		vty_out(vty, "  logging print extended-timestamp 1%s", VTY_NEWLINE);
	else
		vty_out(vty, "  logging timestamp %u%s",
			tgt->print_timestamp ? 1 : 0, VTY_NEWLINE);

	/* stupid old osmo logging API uses uppercase strings... */
	osmo_str2lower(level_lower, log_level_str(tgt->loglevel));
	vty_out(vty, "  logging level all %s%s", level_lower, VTY_NEWLINE);

	for (i = 0; i < osmo_log_info->num_cat; i++) {
		const struct log_category *cat = &tgt->categories[i];
		char cat_lower[32];

		/* skip empty entries in the array */
		if (!osmo_log_info->cat[i].name)
			continue;

		/* stupid old osmo logging API uses uppercase strings... */
		osmo_str2lower(cat_lower, osmo_log_info->cat[i].name+1);
		osmo_str2lower(level_lower, log_level_str(cat->loglevel));

		vty_out(vty, "  logging level %s %s%s", cat_lower, level_lower,
			VTY_NEWLINE);
	}

	/* FIXME: levels */

	return 1;
}

static int config_write_log(struct vty *vty)
{
	struct log_target *dbg = vty->index;

	llist_for_each_entry(dbg, &osmo_log_target_list, entry)
		config_write_log_single(vty, dbg);

	return 1;
}

void logging_vty_add_cmds(const struct log_info *cat)
{
	install_element_ve(&enable_logging_cmd);
	install_element_ve(&disable_logging_cmd);
	install_element_ve(&logging_fltr_all_cmd);
	install_element_ve(&logging_use_clr_cmd);
	install_element_ve(&logging_prnt_timestamp_cmd);
	install_element_ve(&logging_prnt_ext_timestamp_cmd);
	install_element_ve(&logging_prnt_cat_cmd);
	install_element_ve(&logging_set_category_mask_cmd);
	install_element_ve(&logging_set_category_mask_old_cmd);

	/* Logging level strings are generated dynamically. */
	logging_level_cmd.string = log_vty_command_string(cat);
	logging_level_cmd.doc = log_vty_command_description(cat);
	install_element_ve(&logging_level_cmd);
	install_element_ve(&show_logging_vty_cmd);
	install_element_ve(&show_alarms_cmd);

	install_node(&cfg_log_node, config_write_log);
	vty_install_default(CFG_LOG_NODE);
	install_element(CFG_LOG_NODE, &logging_fltr_all_cmd);
	install_element(CFG_LOG_NODE, &logging_use_clr_cmd);
	install_element(CFG_LOG_NODE, &logging_prnt_timestamp_cmd);
	install_element(CFG_LOG_NODE, &logging_prnt_ext_timestamp_cmd);
	install_element(CFG_LOG_NODE, &logging_prnt_cat_cmd);
	install_element(CFG_LOG_NODE, &logging_level_cmd);

	install_element(CONFIG_NODE, &cfg_log_stderr_cmd);
	install_element(CONFIG_NODE, &cfg_no_log_stderr_cmd);
	install_element(CONFIG_NODE, &cfg_log_file_cmd);
	install_element(CONFIG_NODE, &cfg_no_log_file_cmd);
	install_element(CONFIG_NODE, &cfg_log_alarms_cmd);
	install_element(CONFIG_NODE, &cfg_no_log_alarms_cmd);
#ifdef HAVE_SYSLOG_H
	install_element(CONFIG_NODE, &cfg_log_syslog_cmd);
	install_element(CONFIG_NODE, &cfg_log_syslog_local_cmd);
	install_element(CONFIG_NODE, &cfg_no_log_syslog_cmd);
#endif
}