/*
 * log.c -- logging routines
 *
 * Copyright (c) 2020-2023 David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <assert.h>
#include <stdio.h>
#include <syslog.h>
#include <time.h>

#include "log.h"

/* TODO: replace. */
static struct {
	enum log_level verbosity;
} config = {
	.verbosity = LOG_LEVEL_DEBUG
};

static int syslog_levels[] = {
	[LOG_LEVEL_DEBUG]       = LOG_DEBUG,
	[LOG_LEVEL_INFO]        = LOG_INFO,
	[LOG_LEVEL_WARNING]     = LOG_WARNING
};

static const char * const levelsyms[] = {
	[LOG_LEVEL_DEBUG]       = "D",
	[LOG_LEVEL_INFO]        = "I",
	[LOG_LEVEL_WARNING]     = "W"
};

void
log_open(const char *name)
{
	openlog(name, 0, LOG_USER);
}

void
log_write(enum log_level level, const char *fmt, ...)
{
	assert(level >= LOG_LEVEL_WARNING && level <= LOG_LEVEL_DEBUG);
	assert(fmt);

	if (config.verbosity >= level) {
		va_list ap;

		va_start(ap, fmt);
		log_vwrite(level, fmt, ap);
		va_end(ap);
	}
}

void
log_vwrite(enum log_level level, const char *fmt, va_list ap)
{
	assert(level >= LOG_LEVEL_WARNING && level <= LOG_LEVEL_DEBUG);
	assert(fmt);

	char line[BUFSIZ] = {0}, timebuf[32] = {0};
	time_t timestamp = time(NULL);
	struct tm *tm = localtime(&timestamp);

	vsnprintf(line, sizeof (line), fmt, ap);
	syslog(syslog_levels[level], "%s", line);

	strftime(timebuf, sizeof (timebuf), "%F %T", tm);
	printf("%s %s %s\n", timebuf, levelsyms[level], line);
}

void
log_finish(void)
{
	closelog();
}