/*
 * Copyright (c) 2022 Daniel Kroczynski <d@kroczynski.net>
 *
 * Permission to use, copy, modify, and 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 <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>

static int	log_bgnd;
static int	log_verb;
const char     *log_name;

void	log_init(int, int);
void	log_set(int);
int	log_get(void);
void	log_send(const char *, va_list)
	__attribute__((__format__ (printf, 1, 0)));
void	log_info(const char *, ...)
	__attribute__((__format__ (printf, 1, 2)));
void	log_debug(const char *, ...)
	__attribute__((__format__ (printf, 1, 2)));
__dead void log_fatal(const char *, ...)
	__attribute__((__format__ (printf, 1, 2)));

void
log_init(int background, int facility)
{
	extern char *__progname;

	if (__progname != NULL)
		log_name = __progname;

	log_bgnd = background;
	if (log_bgnd)
		openlog(log_name, LOG_PID | LOG_NDELAY, facility);

	tzset();
}

void
log_set(int verb)
{
	log_verb = verb;
}

int
log_get(void)
{
	return (log_verb);
}

void
log_send(const char *info, va_list ap)
{
	char   *ninf;

	if (info != NULL) {
		if (log_bgnd)
			vsyslog(LOG_INFO, info, ap);
		else {
			if (asprintf(&ninf, "%s\n", info) == -1) {
				vfprintf(stderr, info, ap);
				fprintf(stderr, "\n");
			} else {
				vfprintf(stderr, ninf, ap);
				free(ninf);
			}
			fflush(stderr);
		}
	}
}

void
log_info(const char *info, ...)
{
	va_list ap;

	va_start(ap, info);
	log_send(info, ap);
	va_end(ap);
}

void
log_debug(const char *info, ...)
{
	va_list ap;

	if (log_verb) {
		va_start(ap, info);
		log_send(info, ap);
		va_end(ap);
	}
}

void
log_fatal(const char *info, ...)
{
	extern struct blind *bl;
	static char s[BUFSIZ];
	va_list ap;

	va_start(ap, info);
	if (info != NULL)
		(void)vsnprintf(s, sizeof(s), info, ap);
	else
		s[0] = '\0';

	va_end(ap);
	if (errno)
		log_info("%s: %s", strerror(errno), s);
	else
		log_info("Unknown error: %s", s);

	if (bl != NULL)
		free(bl);

	exit(1);
}