/* $OpenBSD: log.c,v 1.33 2026/05/17 16:02:33 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * 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 MIND, 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 <sys/types.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vis.h>

#include "tmux.h"

static FILE     *log_file;
static int       log_level;

/* Log callback for libevent. */
static void
log_event_cb(__unused int severity, const char *msg)
{
        log_debug("%s", msg);
}

/* Increment log level. */
void
log_add_level(void)
{
        log_level++;
}

/* Get log level. */
int
log_get_level(void)
{
        return (log_level);
}

/* Open logging to file. */
void
log_open(const char *name)
{
        char    *path;

        if (log_level == 0)
                return;
        log_close();

        xasprintf(&path, "tmux-%s-%ld.log", name, (long)getpid());
        log_file = fopen(path, "a");
        free(path);
        if (log_file == NULL)
                return;

        setvbuf(log_file, NULL, _IOLBF, 0);
        event_set_log_callback(log_event_cb);
}

/* Toggle logging. */
void
log_toggle(const char *name)
{
        if (log_level == 0) {
                log_level = 1;
                log_open(name);
                log_debug("log opened");
        } else {
                log_debug("log closed");
                log_level = 0;
                log_close();
        }
}

/* Close logging. */
void
log_close(void)
{
        if (log_file != NULL)
                fclose(log_file);
        log_file = NULL;

        event_set_log_callback(NULL);
}

/* Write a log message. */
static void printflike(1, 0)
log_vwrite(const char *msg, va_list ap, const char *prefix)
{
        char            *s, *out;
        struct timeval   tv;

        if (log_file == NULL)
                return;

        if (vasprintf(&s, msg, ap) == -1)
                return;
        if (stravis(&out, s, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL) == -1) {
                free(s);
                return;
        }
        free(s);

        gettimeofday(&tv, NULL);
        if (fprintf(log_file, "%lld.%06d %s%s\n", (long long)tv.tv_sec,
            (int)tv.tv_usec, prefix, out) != -1)
                fflush(log_file);
        free(out);
}

/* Log a debug message. */
void
log_debug(const char *msg, ...)
{
        va_list ap;

        if (log_file == NULL)
                return;

        va_start(ap, msg);
        log_vwrite(msg, ap, "");
        va_end(ap);
}

/* Log a critical error with error string and die. */
__dead void
fatal(const char *msg, ...)
{
        char     tmp[256];
        va_list  ap;

        if (snprintf(tmp, sizeof tmp, "fatal: %s: ", strerror(errno)) < 0)
                exit(1);

        va_start(ap, msg);
        log_vwrite(msg, ap, tmp);
        va_end(ap);

        exit(1);
}

/* Log a critical error and die. */
__dead void
fatalx(const char *msg, ...)
{
        va_list  ap;

        va_start(ap, msg);
        log_vwrite(msg, ap, "fatal: ");
        va_end(ap);

        exit(1);
}