/*
 *  This file is part of capwap-mitm.
 *
 *  Foobar 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  capwap-mitm 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 capwap-mitm.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <assert.h>

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>

#include "log.h"

#if defined(DEBUG)

static __thread int save_errno;

static __thread size_t pos = 0;
static __thread char buf[128 * 1024];

static __thread int ctime_last = 0;
static __thread char ctime_buf[27];

void _debug(const char *filename, int line, const char *func, const char *fmt, ...)
{
        va_list args;
	struct timeval tv;

	gettimeofday(&tv, NULL);

	_debug_head(filename, line, func, &tv);

        va_start(args, fmt);
        pos += vsnprintf(buf + pos, sizeof(buf) - pos, fmt, args);
        va_end(args);

	debug_flush();
}

void _debug_head(const char *filename, int line, const char *func, struct timeval *tv)
{
	save_errno = errno;

        if (ctime_last != tv->tv_sec) {
                ctime_r(&tv->tv_sec, ctime_buf);
                ctime_last = tv->tv_sec;
        }

        pos += snprintf(buf + pos, sizeof(buf) - pos, "%.15s.%03ld %s:%d:%s: ",
			&ctime_buf[4], tv->tv_usec / 1000,
			filename, line, func);
}

void debug_log(const char *fmt, ...)
{
        va_list args;

	/* make sure %m gets the right errno */
	errno = save_errno;

        va_start(args, fmt);
        pos += vsnprintf(buf + pos, sizeof(buf) - pos, fmt, args);
        va_end(args);

	assert(pos < sizeof(buf));
}

void debug_flush()
{
	if (pos > 0 && pos < sizeof(buf) && buf[pos - 1] != '\n')
		buf[pos++] = '\n';

	if (write(STDERR_FILENO, buf, pos) < 0)
		;
	pos = 0;
	errno = save_errno;
}

#endif