/***************************************************************************
 *   Copyright (C) 03/2005 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>

static FILE *log_fd = NULL;

/**
 * log_close()
 * schliesst das logfile
 */
void log_close() {
	fclose(log_fd);
}

/**
 * log_open()
 * oeffnet ein logfile
 * wenn der prozess sich beendet, wird das logfile auch wieder geschlossen
 *
 * @param char *logfile
 */
void log_open(char *logfile) {
	if ((log_fd = fopen(logfile, "a" )) == NULL) {
		fprintf(stderr, "log_open(\"%s\"): %s\n", logfile, strerror(errno));
		exit(-1);
	}
	if (atexit(log_close) != 0) {
		fprintf(stderr, "log_open(): atexit(): %s\n", strerror(errno));
		exit(-1);
	}
}

/**
 * log_print()
 * schreibt eine Zeile ins Logfile oder auf stderr
 * wenn errno gesetzt ist, wird der error-string mit ausgegeben
 *
 * @param variable parameterlist
 */
void log_print(const char *fmt, ...) {
	va_list az;
	char    buffer[256];

	va_start(az, fmt);
	vsprintf(buffer, fmt, az);
	va_end(az);

	if (log_fd) {
		time_t  tzgr;
		char    tbuf[64];
		time(&tzgr);
		strftime(tbuf, 64, "%b %d %H:%M:%S :", localtime(&tzgr));

		if (errno) {
			fprintf(log_fd, "%s %s: %s\n", tbuf, buffer, strerror(errno));
		} else {
			fprintf(log_fd, "%s %s\n", tbuf, buffer);
		}
	} else {
		if (errno) {
			fprintf(stderr, "%s: %s\n", buffer, strerror(errno));
		} else {
			fprintf(stderr, "%s\n", buffer);
		}
	}
	errno = 0;
	fflush(log_fd);
}