/***************************************************************************
 *   Copyright (C) 06/2006 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 <unistd.h>
#include <string.h>
#include <getopt.h>
#include <pwd.h>
#include <sys/stat.h>

#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>

#include "configfile.h"
#include "logging.h"
#include "event.h"
#include "multicast.h"
#include "unixsock.h"

#define DEFAULT_CONFIG "cachesyncd.conf"
#define DEFAULT_LOGFILE "cachesyncd.log"
#define DEFAULT_USER "httpd"
#define BUF_SIZE 256

static struct option opts[] = {
	{"config",	1, 0, 'c'},
	{"debug",	0, 0, 'd'},
	{"help",	0, 0, 'h'},
	{0, 0, 0, 0}
};

static int usock, msock;

int usock_read_callback(int fd, void *privdata)
{
	int len = read(fd, privdata, BUF_SIZE);
	if (len <= 0) {
		close(fd);
		return -1;
	}

	mcast_send(msock, privdata, len);
	return 0;
}

int usock_accept_callback(int fd, void *privdata)
{
	int con = accept(usock, NULL, NULL);
	if (con < 0 ) {
		log_print(LOG_ERROR, "selector: accept()");
		return 0;
	}

	event_add_readfd(con, usock_read_callback, privdata);
	return 0;
}

int msock_read_callback(int fd, void *privdata)
{
	int len = read(fd, privdata, BUF_SIZE);
	if (len <= 0) {
		log_print(LOG_ERROR, "selector: multicast sock closed?");

	} else if (!strncmp(privdata, "KEEPALIVE", 10)) {
		// nothing

	} else if (!strncmp(privdata, "DELETE ", 7)) {
		log_print(LOG_DEBUG, "delete '%s'", privdata +7);
		if (unlink(privdata +7))
            log_print(LOG_ERROR, "delete '%s' failed", privdata +7);

	} else {
		log_print(LOG_DEBUG, "recv unknown cmd via multicast: '%s'", privdata);
	}

	return 0;
}

int msock_keepalive_timeout(void *privdata)
{
	mcast_send(msock, "KEEPALIVE", 10);
	return 0;
}

void drop_privileges(char *user)
{
    struct passwd *user_info;
    user_info = getpwnam(user);
    if (user_info == NULL) {
        log_print(LOG_ERROR,"drop_privileges(): user '%s' not found", user);
    } else {
        if (setregid(user_info->pw_gid, user_info->pw_gid))
            log_print(LOG_ERROR, "setgid() failed");
        if (setreuid(user_info->pw_uid, user_info->pw_uid))
            log_print(LOG_ERROR, "setuid() failed");
    }
}

int main(int argc, char *argv[])
{
	char *config = DEFAULT_CONFIG;
	int code, arg = 0, debug = 0;

	do {
		code = getopt_long(argc, argv, "c:dh", opts, &arg);

		switch (code) {
		case 'c':	/* config */
				config = optarg;
				break;

		case 'd':	/* debug */
				debug = 1;
				break;

		case 'h':	/* help */
				printf("Usage: cachesyncd [options]\n"
					"Options: \n"
					"  --config       -c  configfile  use this configfile\n"
					"  --debug        -d              do not fork and log to stderr\n"
					"  --help         -h              this help\n"
					"\n");
				exit(0);
				break;

		case '?':	/* error */
				exit(-1);
				break;

		default:	/* unknown / all options parsed */
				break;
		}
	} while (code != -1);

	/* parse config file */
	if (!config_parse(config))
		exit(-1);

	/* check logfile */
	char *logfile = config_get_string("global", "logfile", DEFAULT_LOGFILE);
	if (logfile != NULL && debug == 0) {
		/* start logging */
		if (!log_init(logfile))
			exit(-1);

		/* zum daemon mutieren */
		daemon(-1, 0);
	}

	log_print(LOG_EVERYTIME, "cachesyncd started (pid: %d)", getpid());

	char *buf = malloc(BUF_SIZE);
	if (buf == NULL) {
		log_print(LOG_ERROR, "selector: out of memory");
		return -1;
	}

	msock = mcast_init();
	if (msock < 0)
		return -1;

    drop_privileges(config_get_string("global", "user", DEFAULT_USER));
    
    usock = sock_init();
    if (usock < 0)
		return -1;

	event_add_readfd(usock, usock_accept_callback, buf);
	event_add_readfd(msock, msock_read_callback, buf);

	struct timeval tv;
	tv.tv_sec = 60;
	tv.tv_usec = 0;

	event_add_timeout(&tv, msock_keepalive_timeout, NULL);

	event_loop();

	return 0;
}