/*
 * This file is part of the Distributed Network Block Device 3
 *
 * Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
 *
 * This file may be licensed under the terms of of the
 * GNU General Public License Version 2 (the ``GPL'').
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the GPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the GPL along with this
 * program. If not, go to http://www.gnu.org/licenses/gpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "utils.h"
#include "hashtable.h"

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>

void dnbd3_write_pid_file(pid_t pid)
{
	FILE *f = fopen(SERVER_PID_FILE, "w");
	if(f != NULL)
	{
	    fprintf(f, "%i", pid);
	    fclose(f);
	}
	else
	{
		printf("ERROR: Couldn't write pid file (%s).\n", SERVER_PID_FILE);
	}
}

pid_t dnbd3_read_pid_file()
{
	pid_t pid = 0;

	FILE *f = fopen(SERVER_PID_FILE, "r");
	if(f != NULL)
	{
	    fscanf(f, "%i", &pid);
	    fclose(f);
	}
	else
	{
		printf("ERROR: Couldn't read pid file (%s).\n", SERVER_PID_FILE);
	}

	return pid;
}

void dnbd3_delete_pid_file()
{
	 if (unlink(SERVER_PID_FILE) != 0)
	 {
		 printf("ERROR: Couldn't delete pid file (%s).\n", SERVER_PID_FILE);
	 }
}


void dnbd3_load_config(char* config_file_name)
{
	dnbd3_ht_create();
	FILE *config_file = fopen(config_file_name, "r");

	if (config_file == NULL)
	{
		printf("ERROR: Config file not found: %s\n", config_file_name);
		exit(EXIT_FAILURE);
	}

	char line[MAX_FILE_NAME + 1 + MAX_FILE_ID];
	char* image_name = NULL;
	char* image_id = NULL;

	while (fgets(line, sizeof(line), config_file) != NULL)
	{
		sscanf(line, "%as %as", &image_name, &image_id);
		if (dnbd3_ht_insert(image_id, image_name) < 0)
		{
			printf("ERROR: Image name or ID is too big\n");
			exit(EXIT_FAILURE);
		}
	}
	fclose(config_file);
}

void dnbd3_reload_config(char* config_file_name)
{
	dnbd3_ht_destroy();
	dnbd3_load_config(config_file_name);
}

void dnbd3_send_signal(int signum)
{
	pid_t pid = dnbd3_read_pid_file();
	if (pid != 0)
	{
		if (kill(pid, signum) != 0)
		{
			printf("ERROR: dnbd3-server is not running\n");
			dnbd3_delete_pid_file();
		}
	}
	else
	{
		printf("ERROR: dnbd3-server is not running\n");
	}
}