/*
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Library 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
 *   Library General Public License for more details.
 *
 *   For a copy of the GNU Library General Public License
 *   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *   Boston, MA 02111-1307, USA.  or go to http://www.gnu.org
 *
 * $Id: netmeter.c,v 1.2 2005/04/15 16:25:25 mefemal Exp $
 */

/*
 * Read the readings from the meter server for client print out.
 * These routines perform the appropriate actions to the mlogger meter
 * server and return the data.  Most of these routines are stubs to
 * other lower-level implementation routines.  For specific instructions
 * on semantic usage, reference the netmeter.h header file.
 */

#include <unistd.h>
#include <errno.h>
#include "connectsock.h"
#include "meter.h"

extern int errno;

static int sock;

int netmeter_connect(char *hostname, unsigned short port) {
   sock = tcp_connect_port(hostname, port);

   return sock;
}

int netmeter_close() {
   int r;

   netmeter_req_t msg = { NETMETER_CMD_QUIT, NULL, 0, 0 };
   r = write(sock, &msg, sizeof(netmeter_req_t));

   return close(sock);
}

int netmeter_request(netmeter_req_t *msg) {
   int r;

   r = write(sock, msg, sizeof(netmeter_req_t));
   if (r != sizeof(netmeter_req_t))
      return -1;
   if (msg->cmd == NETMETER_CMD_RESET) /* no reply */
      return r;
   r = read(sock, msg, sizeof(netmeter_req_t));
   if (r != sizeof(netmeter_req_t))
      return -1;

   return r;
}

int netmeter_convert(netmeter_req_t *msg, mm_t *mm) {
   if (msg == NULL || mm == NULL) {
      errno = EINVAL;
      return -1;
   }
   mm->units = msg->units;
   if (msg->cmd == NETMETER_CMD_READ)
      mm->value = (float)(((unsigned int)msg->value) / 100000.0);
   else
      mm->value = (float)(unsigned int)msg->value;

   return 0;
}