/** \file busload.c
 *
 *  Load monitor for the SJA1000
 *
 *  \author Cristiano Brudna
 *  \date 2003 
 *
 *  University of Ulm, Germany
 *
 *
 *  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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include <sys/ioctl.h>   
#include <sys/time.h>
#include <curses.h>
#include <term.h>

#include "can.h"

#include "canlib.h"

int                 can, done = 0;
struct itimerval    interval;
struct timeval      start;
unsigned long long  counter = 0;
unsigned long long  init, end;
float               averageRate = 0;
long long           sample = 1;   // 1s


void sigIntHandler (int a)
{
  done = 1;
}


unsigned long long timevalToUs (struct timeval time)
{
  return ((unsigned long long)time.tv_sec*1000000 + (unsigned long long)time.tv_usec);
}


void showBusLoad (int a)
{
  struct timeval now;
  
  tputs( tgetstr( "cl", 0 ), 1, &putchar );
  fflush( stdout );
  printf("\nBusload monitor for CANBus\n\n");
  showStatus(can);
  
  gettimeofday(&now, NULL);
  end = timevalToUs(now);
  
  if((end - init) == 0)
    return;
  
  averageRate = counter / (float)((end - init)/1000000);
  printf("busload is  %.03f messages/s  (Tav = %.06fs) \n\n", averageRate, 1 / (float)counter);
  printf("sample time is %Lds \n\n", sample);

  /* reset the counter */
  init = timevalToUs(start);
  counter = 0;
  setitimer(ITIMER_REAL, &interval, NULL);
}


void monitor (void)
{
  int ret;
  canmsg msg;
  
  while(!done) {
    ret = read(can, &msg, sizeof(canmsg));
    if(ret > 0) {
      counter++;
    }
    fflush(stdout);
  }
}


int main (int argc, char *argv[])
{
  unsigned long  baudrate = B1000;
  long long      acode = -1, amask = -1;
  char           opchr;
  int            par;
  
  setupterm( 0, 2, 0 );
  
  while((opchr = getopt(argc,argv, "hb:m:c:s:")) != -1)
    switch(opchr) {
      
    case 'h':
      printf("\nBus load Monitor for CAN \n\n");
      printf("usage: cansend [-b baud] [-m mask] [-c code] [-h] \n\n");
      printf("-b baud        : set baudrate [1000, 500, 250, 125, 20] kbit/s\n");
      printf("-m amask       : set a 32-bit acceptance mask\n");
      printf("-c acode       : set a 32-bit acceptance code\n");
      printf("-s sample time : set the period of time is seconds used to calculate/update the bus load\n");
      printf("-h             : help\n");
      printf("\n");
      exit(0);
      
    case 'b':
      par = atoi(optarg);
      switch(par) {
      case 1000:
	baudrate = B1000;
	break;
	
      case 500:
	baudrate = B500;
	break;
	
      case 250:
	baudrate = B250;
	break;
	
      case 125:
	baudrate = B125;
	break;
	
      case 20:
	baudrate = B20;
	break;
	
      default:
        printf("\nBaud rate not supported!!! Using 1Mbit/s instead\n");
      }
      break;
      
    case 'm':
      sscanf(optarg, "%Lx", (long long *) &amask);
/*       printf("amask = %Lx\n", amask); */
      break;
      
    case 'c':
      sscanf(optarg, "%Lx", (long long *) &acode);
/*       printf("acode = %Lx\n", acode); */
      break;

    case 's':
      sscanf(optarg, "%Lx", (long long *) &sample);
/*       printf("sample = %Lxs \n", sample); */
      break;
      
    default:
      break;
    }
  
  can = open("/dev/can", O_RDWR);
  if(can == -1)	{
    perror("Error opening /dev/can");
    exit(0);
  }
  
  ioctl(can, CAN_IOCSBAUD, &baudrate);
  
  if(acode != -1) {
    ioctl(can, CAN_IOCSACODE, &acode);
  }
  
  if(amask != -1) {
    ioctl(can, CAN_IOCSAMASK, &amask);
  }
  
  gettimeofday(&start, NULL);
  init = timevalToUs(start);
  
  signal(SIGINT, sigIntHandler);
  siginterrupt(SIGINT, 1);
  
  signal(SIGALRM, showBusLoad);
  siginterrupt(SIGALRM, 1);
  
  /* program the timer */
  interval.it_value.tv_sec = sample;
  interval.it_value.tv_usec = 0;
  setitimer(ITIMER_REAL, &interval, NULL);
  
  monitor();
  close(can);
  return 0;
}