// log_adv_em.c
// $Id: log_adv.c 134 2011-09-16 12:35:19Z csherwood $
//
// This is a modification of log_any to see if we can reduce the CPU time and
// get over the comm port hanging
//
// Testing using standard library calls to write to a file
// Developing UNSAFE signal interupt handler
//
//  NO arguments!- 
//    requires port 4, 19200 N81
//
//  has a function that just adds the Moxa time, since serialByteRead() gets parts of
//  a logical data message, we only want to add the time to the entire line, once read
//
//   csherwood@usgs.gov, emontgomery@usgs.gov
//   11-Sep-2011

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include "serial.h"
#include "moxadevice.h"
#include <unistd.h>
#include <sys/time.h>

#define MAX_FNAME_SIZE 255
#define BUFSIZE 255
#define BUFDSIZE 1023


// Global variables or structure for passing clean-up info to signal interrupt handler?
FILE *fdp, *fdp_log, *fdp_cfg, *fdp_data; /* file stream pointer for stdio library calls */
int   fds,  fds_log,  fds_cfg,  fds_data, fds_port; /* file descriptor for system calls */
char tmp[255], instid[]="armadv";
char bufd[BUFDSIZE];
char datafilename[127]="/var/sda/testdata/instrument_YYYYMMDDHHMMSS.dat";
fd_set readfds;
int tmpfd, maxfd = -1;
  int portnum=3;

// function declarations
static void my_exit(int sig);
int tsout( FILE *fd, char *buf );
int my_output( FILE *fd, char *buf, int disp_data );

int main(int argc, char *argv[])
{
  int len, ier;
  char buf[BUFSIZE]; /* may be too small */
  char logfname[MAX_FNAME_SIZE];
  time_t now;
  struct tm gm, *gmp;
  struct termios options;
  int baudRateConst = B19200;
  char *inst_str="  B227H";
  int display_data = 1;
  pid_t my_pid, parent_pid;
  char svnId[80]="$Id: log_adv.c 134 2011-09-16 12:35:19Z csherwood $";

 // char portname[30];
  char device[30];
  int tstat, knt=0;
  char  *firstc, *ptr;
  struct timeval tv;
  // Set to check every 2 seconds 
  tv.tv_sec = 2;
  tv.tv_usec = 0;

// on dell that has an actual db9 serial port, use /dev/ttyS0
// on lenovo with just USB, not sure what is right- maybe /dev/ttyUSB0?
// on Moxa /dev/ttyM?

  signal(SIGINT,my_exit);  /* terminal interuppt (e.g., ctrl-C) */
  signal(SIGTERM,my_exit); /* terminate process */

  now=time(NULL);
  gmp = gmtime(&now);
  gm = *gmp;
  my_pid = getpid();
  parent_pid = getppid();
  
  // open a log file with a name that includes the PID and date
  // for use with cron, use absolute path to open a log file with a name that includes the PID
  snprintf(logfname,MAX_FNAME_SIZE,"/var/sda/logs/%s_%04d%02d%02d%02d%02d%02d_%06d.log",
	   instid,1900+gm.tm_year,gm.tm_mon+1,gm.tm_mday,gm.tm_hour,gm.tm_min,gm.tm_sec,(int)my_pid);
  
  fdp_log = fopen(logfname,"wt");
  if(fdp_log == NULL)
    {
      // Send this message to a better place? stdout and stderr?
      fprintf(stdout,"Problem opening log file\n");
      fprintf(stderr,"Problem opening log file\n");
      my_exit(SIGUSR1);
    }
  
  // Log program name and PID to log file
  snprintf(buf,sizeof(buf)-1,"%s PID : %d",argv[0],my_pid );
  ier=my_output( fdp_log, buf, display_data );
  snprintf(buf,sizeof(buf)-1,"svnId: %s",svnId);
  ier=my_output( fdp_log, buf, display_data );

  // Make a data file name
  // months in time structure are jan==0, so we need to add one to display correctly
  // this needs to be the full path name for when run in cron
     snprintf(datafilename,sizeof(buf),"/var/sda/data/%s/%s_%04d%02d%02d%02d%02d%02d_%06d.dat",
	    instid,instid,1900+gm.tm_year,gm.tm_mon+1,gm.tm_mday,gm.tm_hour,gm.tm_min,gm.tm_sec,(int)my_pid);
    
    // open data file
    fdp_data = fopen(datafilename,"w");
    if(fdp_data == NULL) {
     snprintf(buf,sizeof(buf)-1,"Problem opening data file: %s",datafilename);
     ier=my_output( fdp_log, buf, display_data );
     my_exit( SIGUSR1 );
    }
    snprintf(buf,sizeof(buf)-1,"Opened data file: %s",datafilename);
    ier=my_output( fdp_log, buf, display_data );

    // Get system fd of log file. See TLPI p. 248
    fds_data = fileno(fdp_data);
    snprintf(buf,sizeof(buf)-1,"System fds for datafile: %2d",fds_data);
    ier=my_output( fdp_log, buf, display_data );

    snprintf(buf,sizeof(buf)-1,"Trying to open serial port %4d",portnum);
    ier=my_output( fdp_log, buf, display_data );

    snprintf(device,29,"/dev/ttyM%1d",portnum);
    snprintf(buf,sizeof(buf)-1,"with device name = %s",device);
    ier=my_output( fdp_log, buf, display_data );

	if ((portnum < 0) | (portnum > 7)) {
	    snprintf(buf,sizeof(buf)-1,"Bad value requested for serial port number.");
	    my_exit( SIGUSR1 );
   } else {
    fds_port = open( device, O_RDWR|O_NOCTTY|O_NONBLOCK );
    if( fds_port == -1){
      snprintf(buf,sizeof(buf)-1,"Port open failed: fd=%d",fds_port);
      ier=my_output( fdp_log, buf, display_data );
      my_exit( SIGUSR1 );
    }

    //from sbgCom/comSerialUnix.c
    if (fcntl(fds_port, F_SETFL, O_NONBLOCK) != -1){
      // Retreive current options
      if (tcgetattr(fds_port, &options) != -1){
	// Define com port options
	options.c_cflag |=  (CLOCAL | CREAD);	   // Enable the receiver and set local mode...
	options.c_cflag &= ~(PARENB|CSTOPB|CSIZE); // No parity, 1 stop bit, mask character size bits
	options.c_cflag |= CS8;			   // Select 8 data bits
	options.c_cflag &= ~CRTSCTS;		   // Disable Hardware flow control
	
	// Disable software flow control
	options.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON);
	
	// We would like raw input
	options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG /*| IEXTEN | ECHONL*/);
	options.c_oflag &= ~OPOST;
	
	// Set our timeout to 0
	options.c_cc[VMIN]     = 0;
	options.c_cc[VTIME]    = 1;
	
	// Set both input and output baud
	if ( (cfsetispeed(&options, baudRateConst) != -1)  && (cfsetospeed(&options, baudRateConst) != -1) ){
	  // Define options
	  if (tcsetattr(fds_port, TCSANOW, &options) != -1){
	    // flush port
	    tcflush(fds_port, TCIOFLUSH);
	  }
	  else{
	    snprintf(buf,sizeof(buf)-1, "tcsetattr failed");
	    ier=my_output( fdp_log, buf, display_data );
	  }
	}
	else{
	  snprintf(buf,sizeof(buf)-1, "set speed failed\n");
	  ier=my_output( fdp_log, buf, display_data );
	}
      }
      else{
	snprintf(buf,sizeof(buf)-1, "tcgetattr failed\n");
	ier=my_output( fdp_log, buf, display_data );
      }
    }
    else {
      snprintf(buf,sizeof(buf)-1, "fcntl failed\n");
      ier=my_output( fdp_log, buf, display_data );
    }
    
    //StartLogger();
    snprintf(buf,sizeof(buf)-1,"Starting to log...");
    ier=my_output( fdp_log, buf, display_data );
    ier=my_output( fdp_data, buf, 0 );    
    
    maxfd = fds_port;

    //This is where it waits until it get's something and then logs it
    while(1){
      //sleep(1);
      FD_ZERO( &readfds);
      FD_SET( fds_port, &readfds);
      
      tmpfd= select( maxfd+1, &readfds, NULL, NULL, &tv);
      if( tmpfd <= 0)
	continue;
      tstat=gettimeofday(&tv, NULL);
      if( FD_ISSET( fds_port, &readfds)){
	    ier=fcntl(fds_port, F_SETFL,FNDELAY );
	    len = read(fds_port, bufd, BUFDSIZE );
	    //len= SerialBlockRead( portnum, bufd, 1024);
	      bufd[len]= '\0';
	    knt=1;
	
	  //write to data file
	  	  // put the last char of each chunk in a place available to strncmp 
	  firstc=&bufd[0];
	  if ( knt > 0 && fds_data != -1){  // knt > 0 avoids partial first line
	     //printf ("string is %s, compare to %s\n",firstc, inst_str);
 	      ptr=strstr(firstc,inst_str);
	      //printf("comparison result is %d\n",ier);	      
	    // needs to match:      B227H         7 2011 09 14 18 00 01
	    // always at the beginning of a line- doesn't need other stuff
 	    if (strstr(firstc,inst_str)!=NULL)
	      {
		   //printf("found it at %d\n", (int)ptr);
		   //printf ("%s\n",ptr);
		   ier=tsout( fdp_data, ptr);
		  } else {
	      // the write makes a sensible looking data record, but it's not written
	      // as one long record, it's a series of chunks, so pre-pending moxa
	      // time doesn't make sense.  If concatenate into a buffer until a <CR>
	      // is recieved, that works better.
	      //write( fds_data, bufd, len);
	      write( fds_data, bufd, len);
	    }
 	  } knt+=1;
      }  
    }	// end while
  }  // end if portnum OK
 // Graceful exit
    my_exit( SIGUSR1 );
}


// MY_EXIT - Clean up, close files, write to log, exit
static void my_exit(int sig)
{
  // sig is assigned by signal or passed by user

  // UNSAFE use of printf() flush(), close(), and exit()
  // TODO - Do this with async-safe calls?

  int ier;
  char buf[255];

  // (0) identify cause of exit
  switch (sig) 
    {
    case SIGINT : {
      sprintf(buf,"Caught SIGINT\n");
      ier = my_output( fdp_log, buf, 0 );
      break;
    }
    case SIGTERM : {
      sprintf(buf,"Caught SIGTERM\n");
      ier = my_output( fdp_log, buf, 0 );
      break;
    }
    case SIGUSR1 : {
      sprintf(buf,"Caught SIGUSR1\n");
      ier = my_output( fdp_log, buf, 0 );
      break;
    }
    default : {
    sprintf(buf,"Unknown signal\n");
    ier = my_output( fdp_log, buf, 0 );
    }
  }

  // Close files in order of importance:
  // (1) close serial port
  if( (ier=SerialClose(portnum)) != SERIAL_OK )
    sprintf(buf,"Problem closing serial port %d; returned %d",portnum,ier);
  sprintf(buf,"Closed serial port %d",portnum);


  // (2) close data file
  if( fdp_data != NULL ){
	write( fds_data, "\n", 1 );
    fflush(fdp_data);
    fclose(fdp_data);
  }

  // (3) close log file
  if( fdp_log != NULL ){
    ier = tsout(fdp_log,buf);
    fflush(fdp_log);
    fclose(fdp_log);
  }
  exit(0);
}

// TSOUT - prepend time stamp, print contents of buf, add CR
int tsout( FILE *fd, char *buf )
{
  //time_t t;
  struct tm gm, *gmp;
  struct timeval tv;
  int iw, tstat, nlen=0;
  char tbuf[255];
  char *lastc;
   
  tstat=gettimeofday(&tv,NULL);
  //gmp = gmtime(&t);
  // pointing at the tv seconds gets the time from gettimeofday, so usecs will be synched
  gmp = gmtime(&tv.tv_sec);   
  gm = *gmp; // save local copy...see TLPI p. 192
 
  snprintf(tbuf,29,"\n%4d %02d %02d %02d %02d %10.7f ",
 	  1900+gm.tm_year,gm.tm_mon+1,gm.tm_mday,gm.tm_hour,gm.tm_min,(gm.tm_sec+((double)tv.tv_usec/1000000)));
 
  //printf("lengths of tbuf and buf are: %d, %d.\n",  strlen(tbuf), strlen(buf));
  nlen=strlen(buf);
  if ((strlen(tbuf) + strlen(buf)) < sizeof(tbuf)-1)
  {
    strncat(tbuf,buf,nlen);
    lastc=&buf[nlen-1];
    if (strncmp(lastc,"\n",1) != 0)
      strncat(tbuf,"\n",1);
    iw = fprintf(fd,"%s",tbuf);
    fflush(fd);
  }  
  else
  {
    printf("string too long- look for error in data!\n");
    printf("%s\n",buf);
    //email manager that something's wrong
     iw=-1;
   }
  return(iw);
}

int my_output( FILE *fd, char *buf, int disp_data )
{
  // Prepend time stamp, print contents of buf, add CR
  struct tm gm, *gmp;
  struct timeval tv;
  int iw=1, tstat, nlen=0;
  char tbuf[255];
   
  tstat=gettimeofday(&tv,NULL);
  // pointing at the tv seconds gets the time from gettimeofday, so usecs will be synched
  gmp = gmtime(&tv.tv_sec);   
  gm = *gmp; // save local copy...see TLPI p. 192
 
  snprintf(tbuf,29,"%4d %02d %02d %02d %02d %10.7f ",
 	  1900+gm.tm_year,gm.tm_mon+1,gm.tm_mday,gm.tm_hour,gm.tm_min,(gm.tm_sec+((double)tv.tv_usec/1000000)));

  //check that concatenated string isn't too big
  nlen=strlen(buf);
  if ((strlen(tbuf) + strlen(buf)) < sizeof(tbuf)-1)
  { 
   strcat(tbuf,buf);
   strcat(tbuf,"\n");
    if (disp_data ==1)				//display data and write to log file
    {
     iw = fprintf(stdout,"%s",tbuf);
     iw = fprintf(fd,"%s",tbuf);
    } else {
     iw = fprintf(fd,"%s",tbuf);	//just write to the log file
    }
   fflush(fd);
  }
  else
  {
    printf("string too long- look for error in data!\n");
    //email manager that something's wrong
     iw=-1;
  }
  return(iw);
}