#!/iag/bin/perl 
#--------------------------------------------------------------------------
# Program: avg-sst.pl
#
# Description: Process the intput-filename to time-stamp averages
#
# Usage: avg-sst.pl input_filename
#
# Inputs: input_filename     File to be processed defaults
#
# Outputs: avg-sst.AVG       Processed file for temperature pods
#
# Dependencies: 
#
# Comments: 
#
#--------------------------------------------------------------------------

initialize ();

#--------------------------------------------------------------------------
#  Loop through the file reading lines
#--------------------------------------------------------------------------
while ($_ = <INP>)
{ 
   s/^\s+//;
   @field = split('\s+',$_);

   #--------------------------------------------------------------------------
   #  calculate the GMT time from first column
   #--------------------------------------------------------------------------
   $day = hex ($field[0]) / 128.0;
   $jday = int ($day);
   $time = ($day - $jday) * 32.0;
   $hours = int ($time);
   $minutes = ($time - $hours) * 60;
   $gmt = sprintf "%03d/%02d:%02d", $jday, $hours, $minutes;

   #--------------------------------------------------------------------------
   #  If the date is not the same as the last one print out averages
   #--------------------------------------------------------------------------
   if ($gmt ne $lastgmt)
   {
      if ($count > 0)
      {
         #--------------------------------------------------------------------
         #  Calculate the average
         #--------------------------------------------------------------------
         $t1  = int ($t1  / $count);

         #--------------------------------------------------------------------
         #  Write needed output to file
         #--------------------------------------------------------------------
         printf OUT "%9s %04X\n", $lastgmt, $t1;
      }

      #--------------------------------------------------------------------
      #  Reinitialize the values
      #--------------------------------------------------------------------
      $lastgmt = $gmt;
      $count = 0;
      $t1 = 0;
   }

   #--------------------------------------------------------------------
   #  Total the temperature readings
   #--------------------------------------------------------------------
   $t1  += hex ($field[2]);
   $count++;
}

#--------------------------------------------------------------------
#  Handle the last date
#--------------------------------------------------------------------
if ($count > 0)
{
   #--------------------------------------------------------------------
   #  Calculate the average
   #--------------------------------------------------------------------
   $t1  = int ($t1  / $count);

   #--------------------------------------------------------------------
   #  Write needed output to file
   #--------------------------------------------------------------------
   printf OUT "%9s %04X\n", $lastgmt, $t1;
}

#--------------------------------------------------------------------------
#  Close the files and exit
#--------------------------------------------------------------------------
close (INP);
close (OUT);
exit;

#\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
#
#   initialize
#
#//////////////////////////////////////////////////////////////////////////////
sub initialize
{
   #---------------------------------------------------------------------------
   #  Verify command line
   #---------------------------------------------------------------------------
   if ($#ARGV ne 0)
   {  print "Usage: avg-sst.pl input_filename\n"; exit; }

   $infile = shift (@ARGV);

   #--------------------------------------------------------------------------
   #  open input file
   #--------------------------------------------------------------------------
   open INP, "./$infile" || die "Couldn't open ./$infile for input";

   #--------------------------------------------------------------------------
   #  open OUTPUT files
   #--------------------------------------------------------------------------
   open OUT, "> ./avg-sst.AVG" || die "Couldn't open ./avg-sst.AVG for output";

   #--------------------------------------------------------------------------
   #  Initialize values
   #--------------------------------------------------------------------------
   $lastgmt = "";
   $count = 0;
   $t1 = 0
}
#---initialize---#