#!/usr/bin/perl -w

#------------------------------------------------------------------------------
#                  GEOS-Chem Global Chemical Transport Model                  !
#------------------------------------------------------------------------------
#BOP
#
# !MODULE: validate
#
# !DESCRIPTION: This perl script validates GEOS-Chem output files.  It tests
#  that the file checksums are identical, and then does a diff on the files.
#  User-friendly output is printed with the results.
#\\
#\\
# !USES:
#
require 5.003;                   # Need this version of Perl or newer
use English;                     # Use English language
use Carp;                        # Get detailed error messages
use strict;                      # Use "IMPLICIT NONE" syntax
#		
# !PUBLIC MEMBER FUNCTIONS:
#  &main()    : Driver routine for gcUnitTest
#
# !PRIVATE MEMBER FUNCTIONS:
#  &doChecks  : Returns the name of the GEOS-Chem run directory
#
# !CALLING SEQUENCE:
#  validate FILE1 FILE2 [ TOPHDR BOTHDR ]
#    where FILE1 and FILE2 are the files to be checked
#    Set TOPHDR=1 if you want to print a header at the top of the output
#    Set BOTHDR=1 if you want to print a header at the bottom of output
#
# !REMARKS:
#  Designed to be used with the GEOS-Chem Unit Tester.
#  Always returns a value of zero so as not to disrupt the make process.
#
# !REVISION HISTORY: 
#  27 Aug 2013 - R. Yantosca - Initial version
#  29 Aug 2013 - R. Yantosca - Now print the directory name in the results
#  24 Mar 2014 - R. Yantosca - Updated ProTeX headers
#  02 Jul 2014 - R. Yantosca - Improved file checking
#EOP
#------------------------------------------------------------------------------
#                  GEOS-Chem Global Chemical Transport Model                  !
#------------------------------------------------------------------------------
#BOP
#
# !IROUTINE: doChecks
#
# !DESCRIPTION: Performs validation checks on GEOS-Chem output files to
#  test whether they are identical or not.
#\\
#\\
# !INTERFACE:
#
sub doChecks($$$$) {
#
# !INPUT PARAMETERS:
#
  # $file1  : First file to be checked
  # $file2  : Second file to be checked
  # $topHdr : Set this = 1 if you want to print a header @ top of output
  # $botHdr : Set this = 1 if you wnat to print a header @ bottom of output
  my ( $file1, $file2, $topHdr, $botHdr ) = @_;
#
# !CALLING SEQUENCE:
#  &doChecks( $file1, $file2, $topHdr, $botHdr );
#
# !REMARKS:
#  Performs a checksum and a binary diff on the files.  This is OK as long
#  as we have bpch files for GEOS-Chem output.  When we migrate to netCDF
#  output we'll come up with a better test.
#
# !REVISION HISTORY:
#  27 Aug 2013 - R. Yantosca - Initial version
#  29 Aug 2013 - R. Yantosca - Now print the base name of the current dir
#  02 Jul 2014 - R. Yantosca - Now trigger a DIFFERENT result if either 
#                              $file1 or $file2 is not found on disk
#  13 Jul 2016 - M. Sulprizio- Obtain run name from the trac_avg filename
#                              instead of the run directory name
#EOP
#------------------------------------------------------------------------------
#BOC
#
# !LOCAL VARIABLES:
#
  # Parameters
  my $DIFFERENT = "DIFFERENT";
  my $IDENTICAL = "IDENTICAL";
  my $NOTFOUND  = "FILE NOT FOUND";

  # Scalars
  my $ckSumOK   = $DIFFERENT;
  my $diffOK    = $DIFFERENT;
  my $cmd       = "";
  my $ckSum1    = $NOTFOUND;
  my $ckSum2    = $NOTFOUND;
  my $header    = '#' x 79;
  my $result    = "";
  my $size1     = $NOTFOUND;
  my $size2     = $NOTFOUND;
  my $sizeOK    = $DIFFERENT;
  my $notFound  = $NOTFOUND;
  my $runstr    = "";

  # Arrays
  my @subStr      = ();
  my @filestrings = ();

  #----------------------------------------
  # Test if the file checksums match
  #----------------------------------------

  # If the 1st file exists, get the CRC checksum and file size
  if ( -f $file1 ) {
    $cmd    = "cksum $file1";
    chomp( $result = qx( $cmd ) );
    @subStr = split( ' ', $result );
    $ckSum1 = $subStr[0];
    $size1  = $subStr[1];
  }

  # If the 2nd file exists, get the CRC checksum and file size
  if ( -f $file2 ) {
    $cmd    = "cksum $file2";
    chomp( $result = qx( $cmd ) );
    @subStr = split( ' ', $result );
    $ckSum2 = $subStr[0];
    $size2  = $subStr[1];
  }
 
  # If the file checksums match, then set a flag   
  if ( !( $ckSum1 eq $NOTFOUND ) && !( $ckSum2 eq "$NOTFOUND" ) ) {
    if ( $ckSum1  eq $ckSum2   ) { $ckSumOK = $IDENTICAL; }
  }

  # If the file sizes match, set a flag
  if ( !( $size1 eq $NOTFOUND ) && !( $size2 eq "$NOTFOUND" ) ) {
    if ( $size1  eq $size2    ) { $sizeOK  = $IDENTICAL; }
  }

  #----------------------------------------
  # Test if the files are identical
  #----------------------------------------
  
  # If both files exist, then take a binary difference w/ Unix "diff" command
  if ( -f $file1 && -f $file2 ) {
    $cmd = "diff $file1 $file2";
    chomp( $result = qx( $cmd ) );

    # If the result is a blank string, they are identical
    if ( length( $result ) == 0 ) { $diffOK = $IDENTICAL; }
  }

  #----------------------------------------
  # Report the results
  #----------------------------------------
  
  # Split filename by periods
  @filestrings = split( /\./, $file1 );

  # Extract the run name
  $runstr = "$filestrings[1]";

  # Print top header if requested
  if ( $topHdr ) { print '#' x 79; 
		   print "\n### VALIDATION OF GEOS-CHEM OUTPUT FILES\n"; 
                   print "### In directory: $runstr\n"; }

  # Print information
  print "###\n";
  print "### File 1    : $file1\n";
  print "### File 2    : $file2\n";
  print "### Sizes     : $sizeOK ($size1 and $size2)\n";
  print "### Checksums : $ckSumOK ($ckSum1 and $ckSum2)\n";
  print "### Diffs     : $diffOK\n";

  # Print bottom header if requested
  if ( $botHdr ) { print '#' x 79; print "\n"; }

  # Return 0 so as not to hold up the Makefiles
  return( 0 );
}
#EOP
#------------------------------------------------------------------------------
#                  GEOS-Chem Global Chemical Transport Model                  !
#------------------------------------------------------------------------------
#BOP
#
# !IROUTINE: main
#
# !DESCRIPTION: Driver routine for the validate script.
#\\
#\\
# !INTERFACE:
#
sub main() {
#
# !CALLING SEQUENCE:
#  validate FILE1 FILE2 [ TOPHDR BOTHDR ]
#    where FILE1 and FILE2 are the files to be checked
#    Set TOPHDR=1 if you want to print a header at the top of the output
#    Set BOTHDR=1 if you want to print a header at the bottom of output
#
# !REVISION HISTORY:
#  27 Aug 2013 - R. Yantosca - Initial version
#EOP
#------------------------------------------------------------------------------
#BOC
#
# !LOCAL VARIABLES:
#
  my $msg = "Usage: validate FILE1 FILE2 TOPHDR BOTHDR\n";

  # If there is the proper # of args, validate the GEOS-Chem files
  # Otherwise exit with an error message
  if    ( scalar( @ARGV ) == 4 ) { &doChecks( @ARGV       ); }
  elsif ( scalar( @ARGV ) == 3 ) { &doChecks( @ARGV, 0    ); }
  elsif ( scalar( @ARGV ) == 2 ) { &doChecks( @ARGV, 0, 0 ); }
  else                           { print "$msg"; exit(1);    }

  # Always return 0 so we don't halt the make process
  return ( 0 );
}

#------------------------------------------------------------------------------

# Call the main program
main();

# Always return zero so we don't halt the make process
exit( 0 );