#!/cis/bin/perl
#
# generate event files from raw Applanix data

if($#ARGV < 0) {
	print "Usage: perl genevents.pl [directory]\n";
	print "Encapsulate the directory location with double quotes if there is space.\n";
	exit 0;
}

my($directory) = $ARGV[0];

if( ! -d $directory ) {
	print "$directory is NOT a valid directory.\n";
	exit 0;
}

opendir(DIR, $directory);
my(@dir_list) = readdir(DIR);
closedir(DIR);

my $element;

foreach (@dir_list) {
	# ignore . and .. filenames
	next if($_ eq "." || $_ eq ".." || $_ eq "applanix" || $_ eq "products"|| $_ eq "applanix-proc" | $_ eq "vnir-proc");
    	
	$element = $directory . "\\" . $_;
#	print "Test: $element \n";

	if( opendir(DIR, $element) ) {
		my(@sub_list) = readdir(DIR);
		closedir(DIR);
		
		$size = scalar @sub_list;

		if( $size > 6 ) {
			print "Processing: $element \n";
			chdir($element);

			$is_big_endian = unpack( "h*", pack( "s", 1 )) =~ /01/;

			open APLX, "<aplx.dat" or die "cannot open Applanix data for reading";
			chdir($directory);
			open LWIR, ">>LWIRevents.txt" or die "cannot open LWIRevents for writing";
			open MWIR, ">>MWIRevents.txt" or die "cannot open MWIRevents for writing";
			open SWIR, ">>SWIRevents.txt" or die "cannot open SWIRevents for writing";
			open VNIR, ">>VNIRevents.txt" or die "cannot open VNIRevents for writing";

			while( sysread( APLX, $header, 8 ) == 8 ) {
				my( $hdr, $grp, $len ) = unpack( "a4vv", $header );
			    sysread( APLX, $body, $len );
				# print "hdr is $hdr\ngrp is $grp\nlen is $len\n";

				if( $hdr eq "\$GRP" ) {
					print ".";
					# print "Found a group $grp record.\n";
	
					if( $grp == 206 || $grp == 207 ) {
						my( $time1, $time2, $dist, $ttypes, $dtype, $event ) = unpack( "a8a8a8ccV", $body );

					    $time1 = reverse( $time1 )	if( $is_big_endian );
						( $time1 ) = unpack( "d", $time1 );

						if( $grp == 206 ) {
							printf LWIR "%f\tLWIR%03u.img\n", $time1, $event;
							printf MWIR "%f\tMWIR%03u.img\n", $time1, $event;
							printf SWIR "%f\tSWIR%03u.img\n", $time1, $event;
					    } else {
							printf VNIR "%f\tVNIR%03u.img\n", $time1, $event;
						} # if ... else
					}
				}
			} # while
		} else {
			print "IGNORED: $element";
		}# if (size > 5) ... else
	

		print "\n# DONE!\n";

		close APLX;
		close VNIR;
		close SWIR;
		close MWIR;
		close LWIR;
	
	} else {
		print ">> $element is NOT a directory \n";
	}# if (directory == true) ... else
} # for loop

exit 0;