#! /usr/bin/perl

if ( ($#ARGV < 0) || ($#ARGV > 1) ) {
    print "showplot: Wrong number of arguments.\n";
    print "\n";
    print "Usage: showplot input_filename [ 'plot_arguments' ]\n";
    print "\n";
    exit 1;
}

# Do not buffer STDIN.

$old_select = select(STDIN);
$| = 1;
select($old_select);

# Do not buffer STDOUT.

$old_select = select(STDOUT);
$| = 1;
select($old_select);

# Process the command line arguments.

$input_filename = $ARGV[0];

if ( $#ARGV == 0 ) {
	$plot_arguments = "\$f[0]";
} else {
	$plot_arguments = $ARGV[1];
}

# Open the input file.

open(INPUT, $input_filename) || die "Cannot open file '$input_filename'";

# Open a pipe to plotgnu.

open(PLOTGNU, "| perl -S -- plotgnu.pl") || die "Cannot open pipe to plotgnu";

# Do not buffer the plotgnu pipe.

$old_select = select(PLOTGNU);
$| = 1;
select($old_select);

# Initialize the plot.

print PLOTGNU "start_plot;1;0;$plot_arguments\n";

print PLOTGNU "set title 'Datafile = $input_filename'\n";

#### Look for file type identifier in the first line of the file. ####

$input_line = <INPUT>;

if ( ! defined( $input_line ) ) {
	print STDERR "No text in plot file.\n";
	exit 1;
}

@line1 = split(/ /, $input_line);

if ( $line1[0] eq "#" ) {
	if ( $line1[1] eq "SFF" ) {
		# Skip header of current SFF file.

		$num_header_lines = $line1[3];

		for ( $i = 0; $i < $num_header_lines; $i++ ) {
			$input_line = <INPUT>;

			if ( ! defined( $input_line ) ) {
			    print STDERR "SFF header terminated at line $i\n";
			}
		}
	}
}
if ( $line1[0] eq "SFF" ) {
	# Skip header of old SFF file.

	$num_header_lines = $line1[2];

	for ( $i = 0; $i < $num_header_lines; $i++ ) {
		$input_line = <INPUT>;

		if ( ! defined( $input_line ) ) {
			print STDERR "SFF header terminated at line $i\n";
		}
	}
}
if ( $line1[0] eq "MRCAT_XAFS" ) {
	# Skip header of MRCAT XAFS file.

	$num_header_lines = 17;

	for ( $i = 0; $i < $num_header_lines; $i++ ) {
		$input_line = <INPUT>;

		if ( ! defined( $input_line ) ) {
		    print STDERR "MRCAT_XAFS header terminated at line $i\n";
		}
	}
}

#### Send the rest of the data file to plotgnu. ####

while ($input_line = <INPUT>) {

	print PLOTGNU "data ";

	# The variable $input_line should have a newline at the end, so we
	# don't have to send one explicitly.

	print PLOTGNU $input_line;
}

close(INPUT);

# Tell plotgnu to display the plot.

print PLOTGNU "plot\n";

print "Hit the return key to close the plot...";

$junk = getc;

print PLOTGNU "exit\n";

close(PLOTGNU);

print "done.\n";