#!/usr/bin/env perl

use Data::Dumper;
use Getopt::Long;

    #...................................................................
    # Config
    #...................................................................

my $input;
my $output;
my $title;
my $ylabel;

GetOptions(
    "input=s"   => \$input,
    "output=s"  => \$output,
    "title=s"   => \$title,
    "ylabel=s"  => \$ylabel,
);

#print "input is [$input]", "\n";
#print "output is [$output]", "\n";
#print "title is [$title]", "\n";

    # Start of the contents for the gnuplot (.gp) file
my $file_gp=<<EOF;
set terminal png size 800 600
set output "$output"
set xtics nomirror rotate -90
set xlabel "DateTime"
set ylabel "$ylabel"
set decimal locale
set format y "%'g"
set title "$title"
set key rmargin
EOF

#print $file_gp;



    #...................................................................
    # Read Data from input file, determine number of index sets and their SeriesName
    #...................................................................
my %series;
open my $fh_in, '<', "$input" or die "cannot open $input: $!\n";
while (my $line = <$fh_in>) {
    next unless ($line =~ /\#Series=/);
    my ($series, $idx) = $line =~ /Series=(\S+) Index=(\d+)/;
#    print $line;
#    print "Series is [$series], Index is [$idx]\n";
    $series{$idx} = $series;
}
close $fh_in;

#print Dumper(\%series), "\n";



    #...................................................................
    # Create the `plot' statement based on the different series
    #...................................................................
my @series;
foreach my $idx (sort keys %series) {
    my $str = sprintf('"%s" index %s using 3:xtic(2) title "%s" with lines', $input, $idx, $series{$idx});
#    print $str, "\n";
    push @series, $str;
}
#print Dumper(\@series), "\n";

$file_gp .= "plot " . join(", \\\n", @series) . "\n";

print $file_gp;