#!/usr/local/bin/perl
use strict;
use warnings;

if (@ARGV != 3) {
    print "Usage: $0 <pattern file> <input file> <output file>\n";
    exit;
}

my ($pattern_filename, $source_filename, $dest_filename) = @ARGV;

open my $pattern_fh, '<', $pattern_filename or die "Failed to open $pattern_filename: $!";
my %output_tokens = ();
while (my $line = <$pattern_fh>) {
    chomp $line;
    $output_tokens{$line} = "$line # Added by script";
}

print "Expected tokens: ", join(', ', keys %output_tokens), "\n";

open my $infile, "<",  $source_filename or die "Failed to open $source_filename: $!";
open my $outfile,">>", $dest_filename   or die "Failed to open $dest_filename: $!";

while(my $line = <$infile>) {
    chomp $line;
    $output_tokens{$line} = $line;
}
for my $token (sort keys %output_tokens) {
    print $output_tokens{$token}, "\n";
}

close($infile);
close($outfile);