#!/usr/bin/perl -w
# vim:ft=perl:

# (C) 2006 Christoph Berg <cb@df7cb.de>
# This program is free software covered by the GNU GPL v2.

use strict;

use MIME::Parser;
use DB_File;

my $db_filename = ".procmail/blacklist.db";
my ($dbh, %db);

$dbh = tie %db, "DB_File", $db_filename, O_RDWR|O_CREAT, 0600, $DB_BTREE
    or die "Can't open database $db_filename: $!";

if ($ARGV[0] eq "-b") {
	$db{$ARGV[1]} = 1;
	exit 0;
}

# Parse the mail
my $parser = MIME::Parser->new();
$parser->output_to_core(1);
my $mail = $parser->parse(\*STDIN) or die "Parse failed !\n";

# Extract the subject and the sender email
my $ref = $mail->head()->get("References") || "";
my $irt = $mail->head()->get("In-Reply-To") || "";

foreach my $id (split /\s+/, "$ref $irt") {
	if ($db{$id}) {
		exit 0;
	}
}

exit 1;