# Copyright (c) 2008 bivio Software, Inc.  All Rights Reserved.
#
# Visit http://www.bivio.biz for more info.
# 
# This library is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of the
# License, or (at your option) any later version.
# 
# This library is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
# 
# You should have received a copy of the GNU Lesser General Public
# License along with this library;  If not, you may get a copy from:
# http://www.opensource.org/licenses/lgpl-license.html
# 
# $Id: Word.pm,v 1.1 2008/01/25 22:39:26 nagler Exp $
package Bivio::MIME::Word;
use strict;
use Bivio::Base 'Bivio::UNIVERSAL';
use MIME::Base64 ();

# See RFC 2047

our($VERSION) = sprintf('%d.%02d', q$Revision: 1.1 $ =~ /\d+/g);

sub decode {
    my(undef, $value) = @_;
    $value =~ s{(\?\=)\s*(\=\?)}{$1$2}gs;
    $value =~ s{\=\?([^?]*)\?([bq])\?([^?]+)\?\=}{
        _strip(
	    $1,
	    lc($2) eq 'q' ? _decode_q($3) : MIME::Base64::decode_base64($3),
	);
    }egisx;
    return $value;
}

sub _decode_q {
    my($v) = @_;
    $v =~ s/_/ /g;
    $v =~ s{=([\da-fA-F]{2})}{pack('C', hex($1))}ge;
    return $v;
}

sub _strip {
    my($encoding, $value) = @_;
    $value =~ s{[\x80-\xFF]}{\?}g
	unless $encoding =~ /^(ISO-8859-1|US-ASCII)$/i;
    $value =~ s{\x00}{\?}g;
    return $value;
}

1;