#!/usr/bin/perl

# Copyright 2005 Messiah College. All rights reserved.
# Jason Long <jlong@messiah.edu>

# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.

use strict;
use warnings;

package Mail::DKIM::Canonicalization::simple;
use base 'Mail::DKIM::Canonicalization::DkimCommon';
use Carp;

sub init {
    my $self = shift;
    $self->SUPER::init;

    $self->{canonicalize_body_empty_lines} = 0;
}

sub canonicalize_header {
    my $self = shift;
    croak 'wrong number of parameters' unless ( @_ == 1 );
    my ($line) = @_;

    #
    # draft-allman-dkim-base-01.txt, section 3.4.1:
    #   the "simple" header field canonicalization algorithm does not
    #   change the header field in any way
    #

    return $line;
}

sub canonicalize_body {
    my $self = shift;
    my ($multiline) = @_;

    #
    # draft-allman-dkim-base-01.txt, section 3.4.3:
    #   the "simple" body canonicalization algorithm ignores all
    #   empty lines at the end of the message body
    #

    #
    # (i.e. do not emit empty lines until a following nonempty line
    # is found)
    #
    my $empty_lines = $self->{canonicalize_body_empty_lines};

    if ( $multiline =~ s/^((?:\015\012)+)// )
    {    # count & strip leading empty lines
        $empty_lines += length($1) / 2;
    }

    if ( length($multiline) > 0 ) {
        $self->{canonicalize_body_started} = 1;
        if ( $empty_lines > 0 )
        {    # re-insert leading white if any nonempty lines exist
            $multiline   = ( "\015\012" x $empty_lines ) . $multiline;
            $empty_lines = 0;
        }
    }

    while ( $multiline =~ /\015\012\015\012\z/ )
    {        # count & strip trailing empty lines
        chop $multiline;
        chop $multiline;
        $empty_lines++;
    }

    $self->{canonicalize_body_empty_lines} = $empty_lines;
    return $multiline;
}

sub finish_body {
    my $self = shift;
    $self->{canonicalize_body_started}
      or $self->output("\015\012");
    $self->SUPER::finish_body;
}

1;