package Sisimai::Bite::Email::EinsUndEins;
use parent 'Sisimai::Bite::Email';
use feature ':5.10';
use strict;
use warnings;

my $Indicators = __PACKAGE__->INDICATORS;
my $StartingOf = {
    'message' => ['This message was created automatically by mail delivery software'],
    'rfc822'  => ['--- The header of the original message is following'],
    'error'   => ['For the following reason:'],
};
my $MessagesOf = { 'mesgtoobig' => ['Mail size limit exceeded'] };

# X-UI-Out-Filterresults: unknown:0;
# sub headerlist  { return ['X-UI-Out-Filterresults'] }
sub description { '1&1: http://www.1and1.de' }
sub scan {
    # Detect an error from 1&1
    # @param         [Hash] mhead       Message headers of a bounce email
    # @options mhead [String] from      From header
    # @options mhead [String] date      Date header
    # @options mhead [String] subject   Subject header
    # @options mhead [Array]  received  Received headers
    # @options mhead [String] others    Other required headers
    # @param         [String] mbody     Message body of a bounce email
    # @return        [Hash, Undef]      Bounce data list and message/rfc822 part
    #                                   or Undef if it failed to parse or the
    #                                   arguments are missing
    # @since v4.1.9
    my $class = shift;
    my $mhead = shift // return undef;
    my $mbody = shift // return undef;

    return undef unless index($mhead->{'from'}, '"Mail Delivery System"') == 0;
    return undef unless $mhead->{'subject'} eq 'Mail delivery failed: returning message to sender';

    my $dscontents = [__PACKAGE__->DELIVERYSTATUS];
    my @hasdivided = split("\n", $$mbody);
    my $rfc822part = '';    # (String) message/rfc822-headers part
    my $rfc822list = [];    # (Array) Each line in message/rfc822 part string
    my $blanklines = 0;     # (Integer) The number of blank lines
    my $readcursor = 0;     # (Integer) Points the current cursor position
    my $recipients = 0;     # (Integer) The number of 'Final-Recipient' header
    my $v = undef;

    for my $e ( @hasdivided ) {
        # Read each line between the start of the message and the start of rfc822 part.
        unless( $readcursor ) {
            # Beginning of the bounce message or delivery status part
            if( index($e, $StartingOf->{'message'}->[0]) == 0 ) {
                $readcursor |= $Indicators->{'deliverystatus'};
                next;
            }
        }

        unless( $readcursor & $Indicators->{'message-rfc822'} ) {
            # Beginning of the original message part
            if( index($e, $StartingOf->{'rfc822'}->[0]) == 0 ) {
                $readcursor |= $Indicators->{'message-rfc822'};
                next;
            }
        }

        if( $readcursor & $Indicators->{'message-rfc822'} ) {
            # After "message/rfc822"
            unless( length $e ) {
                $blanklines++;
                last if $blanklines > 1;
                next;
            }
            push @$rfc822list, $e;

        } else {
            # Before "message/rfc822"
            next unless $readcursor & $Indicators->{'deliverystatus'};
            next unless length $e;

            # The following address failed:
            #
            # general@example.eu
            #
            # For the following reason:
            #
            # Mail size limit exceeded. For explanation visit
            # http://postmaster.1and1.com/en/error-messages?ip=%1s
            $v = $dscontents->[-1];

            if( $e =~ /\A([^ ]+[@][^ ]+)\z/ ) {
                # general@example.eu
                if( $v->{'recipient'} ) {
                    # There are multiple recipient addresses in the message body.
                    push @$dscontents, __PACKAGE__->DELIVERYSTATUS;
                    $v = $dscontents->[-1];
                }
                $v->{'recipient'} = $1;
                $recipients++;

            } elsif( index($e, $StartingOf->{'error'}->[0]) == 0 ) {
                # For the following reason:
                $v->{'diagnosis'} = $e;

            } else {
                # Get error message and append the error message strings
                $v->{'diagnosis'} .= ' '.$e if $v->{'diagnosis'};
            }
        } # End of if: rfc822
    }
    return undef unless $recipients;

    for my $e ( @$dscontents ) {
        $e->{'agent'}     =  __PACKAGE__->smtpagent;
        $e->{'diagnosis'} =~ s/\A$StartingOf->{'error'}->[0]//g;
        $e->{'diagnosis'} =  Sisimai::String->sweep($e->{'diagnosis'});

        SESSION: for my $r ( keys %$MessagesOf ) {
            # Verify each regular expression of session errors
            next unless grep { index($e->{'diagnosis'}, $_) > -1 } @{ $MessagesOf->{ $r } };
            $e->{'reason'} = $r;
            last;
        }
    }
    $rfc822part = Sisimai::RFC5322->weedout($rfc822list);
    return { 'ds' => $dscontents, 'rfc822' => $$rfc822part };
}

1;
__END__

=encoding utf-8

=head1 NAME

Sisimai::Bite::Email::EinsUndEins - bounce mail parser class for C<1&1>.

=head1 SYNOPSIS

    use Sisimai::Bite::Email::EinsUndEins;

=head1 DESCRIPTION

Sisimai::Bite::Email::EinsUndEins parses a bounce email which created by C<1&1>.
Methods in the module are called from only Sisimai::Message.

=head1 CLASS METHODS

=head2 C<B<description()>>

C<description()> returns description string of this module.

    print Sisimai::Bite::Email::EinsUndEins->description;

=head2 C<B<smtpagent()>>

C<smtpagent()> returns MTA name.

    print Sisimai::Bite::Email::EinsUndEins->smtpagent;

=head2 C<B<scan(I<header data>, I<reference to body string>)>>

C<scan()> method parses a bounced email and return results as a array reference.
See Sisimai::Message for more details.

=head1 AUTHOR

azumakuniyuki

=head1 COPYRIGHT

Copyright (C) 2014-2018 azumakuniyuki, All rights reserved.

=head1 LICENSE

This software is distributed under The BSD 2-Clause License.

=cut