package Sisimai::Bite::Email::Exchange2007;
use parent 'Sisimai::Bite::Email';
use feature ':5.10';
use strict;
use warnings;

my $Indicators = __PACKAGE__->INDICATORS;
my $StartingOf = { 'rfc822' => ['Original message headers:'] };
my $MarkingsOf = {
    'message' => qr/[ ]Microsoft[ ]Exchange[ ]Server[ ]20\d{2}/,
    'error'   => qr/[ ]((?:RESOLVER|QUEUE)[.][A-Za-z]+(?:[.]\w+)?);/,
    'rhost'   => qr/\AGenerating[ ]server:[ ]?(.*)/,
};
my $NDRSubject = {
    'SMTPSEND.DNS.NonExistentDomain'=> 'hostunknown',   # 554 5.4.4 SMTPSEND.DNS.NonExistentDomain
    'SMTPSEND.DNS.MxLoopback'       => 'networkerror',  # 554 5.4.4 SMTPSEND.DNS.MxLoopback
    'RESOLVER.ADR.BadPrimary'       => 'systemerror',   # 550 5.2.0 RESOLVER.ADR.BadPrimary
    'RESOLVER.ADR.RecipNotFound'    => 'userunknown',   # 550 5.1.1 RESOLVER.ADR.RecipNotFound
    'RESOLVER.ADR.ExRecipNotFound'  => 'userunknown',   # 550 5.1.1 RESOLVER.ADR.ExRecipNotFound
    'RESOLVER.ADR.RecipLimit'       => 'toomanyconn',   # 550 5.5.3 RESOLVER.ADR.RecipLimit
    'RESOLVER.ADR.InvalidInSmtp'    => 'systemerror',   # 550 5.1.0 RESOLVER.ADR.InvalidInSmtp
    'RESOLVER.ADR.Ambiguous'        => 'systemerror',   # 550 5.1.4 RESOLVER.ADR.Ambiguous, 420 4.2.0 RESOLVER.ADR.Ambiguous
    'RESOLVER.RST.AuthRequired'     => 'filtered',      # 550 5.7.1 RESOLVER.RST.AuthRequired
    'RESOLVER.RST.NotAuthorized'    => 'rejected',      # 550 5.7.1 RESOLVER.RST.NotAuthorized
    'RESOLVER.RST.RecipSizeLimit'   => 'mesgtoobig',    # 550 5.2.3 RESOLVER.RST.RecipSizeLimit
    'QUEUE.Expired'                 => 'expired',       # 550 4.4.7 QUEUE.Expired
};

# Content-Language: en-US
sub headerlist  { return ['Content-Language'] };
sub description { 'Microsoft Exchange Server 2007' }
sub scan {
    # Detect an error from Microsoft Exchange Server 2007
    # @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 v4.1.1
    my $class = shift;
    my $mhead = shift // return undef;
    my $mbody = shift // return undef;

    return undef unless index($mhead->{'subject'},'Undeliverable:') == 0;
    return undef unless defined $mhead->{'content-language'};
    return undef unless $mhead->{'content-language'} =~ /\A[a-z]{2}(?:[-][A-Z]{2})?\z/;

    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 $connvalues = 0;     # (Integer) Flag, 1 if all the value of $connheader have been set
    my $connheader = {
        'rhost' => '',      # The value of Reporting-MTA header or "Generating Server:"
    };
    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( $e =~ $MarkingsOf->{'message'} ) {
                $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'};

            if( $connvalues == scalar(keys %$connheader) ) {
                # Diagnostic information for administrators:
                #
                # Generating server: mta2.neko.example.jp
                #
                # kijitora@example.jp
                # #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ##
                #
                # Original message headers:
                $v = $dscontents->[-1];

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

                } elsif( $e =~ /\A[#]([45]\d{2})[ ]([45][.]\d[.]\d+)[ ].+\z/ ) {
                    # #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ##
                    # #550 5.2.3 RESOLVER.RST.RecipSizeLimit; message too large for this recipien=
                    # t ##
                    $v->{'replycode'} = int $1;
                    $v->{'status'}    = $2;
                    $v->{'diagnosis'} = $e;

                } else {
                    if( length $v->{'diagnosis'} && substr($v->{'diagnosis'}, -1, 1) eq '=' ) {
                        # Continued line of error messages
                        substr($v->{'diagnosis'}, -1, 1, $e);
                    }
                }
            } else {
                # Diagnostic information for administrators:
                #
                # Generating server: mta22.neko.example.org
                if( $e =~ $MarkingsOf->{'rhost'} ) {
                    # Generating server: mta22.neko.example.org
                    next if length $connheader->{'rhost'};
                    $connheader->{'rhost'} = $1;
                    $connvalues++;
                }
            }
        } # End of if: rfc822
    }
    return undef unless $recipients;

    require Sisimai::String;
    for my $e ( @$dscontents ) {
        if( $e->{'diagnosis'} =~ $MarkingsOf->{'error'} ) {
            # #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ##
            my $f = $1;
            for my $r ( keys %$NDRSubject ) {
                # Try to match with error subject strings
                next unless $f eq $r;
                $e->{'reason'} = $NDRSubject->{ $r };
                last;
            }
        }
        $e->{'diagnosis'} = Sisimai::String->sweep($e->{'diagnosis'});
        $e->{'agent'} = __PACKAGE__->smtpagent;
    }
    $rfc822part = Sisimai::RFC5322->weedout($rfc822list);
    return { 'ds' => $dscontents, 'rfc822' => $$rfc822part };
}

1;
__END__

=encoding utf-8

=head1 NAME

Sisimai::Bite::Email::Exchange2007 - bounce mail parser class for C<Microsft Exchange
Server 2007>.

=head1 SYNOPSIS

    use Sisimai::Bite::Email::Exchange2007;

=head1 DESCRIPTION

Sisimai::Bite::Email::Exchange2007 parses a bounce email which created by C<Microsoft
Exchange Server 2007>. 
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::Exchange2007->description;

=head2 C<B<smtpagent()>>

C<smtpagent()> returns MTA name.

    print Sisimai::Bite::Email::Exchange2007->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) 2016-2018 azumakuniyuki, All rights reserved.

=head1 LICENSE

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

=cut
