package Sisimai::Lhost::X1;
use parent 'Sisimai::Lhost';
use v5.26;
use strict;
use warnings;

sub description { 'Unknown MTA #1' }
sub inquire {
    # Detect an error from Unknown MTA #1
    # @param    [Hash] mhead    Message headers of a bounce email
    # @param    [String] mbody  Message body of a bounce email
    # @return   [Hash]          Bounce data list and message/rfc822 part
    # @return   [undef]         failed to decode or the arguments are missing
    # @since v4.1.3
    my $class = shift;
    my $mhead = shift // return undef;
    my $mbody = shift // return undef;

    return undef unless index($mhead->{'subject'}, 'Returned Mail: ') == 0;
    return undef unless index($mhead->{'from'}, '"Mail Deliver System" ') == 0;

    state $indicators = __PACKAGE__->INDICATORS;
    state $boundaries = ['Received: from '];
    state $markingsof = {'message' => ['The original message was received at ']};

    my $dscontents = [__PACKAGE__->DELIVERYSTATUS]; my $v = undef;
    my $emailparts = Sisimai::RFC5322->part($mbody, $boundaries);
    my $readcursor = 0;     # (Integer) Points the current cursor position
    my $recipients = 0;     # (Integer) The number of 'Final-Recipient' header
    my $datestring = '';    # (String) Date string

    for my $e ( split("\n", $emailparts->[0]) ) {
        # Read error messages and delivery status lines from the head of the email to the previous
        # line of the beginning of the original message.
        unless( $readcursor ) {
            # Beginning of the bounce message or message/delivery-status part
            $readcursor |= $indicators->{'deliverystatus'} if index($e, $markingsof->{'message'}->[0]) == 0;
            next;
        }
        next if ($readcursor & $indicators->{'deliverystatus'}) == 0 || $e eq "";

        # The original message was received at Thu, 29 Apr 2010 23:34:45 +0900 (JST)
        # from shironeko@example.jp
        #
        # ---The following addresses had delivery errors---
        #
        # kijitora@example.co.jp [User unknown]
        $v = $dscontents->[-1];

        if( Sisimai::String->aligned(\$e, ['@', ' [', ']']) ) {
            # kijitora@example.co.jp [User unknown]
            if( $v->{'recipient'} ) {
                # There are multiple recipient addresses in the message body.
                push @$dscontents, __PACKAGE__->DELIVERYSTATUS;
                $v = $dscontents->[-1];
            }
            my $p1 = index($e, ' ');
            my $p2 = index($e, ']');
            $v->{'recipient'} = substr($e, 0, $p1);
            $v->{'diagnosis'} = substr($e, $p1 + 2, $p2 - $p1 - 2);
            $recipients++;

        } elsif( index($e, $markingsof->{'message'}->[0]) == 0 ) {
            # The original message was received at Thu, 29 Apr 2010 23:34:45 +0900 (JST)
            $datestring = substr($e, length $markingsof->{'message'}->[0],);
        }
    }
    return undef unless $recipients;

    for my $e ( @$dscontents ) {
        $e->{'diagnosis'} = Sisimai::String->sweep($e->{'diagnosis'});
        $e->{'date'}      = $datestring || '';
    }
    return {"ds" => $dscontents, "rfc822" => $emailparts->[1]};
}

1;
__END__

=encoding utf-8

=head1 NAME

Sisimai::Lhost::X1 - bounce mail decoder class for X1.

=head1 SYNOPSIS

    use Sisimai::Lhost::X1;

=head1 DESCRIPTION

C<Sisimai::Lhost::X1> decodes a bounce email which created by Unknown MTA #1. Methods in the module
are called from only C<Sisimai::Message>.

=head1 CLASS METHODS

=head2 C<B<description()>>

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

    print Sisimai::Lhost::X1->description;

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

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

=head1 AUTHOR

azumakuniyuki

=head1 COPYRIGHT

Copyright (C) 2014-2021,2023-2025 azumakuniyuki, All rights reserved.

=head1 LICENSE

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

=cut

