path: root/lib/Travel/Status/DE/EFA.pm

package Travel::Status::DE::EFA;

use strict;
use warnings;
use 5.010;
use utf8;

our $VERSION = '2.01';

use Carp qw(confess cluck);
use DateTime;
use Encode qw(encode);
use Travel::Status::DE::EFA::Line;
use Travel::Status::DE::EFA::Result;
use Travel::Status::DE::EFA::Stop;
use LWP::UserAgent;
use XML::LibXML;

my %efa_instance = (
	BSVG => {
		url  => 'https://bsvg.efa.de/bsvagstd/XML_DM_REQUEST',
		name => 'Braunschweiger Verkehrs-GmbH',
	},
	DING => {
		url  => 'https://www.ding.eu/ding3/XSLT_DM_REQUEST',
		name => 'Donau-Iller Nahverkehrsverbund',
	},
	KVV => {
		url  => 'https://projekte.kvv-efa.de/sl3-alone/XSLT_DM_REQUEST',
		name => 'Karlsruher Verkehrsverbund',
	},
	LinzAG => {
		url      => 'https://www.linzag.at/static/XSLT_DM_REQUEST',
		name     => 'Linz AG',
		encoding => 'iso-8859-15',
	},
	MVV => {
		url  => 'https://efa.mvv-muenchen.de/mobile/XSLT_DM_REQUEST',
		name => 'Münchner Verkehrs- und Tarifverbund',
	},
	NVBW => {
		url  => 'https://www.efa-bw.de/nvbw/XSLT_DM_REQUEST',
		name => 'Nahverkehrsgesellschaft Baden-Württemberg',
	},
	VAG => {
		url  => 'https://efa.vagfr.de/vagfr3/XSLT_DM_REQUEST',
		name => 'Freiburger Verkehrs AG',
	},
	VGN => {
		url  => 'https://efa.vgn.de/vgnExt_oeffi/XML_DM_REQUEST',
		name => 'Verkehrsverbund Grossraum Nuernberg',
	},

	# HTTPS: certificate verification fails
	VMV => {
		url  => 'http://efa.vmv-mbh.de/vmv/XML_DM_REQUEST',
		name => 'Verkehrsgesellschaft Mecklenburg-Vorpommern',
	},
	VRN => {
		url  => 'https://www.vrn.de/mngvrn//XML_DM_REQUEST',
		name => 'Verkehrsverbund Rhein-Neckar',
	},
	VRR => {
		url  => 'https://efa.vrr.de/vrr/XSLT_DM_REQUEST',
		name => 'Verkehrsverbund Rhein-Ruhr',
	},
	VRR2 => {
		url  => 'https://app.vrr.de/standard/XML_DM_REQUEST',
		name => 'Verkehrsverbund Rhein-Ruhr (alternative)',
	},
	VRR3 => {
		url  => 'https://efa.vrr.de/rbgstd3/XML_DM_REQUEST',
		name => 'Verkehrsverbund Rhein-Ruhr (alternative alternative)',
	},
	VVO => {
		url  => 'https://efa.vvo-online.de/VMSSL3/XSLT_DM_REQUEST',
		name => 'Verkehrsverbund Oberelbe',
	},
	VVS => {
		url  => 'https://www2.vvs.de/vvs/XSLT_DM_REQUEST',
		name => 'Verkehrsverbund Stuttgart',
	},

);

sub new_p {
	my ( $class, %opt ) = @_;
	my $promise = $opt{promise}->new;

	my $self;

	eval { $self = $class->new( %opt, async => 1 ); };
	if ($@) {
		return $promise->reject($@);
	}

	$self->{promise} = $opt{promise};

	$self->{ua}->post_p( $self->{efa_url} => form => $self->{post} )->then(
		sub {
			my ($tx) = @_;
			if ( my $err = $tx->error ) {
				$promise->reject(
"POST $self->{efa_url} returned HTTP $err->{code} $err->{message}"
				);
				return;
			}
			my $content = $tx->res->body;

			if ( $opt{efa_encoding} ) {
				$self->{xml} = encode( $opt{efa_encoding}, $content );
			}
			else {
				$self->{xml} = $content;
			}

			if ( not $self->{xml} ) {

				# LibXML doesn't like empty documents
				$promise->reject('Server returned nothing (empty result)');
				return;
			}

			$self->{tree} = XML::LibXML->load_xml(
				string => $self->{xml},
			);

			if ( $self->{developer_mode} ) {
				say $self->{tree}->toString(1);
			}

			$self->check_for_ambiguous();

			if ( $self->{errstr} ) {
				$promise->reject( $self->{errstr} );
				return;
			}

			$promise->resolve($self);
			return;
		}
	)->catch(
		sub {
			my ($err) = @_;
			$promise->reject($err);
			return;
		}
	)->wait;

	return $promise;
}

sub new {
	my ( $class, %opt ) = @_;

	$opt{timeout} //= 10;
	if ( $opt{timeout} <= 0 ) {
		delete $opt{timeout};
	}

	if ( not( $opt{name} ) ) {
		confess('You must specify a name');
	}
	if ( $opt{type}
		and not( $opt{type} =~ m{ ^ (?: stop stopID address poi ) $ }x ) )
	{
		confess('type must be stop, stopID, address, or poi');
	}

	if ( $opt{service} and exists $efa_instance{ $opt{service} } ) {
		$opt{efa_url} = $efa_instance{ $opt{service} }{url};
		$opt{time_zone} //= $efa_instance{ $opt{service} }{time_zone};
	}

	if ( not $opt{efa_url} ) {
		confess('service or efa_url must be specified');
	}
	my $dt = $opt{datetime}
	  // DateTime->now( time_zone => $opt{time_zone} // 'Europe/Berlin' );

	## no critic (RegularExpressions::ProhibitUnusedCapture)
	## no critic (Variables::ProhibitPunctuationVars)

	if (    $opt{time}
		and $opt{time} =~ m{ ^ (?<hour> \d\d? ) : (?<minute> \d\d ) $ }x )
	{
		$dt->set(
			hour   => $+{hour},
			minute => $+{minute}
		);
	}
	elsif ( $opt{time} ) {
		confess('Invalid time specified');
	}

	if (
		    $opt{date}
		and $opt{date} =~ m{ ^ (?<day> \d\d? ) [.] (?<month> \d\d? ) [.]
			(?<year> \d{4} )? $ }x
	  )
	{
		if ( $+{year} ) {
			$dt->set(
				day   => $+{day},
				month => $+{month},
				year  => $+{year}
			);
		}
		else {
			$dt->set(
				day   => $+{day},
				month => $+{month}
			);
		}
	}
	elsif ( $opt{date} ) {
		confess('Invalid date specified');
	}

	my $self = {
		post => {
			command                => q{},
			deleteAssignedStops_dm => '1',
			help                   => 'Hilfe',
			itdDateDay             => $dt->day,
			itdDateMonth           => $dt->month,
			itdDateYear            => $dt->year,
			itdLPxx_id_dm          => ':dm',
			itdLPxx_mapState_dm    => q{},
			itdLPxx_mdvMap2_dm     => q{},
			itdLPxx_mdvMap_dm      => '3406199:401077:NAV3',
			itdLPxx_transpCompany  => 'vrr',
			itdLPxx_view           => q{},
			itdTimeHour            => $dt->hour,
			itdTimeMinute          => $dt->minute,
			language               => 'de',
			mode                   => 'direct',
			nameInfo_dm            => 'invalid',
			nameState_dm           => 'empty',
			name_dm                => encode( 'UTF-8', $opt{name} ),
			outputFormat           => 'XML',
			ptOptionsActive        => '1',
			requestID              => '0',
			reset                  => 'neue Anfrage',
			sessionID              => '0',
			submitButton           => 'anfordern',
			typeInfo_dm            => 'invalid',
			type_dm                => $opt{type} // 'stop',
			useProxFootSearch      => $opt{proximity_search} ? '1' : '0',
			useRealtime            => '1',
		},
		developer_mode => $opt{developer_mode},
		efa_url        => $opt{efa_url},
		service        => $opt{service},
	};

	if ( $opt{place} ) {
		$self->{post}{placeInfo_dm}  = 'invalid';
		$self->{post}{placeState_dm} = 'empty';
		$self->{post}{place_dm}      = encode( 'UTF-8', $opt{place} );
	}

	if ( $opt{full_routes} ) {
		$self->{post}->{depType}                = 'stopEvents';
		$self->{post}->{includeCompleteStopSeq} = 1;
		$self->{want_full_routes}               = 1;
	}

	bless( $self, $class );

	if ( $opt{user_agent} ) {
		$self->{ua} = $opt{user_agent};
	}
	else {
		my %lwp_options = %{ $opt{lwp_options} // { timeout => 10 } };
		$self->{ua} = LWP::UserAgent->new(%lwp_options);
		$self->{ua}->env_proxy;
	}

	if ( $opt{async} ) {
		return $self;
	}

	my $response = $self->{ua}->post( $self->{efa_url}, $self->{post} );

	if ( $response->is_error ) {
		$self->{errstr} = $response->status_line;
		return $self;
	}

	if ( $opt{efa_encoding} ) {
		$self->{xml} = encode( $opt{efa_encoding}, $response->content );
	}
	else {
		$self->{xml} = $response->decoded_content;
	}

	if ( not $self->{xml} ) {

		# LibXML doesn't like empty documents
		$self->{errstr} = 'Server returned nothing (empty result)';
		return $self;
	}

	$self->{tree} = XML::LibXML->load_xml(
		string => $self->{xml},
	);

	if ( $self->{developer_mode} ) {
		say $self->{tree}->toString(1);
	}

	$self->check_for_ambiguous();

	return $self;
}

sub new_from_xml {
	my ( $class, %opt ) = @_;

	my $self = {
		xml => $opt{xml},
	};

	$self->{tree} = XML::LibXML->load_xml(
		string => $self->{xml},
	);

	return bless( $self, $class );
}

sub errstr {
	my ($self) = @_;

	return $self->{errstr};
}

sub name_candidates {
	my ($self) = @_;

	if ( $self->{name_candidates} ) {
		return @{ $self->{name_candidates} };
	}
	return;
}

sub place_candidates {
	my ($self) = @_;

	if ( $self->{place_candidates} ) {
		return @{ $self->{place_candidates} };
	}
	return;
}

sub check_for_ambiguous {
	my ($self) = @_;

	my $xml = $self->{tree};

	my $xp_place = XML::LibXML::XPathExpression->new('//itdOdv/itdOdvPlace');
	my $xp_name  = XML::LibXML::XPathExpression->new('//itdOdv/itdOdvName');
	my $xp_mesg
	  = XML::LibXML::XPathExpression->new('//itdMessage[@type="error"]');

	my $xp_place_elem = XML::LibXML::XPathExpression->new('./odvPlaceElem');
	my $xp_name_elem  = XML::LibXML::XPathExpression->new('./odvNameElem');

	my $e_place = ( $xml->findnodes($xp_place) )[0];
	my $e_name  = ( $xml->findnodes($xp_name) )[0];
	my @e_mesg  = $xml->findnodes($xp_mesg);

	if ( not( $e_place and $e_name ) ) {

		# this should not happen[tm]
		cluck('skipping ambiguity check- itdOdvPlace/itdOdvName missing');
		return;
	}

	my $s_place = $e_place->getAttribute('state');
	my $s_name  = $e_name->getAttribute('state');

	if ( $s_place eq 'list' ) {
		$self->{place_candidates} = [ map { $_->textContent }
			  @{ $e_place->findnodes($xp_place_elem) } ];
		$self->{errstr} = 'ambiguous place parameter';
		return;
	}
	if ( $s_name eq 'list' ) {
		$self->{name_candidates}
		  = [ map { $_->textContent } @{ $e_name->findnodes($xp_name_elem) } ];

		$self->{errstr} = 'ambiguous name parameter';
		return;
	}
	if ( $s_place eq 'notidentified' ) {
		$self->{errstr} = 'invalid place parameter';
		return;
	}
	if ( $s_name eq 'notidentified' ) {
		$self->{errstr} = 'invalid name parameter';
		return;
	}
	if (@e_mesg) {
		$self->{errstr} = join( q{; }, map { $_->textContent } @e_mesg );
		return;
	}

	return;
}

sub identified_data {
	my ($self) = @_;

	if ( not $self->{tree} ) {
		return;
	}

	my $xp_place
	  = XML::LibXML::XPathExpression->new('//itdOdv/itdOdvPlace/odvPlaceElem');
	my $xp_name
	  = XML::LibXML::XPathExpression->new('//itdOdv/itdOdvName/odvNameElem');

	my $e_place = ( $self->{tree}->findnodes($xp_place) )[0];
	my $e_name  = ( $self->{tree}->findnodes($xp_name) )[0];

	return ( $e_place->textContent, $e_name->textContent );
}

sub lines {
	my ($self) = @_;
	my @lines;

	if ( $self->{lines} ) {
		return @{ $self->{lines} };
	}

	if ( not $self->{tree} ) {
		return;
	}

	my $xp_element
	  = XML::LibXML::XPathExpression->new('//itdServingLines/itdServingLine');

	my $xp_info  = XML::LibXML::XPathExpression->new('./itdNoTrain');
	my $xp_route = XML::LibXML::XPathExpression->new('./itdRouteDescText');
	my $xp_oper  = XML::LibXML::XPathExpression->new('./itdOperator/name');

	for my $e ( $self->{tree}->findnodes($xp_element) ) {

		my $e_info  = ( $e->findnodes($xp_info) )[0];
		my $e_route = ( $e->findnodes($xp_route) )[0];
		my $e_oper  = ( $e->findnodes($xp_oper) )[0];

		if ( not($e_info) ) {
			cluck( 'node with insufficient data. This should not happen. '
				  . $e->getAttribute('number') );
			next;
		}

		my $line       = $e->getAttribute('number');
		my $direction  = $e->getAttribute('direction');
		my $valid      = $e->getAttribute('valid');
		my $type       = $e_info->getAttribute('name');
		my $mot        = $e->getAttribute('motType');
		my $route      = ( $e_route ? $e_route->textContent : undef );
		my $operator   = ( $e_oper  ? $e_oper->textContent  : undef );
		my $identifier = $e->getAttribute('stateless');

		push(
			@lines,
			Travel::Status::DE::EFA::Line->new(
				name       => $line,
				direction  => $direction,
				valid      => $valid,
				type       => $type,
				mot        => $mot,
				route      => $route,
				operator   => $operator,
				identifier => $identifier,
			)
		);
	}

	$self->{lines} = \@lines;

	return @lines;
}

sub parse_route {
	my ( $self, @nodes ) = @_;
	my $xp_routepoint_date
	  = XML::LibXML::XPathExpression->new('./itdDateTime/itdDate');
	my $xp_routepoint_time
	  = XML::LibXML::XPathExpression->new('./itdDateTime/itdTime');

	my @ret;

	for my $e (@nodes) {
		my @dates = $e->findnodes($xp_routepoint_date);
		my @times = $e->findnodes($xp_routepoint_time);

		my ( $arr, $dep );

		# note that the first stop has an arrival node with an invalid
		# timestamp and the terminal stop has a departure node with an
		# invalid timestamp.

		if ( $dates[0] and $times[0] and $dates[0]->getAttribute('day') != -1 )
		{
			$arr = DateTime->new(
				year      => $dates[0]->getAttribute('year'),
				month     => $dates[0]->getAttribute('month'),
				day       => $dates[0]->getAttribute('day'),
				hour      => $times[0]->getAttribute('hour'),
				minute    => $times[0]->getAttribute('minute'),
				second    => $times[0]->getAttribute('second') // 0,
				time_zone => 'Europe/Berlin'
			);
		}

		if (    $dates[-1]
			and $times[-1]
			and $dates[-1]->getAttribute('day') != -1 )
		{
			$dep = DateTime->new(
				year      => $dates[-1]->getAttribute('year'),
				month     => $dates[-1]->getAttribute('month'),
				day       => $dates[-1]->getAttribute('day'),
				hour      => $times[-1]->getAttribute('hour'),
				minute    => $times[-1]->getAttribute('minute'),
				second    => $times[-1]->getAttribute('second') // 0,
				time_zone => 'Europe/Berlin'
			);
		}

		push(
			@ret,
			Travel::Status::DE::EFA::Stop->new(
				arr      => $arr,
				dep      => $dep,
				name     => $e->getAttribute('name'),
				name_suf => $e->getAttribute('nameWO'),
				platform => $e->getAttribute('platformName'),
			)
		);
	}

	return @ret;
}

sub results {
	my ($self) = @_;
	my @results;

	if ( $self->{results} ) {
		return @{ $self->{results} };
	}

	if ( not $self->{tree} ) {
		return;
	}

	my $xp_element = XML::LibXML::XPathExpression->new('//itdDeparture');

	my $xp_date  = XML::LibXML::XPathExpression->new('./itdDateTime/itdDate');
	my $xp_time  = XML::LibXML::XPathExpression->new('./itdDateTime/itdTime');
	my $xp_rdate = XML::LibXML::XPathExpression->new('./itdRTDateTime/itdDate');
	my $xp_rtime = XML::LibXML::XPathExpression->new('./itdRTDateTime/itdTime');
	my $xp_line  = XML::LibXML::XPathExpression->new('./itdServingLine');
	my $xp_info
	  = XML::LibXML::XPathExpression->new('./itdServingLine/itdNoTrain');
	my $xp_prev_route
	  = XML::LibXML::XPathExpression->new('./itdPrevStopSeq/itdPoint');
	my $xp_next_route
	  = XML::LibXML::XPathExpression->new('./itdOnwardStopSeq/itdPoint');

	$self->lines;

	for my $e ( $self->{tree}->findnodes($xp_element) ) {

		my $e_date = ( $e->findnodes($xp_date) )[0];
		my $e_time = ( $e->findnodes($xp_time) )[0];
		my $e_line = ( $e->findnodes($xp_line) )[0];
		my $e_info = ( $e->findnodes($xp_info) )[0];

		my $e_rdate = ( $e->findnodes($xp_rdate) )[0];
		my $e_rtime = ( $e->findnodes($xp_rtime) )[0];

		if ( not( $e_date and $e_time and $e_line ) ) {
			cluck('node with insufficient data. This should not happen');
			next;
		}

		my ( $sched_dt, $real_dt );

		if ( $e_date and $e_time and $e_date->getAttribute('day') != -1 ) {
			$sched_dt = DateTime->new(
				year      => $e_date->getAttribute('year'),
				month     => $e_date->getAttribute('month'),
				day       => $e_date->getAttribute('day'),
				hour      => $e_time->getAttribute('hour'),
				minute    => $e_time->getAttribute('minute'),
				second    => $e_time->getAttribute('second') // 0,
				time_zone => 'Europe/Berlin'
			);
		}

		if ( $e_rdate and $e_rtime and $e_rdate->getAttribute('day') != -1 ) {
			$real_dt = DateTime->new(
				year      => $e_rdate->getAttribute('year'),
				month     => $e_rdate->getAttribute('month'),
				day       => $e_rdate->getAttribute('day'),
				hour      => $e_rtime->getAttribute('hour'),
				minute    => $e_rtime->getAttribute('minute'),
				second    => $e_rtime->getAttribute('second') // 0,
				time_zone => 'Europe/Berlin'
			);
		}

		my $platform      = $e->getAttribute('platform');
		my $platform_name = $e->getAttribute('platformName');
		my $countdown     = $e->getAttribute('countdown');
		my $occupancy     = $e->getAttribute('occupancy');
		my $line          = $e_line->getAttribute('number');
		my $train_type    = $e_line->getAttribute('trainType');
		my $train_name    = $e_line->getAttribute('trainName');
		my $train_no      = $e_line->getAttribute('trainNum');
		my $dest          = $e_line->getAttribute('direction');
		my $info          = $e_info->textContent;
		my $key           = $e_line->getAttribute('key');
		my $delay         = $e_info->getAttribute('delay');
		my $type          = $e_info->getAttribute('name');
		my $mot           = $e_line->getAttribute('motType');

		my $platform_is_db = 0;

		my @prev_route;
		my @next_route;

		if ( $self->{want_full_routes} ) {
			@prev_route
			  = $self->parse_route( @{ [ $e->findnodes($xp_prev_route) ] } );
			@next_route
			  = $self->parse_route( @{ [ $e->findnodes($xp_next_route) ] } );
		}

		my @line_obj
		  = grep { $_->{identifier} eq $e_line->getAttribute('stateless') }
		  @{ $self->{lines} };

		# platform / platformName are inconsistent. The following cases are
		# known:
		#
		# * platform="int", platformName="" : non-DB platform
		# * platform="int", platformName="Bstg. int" : non-DB platform
		# * platform="#int", platformName="Gleis int" : non-DB platform
		# * platform="#int", platformName="Gleis int" : DB platform?
		# * platform="", platformName="Gleis int" : DB platform
		# * platform="DB", platformName="Gleis int" : DB platform
		# * platform="gibberish", platformName="Gleis int" : DB platform

		if ( ( $platform_name and $platform_name =~ m{ ^ Gleis }ox )
			and not( $platform and $platform =~ s{ ^ \# }{}ox ) )
		{
			$platform_is_db = 1;
		}

		if ( $platform_name and $platform_name =~ m{ ^ (Gleis | Bstg[.])}ox ) {
			$platform = ( split( / /, $platform_name ) )[1];
		}
		elsif ( $platform_name and not $platform ) {
			$platform = $platform_name;
		}

		push(
			@results,
			Travel::Status::DE::EFA::Result->new(
				rt_datetime    => $real_dt,
				platform       => $platform,
				platform_db    => $platform_is_db,
				platform_name  => $platform_name,
				key            => $key,
				lineref        => $line_obj[0] // undef,
				line           => $line,
				train_type     => $train_type,
				train_name     => $train_name,
				train_no       => $train_no,
				destination    => $dest,
				occupancy      => $occupancy,
				countdown      => $countdown,
				info           => $info,
				delay          => $delay,
				sched_datetime => $sched_dt,
				type           => $type,
				mot            => $mot,
				prev_route     => \@prev_route,
				next_route     => \@next_route,
			)
		);
	}

	@results = map { $_->[0] }
	  sort { $a->[1] <=> $b->[1] }
	  map { [ $_, $_->countdown ] } @results;

	$self->{results} = \@results;

	return @results;
}

# static
sub get_efa_urls {
	return map {
		{ %{ $efa_instance{$_} }, shortname => $_ }
	} sort keys %efa_instance;
}

sub get_service {
	my ($service) = @_;
	return $efa_instance{$service};
}

1;

__END__

=head1 NAME

Travel::Status::DE::EFA - unofficial EFA departure monitor

=head1 SYNOPSIS

    use Travel::Status::DE::EFA;

    my $status = Travel::Status::DE::EFA->new(
        efa_url => 'https://efa.vrr.de/vrr/XSLT_DM_REQUEST',
        name => 'Essen Helenenstr'
    );

    for my $d ($status->results) {
        printf(
            "%s %-8s %-5s %s\n",
            $d->datetime->strftime('%H:%M'),
            $d->platform_name, $d->line, $d->destination
        );
    }

=head1 VERSION

version 2.01

=head1 DESCRIPTION

Travel::Status::DE::EFA is an unofficial interface to EFA-based departure
monitors.

It reports all upcoming tram/bus/train departures at a given place.

=head1 METHODS

=over

=item my $status = Travel::Status::DE::EFA->new(I<%opt>)

Requests the departures as specified by I<opts> and returns a new
Travel::Status::DE::EFA object.  B<service> and B<name> are
mandatory.  Dies if the wrong I<opts> were passed.

Arguments:

=over

=item B<service> => I<name>

EFA service. See C<< efa-m --list >> for known services.
If you found a service not listed there, please notify
E<lt>derf+efa@finalrewind.orgE<gt>.

=item B<place> => I<place>

Name of the place/city

=item B<type> => B<address>|B<poi>|B<stop>|B<stopID>

Type of the following I<name>.  B<poi> means "point of interest".  Defaults to
B<stop> (stop/station name).

=item B<name> => I<name>

address / poi / stop name to list departures for.

=item B<datetime> => I<DateTime object>

Request departures for the date/time specified by I<DateTime object>.
Default: now.

=item B<efa_encoding> => I<encoding>

Some EFA servers do not correctly specify their response encoding. If you
observe encoding issues, you can manually specify it here. Example:
iso-8859-15.

=item B<full_routes> => B<0>|B<1>

If true: Request full routes for all departures from the backend. This
enables the B<route_pre>, B<route_post> and B<route_interesting> accessors in
Travel::Status::DE::EFA::Result(3pm).

=item B<proximity_search> => B<0>|B<1>

If true: Show departures for stops in the proximity of the requested place
as well.

=item B<timeout> => I<seconds>

Request timeout, the argument is passed on to LWP::UserAgent(3pm).
Default: 10 seconds. Set to 0 or a negative value to disable it.

=back

=item my $status_p = Travel::Status::DE::EFA->new_p(I<%opt>)

Returns a promise that resolves into a Travel::Status::DE::EFA instance
($status) on success and rejects with an error message on failure. In addition
to the arguments of B<new>, the following mandatory arguments must be set.

=over

=item B<promise> => I<promises module>

Promises implementation to use for internal promises as well as B<new_p> return
value. Recommended: Mojo::Promise(3pm).

=item B<user_agent> => I<user agent>

User agent instance to use for asynchronous requests. The object must implement
a B<post_p> function. Recommended: Mojo::UserAgent(3pm).

=back

=item $status->errstr

In case of an HTTP request or EFA error, returns a string describing it. If
none occured, returns undef.

=item $status->identified_data

Returns a list of the identified values for I<place> and I<name>.
For instance, when requesting data for "E", "MartinSTR", B<identified_data>
will return ("Essen", "Martinstr.").

=item $status->lines

Returns a list of Travel::Status::DE::EFA::Line(3pm) objects, each one
describing one line servicing the selected station.

=item $status->name_candidates

Returns a list of B<name> candidates if I<name> is ambiguous. Returns
nothing (undef / empty list) otherwise.

=item $status->place_candidates

Returns a list of B<place> candidates if I<place> is ambiguous. Returns
nothing (undef / empty list) otherwise.

=item $status->results

Returns a list of Travel::Status::DE::EFA::Result(3pm) objects, each one describing
one departure.

=item Travel::Status::DE::EFA::get_efa_urls()

Returns a list of known EFA entry points. Each list element is a hashref with
the following elements.

=over

=item B<url>: service URL as passed to B<efa_url>

=item B<name>: Name of the entity operating this service

=item B<shortname>: Short name of the entity

=item B<encoding>: Server-side encoding override for B<efa_encoding> (optional)

=back

=item Travel::Status::DE::EFA::service(I<$service>)

Returns a hashref describing the service I<$service>, or undef if it is not
known. See B<get_efa_urls> for the hashref layout.

=back

=head1 DIAGNOSTICS

None.

=head1 DEPENDENCIES

=over

=item * Class::Accessor(3pm)

=item * DateTime(3pm)

=item * LWP::UserAgent(3pm)

=item * XML::LibXML(3pm)

=back

=head1 BUGS AND LIMITATIONS

Not all features of the web interface are supported.

=head1 SEE ALSO

efa-m(1), Travel::Status::DE::EFA::Result(3pm).

=head1 AUTHOR

Copyright (C) 2011-2023 by Birte Kristina Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

This module is licensed under the same terms as Perl itself.