#!perl
use strict;
use warnings;
use 5.014;

our $VERSION = '6.11';

use utf8;
use DateTime;
use Encode qw(decode);
use JSON;
use Getopt::Long    qw(:config no_ignore_case);
use List::MoreUtils qw(uniq);
use List::Util      qw(first max);
use Travel::Status::DE::HAFAS;

my ( $date, $time, $language );
my $arrivals;
my $show_jid;
my $num_results = 30;
my $types       = q{};
my $developer_mode;
my $via;
my $use_cache = 1;
my $cache;
my ( $json_output,   $raw_json_output );
my ( $list_services, $service );
my ( @excluded_mots, @exclusive_mots );

my @output;

binmode( STDOUT, ':encoding(utf-8)' );
for my $arg (@ARGV) {
	$arg = decode( 'UTF-8', $arg );
}

my $output_bold  = -t STDOUT ? "\033[1m" : q{};
my $output_reset = -t STDOUT ? "\033[0m" : q{};

GetOptions(
	'a|arrivals'      => \$arrivals,
	'd|date=s'        => \$date,
	'h|help'          => sub { show_help(0) },
	'j|with-jid'      => \$show_jid,
	'l|language=s'    => \$language,
	'm|mot=s'         => \$types,
	'n|num-results=s' => \$num_results,
	's|service=s'     => \$service,
	't|time=s'        => \$time,
	'v|via=s'         => \$via,
	'V|version'       => \&show_version,
	'cache!'          => \$use_cache,
	'devmode'         => \$developer_mode,
	'json'            => \$json_output,
	'raw-json'        => \$raw_json_output,
	'list'            => \$list_services,

) or show_help(1);

if ($list_services) {
	printf(
		"%-40s %-14s %-15s %s\n\n",
		'operator', 'abbr. (-s)', 'languages (-l)',
		'time zone'
	);
	for my $service ( Travel::Status::DE::HAFAS::get_services() ) {
		printf(
			"%-40s %-14s %-15s %s\n",
			@{$service}{qw(name shortname)},
			join( q{ }, @{ $service->{languages} // [] } ),
			$service->{time_zone} // q{},
		);
	}
	exit 0;
}

if ($use_cache) {
	my $cache_path = ( $ENV{XDG_CACHE_HOME} // "$ENV{HOME}/.cache" )
	  . '/Travel-Status-DE-HAFAS';
	eval {
		require Cache::File;
		$cache = Cache::File->new(
			cache_root      => $cache_path,
			default_expires => '90 seconds',
			lock_level      => Cache::File::LOCK_LOCAL(),
		);
	};
	if ($@) {
		$cache = undef;
	}
}

parse_mot_options();

my %opt = (
	cache          => $cache,
	excluded_mots  => \@excluded_mots,
	exclusive_mots => \@exclusive_mots,
	station        => shift || show_help(1),
	arrivals       => $arrivals,
	developer_mode => $developer_mode,
	service        => $service,
	language       => $language,
	results        => $num_results,
);

if ( $opt{station} =~ m{ ^ (?<lat> [0-9.]+ ) : (?<lon> [0-9].+ ) $ }x ) {
	$opt{geoSearch} = {
		lat => $+{lat},
		lon => $+{lon},
	};
	delete $opt{station};
}
elsif ( $opt{station} =~ m{ ^ [?] (?<query> .*) $ }x ) {
	$opt{locationSearch} = $+{query};
	delete $opt{station};
}
elsif ( $opt{station} =~ m{[|]} ) {
	$opt{journey} = { id => $opt{station} };
	delete $opt{station};
}
elsif ( $opt{station} =~ m{ ^ [!] (?<query> .*) $ }x ) {
	$opt{journeyMatch} = $+{query};
	delete $opt{station};
}

if ( $date or $time ) {
	my $desc = Travel::Status::DE::HAFAS::get_service($service) // {};
	my $dt
	  = DateTime->now( time_zone => $desc->{time_zone} // 'Europe/Berlin' );
	if ($date) {
		if ( $date
			=~ m{ ^ (?<day> \d{1,2} ) [.] (?<month> \d{1,2} ) [.] (?<year> \d{4})? $ }x
		  )
		{
			$dt->set(
				day   => $+{day},
				month => $+{month}
			);
			if ( $+{year} ) {
				$dt->set( year => $+{year} );
			}
		}
		else {
			say "--date must be specified as DD.MM.[YYYY]";
			exit 1;
		}
	}
	if ($time) {
		if ( $time =~ m{ ^ (?<hour> \d{1,2} ) : (?<minute> \d{1,2} ) $ }x ) {
			$dt->set(
				hour   => $+{hour},
				minute => $+{minute},
				second => 0,
			);
		}
		else {
			say "--time must be specified as HH:MM";
			exit 1;
		}
	}
	$opt{datetime} = $dt;
}

my $status = Travel::Status::DE::HAFAS->new(%opt);

sub show_help {
	my ($code) = @_;

	print 'Usage: hafas-m [-d <dd.mm.yyyy>] [-m <motlist>] [-t <time>] '
	  . "<station>\n"
	  . "See also: man hafas-m\n";

	exit $code;
}

sub show_version {
	say "hafas-m version ${VERSION}";

	exit 0;
}

sub spacer {
	my ($len) = @_;
	return ( $len % 2 ? q { } : q{} ) . ( q{ ·} x ( $len / 2 ) );
}

sub parse_mot_options {
	my $default_yes = 1;

	for my $type ( split( qr{,}, $types ) ) {
		if ( $type eq 'help' or $type eq 'list' or $type eq q{?} ) {
			$service //= 'DB';
			my $desc = Travel::Status::DE::HAFAS::get_service($service);
			if ($desc) {
				for my $mot ( @{ $desc->{productbits} } ) {
					if ( ref($mot) eq 'ARRAY' ) {
						if ( $mot->[0] ne '_' ) {
							printf( "%-20s (%s)\n", @{$mot} );
						}
					}
					elsif ( $mot ne '_' ) {
						say $mot;
					}
				}
				exit 0;
			}
			else {
				say STDERR 'no modes of transport known for this service';
				exit 1;
			}
		}
		elsif ( substr( $type, 0, 1 ) eq q{!} ) {
			push( @excluded_mots, substr( $type, 1 ) );
		}
		else {
			push( @exclusive_mots, $type );
		}
	}
	return;
}

sub show_similar_stops {
	my @candidates = $status->similar_stops;
	if (@candidates) {
		say 'You might want to try one of the following stops:';
		for my $c (@candidates) {
			printf( "%s (%s)\n", $c->{name}, $c->{id} );
		}
		return;
	}
	my $hafas = Travel::Status::DE::HAFAS->new(
		locationSearch => $opt{station},
		developer_mode => $developer_mode,
		service        => $service,
		language       => $language,
	);
	if ( $hafas->results ) {
		say 'You might want to try one of the following stops:';
		for my $r ( $hafas->results ) {
			printf( "%s (%s)\n", $r->name, $r->eva );
		}
	}
	return;
}

sub journey_has_via {
	my ( $journey, $via ) = @_;

	if ( $via =~ m{ ^ [0-9,]+ $ }x ) {
		for my $eva ( split( qr{,}, $via ) ) {
			if ( my $stop = first { $_->loc->eva == $eva } $journey->route ) {
				return $stop;
			}
		}
		return;
	}

	if ( my $stop = first { $_->loc->name =~ m{$via}io } $journey->route ) {
		return $stop;
	}
	return;
}

sub display_result {
	my (@lines) = @_;

	my @line_length;

	if ( not @lines ) {
		die("Nothing to show\n");
	}

	for my $i ( 0 .. 4 ) {
		$line_length[$i] = max map { length( $_->[$i] ) } @lines;
	}

	for my $line (@lines) {

		my $d             = $line->[6];
		my $first_message = 1;
		for my $msg ( $d->messages ) {
			if ( $msg->ref_count == 0 ) {
				if ($first_message) {
					print "\n";
					$first_message = 0;
				}
				if ( $msg->short ) {
					printf( "# %s\n", $msg->short );
				}
				printf( "# %s\n", $msg->text );
			}
		}

		printf(
			join( q{  }, ( map { "%-${_}s" } @line_length ) ),
			@{$line}[ 0 .. 4 ]
		);
		if ( $line->[5] ) {
			print q{  } . $line->[5];
		}
		print "\n";
	}

	return;
}

sub display_occupancy {
	my ($occupancy) = @_;

	if ( not $occupancy ) {
		return q{ };
	}
	if ( $occupancy == 1 ) {
		return q{.};
	}
	if ( $occupancy == 2 ) {
		return q{o};
	}
	if ( $occupancy == 3 ) {
		return q{*};
	}
	if ( $occupancy == 4 ) {
		return q{!};
	}
	return q{?};
}

sub format_delay {
	my ( $delay, $len ) = @_;
	if ( $delay and $len ) {
		return sprintf( "(%+${len}d)", $delay );
	}
	return q{};
}

if ( my $err = $status->errstr ) {
	say STDERR "Request error: ${err}";
	if (    $status->errcode
		and ( $status->errcode eq 'H730' or $status->errcode eq 'LOCATION' )
		and not $raw_json_output )
	{
		show_similar_stops();
	}
	exit 2;
}

if ($raw_json_output) {
	say JSON->new->convert_blessed->encode( $status->{raw_json} );
	exit 0;
}

if ($json_output) {
	if ( $opt{journey} ) {
		say JSON->new->convert_blessed->encode( $status->result );
	}
	else {
		say JSON->new->convert_blessed->encode( [ $status->results ] );
	}
	exit 0;
}

if ( $opt{journeyMatch} ) {
	if ( scalar $status->results == 1 ) {
		my ($journey) = $status->results;
		$opt{journey} = { id => $journey->id };
		delete $opt{journeyMatch};
		$status = Travel::Status::DE::HAFAS->new(%opt);
		if ( my $err = $status->errstr ) {
			say STDERR "Request error: ${err}";
			if (
				$status->errcode
				and
				( $status->errcode eq 'H730' or $status->errcode eq 'LOCATION' )
				and not $raw_json_output
			  )
			{
				show_similar_stops();
			}
			exit 2;
		}
	}
	else {
		for my $result ( $status->results ) {
			my $start = ( $result->route )[0];
			my $end   = ( $result->route )[-1];
			say $result->id;
			print $result->name;
			if ( $result->number ) {
				printf( "  |  Nr  %s", $result->number );
			}
			if ( $result->line_no ) {
				printf( "  |  Linie %s", $result->line_no );
			}
			say q{};
			printf( "%s  ab  %s\n",
				$start->dep->strftime('%H:%M'),
				$start->loc->name );
			printf( "%s  an  %s\n\n",
				$end->arr->strftime('%H:%M'),
				$end->loc->name );
		}
		exit 0;
	}
}

if ( $opt{geoSearch} ) {
	for my $result ( $status->results ) {
		printf(
			"%5.1f km  %8d  %s\n",
			$result->distance_m * 1e-3,
			$result->eva, $result->name
		);
	}
	exit 0;
}
elsif ( $opt{locationSearch} ) {
	for my $result ( $status->results ) {
		printf( "%8d  %s\n", $result->eva, $result->name );
	}
	exit 0;
}
elsif ( $opt{journey} ) {
	my $result = $status->result;
	my @prods;
	my @directions;
	my $prev_prod = 0;

	printf( "%s → %s", $result->name, $result->route_end );
	if ( $result->number ) {
		printf( " / Nr %s", $result->number );
	}
	if ( $result->line_no ) {
		printf( " / Linie %s", $result->line_no );
	}

	if ( $result->route ) {
		printf( "\nFahrt %s am %s\n",
			$result->id,
			( $result->route )[0]->sched_dep->strftime('%d.%m.%Y') );
	}
	else {
		printf( "\nFahrt %s\n", $result->id );
	}

	my $delay_len     = 0;
	my $delay_fmt     = 0;
	my $occupancy_len = 0;
	my $stop_len      = 0;
	for my $stop ( $result->route ) {
		if ( $stop->delay ) {
			$delay_len = max( $delay_len, length( $stop->delay ) + 1 );
		}
		if ( $stop->load and ( $stop->load->{FIRST} or $stop->load->{SECOND} ) )
		{
			$occupancy_len = 2;
		}
		if ( length( $stop->loc->name ) > $stop_len ) {
			$stop_len = length( $stop->loc->name );
		}
		my $prod = $stop->prod_dep // $stop->prod_arr;
		if ( $prod and $prod != $prev_prod ) {
			push( @prods, $prod );
			$prev_prod = $prod;
		}
		if ( $stop->direction ) {
			push( @directions, $stop->direction );
		}
	}
	if ($delay_len) {
		$delay_fmt = $delay_len + 3;
	}

	if ( $result->operators ) {
		printf( "Betrieb: %s\n", join( q{, }, $result->operators ) );
	}

	$prev_prod = 0;

	my $desc = Travel::Status::DE::HAFAS::get_service($service) // {};
	my $now
	  = DateTime->now( time_zone => $desc->{time_zone} // 'Europe/Berlin' );
	my $mark_stop = 0;
	for my $i ( reverse 1 .. ( scalar $result->route // 0 ) ) {
		my $stop = ( $result->route )[ $i - 1 ];
		if ( not $stop->dep_cancelled and $stop->dep and $now <= $stop->dep ) {
			$mark_stop = $stop;
		}
		elsif ( not $stop->arr_cancelled and $stop->arr and $now <= $stop->arr )
		{
			$mark_stop = $stop;
		}
	}

	my $message_id = 1;

	print "\n";

	if ( not $result->route ) {
		say 'Route unknown: this backend does not provide intermediate stops';
	}

	for my $stop ( $result->route ) {
		my $msg_line = q{};
		for my $message ( $stop->messages ) {
			if (    $message->ref_count > 0
				and $message->code ne
				'text.journeystop.product.or.direction.changes.stop.message'
				and $message->text ne 'Halt entfällt' )
			{
				if ( not $message->{id} ) {
					$message->{id} = $message_id++;
				}
				$msg_line .= sprintf( ' (%d)', $message->{id} );
			}
		}

		my $prod_line = q{};
		if ( @prods > 1 ) {
			my $prod = $stop->prod_dep // $stop->prod_arr;
			if ( $prod and $prod != $prev_prod ) {
				$prod_line
				  = sprintf( " %s (%s)", $prod->name, $prod->operator );
				$prev_prod = $prod;
			}
		}

		my $dir_line = q{};
		if ( @directions > 1 and $stop->direction ) {
			$dir_line = ' → ' . $stop->direction;
		}

		my $tz_line = q{};
		if ( $stop->tz_offset and ( $stop->arr or $stop->dep ) ) {
			$tz_line = ( $prod_line or $dir_line ) ? q{ · } : q{ };
			$tz_line .= 'local ';
			if ( $stop->arr ) {
				$tz_line
				  .= $stop->arr->clone->add( minutes => $stop->tz_offset )
				  ->strftime('%H:%M');
			}
			if ( $stop->arr and $stop->dep ) {
				$tz_line .= ' → ';
			}
			if ( $stop->dep ) {
				$tz_line
				  .= $stop->dep->clone->add( minutes => $stop->tz_offset )
				  ->strftime('%H:%M');
			}
			$tz_line .= q{  };
		}

		printf(
"%s%5s %s %5s %-${delay_fmt}s%${occupancy_len}s%-${occupancy_len}s %s%s%s%s%s%s%s\n",
			$stop == $mark_stop  ? $output_bold : q{},
			$stop->arr_cancelled ? '--:--'
			: ( $stop->arr ? $stop->arr->strftime('%H:%M') : q{} ),
			( $stop->arr and $stop->dep ) ? '→' : q{ },
			$stop->dep_cancelled          ? '--:--'
			: ( $stop->dep ? $stop->dep->strftime('%H:%M') : q{} ),
			format_delay( $stop->delay, $delay_len ),
			$stop->load->{FIRST} ? display_occupancy( $stop->load->{FIRST} )
			: q{},
			$stop->load->{SECOND} ? display_occupancy( $stop->load->{SECOND} )
			: q{},
			$stop->loc->name,
			$stop == $mark_stop ? $output_reset : q{},
			( $tz_line or $prod_line or $dir_line or $msg_line )
			? spacer( $stop_len + 1 - length( $stop->loc->name ) )
			: q{},
			$prod_line,
			$dir_line,
			$tz_line,
			$msg_line,
		);
	}

	for my $msg ( $result->messages ) {
		if ( $msg->code eq
			'text.journeystop.product.or.direction.changes.journey.message' )
		{
			next;
		}
		say '';
		if ( $msg->short ) {
			printf( "%s\n", $msg->short );
		}
		printf( "%s\n", $msg->text );
	}

	for my $msg ( $status->messages ) {
		if ( $msg->{id} ) {
			say '';
			if ( $msg->short ) {
				printf( "(%d) %s\n", $msg->{id}, $msg->short );
			}
			printf( "(%d) %s\n", $msg->{id}, $msg->text );
		}
	}
	exit 0;
}

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

if ($via) {
	@results = grep { journey_has_via( $_, $via ) } @results;
}

my $delay_len     = 0;
my $occupancy_len = 0;
my $offset_len    = 0;
for my $d (@results) {
	if ( $d->delay ) {
		$delay_len = max( $delay_len, length( $d->delay ) + 1 );
	}
	if ( $d->load and ( $d->load->{FIRST} or $d->load->{SECOND} ) ) {
		$occupancy_len = 2;
	}
	if ( $d->tz_offset ) {
		$offset_len = 1;
	}
}

my $message_id = 1;
for my $m ( $status->messages ) {
	if ( $m->ref_count > 0 ) {
		$m->{id} = $message_id++;
	}
}

for my $d (@results) {

	my $info_line = q{};

	for my $message ( $d->messages ) {
		if ( $message->ref_count > 0 ) {
			$message->{show} = 1;
			$info_line = sprintf( '(%d) %s', $message->{id}, $info_line );
		}
	}

	if ( $d->load ) {
		$info_line
		  = display_occupancy( $d->load->{FIRST} )
		  . display_occupancy( $d->load->{SECOND} ) . '  '
		  . $info_line;
	}

	if ($show_jid) {
		$info_line = $d->id . '  ' . $info_line;
	}

	my $entry = [
		  ( $d->is_cancelled ? '--:--' : $d->datetime->strftime('%H:%M') )
		. ( $d->tz_offset    ? q{*}    : ( q{ } x $offset_len ) ),
		$d->is_cancelled
		? q{}
		: format_delay( $d->delay, $delay_len ),
		$d->name,
		$d->route_end,
		( $d->platform // q{} ) . ( $d->is_changed_platform ? ' !' : q{} ),
		$info_line,
		$d
	];

	if ($via) {
		my $stop = journey_has_via( $d, $via );

		# HAFAS does not provide real-time data for route entries, so we have to guesstimate the arrival time
		$entry->[0] .= ' → '
		  . (
			$stop->arr_cancelled
			? '--:--'
			: $stop->arr->clone->add( minutes => $d->delay // 0 )
			  ->strftime('%H:%M')
		  );
	}

	push( @output, $entry, );
}

display_result(@output);

if ($offset_len) {
	printf( "\n* reported for %s; local time differs\n",
		$status->get_active_service->{time_zone} // 'Europe/Berlin' );
}

for my $m ( $status->messages ) {
	if ( $m->ref_count > 0 and $m->{show} ) {
		if ( $m->short and $m->text ) {
			printf( "\n# (%d) %s\n# %s\n", $m->{id}, $m->short, $m->text );
		}
		elsif ( $m->short or $m->text ) {
			printf( "\n# (%d) %s\n", $m->{id}, $m->text || $m->short );
		}
	}
}

__END__

=head1 NAME

hafas-m - Interface to the DeutscheBahn/HAFAS online departure monitor

=head1 SYNOPSIS

B<hafas-m> [B<-a>] [B<-d> I<date>] [B<-t> I<time>] [B<-m> I<motlist>]
[B<-v> I<via>] [B<-s> I<service>] [B<-l> I<language>] I<station>

B<hafas-m> [B<-s> I<service>] B<?>I<query>|I<lat>B<:>I<lon>

B<hafas-m> [B<-s> I<service>] [B<-l> I<language>] B<!>I<query>|I<journeyID>

=head1 VERSION

version 6.11

=head1 DESCRIPTION

hafas-m is an interface to HAFAS public transport services such as the one
operated by Deutsche Bahn.

It can serve as an arrival/departure monitor, request details about a specific
trip/journey, and look up public transport stops by name or geolocation.
The operating mode depends on the contents of its non-option argument.

=head2 Arrival/Departure Monitor (I<station>)

Show departures (or arrivals) at I<station>, optionally filtered by mode of
transport. I<station> may be given as a station name or HAFAS station ID.
For each train, B<hafas-m> shows

=over

=item * estimated departure (or arrival) time,

=item * delay, if known,

=item * trip name, number, or line,

=item * direction / destination,

=item * platform, if known (B<!> indicates a platform change), and

=item * expected occupancy of first and second class, if known.

=back

Times are always given in the selected service's default time zone (see
B<--list>). Times that differ from the queried stop's local time are marked
with C<< * >>. Occupancy indicators are, from least occupied to fully booked:
B<.> B<o> B<*> B<!>.

=head2 Location Search (B<?>I<query>|I<lat>B<:>I<lon>)

List stations that match I<query> or that are located in the vicinity of
I<lat>B<:>I<lon> geocoordinates with EVA ID and name.

=head2 Trip Search (B<!>I<query>)

Show trip details (see below) for the train number provided in I<query>
(e.g. "ICE 205" or "S 31111") if it resolves into a single journey ID.
Otherwise, list all journey IDs that match I<query>.

=head2 Trip Details (I<journeyID>)

List intermediate stops of I<journeyID> (as given by arrival/departure monitor
mode when invoked with B<-j>, B<--with-jid>) with arrival/departure time, delay
(if available), occupancy (if available), and stop name. Also includes
line/journey, operator, and heading information.

Times are reported in the selected HAFAS service's default time zone (typically
Europe/Berlin). If a stop's local time differs, it is also provided.

=head1 OPTIONS

Values in brackets indicate options that only apply to the indicated operating
mode(s).

=over

=item B<-a>, B<--arrivals> (monitor)

Show arrivals instead of departures, including trains ending at the specified
station. Note that this causes the output to display the start instead of
the end station.

=item B<-d>, B<--date> I<dd>.I<mm>.[I<yyyy>]

Request date.  Default: today.

=item B<-j>, B<--with-jid> (monitor)

Show journey IDs in arrival/departure board. These can be used to obtain
details on individual journeys with subsequent B<hafas-m> invocations.

=item B<--json>

Print result(s) as JSON and exit. This is a dump of internal data structures
and not guaranteed to remain stable between minor versions. Please use the
Travel::Status::DE::HAFAS(3pm) module if you need a proper API.

=item B<-l>, B<--language> I<language>

Request free-text messages to be provided in I<language>.
See B<--list> for a list of languages supported by individual HAFAS instances.
Note that requesting an invalid/unsupported language may lead to garbage output.

=item B<--list>

List known HAFAS instances and exit. Use B<-s>|B<--service> to select a
service from this list for a HAFAS request.

=item B<-m>, B<--mot> I<motlist> (monitor)

By default, B<hafas-m> shows all modes of transport arriving/departing at the
specified station. With I<motlist>, it is possible to either exclude a list of
modes, or exclusively show only a select list of modes.

To exclude modes, set I<motlist> to B<!>I<mot1>,B<!>I<mot2>,...

To show them exclusively, set I<motlist> to I<mot1>,I<mot2>,...

The I<mot> types depend on the used service. Use C<< -m help >> to list them.

=item B<-n>, B<--num-results> I<count> (monitor)

Request up to I<count> results. Default: 30.

=item B<--no-cache>

If the Cache::File module is available, server replies are cached in
F<~/.cache/Travel-Status-DE-HAFAS> (or a path relative to C<$XDG_CACHE_HOME>,
if set) for 90 seconds. Use this option to disable caching. You can also use
B<--cache> to re-enable it.

=item B<--raw-json>

Print unprocessed HAFAS response as JSON and exit.
Useful for debugging and development purposes.

=item B<-s>, B<--service> I<service>

Request arrivals/departures using the API provided by I<service>, defaults
to DB (Deutsche Bahn). See B<--list> for a list of known services.

=item B<-t>, B<--time> I<hh>:I<mm> (monitor)

Request time. Must be specified in the selected HAFAS service's default time
zone, see B<--list>. Default: now.

=item B<-v>, B<--via> I<stopname>|I<eva1>,I<eva2>,... (monitor)

Only show departures that pass by I<stopname> (or arivals that have passed by
I<stopname>). If I<stopname> is given as a list of numeric EVA IDs, only
arrivals/departures with an exact EVA ID match are shown. Otherwise I<stopname>
is treated as a regular expression and matched against stop names.

=item B<-V>, B<--version>

Show version information and exit.

=back

=head1 EXIT STATUS

0 upon success, 1 upon internal error, 2 upon backend error.

=head1 CONFIGURATION

None.

=head1 DEPENDENCIES

=over

=item * Class::Accessor(3pm)

=item * LWP::UserAgent(3pm)

=back

=head1 BUGS AND LIMITATIONS

=over

=item * The non-default services (anything other than DB) are not well-tested.

=item * HAFAS does not provide real-time data for routes of stationboard
entries.  Hence, B<--via> estimates the arrival time from scheduled
departure and departure delay

=back

=head1 AUTHOR

Copyright (C) 2015-2023 by Birte Kristina Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

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