#!/usr/bin/env perl
use strict;
use warnings;
use 5.014;
use utf8;

no if $] >= 5.018, warnings => 'experimental::smartmatch';

our $VERSION = '1.05';

use Carp;
use DateTime;
use DateTime::Format::Strptime;
use Encode qw(decode);
use Getopt::Long qw(:config no_ignore_case bundling);
use List::Util qw(first max);
use List::MoreUtils qw(none);
use Travel::Status::DE::IRIS;
use Travel::Status::DE::IRIS::Stations;

my ( $date, $time, $lookahead );
my $datetime       = DateTime->now( time_zone => 'Europe/Berlin' );
my $developer_mode = 0;
my $realtime       = 0;
my $with_related   = 1;
my $emma_url;
my ( $filter_via, $track_via, $status_via );
my ( @grep_class, @grep_type, @grep_platform );
my ( %edata,      @edata_pre );

my @output;

binmode( STDOUT, ':encoding(utf-8)' );

@ARGV = map { decode( 'UTF-8', $_ ) } @ARGV;

GetOptions(
	'c|class=s@'         => \@grep_class,
	'd|date=s'           => \$date,
	'h|help'             => sub { show_help(0) },
	'l|lookahead=i'      => \$lookahead,
	'o|output=s@'        => \@edata_pre,
	'p|platform=s@'      => \@grep_platform,
	'r|realtime'         => \$realtime,
	't|time=s'           => \$time,
	'T|type=s'           => \@grep_type,
	'v|via=s'            => \$filter_via,
	'V|track-via=s'      => \$track_via,
	'x|exact|no-related' => sub { $with_related = 0 },
	'devmode'            => \$developer_mode,
	'emma=s'             => \$emma_url,
	'version'            => \&show_version,

) or show_help(1);

if ( @ARGV != 1 ) {
	show_help(1);
}

# opt=foo,bar support
@edata_pre     = split( qr{,}, join( q{,}, @edata_pre ) );
@grep_class    = split( qr{,}, join( q{,}, @grep_class ) );
@grep_platform = split( qr{,}, join( q{,}, @grep_platform ) );
@grep_type     = split( qr{,}, join( q{,}, @grep_type ) );

my ($station) = @ARGV;
$station = get_station($station);

if ($track_via) {
	$track_via = get_station($track_via);
}

if ($date) {
	my ( $day, $month, $year ) = split( qr{ [.] }ox, $date );
	$datetime->set(
		day   => $day,
		month => $month,
		year  => $year || $datetime->year,
	);
}
if ($time) {
	my ( $hour, $minute, $second ) = split( qr{ : }ox, $time );
	$datetime->set(
		hour   => $hour,
		minute => $minute,
		second => $second || $datetime->second,
	);
}

for my $efield (@edata_pre) {
	given ($efield) {
		when ('a') { $edata{additional}   = 1 }
		when ('c') { $edata{canceled}     = 1 }
		when ('d') { $edata{delay}        = 1 }
		when ('D') { $edata{delays}       = 1 }
		when ('f') { $edata{fullroute}    = 1 }
		when ('m') { $edata{messages}     = 1 }
		when ('M') { $edata{trackinfo}    = 1 }
		when ('q') { $edata{qos}          = 1 }
		when ('r') { $edata{route}        = 1 }
		when ('R') { $edata{replacements} = 1 }
		when ('t') { $edata{times}        = 1 }
		when ('!') { $edata{debug}        = 1 }
		default    { $edata{$efield}      = 1 }
	}
}

my $status = Travel::Status::DE::IRIS->new(
	datetime       => $datetime,
	developer_mode => $developer_mode,
	lookahead      => $lookahead,
	station        => $station,
	with_related   => $with_related,
	emma_url       => $emma_url,
);
if ($track_via) {

	# lookahead should not be used here - the via stop is reached an unknown
	# amount of time later
	$status_via = Travel::Status::DE::IRIS->new(
		datetime => $datetime,
		station  => $track_via,
	);
}

sub get_arrival {
	my ( $result, $fmt ) = @_;

	my $dt_arrival = $realtime ? $result->arrival : $result->sched_arrival;

	if ($fmt) {
		return $dt_arrival ? $dt_arrival->strftime($fmt) : q{};
	}
	return $dt_arrival;
}

sub get_departure {
	my ( $result, $fmt ) = @_;

	my $dt_dep = $realtime ? $result->departure : $result->sched_departure;

	if ($fmt) {
		return $dt_dep ? $dt_dep->strftime($fmt) : q{};
	}
	return $dt_dep;
}

sub get_station {
	my ($input_name) = @_;

	if ( $input_name =~ m{ ^ [[:digit:]]+ $ }x ) {
		return $input_name;
	}

	my @stations = Travel::Status::DE::IRIS::Stations::get_station($input_name);

	if ( @stations == 0 ) {
		say STDERR "No station matches '$input_name'";
		exit(1);
	}
	elsif ( @stations == 1 ) {
		return $stations[0][0];
	}
	else {
		say STDERR "The input '$input_name' is ambiguous. Please choose one "
		  . 'of the following:';
		say STDERR
		  join( "\n", map { $_->[1] . ' (' . $_->[0] . ')' } @stations );
		exit(1);
	}
}

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

	print 'Usage: db-iris [-r] [-c <classlist>] [-d <date>] '
	  . '[-o <output-flags>] [-p <platforms>] [-t <time>] '
	  . '[-T <typelist>] [-v|-V <via>] <station>' . "\n"
	  . "See also: man db-iris\n";

	exit $code;
}

sub show_version {
	say "db-iris version ${VERSION}";

	exit 0;
}

sub sanitize_options {
	if ( $track_via and $edata{times} ) {
		say STDERR 'Note: --track-via cannot be combined with --output=times';
		say STDERR 'Disabling option --output=times';
		delete $edata{times};
	}
	if ( $realtime and $edata{times} ) {
		say STDERR 'Note: --realtime cannot be combined with --output=times';
		say STDERR 'Disabling option --realtime';
		$realtime = 0;
	}
	return;
}

sub format_delay {
	my ($d) = @_;
	my $delay = q{};

	if ( $d->delay ) {
		$delay = ( $d->delay > 0 ? ' +' : q{ } ) . $d->delay;
	}
	if ( $d->is_cancelled ) {
		$delay = ' CANCELED';
	}

	return $delay;
}

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 $line (@lines) {
		printf(
			join( q{  }, ( map { "%-${_}s" } @line_length ) ),
			@{$line}[ 0 .. 4 ]
		);

		my $d = $line->[5];

		if (    $edata{delays}
			and $d->delay_messages )
		{
			printf( '  %s', join( q{  }, map { $_->[1] } $d->delay_messages ) );
		}
		if (    $edata{delay}
			and ( $d->delay or $d->is_cancelled )
			and $d->delay_messages )
		{
			printf( '  %s', ( $d->delay_messages )[-1]->[1] );
		}
		if ( $edata{qos} and $d->qos_messages ) {
			printf( '  %s', join( q{  }, map { $_->[1] } $d->qos_messages ) );
		}
		print "\n";

		if ( $edata{times} ) {
			if ( not defined $d->delay ) {
				print "\n";
			}
			elsif ( $d->delay == 0 ) {
				printf( "%s+0\n", q{ } x 15 );
			}
			else {
				printf(
					"%5s → %5s  %+d\n",
					$d->arrival   ? $d->arrival->strftime('%H:%M')   : q{},
					$d->departure ? $d->departure->strftime('%H:%M') : q{},
					$d->delay,
				);
			}

		}

		if ( $edata{debug} ) {
			if ( $d->{unk_ar_hi} ) {
				say "[DEBUG] arr:hi = $d->{unk_ar_hi}";
			}
			if ( $d->{unk_dp_hi} ) {
				say "[DEBUG] dep:hi = $d->{unk_dp_hi}";
			}
		}

		if ( $edata{trackinfo} ) {
			for my $message ( $d->track_messages ) {

				printf(
					" %s → %s  %s\n",
					$message->[1]->strftime('%d.%m. %H:%M'),
					$message->[2]->strftime('%d.%m. %H:%M'),
					$message->[3]
				);
			}
		}

		if ( $edata{messages} ) {
			for my $message ( $d->messages ) {

				# leading spaces to align with regular output
				printf( " %s  %s\n",
					$message->[0]->strftime('%d.%m. %H:%M'),
					$message->[1] );
			}
			print "\n";
		}

		if ( $edata{replacements} ) {
			for my $e ( $d->replaced_by ) {
				printf(
					"Ersatzzug: %s%s %s\n",
					$e->type, $e->line_no // q{},
					$e->train_no
				);
			}
			for my $e ( $d->replacement_for ) {
				printf(
					"Ersatzzug für: %s%s %s\n",
					$e->type, $e->line_no // q{},
					$e->train_no
				);
			}
		}

		if ( $edata{additional} and $d->additional_stops ) {
			printf( "Zusätzlicher Halt in: %s\n",
				join( q{, }, $d->additional_stops ) );
		}

		if ( $edata{canceled} and $d->canceled_stops ) {
			printf( "Ohne Halt in: %s\n", join( q{, }, $d->canceled_stops ) );
		}

		if ( $edata{fullroute} ) {
			print "\n"
			  . join( "\n", $d->route_pre )
			  . "\n - - - -\n"
			  . join( "\n", $d->route_post ) . "\n\n";
		}
	}

	return;
}

if ( my $err = $status->errstr ) {
	say STDERR "Request error: ${err}";
	exit 2;
}
if ( my $warning = $status->warnstr ) {
	say STDERR "Request warning: ${warning}";
	say STDERR '                 Information may be incomplete';
}

if ( $status_via and $status_via->errstr ) {
	my $err = $status_via->errstr;
	say STDERR "Request error in --via : ${err}";
	exit 2;
}
if ( $status_via and $status_via->warnstr ) {
	my $warning = $status_via->warnstr;
	say STDERR "Request warning in --via : ${warning}";
	say STDERR '                           Information may be incomplete';
}

sanitize_options();

for my $d ( $status->results() ) {

	my @via;

	# route may be incomplete, so check route_end as well
	@via = ( $d->route_post, $d->route_end );

	if (   ( $filter_via and not( first { $_ =~ m{$filter_via}io } @via ) )
		or ( @grep_class and none { $_ ~~ \@grep_class } $d->classes )
		or ( @grep_platform and not( $d->platform ~~ \@grep_platform ) )
		or ( @grep_type     and not( $d->type     ~~ \@grep_type ) )
		or $d->is_wing )
	{
		next;
	}

	my $delay = format_delay($d);

	my $platformstr = $d->platform // q{};
	if ( ( $d->platform // q{} ) ne ( $d->sched_platform // q{} ) ) {
		$platformstr .= ' !';
	}
	my $timestr;
	if ($track_via) {
		$timestr = get_departure( $d, '%H:%M' ) || get_arrival( $d, '%H:%M' );
		if ( not $d->departure ) {
			next;
		}
		my $d_via = first {
			$_->train_id eq $d->train_id
			  or ( $_->old_train_id and $_->old_train_id eq $d->train_id );
		}
		$status_via->results;
		if (   not $d_via
			or not $d_via->sched_arrival
			or $d_via->sched_arrival < $d->departure )
		{
			next;
		}
		my $timestr_via = get_arrival( $d_via, '%H:%M' ) . $delay;
		$timestr .= ' → ' . $timestr_via;
		$platformstr = sprintf( '%2s → %2s', $d->platform // q{},
			$d_via->platform // q{} );
	}
	elsif ( $edata{times} ) {
		$timestr = sprintf( '%5s → %5s',
			$d->sched_arrival   ? $d->sched_arrival->strftime('%H:%M')   : q{},
			$d->sched_departure ? $d->sched_departure->strftime('%H:%M') : q{},
		);
	}
	else {
		$timestr
		  = ( get_departure( $d, '%H:%M' ) || get_arrival( $d, '%H:%M' ) )
		  . $delay;
	}

	push(
		@output,
		[
			$timestr, $d->train,
			$edata{route} ? join( q{  }, $d->route_interesting ) : q{},
			$d->route_end, $platformstr // q{}, $d
		]
	);

	my @processed_wings;
	for my $wing ( $d->departure_wings ) {
		my $wingdelay = format_delay($wing);
		push(
			@output,
			[
				'├'
				  . '─' x ( length($timestr) - 1 - length($delay) )
				  . $wingdelay,
				$wing->train,
				$edata{route} ? join( q{  }, $wing->route_interesting ) : q{},
				$wing->route_end,
				$platformstr // q{},
				$wing
			]
		);
		push( @processed_wings, $wing->wing_id );
	}
	for my $wing ( $d->arrival_wings ) {
		if ( not $wing->wing_id ~~ \@processed_wings ) {
			my $wingdelay = format_delay($wing);
			push(
				@output,
				[
					'├'
					  . '─' x ( length($timestr) - 1 - length($delay) )
					  . $wingdelay,
					$wing->train,
					$edata{route}
					? join( q{  }, $wing->route_interesting )
					: q{},
					$wing->route_end,
					$platformstr // q{},
					$wing
				]
			);
		}
	}
	if ( $d->departure_wings or $d->arrival_wings ) {
		substr( $output[-1][0], 0, 1 ) = '└';
	}
}

display_result(@output);

__END__

=head1 NAME

db-iris - Interface to the DeutscheBahn online departure monitor

=head1 SYNOPSIS

B<db-iris> [B<-r>] [B<-c> I<classlist>] [B<-d> I<date>] [B<-o> I<output-flags>]
[B<-p> I<platforms>] [B<-t> I<time>] [B<-T> I<typelist>] [B<-v>|B<-V> I<via>]
I<station>

=head1 VERSION

version 1.05

=head1 DESCRIPTION

db-iris is an interface to the DeutscheBahn departure monitor
available at L<https://iris.noncd.db.de/wbt/js/index.html>.

It requests all departures at I<station> and lists them on stdout, similar to
the big departure screens installed at most main stations. I<station> can be
either a DS100 station code (such as "EE") or a normal station name
(such as "Essen Hbf" or "DO UniversitE<auml>t"). If no exact match is found,
B<db-iris> will try to find station names containing I<station> as a
substring.

An exclamation mark (C<< ! >>) next to a platform indicates that it is not the
scheduled one.

=head1 OPTIONS

=over

=item B<-c>, B<--class> I<classlist>

Comma-separated list of train classes to filter by. Using this option
causes all trains whose class is not in I<classlist> to be discarded.

Valid classes are:

    D    Non-DB train. Usually local transport
    F    "Fernverkehr", long-distance transport
    N    "Nahverkehr", local and regional transport
    S    S-Bahn, rather slow local/regional transport

=item B<-d>, B<--date> I<date>

Request results for I<date> in dd.mm. or dd.mm.YYYY format. Note that only
slight (a few hours max) deviations from the current time are supported by the
IRIS backend, larger ones will not return data.

=item B<-l>, B<--lookahead> I<int>

Return only those results which are less than I<int> minutes in the future.
Defaults to 240 (4 hours).

Note that this is only an upper limit, not a guarantee to get every train
with a departure in less than I<int> minutes. This guarantee holds only for
I<int> below 120. However, any non-negative number is accepted for this
option.

=item B<-o>, B<--output> I<outputtypes>

For each result, output I<outputtypes> in addition to the normal time, delay,
line and destination information. I<outputtypes> is a comma-separated list,
this option may be repeated. Each output type has both a short and long form,
so both C<< -ot,d >> and C<< --output=times,delay >> are valid.

Valid output types are:

=over

=item a / additional

If a train's route deviates from its schedule: Print a list of additional
(unscheduled) stops it will serve.

=item c / canceled

If a train's route deviates from its schedule: Print a list of canceled
stops (scheduled stops which will not be served).

=item d / delay

If a train is delayed, show the most recent reason for this delay.

=item D / delays

List all delay reasons entered into the IRIS for each train, even if the
particular train is on time by now.

=item f / fullroute

Show the entire route (both before and after I<station>).

=item m / messages

List all messages (delay and qos) entered into the IRIS with timestamps.

=item q / qos

List all quality of service messages entered into the IRIS. These contain
information like "Missing carriage" or "Broken air conditioning".

Note that some qos messages may supersede older ones. superseded messages are
omitted, use the m / messages type to see those as well.

=item r / route

Show up to three stops between I<station> and the train's destination.

=item R / replacements

For cancelled trains: Print their replacement train(s), if present.
For unplanned trains: Print the train(s) they replace, if present.

=item t / times

Show both scheduled and expected arrival and departure times.

=back

=item B<-p>, B<--platforms> I<platforms>

Only show arrivals/departures at I<platforms> (comma-separated list, option may
be repeated).  This applies to actual departures, not schedules.

=item B<-r>, B<--realtime>

Show estimated instead of scheduled time where available. Cannot be combined
with C<< --output=times >>.

=item B<-t>, B<--time> I<time>

Request results for I<time> in HH:MM or HH:MM:SS format. Note that only
slight deviations (a few hours max) from the current time are supported by the
IRIS backend, larger ones will not return data.

=item B<-T>, B<--type> I<typelist>

Comma-separated list of train types to filter by. Using this option
causes all arrivals/departures whose type is not in I<typelist> to be discarded.

The following valid values are known:

    local transport:
    IRE  Inter-Regio Express (rare)
    RB   Regionalbahn (slower than RE)
    RE   Regional-Express
    S    S-Bahn

    regional/interregional transport:
    D    "Schnellzug" (generic fast train, rare)
    EC   Eurocity
    IC   Intercity
    IR   Inter-Regio (rare in Germany, mostly used in Switzerland)
    ICE  Intercity-Express
    THA  Thalys

Depending on the city and country, other types may be used as well. Examples
include "ABR" / "NWB" (private trains included in the local transport tariff
system), "HKX" (private train not included in any DB tariffs) and
"SBB" (unknown swiss train class)

=item B<-v>, B<--via> I<viastation>

Only show trains serving I<viastation> after I<station>. In this case,
I<viastation> must match the station as contained in the train's route
(see B<-of>), DS100 codes are not supported.

=item B<-V>, B<--track-via> I<viastation>

Only show trains serving I<viastation> after I<station>. Show result
timestamps as "HH:MM -> HH:MM +x", where the first time is the scheduled
departure (without delay) at I<station> and the second the scheduled arrival
(also without delay) at I<viastation>. If a delay is known, it will be indicated
by +x.

Note that here, I<viastation> must be a regular station name or DS100 code.

Caveat: Some trains change their identity along the route. For instance, the
line RE11 line in NRW has two identifiers, one for ME<ouml>nchengladbach
<-> Duisburg and one for Duisburg <-> Hamm. B<track-via> is not able to handle
those and will miss trains changing their identifier between I<station> and
I<viastation>

=item B<-x>, B<--exact>, B<--no-related>

Sometimes, Deutsche Bahn splits up major stations in their IRIS interface.
For instance, "KE<ouml>ln Messe/Deutz" actually consists of
"KE<ouml>ln Messe/Deutz" (KKDZ), "KE<ouml>ln Messe/Deutz Gl. 9-10"
(KKDZB) and "KE<ouml>ln Messe/Deutz (tief)" (KKDT).

By default, B<db-iris> will show departures for all of these stations when
queried for any of them. When this option is set, only the departures for the
station part specified on the commandline are shown.

=item B<--version>

Show version information.

=back

=head1 EXIT STATUS

Zero unless things went wrong.

=head1 CONFIGURATION

None.

=head1 DEPENDENCIES

=over

=item * Class::Accessor(3pm)

=item * DateTime(3pm)

=item * LWP::UserAgent(3pm)

=item * XML::LibXML(3pm)

=back

=head1 BUGS AND LIMITATIONS

Unknown.

=head1 AUTHOR

Copyright (C) 2013-2015 by Daniel Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

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