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

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

our $VERSION = '0.00';

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 );
my $datetime = DateTime->now( time_zone => 'Europe/Berlin' );
my $filter_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) },
	'o|output=s@'   => \@edata_pre,
	'p|platform=s@' => \@grep_platform,
	't|time=s'      => \$time,
	'T|type=s'      => \@grep_type,
	'v|via=s'       => \$filter_via,
	'V|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 ($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 ('d') { $edata{delay}     = 1 }
		when ('D') { $edata{delays}    = 1 }
		when ('f') { $edata{fullroute} = 1 }
		when ('m') { $edata{messages}  = 1 }
		when ('q') { $edata{qos}       = 1 }
		when ('r') { $edata{route}     = 1 }
		when ('t') { $edata{times}     = 1 }
		default    { $edata{$efield}   = 1 }
	}
}

my $status = Travel::Status::DE::IRIS->new(
	datetime => $datetime,
	station  => $station,
);

sub get_station {
	my ($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] } @stations );
		exit(1);
	}
}

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

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

	exit $code;
}

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

	exit 0;
}

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{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] } ( reverse $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{messages} ) {
			for my $message ( reverse $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{fullroute} ) {
			print "\n" . join( "\n", $d->route ) . "\n\n";
		}
	}

	return;
}

if ( my $err = $status->errstr ) {
	say STDERR "Request error: ${err}";
	exit 2;
}

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

	my @via;

	@via = $d->route_post;

	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 ) ) )
	{
		next;
	}

	my $delay = q{};

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

	my $timestr;
	if ( $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 = $d->time . $delay;
	}

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

display_result(@output);

__END__

=head1 NAME

db-iris - Interface to the DeutscheBahn online departure monitor

=head1 SYNOPSIS

B<db-iris> [B<-V>] [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> I<via>]
I<station>

=head1 VERSION

version 0.00

=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.

=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. oder 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<-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 >> is valid.

Valid output types are:

=over

=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 of all trains (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. supersed 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 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).

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

Request results for I<time> in HH:MM oder 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:
    IR   Inter-Regio (rare in Germany, mostly used in Switzerland)
    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
    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>.

=item B<-V>, 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

Todo.

=head1 AUTHOR

Copyright (C) 2013-2014 by Daniel Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

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