package Net::Travel::DE::VRR;

use strict;
use warnings;
use 5.010;

use Carp qw(confess);
use Net::Travel::DE::VRR::Route;
use LWP::UserAgent;
use XML::LibXML;

our $VERSION = '1.3';

sub post_time {
	my ( $post, $conf ) = @_;

	my $time;

	if ( $conf->{departure_time} ) {
		$post->{itdTripDateTimeDepArr} = 'dep';
		$time = $conf->{departure_time} || $conf->{time};
	}
	else {
		$post->{itdTripDateTimeDepArr} = 'arr';
		$time = $conf->{arrival_time};
	}

	if ( $time !~ / ^ [0-2]? \d : [0-5]? \d $ /x ) {
		confess("time: must match HH:MM - '${time}'");
	}

	@{$post}{ 'itdTimeHour', 'itdTimeMinute' } = split( /:/, $time );

	return;
}

sub post_date {
	my ( $post, $date ) = @_;

	my ( $day, $month, $year ) = split( /[.]/, $date );

	if ( not defined $day or not length($day) or $day < 1 or $day > 31 ) {
		confess("date: invalid day, must match DD.MM[.[YYYY]] - '${date}'");
	}
	if ( not defined $month or not length($month) or $month < 1 or $month > 12 )
	{
		confess("date: invalid month, must match DD.MM[.[YYYY]] - '${date}'");
	}

	if ( not defined $year or not length($year) ) {
		$year = ( localtime(time) )[5] + 1900;
	}

	@{$post}{ 'itdDateDay', 'itdDateMonth', 'itdDateYear' }
	  = ( $day, $month, $year );

	return;
}

sub post_exclude {
	my ( $post, @exclude ) = @_;

	my @mapping = qw{
	  zug s-bahn u-bahn stadtbahn tram stadtbus regionalbus
	  schnellbus seilbahn schiff ast sonstige
	};

	foreach my $exclude_type (@exclude) {
		my $ok = 0;
		for my $map_id ( 0 .. $#mapping ) {
			if ( $exclude_type eq $mapping[$map_id] ) {
				$post->{"inclMOT_${map_id}"} = undef;
				$ok = 1;
			}
		}
		if ( not $ok ) {
			confess("exclude: Unsupported type '${exclude_type}'");
		}
	}

	return;
}

sub post_prefer {
	my ( $post, $prefer ) = @_;

	given ($prefer) {
		when ('speed')    { $post->{routeType} = 'LEASTTIME' }
		when ('waittime') { $post->{routeType} = 'LEASTINTERCHANGE' }
		when ('distance') { $post->{routeType} = 'LEASTWALKING' }
		default {
			confess(
"select_interchange_by: Must be speed/waittime/distance: '${prefer}'"
			);
		}
	}

	return;
}

sub post_include {
	my ( $post, $include ) = @_;

	given ($include) {
		when ('local') { $post->{lineRestriction} = 403 }
		when ('ic')    { $post->{lineRestriction} = 401 }
		when ('ice')   { $post->{lineRestriction} = 400 }
		default {
			confess("train_type: Must be local/ic/ice: '${include}'");
		}
	}

	return;
}

sub post_walk_speed {
	my ( $post, $walk_speed ) = @_;

	if ( $walk_speed ~~ [ 'normal', 'fast', 'slow' ] ) {
		$post->{changeSpeed} = $walk_speed;
	}
	else {
		confess("walk_speed: Must be normal/fast/slow: '${walk_speed}'");
	}

	return;
}

sub post_place {
	my ( $post, $which, $place, $stop, $type ) = @_;

	if ( not( $place and $stop ) ) {
		confess('place: Need two elements');
	}

	$type //= 'stop';

	@{$post}{ "place_${which}", "name_${which}" } = ( $place, $stop );

	if ( $type ~~ [qw[address poi stop]] ) {
		$post->{"type_${which}"} = $type;
	}

	return;
}

sub create_post {
	my ($conf) = @_;
	my @now    = localtime( time() );
	my $post   = {
		changeSpeed                                        => 'normal',
		command                                            => q{},
		execInst                                           => q{},
		imparedOptionsActive                               => 1,
		inclMOT_0                                          => 'on',
		inclMOT_1                                          => 'on',
		inclMOT_10                                         => 'on',
		inclMOT_11                                         => 'on',
		inclMOT_2                                          => 'on',
		inclMOT_3                                          => 'on',
		inclMOT_4                                          => 'on',
		inclMOT_5                                          => 'on',
		inclMOT_6                                          => 'on',
		inclMOT_7                                          => 'on',
		inclMOT_8                                          => 'on',
		inclMOT_9                                          => 'on',
		includedMeans                                      => 'checkbox',
		itOptionsActive                                    => 1,
		itdDateDay                                         => $now[3],
		itdDateMonth                                       => $now[4] + 1,
		itdDateYear                                        => $now[5] + 1900,
		itdLPxx_ShowFare                                   => q{ },
		itdLPxx_command                                    => q{},
		itdLPxx_enableMobilityRestrictionOptionsWithButton => q{},
		itdLPxx_id_destination                             => ':destination',
		itdLPxx_id_origin                                  => ':origin',
		itdLPxx_id_via                                     => ':via',
		itdLPxx_mapState_destination                       => q{},
		itdLPxx_mapState_origin                            => q{},
		itdLPxx_mapState_via                               => q{},
		itdLPxx_mdvMap2_destination                        => q{},
		itdLPxx_mdvMap2_origin                             => q{},
		itdLPxx_mdvMap2_via                                => q{},
		itdLPxx_mdvMap_destination                         => q{::},
		itdLPxx_mdvMap_origin                              => q{::},
		itdLPxx_mdvMap_via                                 => q{::},
		itdLPxx_priceCalculator                            => q{},
		itdLPxx_transpCompany                              => 'vrr',
		itdLPxx_view                                       => q{},
		itdTimeHour                                        => $now[2],
		itdTimeMinute                                      => $now[1],
		itdTripDateTimeDepArr                              => 'dep',
		language                                           => 'de',
		lineRestriction                                    => 403,
		maxChanges                                         => 9,
		nameInfo_destination                               => 'invalid',
		nameInfo_origin                                    => 'invalid',
		nameInfo_via                                       => 'invalid',
		nameState_destination                              => 'empty',
		nameState_origin                                   => 'empty',
		nameState_via                                      => 'empty',
		name_destination                                   => q{},
		name_origin                                        => q{},
		name_via                                           => q{},
		placeInfo_destination                              => 'invalid',
		placeInfo_origin                                   => 'invalid',
		placeInfo_via                                      => 'invalid',
		placeState_destination                             => 'empty',
		placeState_origin                                  => 'empty',
		placeState_via                                     => 'empty',
		place_destination                                  => q{},
		place_origin                                       => q{},
		place_via                                          => q{},
		ptOptionsActive                                    => 1,
		requestID                                          => 0,
		routeType                                          => 'LEASTTIME',
		sessionID                                          => 0,
		text                                               => 1993,
		trITArrMOT                                         => 100,
		trITArrMOTvalue100                                 => 8,
		trITArrMOTvalue101                                 => 10,
		trITArrMOTvalue104                                 => 10,
		trITArrMOTvalue105                                 => 10,
		trITDepMOT                                         => 100,
		trITDepMOTvalue100                                 => 8,
		trITDepMOTvalue101                                 => 10,
		trITDepMOTvalue104                                 => 10,
		trITDepMOTvalue105                                 => 10,
		typeInfo_destination                               => 'invalid',
		typeInfo_origin                                    => 'invalid',
		typeInfo_via                                       => 'invalid',
		type_destination                                   => 'stop',
		type_origin                                        => 'stop',
		type_via                                           => 'stop',
		useRealtime                                        => 1
	};

	post_place( $post, 'origin',      @{ $conf->{origin} } );
	post_place( $post, 'destination', @{ $conf->{destination} } );

	if ( $conf->{via} ) {
		post_place( $post, 'via', @{ $conf->{via} } );
	}
	if ( $conf->{arrival_time} || $conf->{departure_time} ) {
		post_time( $post, $conf );
	}
	if ( $conf->{date} ) {
		post_date( $post, $conf->{date} );
	}
	if ( $conf->{exclude} ) {
		post_exclude( $post, @{ $conf->{exclude} } );
	}
	if ( $conf->{max_interchanges} ) {
		$post->{maxChanges} = $conf->{max_interchanges};
	}
	if ( $conf->{select_interchange_by} ) {
		post_prefer( $post, $conf->{select_interchange_by} );
	}
	if ( $conf->{use_near_stops} ) {
		$post->{useProxFootSearch} = 1;
	}
	if ( $conf->{train_type} ) {
		post_include( $post, $conf->{train_type} );
	}
	if ( $conf->{walk_speed} ) {
		post_walk_speed( $post, $conf->{walk_speed} );
	}
	if ( $conf->{with_bike} ) {
		$post->{bikeTakeAlong} = 1;
	}

	return $post;
}

sub parse_initial {
	my ($tree) = @_;

	my $con_part = 0;
	my $con_no;
	my $cons = [];

	my $xp_td  = XML::LibXML::XPathExpression->new('//table//table/tr/td');
	my $xp_img = XML::LibXML::XPathExpression->new('./img');

	foreach my $td ( @{ $tree->findnodes($xp_td) } ) {

		my $colspan = $td->getAttribute('colspan') // 0;
		my $class   = $td->getAttribute('class')   // q{};

		if ( $colspan != 8 and $class !~ /^bgColor2?$/ ) {
			next;
		}

		if ( $colspan == 8 ) {
			if ( $td->textContent() =~ m{ (?<no> \d+ ) [.] .+ Fahrt }x ) {
				$con_no   = $+{no} - 1;
				$con_part = 0;
				next;
			}
		}

		if ( $class =~ /^bgColor2?$/ ) {
			if ( $class eq 'bgColor' and ( $con_part % 2 ) == 1 ) {
				$con_part++;
			}
			elsif ( $class eq 'bgColor2' and ( $con_part % 2 ) == 0 ) {
				$con_part++;
			}
		}

		if (    defined $con_no
			and not $td->exists($xp_img)
			and $td->textContent() !~ /^\s*$/ )
		{
			push( @{ $cons->[$con_no]->[$con_part] }, $td->textContent() );
		}
	}

	return $cons;
}

sub parse_pretty {
	my ($con_parts) = @_;

	my @elements;
	my @next_extra;

	for my $con ( @{$con_parts} ) {

		my $hash;

		# Note: Changes @{$con} elements
		foreach my $str ( @{$con} ) {
			$str =~ s/[\s\n\t]+/ /gs;
			$str =~ s/^ //;
			$str =~ s/ $//;
		}

		if ( @{$con} < 5 ) {
			@next_extra = @{$con};
			next;
		}

		# @extra may contain undef values
		foreach my $extra (@next_extra) {
			if ($extra) {
				push( @{ $hash->{extra} }, $extra );
			}
		}
		@next_extra = undef;

		if ( $con->[0] !~ / \d{2} : \d{2} /ox ) {
			splice( @{$con}, 0, 0, q{} );
			splice( @{$con}, 4, 0, q{} );
			$con->[7] = q{};
		}
		elsif ( $con->[4] =~ / Plan: \s ab /ox ) {
			push( @{ $hash->{extra} }, splice( @{$con}, 4, 1 ) );
		}

		foreach my $extra ( splice( @{$con}, 8, -1 ) ) {
			push( @{ $hash->{extra} }, $extra );
		}

		$hash->{departure_time} = $con->[0];

		# always "ab"           $con->[1];
		$hash->{departure_stop} = $con->[2];
		$hash->{train_line}     = $con->[3];
		$hash->{arrival_time}   = $con->[4];

		# always "an"                $con->[5];
		$hash->{arrival_stop}      = $con->[6];
		$hash->{train_destination} = $con->[7];

		push( @elements, $hash );
	}

	return Net::Travel::DE::VRR::Route->new(@elements);
}

sub new {
	my ( $obj, %conf ) = @_;

	my $ref = {};

	$ref->{config} = \%conf;

	$ref->{post} = create_post( \%conf );

	return bless( $ref, $obj );
}

sub submit {
	my ( $self, %conf ) = @_;

	$conf{autocheck} = 1;

	$self->{ua} = LWP::UserAgent->new(%conf);

	my $response = $self->{ua}
	  ->post( 'http://efa.vrr.de/vrr/XSLT_TRIP_REQUEST2', $self->{post} );

	# XXX (workaround)
	# The content actually is iso-8859-1. But HTML::Message doesn't actually
	# decode character strings when they have that encoding. However, it
	# doesn't check for latin-1, which is an alias for iso-8859-1.

	$self->{html_reply} = $response->decoded_content( charset => 'latin-1' );

	$self->parse();

	return;
}

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

	my $tree = XML::LibXML->load_html( string => $self->{html_reply}, );

	my $raw_cons = parse_initial($tree);

	for my $raw_con ( @{$raw_cons} ) {
		push( @{ $self->{routes} }, parse_pretty($raw_con) );
	}
	$self->{tree} = $tree;

	$self->check_ambiguous();
	$self->check_no_connections();

	if ( @{$raw_cons} == 0 ) {
		confess('Got no data to parse');
	}

	return 1;
}

sub check_ambiguous {
	my ($self) = @_;
	my $tree = $self->{tree};

	my $xp_select = XML::LibXML::XPathExpression->new('//select');
	my $xp_option = XML::LibXML::XPathExpression->new('./option');

	foreach my $select ( @{ $tree->findnodes($xp_select) } ) {

		my $post_key = $select->getAttribute('name');
		my @possible;

		foreach my $val ( $select->findnodes($xp_option) ) {
			push( @possible, $val->textContent() );
		}
		my $err_text = join( q{, }, @possible );

		confess("Ambiguous input for '${post_key}': '${err_text}'");
	}

	return;
}

sub check_no_connections {
	my ($self) = @_;
	my $tree = $self->{tree};

	my $xp_err_img = XML::LibXML::XPathExpression->new(
		'//td/img[@src="images/ausrufezeichen.jpg"]');

	my $err_node = $tree->findnodes($xp_err_img)->[0];

	if ($err_node) {
		my $text = $err_node->parentNode()->parentNode()->textContent();
		confess("Got no connections: '${text}'");
	}

	return;
}

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

	return @{ $self->{routes} };
}

1;

__END__

=head1 NAME

Net::Travel::DE::VRR - inofficial interface to the efa.vrr.de German itinerary service

=head1 SYNOPSIS

	use Net::Travel::DE::VRR;

	my $efa = Net::Travel::DE::VRR->new(
		from => [ 'Essen',    'HBf' ],
		to   => [ 'Duisburg', 'HBf' ],
	);

	$efa->submit();

	for my $route ( $efa->routes() ) {
		for my $part ( $route->parts() ) {
			printf(
				"%s at %s -> %s at %s, via %s to %s",
				$part->departure_time, $part->departure_stop,
				$part->arrival_time,   $part->arrival_stop,
				$part->train_line,     $part->train_destination,
			);
		}
		print "\n\n";
	}

=head1 VERSION

version 1.3

=head1 DESCRIPTION

B<Net::Travel::DE::VRR> is a client for the efa.vrr.de web interface.
You pass it the start/stop of your journey, maybe a time and a date and more
details, and it returns the up-to-date scheduled connections between those two
stops.

It uses B<LWP::USerAgent> and B<XML::LibXML> for this.

=head1 METHODS

=over

=item $efa = Net::Travel::DE::VRR->new(I<%conf>)

Returns a new Net::Travel::DE::VRR object and sets up its POST data via %conf.

Valid hash keys and their values are:

=over

=item B<origin> => B<[> I<city>B<,> I<stop> [ B<,> I<type> ] B<]>

Mandatory.  Sets the start of the journey.
I<type> is optional and may be one of B<stop> (default), B<address> (street
and house number) or B<poi> ("point of interest").

=item B<destination> => B<[> I<city>B<,> I<stop> [ B<,> I<type> ] B<]>

Mandatory.  Sets the end of the journey, see B<origin>.

=item B<via> => B<[> I<city>B<,> I<stop> [ B<,> I<type> ] B<]>

Optional.  Specifies an intermediate stop which the resulting itinerary must
contain.  See B<origin> for arguments.

=item B<arrival_time> => I<HH:MM>

Sets the journey end time

=item B<departure_time> => I<HH:MM>

Sets the journey start time.  Can not be used together with B<arrival_time>

=item B<date> => I<DD.MM.>[I<YYYY>]

Set journey date, in case it is not today

=item B<exclude> => \@exclude

Do not use certain transport types for itinerary.  Accepted arguments:
zug, s-bahn, u-bahn, stadtbahn, tram, stadtbus, regionalbus, schnellbus,
seilbahn, schiff, ast, sonstige

=item B<max_interchanges> => I<num>

Set maximum number of interchanges

=item B<select_interchange_by> => B<speed>|B<waittime>|B<distance>

Prefer either fast connections (default), connections with low wait time or
connections with little distance to walk

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

If true: Try using near stops instead of the specified origin/destination ones

=item B<train_type> => B<local>|B<ic>|B<ice>

Include only local trains into itinarery (default), all but ICEs, or all.

The latter two are usually way more expensive for short routes.

=item B<walk_speed> => B<slow>|B<fast>|B<normal>

Set walk speed.  Default: B<normal>

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

If true: Prefer connections allowing passengers with bikes

=back

=item $efa->submit(I<%opts>)

Submit the query to B<http://efa.vrr.de>.
I<%opts> is passed on to LWP::UserAgent->new(%opts).

=item $efa->routes()

Returns a list of Net::Travel::DE::VRR::Route(3pm) elements. Each one contains
one method of getting from start to stop.

=back

=head1 DIAGNOSTICS

Dies with a backtrace when anything goes wrong.

=head1 DEPENDENCIES

=over

=item * LWP::UserAgent(3pm)

=item * XML::LibXML(3pm)

=back

=head1 BUGS AND LIMITATIONS

The parser is still somewhat fragile and has no proper error handling.

It is best not to pass Unicode characters to B<Net::Travel::DE::VRR>.

=head1 AUTHOR

Copyright (C) 2009-2011 by Daniel Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

  0. You just DO WHAT THE FUCK YOU WANT TO.