package Travel::Status::DE::HAFAS;

# vim:foldmethod=marker

use strict;
use warnings;
use 5.014;
use utf8;

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

use Carp qw(confess);
use DateTime;
use DateTime::Format::Strptime;
use Digest::MD5 qw(md5_hex);
use Encode      qw(decode encode);
use JSON;
use LWP::UserAgent;
use Travel::Status::DE::HAFAS::Message;
use Travel::Status::DE::HAFAS::Polyline qw(decode_polyline);
use Travel::Status::DE::HAFAS::Journey;
use Travel::Status::DE::HAFAS::StopFinder;

our $VERSION = '4.00';

# {{{ Endpoint Definition

my %hafas_instance = (
	DB => {
		stopfinder  => 'https://reiseauskunft.bahn.de/bin/ajax-getstop.exe',
		mgate       => 'https://reiseauskunft.bahn.de/bin/mgate.exe',
		name        => 'Deutsche Bahn',
		productbits => [qw[ice ic_ec d regio s bus ferry u tram ondemand]],
		salt        => 'bdI8UVj4' . '0K5fvxwf',
		request     => {
			client => {
				id   => 'DB',
				v    => '20100000',
				type => 'IPH',
				name => 'DB Navigator',
			},
			ext  => 'DB.R21.12.a',
			ver  => '1.15',
			auth => {
				type => 'AID',
				aid  => 'n91dB8Z77' . 'MLdoR0K'
			},
		},
	},
	NAHSH => {
		mgate       => 'https://nah.sh.hafas.de/bin/mgate.exe',
		stopfinder  => 'https://nah.sh.hafas.de/bin/ajax-getstop.exe',
		name        => 'Nahverkehrsverbund Schleswig-Holstein',
		productbits => [qw[ice ice ice regio s bus ferry u tram ondemand]],
		request     => {
			client => {
				id   => 'NAHSH',
				v    => '3000700',
				type => 'IPH',
				name => 'NAHSHPROD',
			},
			ver  => '1.16',
			auth => {
				type => 'AID',
				aid  => 'r0Ot9FLF' . 'NAFxijLW'
			},
		},
	},
	NASA => {
		mgate       => 'https://reiseauskunft.insa.de/bin/mgate.exe',
		stopfinder  => 'https://reiseauskunft.insa.de/bin/ajax-getstop.exe',
		name        => 'Nahverkehrsservice Sachsen-Anhalt',
		productbits => [qw[ice ice regio regio regio tram bus ondemand]],
		request     => {
			client => {
				id   => 'NASA',
				v    => '4000200',
				type => 'IPH',
				name => 'nasaPROD',
				os   => 'iPhone OS 13.1.2',
			},
			ver  => '1.18',
			auth => {
				type => 'AID',
				aid  => 'nasa-' . 'apps',
			},
			lang => 'deu',
		},
	},
	NVV => {
		mgate      => 'https://auskunft.nvv.de/auskunft/bin/app/mgate.exe',
		stopfinder =>
		  'https://auskunft.nvv.de/auskunft/bin/jp/ajax-getstop.exe',
		name        => 'Nordhessischer VerkehrsVerbund',
		productbits =>
		  [qw[ice ic_ec regio s u tram bus bus ferry ondemand regio regio]],
		request => {
			client => {
				id   => 'NVV',
				v    => '5000300',
				type => 'IPH',
				name => 'NVVMobilPROD_APPSTORE',
				os   => 'iOS 13.1.2',
			},
			ext  => 'NVV.6.0',
			ver  => '1.18',
			auth => {
				type => 'AID',
				aid  => 'Kt8eNOH7' . 'qjVeSxNA',
			},
			lang => 'deu',
		},
	},
	'ÖBB' => {
		mgate       => 'https://fahrplan.oebb.at/bin/mgate.exe',
		stopfinder  => 'https://fahrplan.oebb.at/bin/ajax-getstop.exe',
		name        => 'Österreichische Bundesbahnen',
		productbits =>
		  [qw[ice ice ice regio regio s bus ferry u tram ice ondemand ice]],
		request => {
			client => {
				id   => 'OEBB',
				v    => '6030600',
				type => 'IPH',
				name => 'oebbPROD-ADHOC',
			},
			ver  => '1.41',
			auth => {
				type => 'AID',
				aid  => 'OWDL4fE4' . 'ixNiPBBm',
			},
			lang => 'deu',
		},
	},
	VBB => {
		mgate       => 'https://fahrinfo.vbb.de/bin/mgate.exe',
		stopfinder  => 'https://fahrinfo.vbb.de/bin/ajax-getstop.exe',
		name        => 'Verkehrsverbund Berlin-Brandenburg',
		productbits => [qw[s u tram bus ferry ice regio]],
		request     => {
			client => {
				id   => 'VBB',
				type => 'WEB',
				name => 'VBB WebApp',
				l    => 'vs_webapp_vbb',
			},
			ext  => 'VBB.1',
			ver  => '1.33',
			auth => {
				type => 'AID',
				aid  => 'hafas-vb' . 'b-webapp',
			},
			lang => 'deu',
		},
	},
	VBN => {
		mgate       => 'https://fahrplaner.vbn.de/bin/mgate.exe',
		stopfinder  => 'https://fahrplaner.vbn.de/hafas/ajax-getstop.exe',
		name        => 'Verkehrsverbund Bremen/Niedersachsen',
		productbits => [qw[ice ice regio regio s bus ferry u tram ondemand]],
		salt        => 'SP31mBu' . 'fSyCLmNxp',
		micmac      => 1,
		request     => {
			client => {
				id   => 'VBN',
				v    => '6000000',
				type => 'IPH',
				name => 'vbn',
			},
			ver  => '1.42',
			auth => {
				type => 'AID',
				aid  => 'kaoxIXLn' . '03zCr2KR',
			},
			lang => 'deu',
		},
	},
);

# }}}
# {{{ Constructors

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

	my $ua = $conf{user_agent};

	if ( not $ua ) {
		my %lwp_options = %{ $conf{lwp_options} // { timeout => 10 } };
		$ua = LWP::UserAgent->new(%lwp_options);
		$ua->env_proxy;
	}

	if ( not $conf{station} and not $conf{journey} ) {
		confess('station or journey must be specified');
	}

	if ( not defined $service ) {
		$service = $conf{service} = 'DB';
	}

	if ( defined $service and not exists $hafas_instance{$service} ) {
		confess("The service '$service' is not supported");
	}

	my $now  = DateTime->now( time_zone => 'Europe/Berlin' );
	my $self = {
		active_service => $service,
		arrivals       => $conf{arrivals},
		cache          => $conf{cache},
		developer_mode => $conf{developer_mode},
		exclusive_mots => $conf{exclusive_mots},
		excluded_mots  => $conf{excluded_mots},
		messages       => [],
		results        => [],
		station        => $conf{station},
		ua             => $ua,
		now            => $now,
	};

	bless( $self, $obj );

	my $req;

	if ( $conf{journey} ) {
		$req = {
			svcReqL => [
				{
					meth => 'JourneyDetails',
					req  => {
						jid         => $conf{journey}{id},
						name        => $conf{journey}{name} // '0',
						getPolyline => $conf{with_polyline} ? \1 : \0,
					},
				}
			],
			%{ $hafas_instance{$service}{request} }
		};
	}
	else {
		my $date = ( $conf{datetime} // $now )->strftime('%Y%m%d');
		my $time = ( $conf{datetime} // $now )->strftime('%H%M%S');

		my $lid;
		if ( $self->{station} =~ m{ ^ [0-9]+ $ }x ) {
			$lid = 'A=1@L=' . $self->{station} . '@';
		}
		else {
			$lid = 'A=1@O=' . $self->{station} . '@';
		}

		my $mot_mask = 2**@{ $hafas_instance{$service}{productbits} } - 1;

		my %mot_pos;
		for my $i ( 0 .. $#{ $hafas_instance{$service}{productbits} } ) {
			$mot_pos{ $hafas_instance{$service}{productbits}[$i] } = $i;
		}

		if ( my @mots = @{ $self->{exclusive_mots} // [] } ) {
			$mot_mask = 0;
			for my $mot (@mots) {
				$mot_mask |= 1 << $mot_pos{$mot};
			}
		}

		if ( my @mots = @{ $self->{excluded_mots} // [] } ) {
			for my $mot (@mots) {
				$mot_mask &= ~( 1 << $mot_pos{$mot} );
			}
		}

		$req = {
			svcReqL => [
				{
					meth => 'StationBoard',
					req  => {
						type     => ( $conf{arrivals} ? 'ARR' : 'DEP' ),
						stbLoc   => { lid => $lid },
						dirLoc   => undef,
						maxJny   => 30,
						date     => $date,
						time     => $time,
						dur      => -1,
						jnyFltrL => [
							{
								type  => "PROD",
								mode  => "INC",
								value => $mot_mask
							}
						]
					},
				},
			],
			%{ $hafas_instance{$service}{request} }
		};
	}

	$self->{strptime_obj} //= DateTime::Format::Strptime->new(
		pattern   => '%Y%m%dT%H%M%S',
		time_zone => 'Europe/Berlin',
	);

	my $json = $self->{json} = JSON->new->utf8;

	# The JSON request is the cache key, so if we have a cache we must ensure
	# that JSON serialization is deterministic.
	if ( $self->{cache} ) {
		$json->canonical;
	}

	$req = $json->encode($req);
	$self->{post} = $req;

	my $url = $conf{url} // $hafas_instance{$service}{mgate};

	if ( my $salt = $hafas_instance{$service}{salt} ) {
		if ( $hafas_instance{$service}{micmac} ) {
			my $mic = md5_hex( $self->{post} );
			my $mac = md5_hex( $mic . $salt );
			$url .= "?mic=$mic&mac=$mac";
		}
		else {
			$url .= '?checksum=' . md5_hex( $self->{post} . $salt );
		}
	}

	if ( $conf{async} ) {
		$self->{url} = $url;
		return $self;
	}

	if ( $conf{json} ) {
		$self->{raw_json} = $conf{json};
	}
	else {
		if ( $self->{developer_mode} ) {
			say "requesting $req from $url";
		}

		my ( $content, $error ) = $self->post_with_cache($url);

		if ($error) {
			$self->{errstr} = $error;
			return $self;
		}

		if ( $self->{developer_mode} ) {
			say decode( 'utf-8', $content );
		}

		$self->{raw_json} = $json->decode($content);
	}

	$self->check_mgate;

	if ( $conf{journey} ) {
		$self->parse_journey;
	}
	else {
		$self->parse_board;
	}

	return $self;
}

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

	if ( not $conf{station} and not $conf{journey} ) {
		return $promise->reject('station or journey flag must be passed');
	}

	my $self = $obj->new( %conf, async => 1 );
	$self->{promise} = $conf{promise};

	$self->post_with_cache_p( $self->{url} )->then(
		sub {
			my ($content) = @_;
			$self->{raw_json} = $self->{json}->decode($content);
			$self->check_mgate;
			if ( $conf{journey} ) {
				$self->parse_journey;
			}
			else {
				$self->parse_board;
			}
			if ( $self->errstr ) {
				$promise->reject( $self->errstr );
			}
			else {
				$promise->resolve($self);
			}
			return;
		}
	)->catch(
		sub {
			my ($err) = @_;
			$promise->reject($err);
			return;
		}
	)->wait;

	return $promise;
}

# }}}
# {{{ Internal Helpers

sub post_with_cache {
	my ( $self, $url ) = @_;
	my $cache = $self->{cache};

	if ( $self->{developer_mode} ) {
		say "POST $url";
	}

	if ($cache) {
		my $content = $cache->thaw( $self->{post} );
		if ($content) {
			if ( $self->{developer_mode} ) {
				say '  cache hit';
			}
			return ( ${$content}, undef );
		}
	}

	if ( $self->{developer_mode} ) {
		say '  cache miss';
	}

	my $ua    = $self->{user_agent};
	my $reply = $self->{ua}->post(
		$url,
		'Content-Type' => 'application/json',
		Content        => $self->{post}
	);

	if ( $reply->is_error ) {
		return ( undef, $reply->status_line );
	}
	my $content = $reply->content;

	if ($cache) {
		say "freeeez";
		$cache->freeze( $self->{post}, \$content );
	}

	return ( $content, undef );
}

sub post_with_cache_p {
	my ( $self, $url ) = @_;
	my $cache = $self->{cache};

	if ( $self->{developer_mode} ) {
		say "POST $url";
	}

	my $promise = $self->{promise}->new;

	if ($cache) {
		my $content = $cache->thaw( $self->{post} );
		if ($content) {
			if ( $self->{developer_mode} ) {
				say '  cache hit';
			}
			return $promise->resolve( ${$content} );
		}
	}

	if ( $self->{developer_mode} ) {
		say '  cache miss';
	}

	$self->{ua}->post_p( $url, $self->{post} )->then(
		sub {
			my ($tx) = @_;
			if ( my $err = $tx->error ) {
				$promise->reject(
					"POST $url returned HTTP $err->{code} $err->{message}");
				return;
			}
			my $content = $tx->res->body;
			if ($cache) {
				$cache->freeze( $self->{post}, \$content );
			}
			$promise->resolve($content);
			return;
		}
	)->catch(
		sub {
			my ($err) = @_;
			$promise->reject($err);
			return;
		}
	)->wait;

	return $promise;
}

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

	if ( $self->{raw_json}{err} and $self->{raw_json}{err} ne 'OK' ) {
		$self->{errstr} = $self->{raw_json}{errTxt}
		  // 'error code is ' . $self->{raw_json}{err};
		$self->{errcode} = $self->{raw_json}{err};
	}
	elsif ( defined $self->{raw_json}{cInfo}{code}
		and $self->{raw_json}{cInfo}{code} ne 'OK'
		and $self->{raw_json}{cInfo}{code} ne 'VH' )
	{
		$self->{errstr}  = 'cInfo code is ' . $self->{raw_json}{cInfo}{code};
		$self->{errcode} = $self->{raw_json}{cInfo}{code};
	}
	elsif ( @{ $self->{raw_json}{svcResL} // [] } == 0 ) {
		$self->{errstr} = 'svcResL is empty';
	}
	elsif ( $self->{raw_json}{svcResL}[0]{err} ne 'OK' ) {
		$self->{errstr}
		  = 'svcResL[0].err is ' . $self->{raw_json}{svcResL}[0]{err};
		$self->{errcode} = $self->{raw_json}{svcResL}[0]{err};
	}

	return $self;
}

sub add_message {
	my ( $self, $json, $is_him ) = @_;

	my $short = $json->{txtS};
	my $text  = $json->{txtN};
	my $code  = $json->{code};
	my $prio  = $json->{prio};

	if ($is_him) {
		$short = $json->{head};
		$text  = $json->{text};
		$code  = $json->{hid};
	}

	# Some backends use remL for operator information. We don't want that.
	if ( $code eq 'OPERATOR' ) {
		return;
	}

	for my $message ( @{ $self->{messages} } ) {
		if ( $code eq $message->{code} and $text eq $message->{text} ) {
			$message->{ref_count}++;
			return $message;
		}
	}

	my $message = Travel::Status::DE::HAFAS::Message->new(
		short     => $short,
		text      => $text,
		code      => $code,
		prio      => $prio,
		is_him    => $is_him,
		ref_count => 1,
	);
	push( @{ $self->{messages} }, $message );
	return $message;
}

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

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

	my @locL    = @{ $self->{raw_json}{svcResL}[0]{res}{common}{locL} // [] };
	my $journey = $self->{raw_json}{svcResL}[0]{res}{journey};
	my @polyline;

	if ( $journey->{poly} ) {
		@polyline = decode_polyline( $journey->{poly}{crdEncYX} );
		for my $ref ( @{ $journey->{poly}{ppLocRefL} // [] } ) {
			my $poly = $polyline[ $ref->{ppIdx} ];
			my $loc  = $locL[ $ref->{locX} ];

			$poly->{name} = $loc->{name};
			$poly->{eva}  = $loc->{extId} + 0;
		}
	}

	$self->{result} = Travel::Status::DE::HAFAS::Journey->new(
		common   => $self->{raw_json}{svcResL}[0]{res}{common},
		journey  => $journey,
		polyline => \@polyline,
		hafas    => $self,
	);
}

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

	$self->{results} = [];

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

	my @jnyL = @{ $self->{raw_json}{svcResL}[0]{res}{jnyL} // [] };

	for my $result (@jnyL) {
		push(
			@{ $self->{results} },
			Travel::Status::DE::HAFAS::Journey->new(
				common  => $self->{raw_json}{svcResL}[0]{res}{common},
				journey => $result,
				hafas   => $self,
			)
		);
	}
	return $self;
}

# }}}
# {{{ Public Functions

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

	return $self->{errcode};
}

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

	return $self->{errstr};
}

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

	my $service = $self->{active_service};

	if ( $service and exists $hafas_instance{$service}{stopfinder} ) {

		my $sf = Travel::Status::DE::HAFAS::StopFinder->new(
			url            => $hafas_instance{$service}{stopfinder},
			input          => $self->{station},
			ua             => $self->{ua},
			developer_mode => $self->{developer_mode},
		);
		if ( my $err = $sf->errstr ) {
			$self->{errstr} = $err;
			return;
		}
		return $sf->results;
	}
	return;
}

sub messages {
	my ($self) = @_;
	return @{ $self->{messages} };
}

sub results {
	my ($self) = @_;
	return @{ $self->{results} };
}

sub result {
	my ($self) = @_;
	return $self->{result};
}

# static
sub get_services {
	my @services;
	for my $service ( sort keys %hafas_instance ) {
		my %desc = %{ $hafas_instance{$service} };
		$desc{shortname} = $service;
		push( @services, \%desc );
	}
	return @services;
}

# static
sub get_service {
	my ($service) = @_;

	if ( defined $service and exists $hafas_instance{$service} ) {
		return $hafas_instance{$service};
	}
	return;
}

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

	if ( defined $self->{active_service} ) {
		return $hafas_instance{ $self->{active_service} };
	}
	return;
}

# }}}

1;

__END__

=head1 NAME

Travel::Status::DE::HAFAS - Interface to HAFAS-based online arrival/departure
monitors

=head1 SYNOPSIS

	use Travel::Status::DE::HAFAS;

	my $status = Travel::Status::DE::HAFAS->new(
		station => 'Essen Hbf',
	);

	if (my $err = $status->errstr) {
		die("Request error: ${err}\n");
	}

	for my $departure ($status->results) {
		printf(
			"At %s: %s to %s from platform %s\n",
			$departure->time,
			$departure->line,
			$departure->destination,
			$departure->platform,
		);
	}

=head1 VERSION

version 4.00

=head1 DESCRIPTION

Travel::Status::DE::HAFAS is an interface to HAFAS-based
arrival/departure monitors using the mgate.exe interface.

It can report departures/arrivals at a specific station, or provide details
about a specific journey. It supports non-blocking operation via promises.

=head1 METHODS

=over

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

Requests departures/arrivals/journey as specified by I<opt> and returns a new
Travel::Status::DE::HAFAS element with the results.  Dies if the wrong
I<opt> were passed.

I<opt> must contain either a B<station> or a B<journey> flag:

=over

=item B<station> => I<station>

Request station board (arrivals or departures) for I<station>, e.g. "Essen HBf" or
"Alfredusbad, Essen (Ruhr)". Results are available via C<< $status->results >>.

=item B<journey> => B<{> B<id> => I<tripid> [, B<name> => I<line> ] B<}>

Request details about the journey identified by I<tripid> and I<line>.
The result is available via C<< $status->result >>.

=back

The following optional flags may be set:

=over

=item B<arrivals> => I<bool>

Request arrivals (if I<bool> is true) rather than departures (if I<bool> is
false or B<arrivals> is not specified).  Only relevant in station board mode.

=item B<cache> => I<Cache::File object>

Store HAFAS replies in the provided cache object.  This module works with
real-time data, so the object should be configured for an expiry of one to two
minutes.

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

Date and time to report for.  Defaults to now.  Only relevant in station board mode.

=item B<excluded_mots> => [I<mot1>, I<mot2>, ...]

By default, all modes of transport (trains, trams, buses etc.) are returned.
If this option is set, all modes appearing in I<mot1>, I<mot2>, ... will
be excluded. The supported modes depend on B<service>, use
B<get_services> or B<get_service> to get the supported values.
Only relevant in station board mode.

=item B<exclusive_mots> => [I<mot1>, I<mot2>, ...]

If this option is set, only the modes of transport appearing in I<mot1>,
I<mot2>, ...  will be returned.  The supported modes depend on B<service>, use
B<get_services> or B<get_service> to get the supported values.
Only relevant in station board mode.

=item B<lwp_options> => I<\%hashref>

Passed on to C<< LWP::UserAgent->new >>. Defaults to C<< { timeout => 10 } >>,
pass an empty hashref to call the LWP::UserAgent constructor without arguments.

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

Request results from I<service>, defaults to "DB".
See B<get_services> (and C<< hafas-m --list >>) for a list of supported
services.

=item B<with_polyline> => I<bool>

Request a polyline (series of geo-coordinates) indicating the train's route.
Only relevant in journey mode.

=back

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

Return a promise that resolves into a Travel::Status::DE::HAFAS instance
($status) on success and rejects with an error message ($status->errstr) 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->errcode

In case of an error in the HAFAS backend, returns the corresponding error code
as string. If no backend error occurred, returns undef.

=item $status->errstr

In case of an error in the HTTP request or HAFAS backend, returns a string
describing it.  If no error occurred, returns undef.

=item $status->results

Returns a list of arrivals/departures.  Each list element is a
Travel::Status::DE::HAFAS::Journey(3pm) object. Unavailable in journey mode.

If no matching results were found or the parser / http request failed, returns
undef.

=item $status->result

Returns a single Travel::Status::DE::HAFAS::Journey(3pm) object that describes
the requested journey. Unavailable in station board mode.

If no result was found or the parser / http request failed, returns undef.

=item $status->messages

Returns a list of Travel::Status::DE::HAFAS::Message(3pm) objects with
service messages. Each message belongs to at least one arrival/departure.

=item $status->similar_stops

Returns a list of hashrefs describing stops whose name is similar to the one
requested in the constructor's B<station> parameter. Returns nothing if
the active service does not support this feature.
This is most useful if B<errcode> returns 'H730', which means that the
HAFAS backend could not identify the stop.

See Travel::Status::DE::HAFAS::StopFinder(3pm)'s B<results> method for details
on the return value.

=item $status->get_active_service

Returns a hashref describing the active service when a service is active and
nothing otherwise. The hashref contains the keys B<url> (URL to the station
board service), B<stopfinder> (URL to the stopfinder service, if supported),
B<name>, and B<productbits> (arrayref describing the supported modes of
transport, may contain duplicates).

=item Travel::Status::DE::HAFAS::get_services()

Returns an array containing all supported HAFAS services. Each element is a
hashref and contains all keys mentioned in B<get_active_service>.
It also contains a B<shortname> key, which is the service name used by
the constructor's B<service> parameter.

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

Returns a hashref describing the service I<$service>. Returns nothing if
I<$service> is not supported. See B<get_active_service> for the hashref layout.

=back

=head1 DIAGNOSTICS

None.

=head1 DEPENDENCIES

=over

=item * Class::Accessor(3pm)

=item * DateTime(3pm)

=item * DateTime::Format::Strptime(3pm)

=item * LWP::UserAgent(3pm)

=back

=head1 BUGS AND LIMITATIONS

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

=head1 SEE ALSO

Travel::Status::DE::HAFAS::Journey(3pm), Travel::Status::DE::HAFAS::StopFinder(3pm).

=head1 AUTHOR

Copyright (C) 2015-2022 by Daniel Friesel E<lt>derf@finalrewind.orgE<gt>

=head1 LICENSE

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