#!/usr/bin/env perl

use strict;
use warnings;
use 5.010;

use File::Slurp qw(read_file write_file);
use JSON;
use List::Util qw(any);
use XML::LibXML;

# old / new / renamed / reappeared / missing
my $mode  = shift;
my $extra = shift // q{};

if ( $extra eq 'if-active' ) {
	use Travel::Status::DE::IRIS;
}

my $json     = JSON->new->utf8;
my $json_str = read_file('stations.json');
my $stations = $json->decode($json_str);
@{$stations}
  = sort { $a->{name} cmp $b->{name} or $a->{eva} <=> $b->{eva} } @{$stations};

$json_str = read_file('old_stations.json');
my $old_stations = $json->decode($json_str);
@{$old_stations} = sort { $a->{name} cmp $b->{name} or $a->{eva} <=> $b->{eva} }
  @{$old_stations};

my %station_by_ds100;
for my $station ( @{$stations} ) {
	$station_by_ds100{ $station->{ds100} } = $station;
}

my %old_station_by_ds100;
for my $old_station ( @{$old_stations} ) {
	$old_station_by_ds100{ $old_station->{ds100} } = $old_station;
}

my %station_by_eva;
for my $station ( @{$stations} ) {
	$station_by_eva{ $station->{eva} } = $station;
}

my %old_station_by_eva;
for my $old_station ( @{$old_stations} ) {
	$old_station_by_eva{ $old_station->{eva} } = $old_station;
}

my %station_by_name;
for my $station ( @{$stations} ) {
	push( @{ $station_by_name{ $station->{name} } }, $station );
}

my %old_station_by_name;
for my $old_station ( @{$old_stations} ) {
	push( @{ $old_station_by_name{ $old_station->{name} } }, $old_station );
}

my %xml_by_ds100;
my %xml_by_eva;
my %xml_by_name;

my $xml_str = read_file('stations.xml');
my $tree    = XML::LibXML->load_xml( string => $xml_str );

my @missing;

sub add_station {
	my ( $name, $ds100, $eva ) = @_;
	my $station = {
		name  => $name,
		ds100 => $ds100,
		eva   => $eva,
	};
	push( @{$stations}, $station );
	$station_by_eva{$eva}     = $station;
	$station_by_ds100{$ds100} = $station;
	push( @{ $station_by_name{$name} }, $station );
}

sub add_old_station {
	my ( $name, $ds100, $eva, $latlong ) = @_;
	my $station = {
		name    => $name,
		ds100   => $ds100,
		eva     => $eva,
		latlong => $latlong
	};
	push( @{$old_stations}, $station );
	$old_station_by_eva{$eva}     = $station;
	$old_station_by_ds100{$ds100} = $station;
	push( @{ $old_station_by_name{$name} }, $station );
}

sub delete_station {
	my ( $name, $ds100, $eva ) = @_;
	delete $station_by_name{$name};
	delete $station_by_ds100{$ds100};
	delete $station_by_eva{$eva};
	@{$stations} = grep {
		$_->{name} ne $name and $_->{ds100} ne $ds100 and $_->{eva} != $eva
	} @{$stations};
}

sub delete_old_station {
	my ( $name, $ds100, $eva ) = @_;
	delete $old_station_by_name{$name};
	delete $old_station_by_ds100{$ds100};
	delete $old_station_by_eva{$eva};
	@{$old_stations} = grep {
		$_->{name} ne $name and $_->{ds100} ne $ds100 and $_->{eva} != $eva
	} @{$old_stations};
}

sub has_departures {
	my ($eva) = @_;

	my $status = Travel::Status::DE::IRIS->new(
		station    => $eva,
		lookbehind => 120,
		lookahead  => 240
	);

	if ( $status->results ) {
		return 1;
	}
	return;
}

# TODO falls ein eintrag aus old_stations im XML auftaucht sollte er aus old_stations raus und wieder in stations rein

if ( -e 'missing.txt' ) {
	for my $line ( read_file('missing.txt') ) {
		chomp $line;
		push( @missing, $line );
	}
}

my %renamed;
if ( -e 'renamed.json' ) {
	$json_str = read_file('renamed.json');
	%renamed  = %{ $json->decode($json_str) };
}

for my $station ( $tree->findnodes('//station') ) {
	my $name  = $station->getAttribute('name');
	my $eva   = $station->getAttribute('eva');
	my $ds100 = $station->getAttribute('ds100');
	my $is_db = $station->getAttribute('db') eq 'true';

	my $xml_station = {
		name  => $name,
		eva   => $eva,
		ds100 => $ds100,
		is_db => $is_db,
	};
	$xml_by_ds100{$ds100} = $xml_station;
	$xml_by_eva{$eva}     = $xml_station;

	if ( exists $xml_by_eva{$name} ) {
		push( @{ $xml_by_name{$name}{extra} }, $xml_station );
	}
	else {
		$xml_by_name{$name} = $xml_station;
	}
}

for my $station ( $tree->findnodes('//station') ) {
	my $name  = $station->getAttribute('name');
	my $eva   = $station->getAttribute('eva');
	my $ds100 = $station->getAttribute('ds100');
	my $is_db = $station->getAttribute('db') eq 'true';

	my $found = 0;

	if ( $station_by_name{$name} or $station_by_eva{$eva} ) {
		$found = 1;
	}

	if (    $station_by_ds100{$ds100}
		and $station_by_ds100{$ds100}{name} ne $name )
	{
		printf( "%8s has been renamed: %30s -> %30s\n",
			$ds100, $station_by_ds100{$ds100}{name}, $name );
		if ( not $mode or $mode eq 'renamed' ) {
			$renamed{ $station_by_ds100{$ds100}{name} } = $name;
			$station_by_ds100{$ds100}{name} = $name;
		}
	}
	elsif ( $station_by_eva{$eva} and $station_by_eva{$eva}{name} ne $name ) {
		printf(
			"%d mismatch: (%s -> %s), (%s -> %s)\n",
			$eva,  $station_by_eva{$eva}{name},
			$name, $station_by_eva{$eva}{ds100}, $ds100
		);
	}
	elsif ( $station_by_name{$name}
		and not any { $_->{ds100} eq $ds100 } @{ $station_by_name{$name} }
		and $is_db )
	{
		printf( "%30s has a new DS100 alias: %8s\n", $name, $ds100 );
		if ( not $mode or $mode eq 'new' ) {
			add_station( $name, $ds100, $eva );
		}
	}
	elsif ( $station_by_name{$name}
		and not any { $_->{eva} == $eva } @{ $station_by_name{$name} }
		and $is_db )
	{
		printf( "%30s has a new EVA alias: %d\n", $name, $eva );
		if ( not $mode or $mode eq 'new' ) {
			add_station( $name, $ds100, $eva );
		}
	}

	if (
		$name !~ m{Betriebsstelle nicht bekannt}
		and my $old = (
			$old_station_by_name{$name} // $old_station_by_ds100{$ds100}
			  // $old_station_by_eva{$eva}
		)
	  )
	{
		printf( "%30s has re-appeared as %s %d\n", $name, $ds100, $eva );
		if ( not $mode or $mode eq 'reappeared' ) {
			if ( $extra ne 'if-active' or has_departures($eva) ) {
				if ( ref($old) eq 'ARRAY' ) {
					for my $o ( @{$old} ) {
						delete_old_station( $o->{name}, $o->{ds100},
							$o->{eva} );
					}
				}
				else {
					delete_old_station( $old->{name}, $old->{ds100},
						$old->{eva} );
				}
				add_station( $name, $ds100, $eva );
			}
			if ( $extra eq 'if-active' ) {
				sleep(1);
			}
		}
	}

	if ( not $found
		and any { $_ eq $name or $_ eq $ds100 } @missing )
	{
		say "missing $eva  $ds100  \"$name\"";

		if ( not $mode or $mode eq 'missing' ) {
			add_station( $name, $ds100, $eva );
			if ( $old_station_by_name{$name} ) {
				delete_old_station( $name, $ds100, $eva );
			}
		}
	}
}

my @to_delete;

for my $i ( 0 .. $#{$stations} ) {
	$stations->[$i]{eva} = 0 + $stations->[$i]{eva};
	my $j_station = $stations->[$i];
	my $j_name    = $j_station->{name};
	my $j_ds100   = $j_station->{ds100};
	my $j_eva     = $j_station->{eva};

	if ( not( $xml_by_name{$j_name} or $xml_by_eva{$j_eva} ) ) {
		say "station no longer exists: $j_eva  $j_ds100  \"$j_name\"";
		if ( not $mode or $mode eq 'old' ) {
			unshift( @to_delete, $i );
			add_old_station( $j_name, $j_ds100, $j_eva, $j_station->{latlong} );
		}
	}
}

for my $i ( 0 .. $#{$old_stations} ) {
	$old_stations->[$i]{eva} = 0 + $old_stations->[$i]{eva};
}

for my $i (@to_delete) {
	splice( @{$stations}, $i, 1 );
}

my $json_out = $json->canonical->pretty->encode($stations);
write_file( 'stations.json', $json_out );

$json_out = $json->canonical->pretty->encode($old_stations);
write_file( 'old_stations.json', $json_out );

$json_out = $json->encode( \%renamed );
write_file( 'renamed.json', $json_out );