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

use Pod::Usage ();
use Getopt::Long ();

BEGIN {
    eval "require MediaWiki::API; require YAML::XS;" or do {
        print "You have to install some modules via CPAN to run this:\n";
        print "   sudo cpanp MediaWiki::API YAML::XS\n";
        exit 1;
    };
}

use MediaWiki::API;
use YAML::XS qw(Dump);
use Test::More 'no_plan';

=head1 NAME

update-key-and-tag-description-pages-from-wiki - Screen-scrape the wiki for key/value wiki description pages

=head1 SYNOPSIS

    perl script/misc/update-key-and-tag-description-pages-from-wiki config/wiki-tag-and-key-description.yml 

=head1 BUGS

This will break if there are more than 500 key or value pages. Paging
needs to be implemenented.

That or using a proper API or something (if it's there) or making a
direct query to the wiki database.

=cut

# Get the command-line options
Getopt::Long::Parser->new(
    config => [ qw< bundling no_ignore_case no_require_order pass_through > ],
)->getoptions(
    'h|help' => \my $help,
) or help();

# On --help
help() if $help;

help() unless $ARGV[0];

# Get a API interface
my $mw = MediaWiki::API->new();
ok($mw, "Got a MediaWiki API");
$mw->{config}->{api_url} = 'http://wiki.openstreetmap.org/w/api.php';

# All our goodies
my (%feature, %count);

# This is what you get on:
## http://wiki.openstreetmap.org/w/index.php?search=Template:KeyDescription&fulltext=Search&fulltext=Search
for my $lang ('', map { "${_}:" } qw[ Pt Fi De It HU Cz Fr RU Pl ]) {
    ok(1, "  Templates for language '$lang'");

    # Key pages
    ok(1, "    Getting key pages");
    my $cnt = stick_content_in_hash("key", "Template:${lang}KeyDescription", \%feature);
    ok(1, "    Got $cnt key pages");
    $count{key} += $cnt;

    # Value pages
    ok(1, "    Getting value pages");
    my $cnt = stick_content_in_hash("tag", "Template:${lang}ValueDescription", \%feature);
    ok(1, "    Got $cnt value pages");
    $count{value} += $cnt;
}

ok(1, "Got a total of $count{$_} ${_}s") for qw[ key value ];

# Dump to .yml file
open my $out, ">", $ARGV[0] or die "Can't open file '$ARGV[0]' supplied on the command line";
say $out "# THIS FILE IS AUTOGENERATED WITH THE script/misc/update-key-and-tag-description-pages-from-wiki";
say $out "# PROGRAM DO NOT MANUALLY EDIT IT";
say $out "";
say $out Dump(\%feature);
close $out;

exit 0;

sub stick_content_in_hash
{
    my ($key, $title, $hash) = @_;
    my $ukey = ucfirst $key;

    my $space_to_underscore = sub {
        my $txt = shift;
        $txt =~ s/ /_/g;
        $txt;
    };

    my $count = 0;
    get_embeddedin(
        $title,
        sub {
            my ($links) = @_;
            my (@links) = @$links;
            ok(1, "    ... got " . scalar(@links) . " more links");
            for my $link (@links) {
                $count++;
                my $title = $link->{title};

                if ($title =~ /^$ukey:(?<key_name>.*?)$/) {
                    # English by default
                    $hash->{en}->{$key}->{ $space_to_underscore->($+{key_name}) } = $title;
                } elsif ($title =~ /^(?<lang>[^:]+):$ukey:(?<key_name>.*?)$/) {
                    $hash->{lc $+{lang}}->{$key}->{ $space_to_underscore->($+{key_name}) } = $title;
                }
            }
        }
    );

    return $count;
}

sub get_embeddedin
{
    my ($title, $callback) = @_;
    my $articles = $mw->list(
        {
            action => 'query',
            list => 'embeddedin',
            eititle => $title,
            eifilterredir => 'nonredirects',
            # Doesn't work for De:* and anything non-en. Odd.
            # einamespace => '0|8',
            eilimit => '200',
        },
        {
            max => '0',
            hook => $callback,
            skip_encoding => 1,
        }
    ) || die $mw->{error}->{code} . ': ' . $mw->{error}->{details};
}

sub help
{
    my %arg = @_;

    Pod::Usage::pod2usage(
        -verbose => $arg{ verbose },
        -exitval => $arg{ exitval } || 0,
    );
}