package tasks::EnDashRedirectCreator;

=pod

=begin metadata

Bot:      AnomieBOT
Task:     EnDashRedirectCreator
BRFA:     Wikipedia:Bots/Requests for approval/AnomieBOT 74
Status:   Approved 2016-03-08
+BRFA:    Wikipedia:Bots/Requests for approval/AnomieBOT 80
+Status:  Approved 2020-06-19
Created:  2016-03-03

Create redirects for articles with titles containing en-dashes from the
corresponding title with ASCII hyphens. Update these redirects later as
targets change.

=end metadata

=cut

use utf8;
use strict;

use AnomieBOT::Task;
use Data::Dumper;
use Time::HiRes;
use vars qw/@ISA/;
@ISA=qw/AnomieBOT::Task/;

my @skipNs = (
    2, 3, # User, probably not useful in most cases
    14, 15, # Category, doesn't use normal redirects
    118, 119, # Draft, probably not useful
    446, 447, # Education Program, probably not useful
    828, 829, # Module, doesn't use normal redirects
    2300, 2301, # Gadget, probably doesn't use normal redirects
    2302, 2303, # Gadget definition, probably doesn't use normal redirects
    2600, 2601, # Topic, probably doesn't use normal redirects
);

# Titles that the bot can't and shouldn't create redirects for, to avoid logspam.
my %skipTitles = (
    0 => {
        "List_of_''Late_Night_with_Jimmy_Fallon''_episodes_(2013–14)" => 1,
    },
    6 => {
        "Velázquez_–_Bufón_don_Sebastián_de_Morra_(Museo_del_Prado,_c._1645).jpg" => 1,
    },
    10 => {
        "Location_map_Minneapolis–Saint_Paul" => 1,
    },
);

my %crossNsOk = (
    0 => 1, # Not actually cross
    4 => 1, # Wikipedia, not eligible for CSD:R2
    10 => 1, # Template, not eligible for CSD:R2
    12 => 1, # Help, not eligible for CSD:R2
    14 => 1, # Category, not eligible for CSD:R2
    100 => 1, # Portal, not eligible for CSD:R2
);

my %dashes = (
    '–' => 'en-dashes',
);

sub new {
    my $class = shift;
    my $self = $class->SUPER::new();
    bless $self, $class;
    return $self;
}

=pod

=for info
Approved 2016-03-08<br />[[Wikipedia:Bots/Requests for approval/AnomieBOT 74]]

=for info
Supplemental BFRA approved 2020-06-19<br />[[Wikipedia:Bots/Requests for approval/AnomieBOT 80]]

=cut

sub approved {
    return 3;
}

sub run {
    my ($self, $api) = @_;

    $api->task('EnDashRedirectCreator', 0, 10, qw/d::Redirects d::IWNS d::Talk d::Timestamp/);
    my $screwup=' Errors? [[User:'.$api->user.'/shutoff/EnDashRedirectCreator]]';

    my %ns = $api->namespace_map();
    my %rns = $api->namespace_reverse_map();

    my ($dbh);
    eval {
        ($dbh) = $api->connectToReplica( 'enwiki' );
    };
    if ( $@ ) {
        $api->warn( "Error connecting to replica: $@\n" );
        return 300;
    }

    my $cont = $self->{'dbcontinue'} // '';
    my $skipNs = join( ',', @skipNs );
    my $dashstr = join( '', keys %dashes );
    my $dashcond = join( ' OR ', map { "p1.page_title LIKE '%$_%'" } keys %dashes );

    # Spend a max of 5 minutes on this task before restarting
    my $endtime=time()+300;

    $dbh->do( q{SET NAMES 'utf8'} );

    my $actorIds;
    eval {
        $actorIds = join( ',', @{ $dbh->selectcol_arrayref( "SELECT actor_id FROM actor_user WHERE actor_name = 'AnomieBOT'" ) } );
    };
    if ( $@ ) {
        $api->warn( "Error fetching actor ID from replica: $@\n" );
        return 300;
    }

    while ( 1 ) {
        return 0 if $api->halting;

        # Load the list of redirects needing creation
        my @rows;
        my $t0 = Time::HiRes::time();
        eval {
            @rows = @{ $dbh->selectall_arrayref( qq{
                SET STATEMENT max_statement_time=300 FOR
                SELECT p1.page_namespace AS ns, p1.page_title AS title
                FROM page as p1
                    LEFT JOIN page AS p2 ON ( p1.page_namespace = p2.page_namespace AND REGEXP_REPLACE( CONVERT(p1.page_title USING utf8), '[$dashstr]', '-' ) = p2.page_title )
                    LEFT JOIN redirect AS r1 ON(r1.rd_from=p1.page_id)
                    LEFT JOIN redirect AS r2 ON(r2.rd_from=p2.page_id)
                WHERE
                    ($dashcond) AND p1.page_namespace NOT IN ($skipNs)
                    AND (
                        p2.page_id IS NULL
                        OR (
                            r2.rd_namespace != COALESCE( r1.rd_namespace, p1.page_namespace )
                            OR r2.rd_title != COALESCE( r1.rd_title, p1.page_title )
                            OR r2.rd_fragment != r1.rd_fragment
                        ) AND EXISTS( SELECT 1 FROM revision WHERE rev_page = p2.page_id AND rev_actor IN ($actorIds) AND rev_parent_id = 0 )
                    )
                    $cont
                ORDER BY p1.page_namespace, p1.page_title
                LIMIT 50
            }, { Slice => {} } ) };
        };
        if ( $@ ) {
            $api->warn( "Error fetching page list from replica: $@\n" );
            return 300;
        }
        my $t1 = Time::HiRes::time();
        $api->log( 'DB query took ' . ($t1-$t0) . ' seconds' );
        last unless @rows;

        my %redirects = ();
        for my $row (@rows) {
            utf8::decode( $row->{'title'} ); # Data from database is binary

            next if exists( $skipTitles{$row->{'ns'} & ~1}{$row->{'title')) );
            next if $row->{'ns'} == 10 && $row->{'title'} =~ m!^Editnotices/!; # None of these will be editable by the bot
            next if ( $row->{'ns'} & ~1 ) == 10 && $row->{'title'} =~ m!\.css$!; # Skip pages that will be TemplateStyles css, and their talk pages

            my $to = ( $row->{'ns'} ? $rns{$row->{'ns')) . ':' : '' ) . $row->{'title'};
            $to =~ s/_/ /g;
            my $from = $to;
            $from =~ s/[$dashstr]/-/g;
            $redirects{$to} = [ $from, $to, $to, undef ];
        }

        if ( %redirects ) {
            # Bypass double redirects and remove missing target pages
            my $res = $api->query(
                titles => join('|', keys %redirects),
                redirects => 1
            );
            if($res->{'code'} ne 'success'){
                $api->warn("Failed to retrieve redirect list: ".$res->{'error'}."\n");
                return 60;
            }
            my %map = ();
            if ( exists($res->{'query'}{'normalized'} ) ) {
                $map{$_->{'from')) = [ $_->{'to'}, $_->{'tofragment'} // undef ] foreach @{$res->{'query'}{'normalized'));
            }
            if ( exists($res->{'query'}{'redirects'} ) ) {
                $map{$_->{'from')) = [ $_->{'to'}, $_->{'tofragment'} // undef ] foreach @{$res->{'query'}{'redirects'));
            }
            my %exists = ();
            if ( exists($res->{'query'}{'pages'} ) ) {
                for my $p (values %{$res->{'query'}{'pages'))) {
                    $exists{$p->{'title')) = 1 if $p->{'pageid'}//0;
                }
            }
            while( my ($key, $targets) = each( %redirects ) ) {
                my ($redir, $origtarget, $target, $fragment) = @$targets;
                my %seen=( $target => 1 );
                while ( exists( $map{$target} ) ) {
                    $fragment = $map{$target}[1] // $fragment;
                    $target = $map{$target}[0];
                    $redirects{$key} = [ $redir, $origtarget, $target, $fragment ];
                    if ( exists( $seen{$target} ) ) {
                        $api->warn("Redirect loop involving [[$target]]");
                        delete $redirects{$key};
                        last;
                    }
                    $seen{$target}=1;
                }
                delete $redirects{$key} unless exists( $exists{$target} );
            }

            # Now, create the redirects
            while( my ($key, $targets) = each( %redirects ) ) {
                return 0 if $api->halting;

                my ($redir, $origtarget, $target, $fragment) = @$targets;

                my $tok=$api->edittoken($redir, EditRedir => 1, imageinfo => { prop => '', limit => 1 });
                if($tok->{'code'} eq 'shutoff'){
                    $api->warn("Task disabled: ".$tok->{'content'}."\n");
                    return 300;
                }
                if($tok->{'code'} ne 'success'){
                    $api->warn("Failed to get edit token for $redir: ".$tok->{'error'}."\n");
                    next;
                }
                if ( !exists( $tok->{'missing'} ) ) {
                    my $res = $api->query(
                        titles => $redir,
                        prop => 'revisions',
                        rvprop => 'user',
                        rvdir => 'newer',
                        rvlimit => 1,
                        formatversion => 2,
                    );
                    my $user = $res->{'query'}{'pages'}[0]{'revisions'}[0]{'user'} // '';
                    if ( $user ne 'AnomieBOT' ) {
                        $api->log("$redir already exists and wasn't originally created by the bot, skipping");
                        next;
                    }

                    my $txt = $tok->{'revisions'}[0]{'slots'}{'main'}{'*'};
                    if ( $txt =~ m!\{\{User:AnomieBOT/Auto-G8\|target=(.*?)\}\}! && $1 ne $origtarget ) {
                        my $oldtarget = $1;
                        my $tmp = $oldtarget;
                        $tmp =~ s/[$dashstr]/-/gu;
                        if ( $tmp eq $redir ) {
                            $api->warn("[[$redir]] apparently exists for both [[$oldtarget]] and [[$origtarget]], not updating");
                            next;
                        }
                        $api->warn("[[$redir]] claims to exist for [[$oldtarget]], but that's not valid so overwriting");
                    }
                }
                if ( exists( $tok->{'imagerepository'} ) && $tok->{'imagerepository'} ne '' ) {
                    $api->log("$redir is an existing image (repo=$tok->{imagerepository}), skipping");
                    next;
                }

                my $redirNs = ( $redir =~ /^([^:]+):/ && exists( $ns{$1} ) ? $ns{$1} : 0 );
                my $targetNs = ( $target =~ /^([^:]+):/ && exists( $ns{$1} ) ? $ns{$1} : 0 );

                if ( $redirNs == 0 && !( $crossNsOk{$targetNs} // 0 ) ) {
                    $api->log("$redir to $target would be a cross-namespace redirect, skipping");
                    next;
                }

                if ( $redirNs == 1 && !( $crossNsOk{$targetNs & ~1} // 0 ) ) {
                    $api->log("$redir to $target is the talk page of what would be a cross-namespace redirect, skipping");
                    next;
                }

                if ( $targetNs == 7 ) {
                    # Special rule for File talk: If the corresponding file doesn't exist, forget it.
                    my $n = $target;
                    $n =~ s/^[^:]*/File/;
                    my $res = $api->query( titles => $n );
                    if($res->{'code'} eq 'shutoff'){
                        $api->warn("Task disabled: ".$res->{'content'}."\n");
                        return 300;
                    }
                    if($res->{'code'} ne 'success'){
                        $api->warn("Failed to get status for $n: ".$res->{'error'}."\n");
                        next;
                    }
                    if ( exists( (values %{$res->{'query'}{'pages')) )[0]{'missing'} ) ) {
                        #$api->log("File talk page redirect [[$redir]] -> [[$target]] has no corresponding target file page, skipping");
                        next;
                    }
                }

                $target .= '#' . $fragment if defined( $fragment );
                my $tosection = defined( $fragment ) ? "\n((R to section))" : '';
                my $double = $origtarget eq $target ? '' : "\n((R avoided double redirect|1=$origtarget))";
                my $txt = "#REDIRECT [[:$target]]\n\n((Redirect category shell|\n((R from modification|1=((-r|1=$origtarget))))$double$tosection\n))\n((User:AnomieBOT/Auto-G8|target=$origtarget))";
                my $summary;
                if ( exists( $tok->{'missing'} ) ) {
                    my @what = ();
                    while ( my ($char, $what) = each %dashes ) {
                        push @what, $what if $origtarget =~ /$char/;
                    }
                    $what[$#what] = 'and ' . $what[$#what] if @what > 1;
                    my $what = join( @what > 2 ? ", " : " ", @what );
                    $summary = "Redirecting to [[:$origtarget]] because titles with $what are hard to type";
                } else {
                    $summary = "Updating redirect to [[:$origtarget]]";
                }
                $summary.=" (and resolving the double redirect to [[:$target]])" if $origtarget ne $target;

                # Create/update page
                $api->log("$summary in $redir");
                my $r = $api->edit($tok, $txt, "$summary. $screwup", 0, 1);
                if($r->{'code'} ne 'success'){
                    $api->warn("Write failed on $redir: ".$r->{'error'}."\n");
                    next;
                }

                # Check for edit warring.
                if ( ! exists( $tok->{'missing'} ) ) {
                    my $res = $api->query(
                        titles => $redir,
                        prop => 'revisions',
                        rvprop => 'user|sha1',
                        rvlimit => 'max',
                        rvend => $api->timestamp2ISO( time() - 30 * 86400 ),
                        formatversion => 2,
                    );
                    my %shas = ();
                    my $bot1058 = 0;
                    for my $rev (@{$res->{'query'}{'pages'}[0]{'revisions'))) {
                        $shas{$rev->{'sha1')) = ( $shas{$rev->{'sha1')) // -1 ) + 1;
                        $bot1058++ if $rev->{'user'} eq 'Bot1058';
                    }
                    my $ct = 0;
                    for my $sha (keys %shas) {
                        $ct += $shas{$sha};
                    }
                    if ( $ct > 2 ) {
                        my $extra = $bot1058 > 2 ? "If it's AnomieBOT and Bot1058 fighting, that probably means ((-r|1=$origtarget)) needs to be updated to match ((-r|1=((subst:SUBJECTPAGENAME:$origtarget)))) or vice versa." : "";
                        $api->whine( "Possible edit warring on [[:$redir]]", "In the past 30 days, there appear to have been $ct reverts on ((-r|1=$redir)). This suggests that vandalism or edit warring of some sort may be occurring (there or on ((-r|1=$origtarget))). A human should look into it. $extra" );
                    }
                }

                # If we've been at it long enough, let another task have a go.
                return 0 if time()>=$endtime;
            }
        }

        # On the next time around, skip any we've already processed this run
        my ($ns, $title) = @{$rows[$#rows]}{'ns','title'};
        $title = $dbh->quote( $title );
        $cont = " AND (p1.page_namespace > $ns OR p1.page_namespace = $ns AND p1.page_title > $title)";
        $self->{'dbcontinue'} = $cont;

        # If we've been at it long enough, let another task have a go.
        return 0 if time()>=$endtime;
    }

    $self->{'dbcontinue'} = '';

    return 21600;
}

1;