Merge "Use adaptive CDN TTLs for page views"

[mediawiki.git] / includes / actions / InfoAction.php

<?php
/**
 * Displays information about a page.
 *
 * Copyright © 2011 Alexandre Emsenhuber
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * @file
 * @ingroup Actions
 */

use MediaWiki\MediaWikiServices;

/**
 * Displays information about a page.
 *
 * @ingroup Actions
 */
class InfoAction extends FormlessAction {
        const VERSION = 1;

        /**
         * Returns the name of the action this object responds to.
         *
         * @return string Lowercase name
         */
        public function getName() {
                return 'info';
        }

        /**
         * Whether this action can still be executed by a blocked user.
         *
         * @return bool
         */
        public function requiresUnblock() {
                return false;
        }

        /**
         * Whether this action requires the wiki not to be locked.
         *
         * @return bool
         */
        public function requiresWrite() {
                return false;
        }

        /**
         * Clear the info cache for a given Title.
         *
         * @since 1.22
         * @param Title $title Title to clear cache for
         * @param int|null $revid Revision id to clear
         */
        public static function invalidateCache( Title $title, $revid = null ) {
                if ( !$revid ) {
                        $revision = Revision::newFromTitle( $title, 0, Revision::READ_LATEST );
                        $revid = $revision ? $revision->getId() : null;
                }
                if ( $revid !== null ) {
                        $key = self::getCacheKey( $title, $revid );
                        ObjectCache::getMainWANInstance()->delete( $key );
                }
        }

        /**
         * Shows page information on GET request.
         *
         * @return string Page information that will be added to the output
         */
        public function onView() {
                $content = '';

                // Validate revision
                $oldid = $this->page->getOldID();
                if ( $oldid ) {
                        $revision = $this->page->getRevisionFetched();

                        // Revision is missing
                        if ( $revision === null ) {
                                return $this->msg( 'missing-revision', $oldid )->parse();
                        }

                        // Revision is not current
                        if ( !$revision->isCurrent() ) {
                                return $this->msg( 'pageinfo-not-current' )->plain();
                        }
                }

                // Page header
                if ( !$this->msg( 'pageinfo-header' )->isDisabled() ) {
                        $content .= $this->msg( 'pageinfo-header' )->parse();
                }

                // Hide "This page is a member of # hidden categories" explanation
                $content .= Html::element( 'style', [],
                        '.mw-hiddenCategoriesExplanation { display: none; }' ) . "\n";

                // Hide "Templates used on this page" explanation
                $content .= Html::element( 'style', [],
                        '.mw-templatesUsedExplanation { display: none; }' ) . "\n";

                // Get page information
                $pageInfo = $this->pageInfo();

                // Allow extensions to add additional information
                Hooks::run( 'InfoAction', [ $this->getContext(), &$pageInfo ] );

                // Render page information
                foreach ( $pageInfo as $header => $infoTable ) {
                        // Messages:
                        // pageinfo-header-basic, pageinfo-header-edits, pageinfo-header-restrictions,
                        // pageinfo-header-properties, pageinfo-category-info
                        $content .= $this->makeHeader( $this->msg( "pageinfo-${header}" )->escaped() ) . "\n";
                        $table = "\n";
                        foreach ( $infoTable as $infoRow ) {
                                $name = ( $infoRow[0] instanceof Message ) ? $infoRow[0]->escaped() : $infoRow[0];
                                $value = ( $infoRow[1] instanceof Message ) ? $infoRow[1]->escaped() : $infoRow[1];
                                $id = ( $infoRow[0] instanceof Message ) ? $infoRow[0]->getKey() : null;
                                $table = $this->addRow( $table, $name, $value, $id ) . "\n";
                        }
                        $content = $this->addTable( $content, $table ) . "\n";
                }

                // Page footer
                if ( !$this->msg( 'pageinfo-footer' )->isDisabled() ) {
                        $content .= $this->msg( 'pageinfo-footer' )->parse();
                }

                return $content;
        }

        /**
         * Creates a header that can be added to the output.
         *
         * @param string $header The header text.
         * @return string The HTML.
         */
        protected function makeHeader( $header ) {
                $spanAttribs = [ 'class' => 'mw-headline', 'id' => Sanitizer::escapeId( $header ) ];

                return Html::rawElement( 'h2', [], Html::element( 'span', $spanAttribs, $header ) );
        }

        /**
         * Adds a row to a table that will be added to the content.
         *
         * @param string $table The table that will be added to the content
         * @param string $name The name of the row
         * @param string $value The value of the row
         * @param string $id The ID to use for the 'tr' element
         * @return string The table with the row added
         */
        protected function addRow( $table, $name, $value, $id ) {
                return $table .
                        Html::rawElement(
                                'tr',
                                $id === null ? [] : [ 'id' => 'mw-' . $id ],
                                Html::rawElement( 'td', [ 'style' => 'vertical-align: top;' ], $name ) .
                                        Html::rawElement( 'td', [], $value )
                        );
        }

        /**
         * Adds a table to the content that will be added to the output.
         *
         * @param string $content The content that will be added to the output
         * @param string $table The table
         * @return string The content with the table added
         */
        protected function addTable( $content, $table ) {
                return $content . Html::rawElement( 'table', [ 'class' => 'wikitable mw-page-info' ],
                        $table );
        }

        /**
         * Returns page information in an easily-manipulated format. Array keys are used so extensions
         * may add additional information in arbitrary positions. Array values are arrays with one
         * element to be rendered as a header, arrays with two elements to be rendered as a table row.
         *
         * @return array
         */
        protected function pageInfo() {
                global $wgContLang;

                $user = $this->getUser();
                $lang = $this->getLanguage();
                $title = $this->getTitle();
                $id = $title->getArticleID();
                $config = $this->context->getConfig();
                $linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();

                $pageCounts = $this->pageCounts( $this->page );

                $pageProperties = [];
                $props = PageProps::getInstance()->getAllProperties( $title );
                if ( isset( $props[$id] ) ) {
                        $pageProperties = $props[$id];
                }

                // Basic information
                $pageInfo = [];
                $pageInfo['header-basic'] = [];

                // Display title
                $displayTitle = $title->getPrefixedText();
                if ( isset( $pageProperties['displaytitle'] ) ) {
                        $displayTitle = $pageProperties['displaytitle'];
                }

                $pageInfo['header-basic'][] = [
                        $this->msg( 'pageinfo-display-title' ), $displayTitle
                ];

                // Is it a redirect? If so, where to?
                if ( $title->isRedirect() ) {
                        $pageInfo['header-basic'][] = [
                                $this->msg( 'pageinfo-redirectsto' ),
                                Linker::link( $this->page->getRedirectTarget() ) .
                                $this->msg( 'word-separator' )->escaped() .
                                $this->msg( 'parentheses' )->rawParams( Linker::link(
                                        $this->page->getRedirectTarget(),
                                        $this->msg( 'pageinfo-redirectsto-info' )->escaped(),
                                        [],
                                        [ 'action' => 'info' ]
                                ) )->escaped()
                        ];
                }

                // Default sort key
                $sortKey = $title->getCategorySortkey();
                if ( isset( $pageProperties['defaultsort'] ) ) {
                        $sortKey = $pageProperties['defaultsort'];
                }

                $sortKey = htmlspecialchars( $sortKey );
                $pageInfo['header-basic'][] = [ $this->msg( 'pageinfo-default-sort' ), $sortKey ];

                // Page length (in bytes)
                $pageInfo['header-basic'][] = [
                        $this->msg( 'pageinfo-length' ), $lang->formatNum( $title->getLength() )
                ];

                // Page ID (number not localised, as it's a database ID)
                $pageInfo['header-basic'][] = [ $this->msg( 'pageinfo-article-id' ), $id ];

                // Language in which the page content is (supposed to be) written
                $pageLang = $title->getPageLanguage()->getCode();

                if ( $config->get( 'PageLanguageUseDB' )
                        && $this->getTitle()->userCan( 'pagelang', $this->getUser() )
                ) {
                        // Link to Special:PageLanguage with pre-filled page title if user has permissions
                        $titleObj = SpecialPage::getTitleFor( 'PageLanguage', $title->getPrefixedText() );
                        $langDisp = Linker::link(
                                $titleObj,
                                $this->msg( 'pageinfo-language' )->escaped()
                        );
                } else {
                        // Display just the message
                        $langDisp = $this->msg( 'pageinfo-language' )->escaped();
                }

                $pageInfo['header-basic'][] = [ $langDisp,
                        Language::fetchLanguageName( $pageLang, $lang->getCode() )
                        . ' ' . $this->msg( 'parentheses', $pageLang )->escaped() ];

                // Content model of the page
                $modelHtml = htmlspecialchars( ContentHandler::getLocalizedName( $title->getContentModel() ) );
                // If the user can change it, add a link to Special:ChangeContentModel
                if ( $title->quickUserCan( 'editcontentmodel' ) ) {
                        $modelHtml .= ' ' . $this->msg( 'parentheses' )->rawParams( $linkRenderer->makeLink(
                                SpecialPage::getTitleValueFor( 'ChangeContentModel', $title->getPrefixedText() ),
                                $this->msg( 'pageinfo-content-model-change' )->text()
                        ) )->escaped();
                }

                $pageInfo['header-basic'][] = [
                        $this->msg( 'pageinfo-content-model' ),
                        $modelHtml
                ];

                if ( $title->inNamespace( NS_USER ) ) {
                        $pageUser = User::newFromName( $title->getRootText() );
                        if ( $pageUser && $pageUser->getId() && !$pageUser->isHidden() ) {
                                $pageInfo['header-basic'][] = [
                                        $this->msg( 'pageinfo-user-id' ),
                                        $pageUser->getId()
                                ];
                        }
                }

                // Search engine status
                $pOutput = new ParserOutput();
                if ( isset( $pageProperties['noindex'] ) ) {
                        $pOutput->setIndexPolicy( 'noindex' );
                }
                if ( isset( $pageProperties['index'] ) ) {
                        $pOutput->setIndexPolicy( 'index' );
                }

                // Use robot policy logic
                $policy = $this->page->getRobotPolicy( 'view', $pOutput );
                $pageInfo['header-basic'][] = [
                        // Messages: pageinfo-robot-index, pageinfo-robot-noindex
                        $this->msg( 'pageinfo-robot-policy' ),
                        $this->msg( "pageinfo-robot-${policy['index']}" )
                ];

                $unwatchedPageThreshold = $config->get( 'UnwatchedPageThreshold' );
                if (
                        $user->isAllowed( 'unwatchedpages' ) ||
                        ( $unwatchedPageThreshold !== false &&
                                $pageCounts['watchers'] >= $unwatchedPageThreshold )
                ) {
                        // Number of page watchers
                        $pageInfo['header-basic'][] = [
                                $this->msg( 'pageinfo-watchers' ),
                                $lang->formatNum( $pageCounts['watchers'] )
                        ];
                        if (
                                $config->get( 'ShowUpdatedMarker' ) &&
                                isset( $pageCounts['visitingWatchers'] )
                        ) {
                                $minToDisclose = $config->get( 'UnwatchedPageSecret' );
                                if ( $pageCounts['visitingWatchers'] > $minToDisclose ||
                                        $user->isAllowed( 'unwatchedpages' ) ) {
                                        $pageInfo['header-basic'][] = [
                                                $this->msg( 'pageinfo-visiting-watchers' ),
                                                $lang->formatNum( $pageCounts['visitingWatchers'] )
                                        ];
                                } else {
                                        $pageInfo['header-basic'][] = [
                                                $this->msg( 'pageinfo-visiting-watchers' ),
                                                $this->msg( 'pageinfo-few-visiting-watchers' )
                                        ];
                                }
                        }
                } elseif ( $unwatchedPageThreshold !== false ) {
                        $pageInfo['header-basic'][] = [
                                $this->msg( 'pageinfo-watchers' ),
                                $this->msg( 'pageinfo-few-watchers' )->numParams( $unwatchedPageThreshold )
                        ];
                }

                // Redirects to this page
                $whatLinksHere = SpecialPage::getTitleFor( 'Whatlinkshere', $title->getPrefixedText() );
                $pageInfo['header-basic'][] = [
                        Linker::link(
                                $whatLinksHere,
                                $this->msg( 'pageinfo-redirects-name' )->escaped(),
                                [],
                                [
                                        'hidelinks' => 1,
                                        'hidetrans' => 1,
                                        'hideimages' => $title->getNamespace() == NS_FILE
                                ]
                        ),
                        $this->msg( 'pageinfo-redirects-value' )
                                ->numParams( count( $title->getRedirectsHere() ) )
                ];

                // Is it counted as a content page?
                if ( $this->page->isCountable() ) {
                        $pageInfo['header-basic'][] = [
                                $this->msg( 'pageinfo-contentpage' ),
                                $this->msg( 'pageinfo-contentpage-yes' )
                        ];
                }

                // Subpages of this page, if subpages are enabled for the current NS
                if ( MWNamespace::hasSubpages( $title->getNamespace() ) ) {
                        $prefixIndex = SpecialPage::getTitleFor(
                                'Prefixindex', $title->getPrefixedText() . '/' );
                        $pageInfo['header-basic'][] = [
                                Linker::link( $prefixIndex, $this->msg( 'pageinfo-subpages-name' )->escaped() ),
                                $this->msg( 'pageinfo-subpages-value' )
                                        ->numParams(
                                                $pageCounts['subpages']['total'],
                                                $pageCounts['subpages']['redirects'],
                                                $pageCounts['subpages']['nonredirects'] )
                        ];
                }

                if ( $title->inNamespace( NS_CATEGORY ) ) {
                        $category = Category::newFromTitle( $title );

                        // $allCount is the total number of cat members,
                        // not the count of how many members are normal pages.
                        $allCount = (int)$category->getPageCount();
                        $subcatCount = (int)$category->getSubcatCount();
                        $fileCount = (int)$category->getFileCount();
                        $pagesCount = $allCount - $subcatCount - $fileCount;

                        $pageInfo['category-info'] = [
                                [
                                        $this->msg( 'pageinfo-category-total' ),
                                        $lang->formatNum( $allCount )
                                ],
                                [
                                        $this->msg( 'pageinfo-category-pages' ),
                                        $lang->formatNum( $pagesCount )
                                ],
                                [
                                        $this->msg( 'pageinfo-category-subcats' ),
                                        $lang->formatNum( $subcatCount )
                                ],
                                [
                                        $this->msg( 'pageinfo-category-files' ),
                                        $lang->formatNum( $fileCount )
                                ]
                        ];
                }

                // Page protection
                $pageInfo['header-restrictions'] = [];

                // Is this page affected by the cascading protection of something which includes it?
                if ( $title->isCascadeProtected() ) {
                        $cascadingFrom = '';
                        $sources = $title->getCascadeProtectionSources()[0];

                        foreach ( $sources as $sourceTitle ) {
                                $cascadingFrom .= Html::rawElement(
                                        'li', [], Linker::linkKnown( $sourceTitle ) );
                        }

                        $cascadingFrom = Html::rawElement( 'ul', [], $cascadingFrom );
                        $pageInfo['header-restrictions'][] = [
                                $this->msg( 'pageinfo-protect-cascading-from' ),
                                $cascadingFrom
                        ];
                }

                // Is out protection set to cascade to other pages?
                if ( $title->areRestrictionsCascading() ) {
                        $pageInfo['header-restrictions'][] = [
                                $this->msg( 'pageinfo-protect-cascading' ),
                                $this->msg( 'pageinfo-protect-cascading-yes' )
                        ];
                }

                // Page protection
                foreach ( $title->getRestrictionTypes() as $restrictionType ) {
                        $protectionLevel = implode( ', ', $title->getRestrictions( $restrictionType ) );

                        if ( $protectionLevel == '' ) {
                                // Allow all users
                                $message = $this->msg( 'protect-default' )->escaped();
                        } else {
                                // Administrators only
                                // Messages: protect-level-autoconfirmed, protect-level-sysop
                                $message = $this->msg( "protect-level-$protectionLevel" );
                                if ( $message->isDisabled() ) {
                                        // Require "$1" permission
                                        $message = $this->msg( "protect-fallback", $protectionLevel )->parse();
                                } else {
                                        $message = $message->escaped();
                                }
                        }
                        $expiry = $title->getRestrictionExpiry( $restrictionType );
                        $formattedexpiry = $this->msg( 'parentheses',
                                $this->getLanguage()->formatExpiry( $expiry ) )->escaped();
                        $message .= $this->msg( 'word-separator' )->escaped() . $formattedexpiry;

                        // Messages: restriction-edit, restriction-move, restriction-create,
                        // restriction-upload
                        $pageInfo['header-restrictions'][] = [
                                $this->msg( "restriction-$restrictionType" ), $message
                        ];
                }

                if ( !$this->page->exists() ) {
                        return $pageInfo;
                }

                // Edit history
                $pageInfo['header-edits'] = [];

                $firstRev = $this->page->getOldestRevision();
                $lastRev = $this->page->getRevision();
                $batch = new LinkBatch;

                if ( $firstRev ) {
                        $firstRevUser = $firstRev->getUserText( Revision::FOR_THIS_USER );
                        if ( $firstRevUser !== '' ) {
                                $firstRevUserTitle = Title::makeTitle( NS_USER, $firstRevUser );
                                $batch->addObj( $firstRevUserTitle );
                                $batch->addObj( $firstRevUserTitle->getTalkPage() );
                        }
                }

                if ( $lastRev ) {
                        $lastRevUser = $lastRev->getUserText( Revision::FOR_THIS_USER );
                        if ( $lastRevUser !== '' ) {
                                $lastRevUserTitle = Title::makeTitle( NS_USER, $lastRevUser );
                                $batch->addObj( $lastRevUserTitle );
                                $batch->addObj( $lastRevUserTitle->getTalkPage() );
                        }
                }

                $batch->execute();

                if ( $firstRev ) {
                        // Page creator
                        $pageInfo['header-edits'][] = [
                                $this->msg( 'pageinfo-firstuser' ),
                                Linker::revUserTools( $firstRev )
                        ];

                        // Date of page creation
                        $pageInfo['header-edits'][] = [
                                $this->msg( 'pageinfo-firsttime' ),
                                Linker::linkKnown(
                                        $title,
                                        htmlspecialchars( $lang->userTimeAndDate( $firstRev->getTimestamp(), $user ) ),
                                        [],
                                        [ 'oldid' => $firstRev->getId() ]
                                )
                        ];
                }

                if ( $lastRev ) {
                        // Latest editor
                        $pageInfo['header-edits'][] = [
                                $this->msg( 'pageinfo-lastuser' ),
                                Linker::revUserTools( $lastRev )
                        ];

                        // Date of latest edit
                        $pageInfo['header-edits'][] = [
                                $this->msg( 'pageinfo-lasttime' ),
                                Linker::linkKnown(
                                        $title,
                                        htmlspecialchars(
                                                $lang->userTimeAndDate( $this->page->getTimestamp(), $user )
                                        ),
                                        [],
                                        [ 'oldid' => $this->page->getLatest() ]
                                )
                        ];
                }

                // Total number of edits
                $pageInfo['header-edits'][] = [
                        $this->msg( 'pageinfo-edits' ), $lang->formatNum( $pageCounts['edits'] )
                ];

                // Total number of distinct authors
                if ( $pageCounts['authors'] > 0 ) {
                        $pageInfo['header-edits'][] = [
                                $this->msg( 'pageinfo-authors' ), $lang->formatNum( $pageCounts['authors'] )
                        ];
                }

                // Recent number of edits (within past 30 days)
                $pageInfo['header-edits'][] = [
                        $this->msg( 'pageinfo-recent-edits',
                                $lang->formatDuration( $config->get( 'RCMaxAge' ) ) ),
                        $lang->formatNum( $pageCounts['recent_edits'] )
                ];

                // Recent number of distinct authors
                $pageInfo['header-edits'][] = [
                        $this->msg( 'pageinfo-recent-authors' ),
                        $lang->formatNum( $pageCounts['recent_authors'] )
                ];

                // Array of MagicWord objects
                $magicWords = MagicWord::getDoubleUnderscoreArray();

                // Array of magic word IDs
                $wordIDs = $magicWords->names;

                // Array of IDs => localized magic words
                $localizedWords = $wgContLang->getMagicWords();

                $listItems = [];
                foreach ( $pageProperties as $property => $value ) {
                        if ( in_array( $property, $wordIDs ) ) {
                                $listItems[] = Html::element( 'li', [], $localizedWords[$property][1] );
                        }
                }

                $localizedList = Html::rawElement( 'ul', [], implode( '', $listItems ) );
                $hiddenCategories = $this->page->getHiddenCategories();

                if (
                        count( $listItems ) > 0 ||
                        count( $hiddenCategories ) > 0 ||
                        $pageCounts['transclusion']['from'] > 0 ||
                        $pageCounts['transclusion']['to'] > 0
                ) {
                        $options = [ 'LIMIT' => $config->get( 'PageInfoTransclusionLimit' ) ];
                        $transcludedTemplates = $title->getTemplateLinksFrom( $options );
                        if ( $config->get( 'MiserMode' ) ) {
                                $transcludedTargets = [];
                        } else {
                                $transcludedTargets = $title->getTemplateLinksTo( $options );
                        }

                        // Page properties
                        $pageInfo['header-properties'] = [];

                        // Magic words
                        if ( count( $listItems ) > 0 ) {
                                $pageInfo['header-properties'][] = [
                                        $this->msg( 'pageinfo-magic-words' )->numParams( count( $listItems ) ),
                                        $localizedList
                                ];
                        }

                        // Hidden categories
                        if ( count( $hiddenCategories ) > 0 ) {
                                $pageInfo['header-properties'][] = [
                                        $this->msg( 'pageinfo-hidden-categories' )
                                                ->numParams( count( $hiddenCategories ) ),
                                        Linker::formatHiddenCategories( $hiddenCategories )
                                ];
                        }

                        // Transcluded templates
                        if ( $pageCounts['transclusion']['from'] > 0 ) {
                                if ( $pageCounts['transclusion']['from'] > count( $transcludedTemplates ) ) {
                                        $more = $this->msg( 'morenotlisted' )->escaped();
                                } else {
                                        $more = null;
                                }

                                $templateListFormatter = new TemplatesOnThisPageFormatter(
                                        $this->getContext(),
                                        $linkRenderer
                                );

                                $pageInfo['header-properties'][] = [
                                        $this->msg( 'pageinfo-templates' )
                                                ->numParams( $pageCounts['transclusion']['from'] ),
                                        $templateListFormatter->format( $transcludedTemplates, false, $more )
                                ];
                        }

                        if ( !$config->get( 'MiserMode' ) && $pageCounts['transclusion']['to'] > 0 ) {
                                if ( $pageCounts['transclusion']['to'] > count( $transcludedTargets ) ) {
                                        $more = Linker::link(
                                                $whatLinksHere,
                                                $this->msg( 'moredotdotdot' )->escaped(),
                                                [],
                                                [ 'hidelinks' => 1, 'hideredirs' => 1 ]
                                        );
                                } else {
                                        $more = null;
                                }

                                $templateListFormatter = new TemplatesOnThisPageFormatter(
                                        $this->getContext(),
                                        $linkRenderer
                                );

                                $pageInfo['header-properties'][] = [
                                        $this->msg( 'pageinfo-transclusions' )
                                                ->numParams( $pageCounts['transclusion']['to'] ),
                                        $templateListFormatter->format( $transcludedTargets, false, $more )
                                ];
                        }
                }

                return $pageInfo;
        }

        /**
         * Returns page counts that would be too "expensive" to retrieve by normal means.
         *
         * @param WikiPage|Article|Page $page
         * @return array
         */
        protected function pageCounts( Page $page ) {
                $fname = __METHOD__;
                $config = $this->context->getConfig();

                return ObjectCache::getMainWANInstance()->getWithSetCallback(
                        self::getCacheKey( $page->getTitle(), $page->getLatest() ),
                        WANObjectCache::TTL_WEEK,
                        function ( $oldValue, &$ttl, &$setOpts ) use ( $page, $config, $fname ) {
                                $title = $page->getTitle();
                                $id = $title->getArticleID();

                                $dbr = wfGetDB( DB_REPLICA );
                                $dbrWatchlist = wfGetDB( DB_REPLICA, 'watchlist' );
                                $setOpts += Database::getCacheSetOptions( $dbr, $dbrWatchlist );

                                $watchedItemStore = MediaWikiServices::getInstance()->getWatchedItemStore();

                                $result = [];
                                $result['watchers'] = $watchedItemStore->countWatchers( $title );

                                if ( $config->get( 'ShowUpdatedMarker' ) ) {
                                        $updated = wfTimestamp( TS_UNIX, $page->getTimestamp() );
                                        $result['visitingWatchers'] = $watchedItemStore->countVisitingWatchers(
                                                $title,
                                                $updated - $config->get( 'WatchersMaxAge' )
                                        );
                                }

                                // Total number of edits
                                $edits = (int)$dbr->selectField(
                                        'revision',
                                        'COUNT(*)',
                                        [ 'rev_page' => $id ],
                                        $fname
                                );
                                $result['edits'] = $edits;

                                // Total number of distinct authors
                                if ( $config->get( 'MiserMode' ) ) {
                                        $result['authors'] = 0;
                                } else {
                                        $result['authors'] = (int)$dbr->selectField(
                                                'revision',
                                                'COUNT(DISTINCT rev_user_text)',
                                                [ 'rev_page' => $id ],
                                                $fname
                                        );
                                }

                                // "Recent" threshold defined by RCMaxAge setting
                                $threshold = $dbr->timestamp( time() - $config->get( 'RCMaxAge' ) );

                                // Recent number of edits
                                $edits = (int)$dbr->selectField(
                                        'revision',
                                        'COUNT(rev_page)',
                                        [
                                                'rev_page' => $id,
                                                "rev_timestamp >= " . $dbr->addQuotes( $threshold )
                                        ],
                                        $fname
                                );
                                $result['recent_edits'] = $edits;

                                // Recent number of distinct authors
                                $result['recent_authors'] = (int)$dbr->selectField(
                                        'revision',
                                        'COUNT(DISTINCT rev_user_text)',
                                        [
                                                'rev_page' => $id,
                                                "rev_timestamp >= " . $dbr->addQuotes( $threshold )
                                        ],
                                        $fname
                                );

                                // Subpages (if enabled)
                                if ( MWNamespace::hasSubpages( $title->getNamespace() ) ) {
                                        $conds = [ 'page_namespace' => $title->getNamespace() ];
                                        $conds[] = 'page_title ' .
                                                $dbr->buildLike( $title->getDBkey() . '/', $dbr->anyString() );

                                        // Subpages of this page (redirects)
                                        $conds['page_is_redirect'] = 1;
                                        $result['subpages']['redirects'] = (int)$dbr->selectField(
                                                'page',
                                                'COUNT(page_id)',
                                                $conds,
                                                $fname
                                        );

                                        // Subpages of this page (non-redirects)
                                        $conds['page_is_redirect'] = 0;
                                        $result['subpages']['nonredirects'] = (int)$dbr->selectField(
                                                'page',
                                                'COUNT(page_id)',
                                                $conds,
                                                $fname
                                        );

                                        // Subpages of this page (total)
                                        $result['subpages']['total'] = $result['subpages']['redirects']
                                                + $result['subpages']['nonredirects'];
                                }

                                // Counts for the number of transclusion links (to/from)
                                if ( $config->get( 'MiserMode' ) ) {
                                        $result['transclusion']['to'] = 0;
                                } else {
                                        $result['transclusion']['to'] = (int)$dbr->selectField(
                                                'templatelinks',
                                                'COUNT(tl_from)',
                                                [
                                                        'tl_namespace' => $title->getNamespace(),
                                                        'tl_title' => $title->getDBkey()
                                                ],
                                                $fname
                                        );
                                }

                                $result['transclusion']['from'] = (int)$dbr->selectField(
                                        'templatelinks',
                                        'COUNT(*)',
                                        [ 'tl_from' => $title->getArticleID() ],
                                        $fname
                                );

                                return $result;
                        }
                );
        }

        /**
         * Returns the name that goes in the "<h1>" page title.
         *
         * @return string
         */
        protected function getPageTitle() {
                return $this->msg( 'pageinfo-title', $this->getTitle()->getPrefixedText() )->text();
        }

        /**
         * Get a list of contributors of $article
         * @return string Html
         */
        protected function getContributors() {
                $contributors = $this->page->getContributors();
                $real_names = [];
                $user_names = [];
                $anon_ips = [];

                # Sift for real versus user names
                /** @var $user User */
                foreach ( $contributors as $user ) {
                        $page = $user->isAnon()
                                ? SpecialPage::getTitleFor( 'Contributions', $user->getName() )
                                : $user->getUserPage();

                        $hiddenPrefs = $this->context->getConfig()->get( 'HiddenPrefs' );
                        if ( $user->getId() == 0 ) {
                                $anon_ips[] = Linker::link( $page, htmlspecialchars( $user->getName() ) );
                        } elseif ( !in_array( 'realname', $hiddenPrefs ) && $user->getRealName() ) {
                                $real_names[] = Linker::link( $page, htmlspecialchars( $user->getRealName() ) );
                        } else {
                                $user_names[] = Linker::link( $page, htmlspecialchars( $user->getName() ) );
                        }
                }

                $lang = $this->getLanguage();

                $real = $lang->listToText( $real_names );

                # "ThisSite user(s) A, B and C"
                if ( count( $user_names ) ) {
                        $user = $this->msg( 'siteusers' )
                                ->rawParams( $lang->listToText( $user_names ) )
                                ->params( count( $user_names ) )->escaped();
                } else {
                        $user = false;
                }

                if ( count( $anon_ips ) ) {
                        $anon = $this->msg( 'anonusers' )
                                ->rawParams( $lang->listToText( $anon_ips ) )
                                ->params( count( $anon_ips ) )->escaped();
                } else {
                        $anon = false;
                }

                # This is the big list, all mooshed together. We sift for blank strings
                $fulllist = [];
                foreach ( [ $real, $user, $anon ] as $s ) {
                        if ( $s !== '' ) {
                                array_push( $fulllist, $s );
                        }
                }

                $count = count( $fulllist );

                # "Based on work by ..."
                return $count
                        ? $this->msg( 'othercontribs' )->rawParams(
                                $lang->listToText( $fulllist ) )->params( $count )->escaped()
                        : '';
        }

        /**
         * Returns the description that goes below the "<h1>" tag.
         *
         * @return string
         */
        protected function getDescription() {
                return '';
        }

        /**
         * @param Title $title
         * @param int $revId
         * @return string
         */
        protected static function getCacheKey( Title $title, $revId ) {
                return wfMemcKey( 'infoaction', md5( $title->getPrefixedText() ), $revId, self::VERSION );
        }
}