ApiQueryInfo.php

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<?php
use MediaWiki\MediaWikiServices;
use MediaWiki\Linker\LinkTarget;

class ApiQueryInfo extends ApiQueryBase {

    private $fld_protection = false, $fld_talkid = false,
        $fld_subjectid = false, $fld_url = false,
        $fld_readable = false, $fld_watched = false,
        $fld_watchers = false, $fld_visitingwatchers = false,
        $fld_notificationtimestamp = false,
        $fld_preload = false, $fld_displaytitle = false;

    private $params;

    private $titles;
    private $missing;
    private $everything;

    private $pageRestrictions, $pageIsRedir, $pageIsNew, $pageTouched,
        $pageLatest, $pageLength;

    private $protections, $restrictionTypes, $watched, $watchers, $visitingwatchers,
        $notificationtimestamps, $talkids, $subjectids, $displaytitles;
    private $showZeroWatchers = false;

    private $tokenFunctions;

    private $countTestedActions = 0;

    public function __construct( ApiQuery $query, $moduleName ) {
        parent::__construct( $query, $moduleName, 'in' );
    }

    public function requestExtraData( $pageSet ) {
        $pageSet->requestField( 'page_restrictions' );
        // If the pageset is resolving redirects we won't get page_is_redirect.
        // But we can't know for sure until the pageset is executed (revids may
        // turn it off), so request it unconditionally.
        $pageSet->requestField( 'page_is_redirect' );
        $pageSet->requestField( 'page_is_new' );
        $config = $this->getConfig();
        $pageSet->requestField( 'page_touched' );
        $pageSet->requestField( 'page_latest' );
        $pageSet->requestField( 'page_len' );
        if ( $config->get( 'ContentHandlerUseDB' ) ) {
            $pageSet->requestField( 'page_content_model' );
        }
        if ( $config->get( 'PageLanguageUseDB' ) ) {
            $pageSet->requestField( 'page_lang' );
        }
    }

    protected function getTokenFunctions() {
        // Don't call the hooks twice
        if ( isset( $this->tokenFunctions ) ) {
            return $this->tokenFunctions;
        }

        // If we're in a mode that breaks the same-origin policy, no tokens can
        // be obtained
        if ( $this->lacksSameOriginSecurity() ) {
            return [];
        }

        $this->tokenFunctions = [
            'edit' => [ 'ApiQueryInfo', 'getEditToken' ],
            'delete' => [ 'ApiQueryInfo', 'getDeleteToken' ],
            'protect' => [ 'ApiQueryInfo', 'getProtectToken' ],
            'move' => [ 'ApiQueryInfo', 'getMoveToken' ],
            'block' => [ 'ApiQueryInfo', 'getBlockToken' ],
            'unblock' => [ 'ApiQueryInfo', 'getUnblockToken' ],
            'email' => [ 'ApiQueryInfo', 'getEmailToken' ],
            'import' => [ 'ApiQueryInfo', 'getImportToken' ],
            'watch' => [ 'ApiQueryInfo', 'getWatchToken' ],
        ];
        Hooks::run( 'APIQueryInfoTokens', [ &$this->tokenFunctions ] );

        return $this->tokenFunctions;
    }

    static protected $cachedTokens = [];

    public static function resetTokenCache() {
        ApiQueryInfo::$cachedTokens = [];
    }

    public static function getEditToken( $pageid, $title ) {
        // We could check for $title->userCan('edit') here,
        // but that's too expensive for this purpose
        // and would break caching
        global $wgUser;
        if ( !$wgUser->isAllowed( 'edit' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['edit'] ) ) {
            ApiQueryInfo::$cachedTokens['edit'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['edit'];
    }

    public static function getDeleteToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isAllowed( 'delete' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['delete'] ) ) {
            ApiQueryInfo::$cachedTokens['delete'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['delete'];
    }

    public static function getProtectToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isAllowed( 'protect' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['protect'] ) ) {
            ApiQueryInfo::$cachedTokens['protect'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['protect'];
    }

    public static function getMoveToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isAllowed( 'move' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['move'] ) ) {
            ApiQueryInfo::$cachedTokens['move'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['move'];
    }

    public static function getBlockToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isAllowed( 'block' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['block'] ) ) {
            ApiQueryInfo::$cachedTokens['block'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['block'];
    }

    public static function getUnblockToken( $pageid, $title ) {
        // Currently, this is exactly the same as the block token
        return self::getBlockToken( $pageid, $title );
    }

    public static function getEmailToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->canSendEmail() || $wgUser->isBlockedFromEmailuser() ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['email'] ) ) {
            ApiQueryInfo::$cachedTokens['email'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['email'];
    }

    public static function getImportToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isAllowedAny( 'import', 'importupload' ) ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['import'] ) ) {
            ApiQueryInfo::$cachedTokens['import'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['import'];
    }

    public static function getWatchToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isLoggedIn() ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['watch'] ) ) {
            ApiQueryInfo::$cachedTokens['watch'] = $wgUser->getEditToken( 'watch' );
        }

        return ApiQueryInfo::$cachedTokens['watch'];
    }

    public static function getOptionsToken( $pageid, $title ) {
        global $wgUser;
        if ( !$wgUser->isLoggedIn() ) {
            return false;
        }

        // The token is always the same, let's exploit that
        if ( !isset( ApiQueryInfo::$cachedTokens['options'] ) ) {
            ApiQueryInfo::$cachedTokens['options'] = $wgUser->getEditToken();
        }

        return ApiQueryInfo::$cachedTokens['options'];
    }

    public function execute() {
        $this->params = $this->extractRequestParams();
        if ( !is_null( $this->params['prop'] ) ) {
            $prop = array_flip( $this->params['prop'] );
            $this->fld_protection = isset( $prop['protection'] );
            $this->fld_watched = isset( $prop['watched'] );
            $this->fld_watchers = isset( $prop['watchers'] );
            $this->fld_visitingwatchers = isset( $prop['visitingwatchers'] );
            $this->fld_notificationtimestamp = isset( $prop['notificationtimestamp'] );
            $this->fld_talkid = isset( $prop['talkid'] );
            $this->fld_subjectid = isset( $prop['subjectid'] );
            $this->fld_url = isset( $prop['url'] );
            $this->fld_readable = isset( $prop['readable'] );
            $this->fld_preload = isset( $prop['preload'] );
            $this->fld_displaytitle = isset( $prop['displaytitle'] );
        }

        $pageSet = $this->getPageSet();
        $this->titles = $pageSet->getGoodTitles();
        $this->missing = $pageSet->getMissingTitles();
        $this->everything = $this->titles + $this->missing;
        $result = $this->getResult();

        uasort( $this->everything, [ 'Title', 'compare' ] );
        if ( !is_null( $this->params['continue'] ) ) {
            // Throw away any titles we're gonna skip so they don't
            // clutter queries
            $cont = explode( '|', $this->params['continue'] );
            $this->dieContinueUsageIf( count( $cont ) != 2 );
            $conttitle = Title::makeTitleSafe( $cont[0], $cont[1] );
            foreach ( $this->everything as $pageid => $title ) {
                if ( Title::compare( $title, $conttitle ) >= 0 ) {
                    break;
                }
                unset( $this->titles[$pageid] );
                unset( $this->missing[$pageid] );
                unset( $this->everything[$pageid] );
            }
        }

        $this->pageRestrictions = $pageSet->getCustomField( 'page_restrictions' );
        // when resolving redirects, no page will have this field
        $this->pageIsRedir = !$pageSet->isResolvingRedirects()
            ? $pageSet->getCustomField( 'page_is_redirect' )
            : [];
        $this->pageIsNew = $pageSet->getCustomField( 'page_is_new' );

        $this->pageTouched = $pageSet->getCustomField( 'page_touched' );
        $this->pageLatest = $pageSet->getCustomField( 'page_latest' );
        $this->pageLength = $pageSet->getCustomField( 'page_len' );

        // Get protection info if requested
        if ( $this->fld_protection ) {
            $this->getProtectionInfo();
        }

        if ( $this->fld_watched || $this->fld_notificationtimestamp ) {
            $this->getWatchedInfo();
        }

        if ( $this->fld_watchers ) {
            $this->getWatcherInfo();
        }

        if ( $this->fld_visitingwatchers ) {
            $this->getVisitingWatcherInfo();
        }

        // Run the talkid/subjectid query if requested
        if ( $this->fld_talkid || $this->fld_subjectid ) {
            $this->getTSIDs();
        }

        if ( $this->fld_displaytitle ) {
            $this->getDisplayTitle();
        }

        foreach ( $this->everything as $pageid => $title ) {
            $pageInfo = $this->extractPageInfo( $pageid, $title );
            $fit = $pageInfo !== null && $result->addValue( [
                'query',
                'pages'
            ], $pageid, $pageInfo );
            if ( !$fit ) {
                $this->setContinueEnumParameter( 'continue',
                    $title->getNamespace() . '|' .
                    $title->getText() );
                break;
            }
        }
    }

    private function extractPageInfo( $pageid, $title ) {
        $pageInfo = [];
        // $title->exists() needs pageid, which is not set for all title objects
        $titleExists = $pageid > 0;
        $ns = $title->getNamespace();
        $dbkey = $title->getDBkey();

        $pageInfo['contentmodel'] = $title->getContentModel();

        $pageLanguage = $title->getPageLanguage();
        $pageInfo['pagelanguage'] = $pageLanguage->getCode();
        $pageInfo['pagelanguagehtmlcode'] = $pageLanguage->getHtmlCode();
        $pageInfo['pagelanguagedir'] = $pageLanguage->getDir();

        if ( $titleExists ) {
            $pageInfo['touched'] = wfTimestamp( TS_ISO_8601, $this->pageTouched[$pageid] );
            $pageInfo['lastrevid'] = intval( $this->pageLatest[$pageid] );
            $pageInfo['length'] = intval( $this->pageLength[$pageid] );

            if ( isset( $this->pageIsRedir[$pageid] ) && $this->pageIsRedir[$pageid] ) {
                $pageInfo['redirect'] = true;
            }
            if ( $this->pageIsNew[$pageid] ) {
                $pageInfo['new'] = true;
            }
        }

        if ( !is_null( $this->params['token'] ) ) {
            $tokenFunctions = $this->getTokenFunctions();
            $pageInfo['starttimestamp'] = wfTimestamp( TS_ISO_8601, time() );
            foreach ( $this->params['token'] as $t ) {
                $val = call_user_func( $tokenFunctions[$t], $pageid, $title );
                if ( $val === false ) {
                    $this->setWarning( "Action '$t' is not allowed for the current user" );
                } else {
                    $pageInfo[$t . 'token'] = $val;
                }
            }
        }

        if ( $this->fld_protection ) {
            $pageInfo['protection'] = [];
            if ( isset( $this->protections[$ns][$dbkey] ) ) {
                $pageInfo['protection'] =
                    $this->protections[$ns][$dbkey];
            }
            ApiResult::setIndexedTagName( $pageInfo['protection'], 'pr' );

            $pageInfo['restrictiontypes'] = [];
            if ( isset( $this->restrictionTypes[$ns][$dbkey] ) ) {
                $pageInfo['restrictiontypes'] =
                    $this->restrictionTypes[$ns][$dbkey];
            }
            ApiResult::setIndexedTagName( $pageInfo['restrictiontypes'], 'rt' );
        }

        if ( $this->fld_watched && $this->watched !== null ) {
            $pageInfo['watched'] = $this->watched[$ns][$dbkey];
        }

        if ( $this->fld_watchers ) {
            if ( $this->watchers !== null && $this->watchers[$ns][$dbkey] !== 0 ) {
                $pageInfo['watchers'] = $this->watchers[$ns][$dbkey];
            } elseif ( $this->showZeroWatchers ) {
                $pageInfo['watchers'] = 0;
            }
        }

        if ( $this->fld_visitingwatchers ) {
            if ( $this->visitingwatchers !== null && $this->visitingwatchers[$ns][$dbkey] !== 0 ) {
                $pageInfo['visitingwatchers'] = $this->visitingwatchers[$ns][$dbkey];
            } elseif ( $this->showZeroWatchers ) {
                $pageInfo['visitingwatchers'] = 0;
            }
        }

        if ( $this->fld_notificationtimestamp ) {
            $pageInfo['notificationtimestamp'] = '';
            if ( $this->notificationtimestamps[$ns][$dbkey] ) {
                $pageInfo['notificationtimestamp'] =
                    wfTimestamp( TS_ISO_8601, $this->notificationtimestamps[$ns][$dbkey] );
            }
        }

        if ( $this->fld_talkid && isset( $this->talkids[$ns][$dbkey] ) ) {
            $pageInfo['talkid'] = $this->talkids[$ns][$dbkey];
        }

        if ( $this->fld_subjectid && isset( $this->subjectids[$ns][$dbkey] ) ) {
            $pageInfo['subjectid'] = $this->subjectids[$ns][$dbkey];
        }

        if ( $this->fld_url ) {
            $pageInfo['fullurl'] = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
            $pageInfo['editurl'] = wfExpandUrl( $title->getFullURL( 'action=edit' ), PROTO_CURRENT );
            $pageInfo['canonicalurl'] = wfExpandUrl( $title->getFullURL(), PROTO_CANONICAL );
        }
        if ( $this->fld_readable ) {
            $pageInfo['readable'] = $title->userCan( 'read', $this->getUser() );
        }

        if ( $this->fld_preload ) {
            if ( $titleExists ) {
                $pageInfo['preload'] = '';
            } else {
                $text = null;
                Hooks::run( 'EditFormPreloadText', [ &$text, &$title ] );

                $pageInfo['preload'] = $text;
            }
        }

        if ( $this->fld_displaytitle ) {
            if ( isset( $this->displaytitles[$pageid] ) ) {
                $pageInfo['displaytitle'] = $this->displaytitles[$pageid];
            } else {
                $pageInfo['displaytitle'] = $title->getPrefixedText();
            }
        }

        if ( $this->params['testactions'] ) {
            $limit = $this->getMain()->canApiHighLimits() ? self::LIMIT_SML1 : self::LIMIT_SML2;
            if ( $this->countTestedActions >= $limit ) {
                return null; // force a continuation
            }

            $user = $this->getUser();
            $pageInfo['actions'] = [];
            foreach ( $this->params['testactions'] as $action ) {
                $this->countTestedActions++;
                $pageInfo['actions'][$action] = $title->userCan( $action, $user );
            }
        }

        return $pageInfo;
    }

    private function getProtectionInfo() {
        global $wgContLang;
        $this->protections = [];
        $db = $this->getDB();

        // Get normal protections for existing titles
        if ( count( $this->titles ) ) {
            $this->resetQueryParams();
            $this->addTables( 'page_restrictions' );
            $this->addFields( [ 'pr_page', 'pr_type', 'pr_level',
                'pr_expiry', 'pr_cascade' ] );
            $this->addWhereFld( 'pr_page', array_keys( $this->titles ) );

            $res = $this->select( __METHOD__ );
            foreach ( $res as $row ) {
                $title = $this->titles[$row->pr_page];
                $a = [
                    'type' => $row->pr_type,
                    'level' => $row->pr_level,
                    'expiry' => $wgContLang->formatExpiry( $row->pr_expiry, TS_ISO_8601 )
                ];
                if ( $row->pr_cascade ) {
                    $a['cascade'] = true;
                }
                $this->protections[$title->getNamespace()][$title->getDBkey()][] = $a;
            }
            // Also check old restrictions
            foreach ( $this->titles as $pageId => $title ) {
                if ( $this->pageRestrictions[$pageId] ) {
                    $namespace = $title->getNamespace();
                    $dbKey = $title->getDBkey();
                    $restrictions = explode( ':', trim( $this->pageRestrictions[$pageId] ) );
                    foreach ( $restrictions as $restrict ) {
                        $temp = explode( '=', trim( $restrict ) );
                        if ( count( $temp ) == 1 ) {
                            // old old format should be treated as edit/move restriction
                            $restriction = trim( $temp[0] );

                            if ( $restriction == '' ) {
                                continue;
                            }
                            $this->protections[$namespace][$dbKey][] = [
                                'type' => 'edit',
                                'level' => $restriction,
                                'expiry' => 'infinity',
                            ];
                            $this->protections[$namespace][$dbKey][] = [
                                'type' => 'move',
                                'level' => $restriction,
                                'expiry' => 'infinity',
                            ];
                        } else {
                            $restriction = trim( $temp[1] );
                            if ( $restriction == '' ) {
                                continue;
                            }
                            $this->protections[$namespace][$dbKey][] = [
                                'type' => $temp[0],
                                'level' => $restriction,
                                'expiry' => 'infinity',
                            ];
                        }
                    }
                }
            }
        }

        // Get protections for missing titles
        if ( count( $this->missing ) ) {
            $this->resetQueryParams();
            $lb = new LinkBatch( $this->missing );
            $this->addTables( 'protected_titles' );
            $this->addFields( [ 'pt_title', 'pt_namespace', 'pt_create_perm', 'pt_expiry' ] );
            $this->addWhere( $lb->constructSet( 'pt', $db ) );
            $res = $this->select( __METHOD__ );
            foreach ( $res as $row ) {
                $this->protections[$row->pt_namespace][$row->pt_title][] = [
                    'type' => 'create',
                    'level' => $row->pt_create_perm,
                    'expiry' => $wgContLang->formatExpiry( $row->pt_expiry, TS_ISO_8601 )
                ];
            }
        }

        // Separate good and missing titles into files and other pages
        // and populate $this->restrictionTypes
        $images = $others = [];
        foreach ( $this->everything as $title ) {
            if ( $title->getNamespace() == NS_FILE ) {
                $images[] = $title->getDBkey();
            } else {
                $others[] = $title;
            }
            // Applicable protection types
            $this->restrictionTypes[$title->getNamespace()][$title->getDBkey()] =
                array_values( $title->getRestrictionTypes() );
        }

        if ( count( $others ) ) {
            // Non-images: check templatelinks
            $lb = new LinkBatch( $others );
            $this->resetQueryParams();
            $this->addTables( [ 'page_restrictions', 'page', 'templatelinks' ] );
            $this->addFields( [ 'pr_type', 'pr_level', 'pr_expiry',
                'page_title', 'page_namespace',
                'tl_title', 'tl_namespace' ] );
            $this->addWhere( $lb->constructSet( 'tl', $db ) );
            $this->addWhere( 'pr_page = page_id' );
            $this->addWhere( 'pr_page = tl_from' );
            $this->addWhereFld( 'pr_cascade', 1 );

            $res = $this->select( __METHOD__ );
            foreach ( $res as $row ) {
                $source = Title::makeTitle( $row->page_namespace, $row->page_title );
                $this->protections[$row->tl_namespace][$row->tl_title][] = [
                    'type' => $row->pr_type,
                    'level' => $row->pr_level,
                    'expiry' => $wgContLang->formatExpiry( $row->pr_expiry, TS_ISO_8601 ),
                    'source' => $source->getPrefixedText()
                ];
            }
        }

        if ( count( $images ) ) {
            // Images: check imagelinks
            $this->resetQueryParams();
            $this->addTables( [ 'page_restrictions', 'page', 'imagelinks' ] );
            $this->addFields( [ 'pr_type', 'pr_level', 'pr_expiry',
                'page_title', 'page_namespace', 'il_to' ] );
            $this->addWhere( 'pr_page = page_id' );
            $this->addWhere( 'pr_page = il_from' );
            $this->addWhereFld( 'pr_cascade', 1 );
            $this->addWhereFld( 'il_to', $images );

            $res = $this->select( __METHOD__ );
            foreach ( $res as $row ) {
                $source = Title::makeTitle( $row->page_namespace, $row->page_title );
                $this->protections[NS_FILE][$row->il_to][] = [
                    'type' => $row->pr_type,
                    'level' => $row->pr_level,
                    'expiry' => $wgContLang->formatExpiry( $row->pr_expiry, TS_ISO_8601 ),
                    'source' => $source->getPrefixedText()
                ];
            }
        }
    }

    private function getTSIDs() {
        $getTitles = $this->talkids = $this->subjectids = [];

        foreach ( $this->everything as $t ) {
            if ( MWNamespace::isTalk( $t->getNamespace() ) ) {
                if ( $this->fld_subjectid ) {
                    $getTitles[] = $t->getSubjectPage();
                }
            } elseif ( $this->fld_talkid ) {
                $getTitles[] = $t->getTalkPage();
            }
        }
        if ( !count( $getTitles ) ) {
            return;
        }

        $db = $this->getDB();

        // Construct a custom WHERE clause that matches
        // all titles in $getTitles
        $lb = new LinkBatch( $getTitles );
        $this->resetQueryParams();
        $this->addTables( 'page' );
        $this->addFields( [ 'page_title', 'page_namespace', 'page_id' ] );
        $this->addWhere( $lb->constructSet( 'page', $db ) );
        $res = $this->select( __METHOD__ );
        foreach ( $res as $row ) {
            if ( MWNamespace::isTalk( $row->page_namespace ) ) {
                $this->talkids[MWNamespace::getSubject( $row->page_namespace )][$row->page_title] =
                    intval( $row->page_id );
            } else {
                $this->subjectids[MWNamespace::getTalk( $row->page_namespace )][$row->page_title] =
                    intval( $row->page_id );
            }
        }
    }

    private function getDisplayTitle() {
        $this->displaytitles = [];

        $pageIds = array_keys( $this->titles );

        if ( !count( $pageIds ) ) {
            return;
        }

        $this->resetQueryParams();
        $this->addTables( 'page_props' );
        $this->addFields( [ 'pp_page', 'pp_value' ] );
        $this->addWhereFld( 'pp_page', $pageIds );
        $this->addWhereFld( 'pp_propname', 'displaytitle' );
        $res = $this->select( __METHOD__ );

        foreach ( $res as $row ) {
            $this->displaytitles[$row->pp_page] = $row->pp_value;
        }
    }

    private function getWatchedInfo() {
        $user = $this->getUser();

        if ( $user->isAnon() || count( $this->everything ) == 0
            || !$user->isAllowed( 'viewmywatchlist' )
        ) {
            return;
        }

        $this->watched = [];
        $this->notificationtimestamps = [];

        $store = MediaWikiServices::getInstance()->getWatchedItemStore();
        $timestamps = $store->getNotificationTimestampsBatch( $user, $this->everything );

        if ( $this->fld_watched ) {
            foreach ( $timestamps as $namespaceId => $dbKeys ) {
                $this->watched[$namespaceId] = array_map(
                    function( $x ) {
                        return $x !== false;
                    },
                    $dbKeys
                );
            }
        }
        if ( $this->fld_notificationtimestamp ) {
            $this->notificationtimestamps = $timestamps;
        }
    }

    private function getWatcherInfo() {
        if ( count( $this->everything ) == 0 ) {
            return;
        }

        $user = $this->getUser();
        $canUnwatchedpages = $user->isAllowed( 'unwatchedpages' );
        $unwatchedPageThreshold = $this->getConfig()->get( 'UnwatchedPageThreshold' );
        if ( !$canUnwatchedpages && !is_int( $unwatchedPageThreshold ) ) {
            return;
        }

        $this->showZeroWatchers = $canUnwatchedpages;

        $countOptions = [];
        if ( !$canUnwatchedpages ) {
            $countOptions['minimumWatchers'] = $unwatchedPageThreshold;
        }

        $this->watchers = MediaWikiServices::getInstance()->getWatchedItemStore()->countWatchersMultiple(
            $this->everything,
            $countOptions
        );
    }

    private function getVisitingWatcherInfo() {
        $config = $this->getConfig();
        $user = $this->getUser();
        $db = $this->getDB();

        $canUnwatchedpages = $user->isAllowed( 'unwatchedpages' );
        $unwatchedPageThreshold = $this->getConfig()->get( 'UnwatchedPageThreshold' );
        if ( !$canUnwatchedpages && !is_int( $unwatchedPageThreshold ) ) {
            return;
        }

        $this->showZeroWatchers = $canUnwatchedpages;

        $titlesWithThresholds = [];
        if ( $this->titles ) {
            $lb = new LinkBatch( $this->titles );

            // Fetch last edit timestamps for pages
            $this->resetQueryParams();
            $this->addTables( [ 'page', 'revision' ] );
            $this->addFields( [ 'page_namespace', 'page_title', 'rev_timestamp' ] );
            $this->addWhere( [
                'page_latest = rev_id',
                $lb->constructSet( 'page', $db ),
            ] );
            $this->addOption( 'GROUP BY', [ 'page_namespace', 'page_title' ] );
            $timestampRes = $this->select( __METHOD__ );

            $age = $config->get( 'WatchersMaxAge' );
            $timestamps = [];
            foreach ( $timestampRes as $row ) {
                $revTimestamp = wfTimestamp( TS_UNIX, (int)$row->rev_timestamp );
                $timestamps[$row->page_namespace][$row->page_title] = $revTimestamp - $age;
            }
            $titlesWithThresholds = array_map(
                function( LinkTarget $target ) use ( $timestamps ) {
                    return [
                        $target, $timestamps[$target->getNamespace()][$target->getDBkey()]
                    ];
                },
                $this->titles
            );
        }

        if ( $this->missing ) {
            $titlesWithThresholds = array_merge(
                $titlesWithThresholds,
                array_map(
                    function( LinkTarget $target ) {
                        return [ $target, null ];
                    },
                    $this->missing
                )
            );
        }
        $store = MediaWikiServices::getInstance()->getWatchedItemStore();
        $this->visitingwatchers = $store->countVisitingWatchersMultiple(
            $titlesWithThresholds,
            !$canUnwatchedpages ? $unwatchedPageThreshold : null
        );
    }

    public function getCacheMode( $params ) {
        // Other props depend on something about the current user
        $publicProps = [
            'protection',
            'talkid',
            'subjectid',
            'url',
            'preload',
            'displaytitle',
        ];
        if ( array_diff( (array)$params['prop'], $publicProps ) ) {
            return 'private';
        }

        // testactions also depends on the current user
        if ( $params['testactions'] ) {
            return 'private';
        }

        if ( !is_null( $params['token'] ) ) {
            return 'private';
        }

        return 'public';
    }

    public function getAllowedParams() {
        return [
            'prop' => [
                ApiBase::PARAM_ISMULTI => true,
                ApiBase::PARAM_TYPE => [
                    'protection',
                    'talkid',
                    'watched', # private
                    'watchers', # private
                    'visitingwatchers', # private
                    'notificationtimestamp', # private
                    'subjectid',
                    'url',
                    'readable', # private
                    'preload',
                    'displaytitle',
                    // If you add more properties here, please consider whether they
                    // need to be added to getCacheMode()
                ],
                ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
            ],
            'testactions' => [
                ApiBase::PARAM_TYPE => 'string',
                ApiBase::PARAM_ISMULTI => true,
            ],
            'token' => [
                ApiBase::PARAM_DEPRECATED => true,
                ApiBase::PARAM_ISMULTI => true,
                ApiBase::PARAM_TYPE => array_keys( $this->getTokenFunctions() )
            ],
            'continue' => [
                ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
            ],
        ];
    }

    protected function getExamplesMessages() {
        return [
            'action=query&prop=info&titles=Main%20Page'
                => 'apihelp-query+info-example-simple',
            'action=query&prop=info&inprop=protection&titles=Main%20Page'
                => 'apihelp-query+info-example-protection',
        ];
    }

    public function getHelpUrls() {
        return 'https://www.mediawiki.org/wiki/API:Info';
    }
}