Merge "docs: Fix typo"

[mediawiki.git] / includes / specials / SpecialSearch.php

<?php
/**
 * Copyright © 2004 Brooke Vibber <bvibber@wikimedia.org>
 *
 * 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.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

namespace MediaWiki\Specials;

use ISearchResultSet;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Content\IContentHandlerFactory;
use MediaWiki\Deferred\DeferredUpdates;
use MediaWiki\Html\Html;
use MediaWiki\Interwiki\InterwikiLookup;
use MediaWiki\Languages\LanguageConverterFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\Message\Message;
use MediaWiki\Output\OutputPage;
use MediaWiki\Request\WebRequest;
use MediaWiki\Search\SearchResultThumbnailProvider;
use MediaWiki\Search\SearchWidgets\BasicSearchResultSetWidget;
use MediaWiki\Search\SearchWidgets\DidYouMeanWidget;
use MediaWiki\Search\SearchWidgets\FullSearchResultWidget;
use MediaWiki\Search\SearchWidgets\InterwikiSearchResultSetWidget;
use MediaWiki\Search\SearchWidgets\InterwikiSearchResultWidget;
use MediaWiki\Search\SearchWidgets\SearchFormWidget;
use MediaWiki\Search\TitleMatcher;
use MediaWiki\SpecialPage\SpecialPage;
use MediaWiki\Status\Status;
use MediaWiki\Title\NamespaceInfo;
use MediaWiki\Title\Title;
use MediaWiki\User\Options\UserOptionsManager;
use MediaWiki\Xml\Xml;
use RepoGroup;
use SearchEngine;
use SearchEngineConfig;
use SearchEngineFactory;
use Wikimedia\Rdbms\ReadOnlyMode;

/**
 * Run text & title search and display the output
 *
 * @ingroup SpecialPage
 * @ingroup Search
 */
class SpecialSearch extends SpecialPage {
        /**
         * Current search profile. Search profile is just a name that identifies
         * the active search tab on the search page (content, discussions...)
         * For users tt replaces the set of enabled namespaces from the query
         * string when applicable. Extensions can add new profiles with hooks
         * with custom search options just for that profile.
         * @var null|string
         */
        protected $profile;

        /** @var SearchEngine Search engine */
        protected $searchEngine;

        /** @var string|null Search engine type, if not default */
        protected $searchEngineType = null;

        /** @var array For links */
        protected $extraParams = [];

        /**
         * @var string The prefix url parameter. Set on the searcher and the
         * is expected to treat it as prefix filter on titles.
         */
        protected $mPrefix;

        protected int $limit;
        protected int $offset;

        /**
         * @var array
         */
        protected $namespaces;

        /**
         * @var string
         */
        protected $fulltext;

        /**
         * @var string
         */
        protected $sort = SearchEngine::DEFAULT_SORT;

        /**
         * @var bool
         */
        protected $runSuggestion = true;

        /**
         * Search engine configurations.
         * @var SearchEngineConfig
         */
        protected $searchConfig;

        private SearchEngineFactory $searchEngineFactory;
        private NamespaceInfo $nsInfo;
        private IContentHandlerFactory $contentHandlerFactory;
        private InterwikiLookup $interwikiLookup;
        private ReadOnlyMode $readOnlyMode;
        private UserOptionsManager $userOptionsManager;
        private LanguageConverterFactory $languageConverterFactory;
        private RepoGroup $repoGroup;
        private SearchResultThumbnailProvider $thumbnailProvider;
        private TitleMatcher $titleMatcher;

        /**
         * @var Status Holds any parameter validation errors that should
         *  be displayed back to the user.
         */
        private $loadStatus;

        private const NAMESPACES_CURRENT = 'sense';

        /**
         * @param SearchEngineConfig $searchConfig
         * @param SearchEngineFactory $searchEngineFactory
         * @param NamespaceInfo $nsInfo
         * @param IContentHandlerFactory $contentHandlerFactory
         * @param InterwikiLookup $interwikiLookup
         * @param ReadOnlyMode $readOnlyMode
         * @param UserOptionsManager $userOptionsManager
         * @param LanguageConverterFactory $languageConverterFactory
         * @param RepoGroup $repoGroup
         * @param SearchResultThumbnailProvider $thumbnailProvider
         * @param TitleMatcher $titleMatcher
         */
        public function __construct(
                SearchEngineConfig $searchConfig,
                SearchEngineFactory $searchEngineFactory,
                NamespaceInfo $nsInfo,
                IContentHandlerFactory $contentHandlerFactory,
                InterwikiLookup $interwikiLookup,
                ReadOnlyMode $readOnlyMode,
                UserOptionsManager $userOptionsManager,
                LanguageConverterFactory $languageConverterFactory,
                RepoGroup $repoGroup,
                SearchResultThumbnailProvider $thumbnailProvider,
                TitleMatcher $titleMatcher
        ) {
                parent::__construct( 'Search' );
                $this->searchConfig = $searchConfig;
                $this->searchEngineFactory = $searchEngineFactory;
                $this->nsInfo = $nsInfo;
                $this->contentHandlerFactory = $contentHandlerFactory;
                $this->interwikiLookup = $interwikiLookup;
                $this->readOnlyMode = $readOnlyMode;
                $this->userOptionsManager = $userOptionsManager;
                $this->languageConverterFactory = $languageConverterFactory;
                $this->repoGroup = $repoGroup;
                $this->thumbnailProvider = $thumbnailProvider;
                $this->titleMatcher = $titleMatcher;
        }

        /**
         * Entry point
         *
         * @param string|null $par
         */
        public function execute( $par ) {
                $request = $this->getRequest();
                $out = $this->getOutput();

                // Fetch the search term
                $term = str_replace( "\n", " ", $request->getText( 'search' ) );

                // Historically search terms have been accepted not only in the search query
                // parameter, but also as part of the primary url. This can have PII implications
                // in releasing page view data. As such issue a 301 redirect to the correct
                // URL.
                if ( $par !== null && $par !== '' && $term === '' ) {
                        $query = $request->getQueryValues();
                        unset( $query['title'] );
                        // Strip underscores from title parameter; most of the time we'll want
                        // text form here. But don't strip underscores from actual text params!
                        $query['search'] = str_replace( '_', ' ', $par );
                        $out->redirect( $this->getPageTitle()->getFullURL( $query ), 301 );
                        return;
                }

                // Need to load selected namespaces before handling nsRemember
                $this->load();
                // TODO: This performs database actions on GET request, which is going to
                // be a problem for our multi-datacenter work.
                if ( $request->getCheck( 'nsRemember' ) ) {
                        $this->saveNamespaces();
                        // Remove the token from the URL to prevent the user from inadvertently
                        // exposing it (e.g. by pasting it into a public wiki page) or undoing
                        // later settings changes (e.g. by reloading the page).
                        $query = $request->getQueryValues();
                        unset( $query['title'], $query['nsRemember'] );
                        $out->redirect( $this->getPageTitle()->getFullURL( $query ) );
                        return;
                }

                if ( !$request->getVal( 'fulltext' ) && !$request->getCheck( 'offset' ) ) {
                        $url = $this->goResult( $term );
                        if ( $url !== null ) {
                                // successful 'go'
                                $out->redirect( $url );
                                return;
                        }
                        // No match. If it could plausibly be a title
                        // run the No go match hook.
                        $title = Title::newFromText( $term );
                        if ( $title !== null ) {
                                $this->getHookRunner()->onSpecialSearchNogomatch( $title );
                        }
                }

                $this->setupPage( $term );

                if ( $this->getConfig()->get( MainConfigNames::DisableTextSearch ) ) {
                        $searchForwardUrl = $this->getConfig()->get( MainConfigNames::SearchForwardUrl );
                        if ( $searchForwardUrl ) {
                                $url = str_replace( '$1', urlencode( $term ), $searchForwardUrl );
                                $out->redirect( $url );
                        } else {
                                $out->addHTML( $this->showGoogleSearch( $term ) );
                        }

                        return;
                }

                $this->showResults( $term );
        }

        /**
         * Output a google search form if search is disabled
         *
         * @param string $term Search term
         * @todo FIXME Maybe we should get rid of this raw html message at some future time
         * @return string HTML
         * @return-taint escaped
         */
        private function showGoogleSearch( $term ) {
                return "<fieldset>" .
                                "<legend>" .
                                        $this->msg( 'search-external' )->escaped() .
                                "</legend>" .
                                "<p class='mw-searchdisabled'>" .
                                        $this->msg( 'searchdisabled' )->escaped() .
                                "</p>" .
                                // googlesearch is part of $wgRawHtmlMessages and safe to use as is here
                                $this->msg( 'googlesearch' )->rawParams(
                                        htmlspecialchars( $term ),
                                        'UTF-8',
                                        $this->msg( 'searchbutton' )->escaped()
                                )->text() .
                        "</fieldset>";
        }

        /**
         * Set up basic search parameters from the request and user settings.
         *
         * @see tests/phpunit/includes/specials/SpecialSearchTest.php
         */
        public function load() {
                $this->loadStatus = new Status();

                $request = $this->getRequest();
                $this->searchEngineType = $request->getVal( 'srbackend' );

                [ $this->limit, $this->offset ] = $request->getLimitOffsetForUser(
                        $this->getUser(),
                        20,
                        'searchlimit'
                );
                $this->mPrefix = $request->getVal( 'prefix', '' );
                if ( $this->mPrefix !== '' ) {
                        $this->setExtraParam( 'prefix', $this->mPrefix );
                }

                $sort = $request->getVal( 'sort', SearchEngine::DEFAULT_SORT );
                $validSorts = $this->getSearchEngine()->getValidSorts();
                if ( !in_array( $sort, $validSorts ) ) {
                        $this->loadStatus->warning( 'search-invalid-sort-order', $sort,
                                implode( ', ', $validSorts ) );
                } elseif ( $sort !== $this->sort ) {
                        $this->sort = $sort;
                        $this->setExtraParam( 'sort', $this->sort );
                }

                $user = $this->getUser();

                # Extract manually requested namespaces
                $nslist = $this->powerSearch( $request );
                if ( $nslist === [] ) {
                        # Fallback to user preference
                        $nslist = $this->searchConfig->userNamespaces( $user );
                }

                $profile = null;
                if ( $nslist === [] ) {
                        $profile = 'default';
                }

                $profile = $request->getVal( 'profile', $profile );
                $profiles = $this->getSearchProfiles();
                if ( $profile === null ) {
                        // BC with old request format
                        $profile = 'advanced';
                        foreach ( $profiles as $key => $data ) {
                                if ( $nslist === $data['namespaces'] && $key !== 'advanced' ) {
                                        $profile = $key;
                                }
                        }
                        $this->namespaces = $nslist;
                } elseif ( $profile === 'advanced' ) {
                        $this->namespaces = $nslist;
                } elseif ( isset( $profiles[$profile]['namespaces'] ) ) {
                        $this->namespaces = $profiles[$profile]['namespaces'];
                } else {
                        // Unknown profile requested
                        $this->loadStatus->warning( 'search-unknown-profile', $profile );
                        $profile = 'default';
                        $this->namespaces = $profiles['default']['namespaces'];
                }

                $this->fulltext = $request->getVal( 'fulltext' );
                $this->runSuggestion = (bool)$request->getVal( 'runsuggestion', '1' );
                $this->profile = $profile;
        }

        /**
         * If an exact title match can be found, jump straight ahead to it.
         *
         * @param string $term
         * @return string|null The url to redirect to, or null if no redirect.
         */
        public function goResult( $term ) {
                # If the string cannot be used to create a title
                if ( Title::newFromText( $term ) === null ) {
                        return null;
                }
                # If there's an exact or very near match, jump right there.
                $title = $this->titleMatcher->getNearMatch( $term );
                if ( $title === null ) {
                        return null;
                }
                $url = null;
                if ( !$this->getHookRunner()->onSpecialSearchGoResult( $term, $title, $url ) ) {
                        return null;
                }

                if (
                        // If there is a preference set to NOT redirect on exact page match
                        // then return null (which prevents direction)
                        !$this->redirectOnExactMatch()
                        // BUT ...
                        // ... ignore no-redirect preference if the exact page match is an interwiki link
                        && !$title->isExternal()
                        // ... ignore no-redirect preference if the exact page match is NOT in the main
                        // namespace AND there's a namespace in the search string
                        && !( $title->getNamespace() !== NS_MAIN && strpos( $term, ':' ) > 0 )
                ) {
                        return null;
                }

                return $url ?? $title->getFullUrlForRedirect();
        }

        private function redirectOnExactMatch() {
                if ( !$this->getConfig()->get( MainConfigNames::SearchMatchRedirectPreference ) ) {
                        // If the preference for whether to redirect is disabled, use the default setting
                        return $this->userOptionsManager->getDefaultOption(
                                'search-match-redirect',
                                $this->getUser()
                        );
                } else {
                        // Otherwise use the user's preference
                        return $this->userOptionsManager->getOption( $this->getUser(), 'search-match-redirect' );
                }
        }

        /**
         * @param string $term
         */
        public function showResults( $term ) {
                if ( $this->searchEngineType !== null ) {
                        $this->setExtraParam( 'srbackend', $this->searchEngineType );
                }

                $out = $this->getOutput();
                $widgetOptions = $this->getConfig()->get( MainConfigNames::SpecialSearchFormOptions );
                $formWidget = new SearchFormWidget(
                        new ServiceOptions(
                                SearchFormWidget::CONSTRUCTOR_OPTIONS,
                                $this->getConfig()
                        ),
                        $this,
                        $this->searchConfig,
                        $this->getHookContainer(),
                        $this->languageConverterFactory->getLanguageConverter( $this->getLanguage() ),
                        $this->nsInfo,
                        $this->getSearchProfiles()
                );
                $filePrefix = $this->getContentLanguage()->getFormattedNsText( NS_FILE ) . ':';
                if ( trim( $term ) === '' || $filePrefix === trim( $term ) ) {
                        // Empty query -- straight view of search form
                        if ( !$this->getHookRunner()->onSpecialSearchResultsPrepend( $this, $out, $term ) ) {
                                # Hook requested termination
                                return;
                        }
                        $out->enableOOUI();
                        // The form also contains the 'Showing results 0 - 20 of 1234' so we can
                        // only do the form render here for the empty $term case. Rendering
                        // the form when a search is provided is repeated below.
                        $out->addHTML( $formWidget->render(
                                $this->profile, $term, 0, 0, false, $this->offset, $this->isPowerSearch(), $widgetOptions
                        ) );
                        return;
                }

                $engine = $this->getSearchEngine();
                $engine->setFeatureData( 'rewrite', $this->runSuggestion );
                $engine->setLimitOffset( $this->limit, $this->offset );
                $engine->setNamespaces( $this->namespaces );
                $engine->setSort( $this->sort );
                $engine->prefix = $this->mPrefix;

                $this->getHookRunner()->onSpecialSearchSetupEngine( $this, $this->profile, $engine );
                if ( !$this->getHookRunner()->onSpecialSearchResultsPrepend( $this, $out, $term ) ) {
                        # Hook requested termination
                        return;
                }

                $title = Title::newFromText( $term );
                $languageConverter = $this->languageConverterFactory->getLanguageConverter( $this->getContentLanguage() );
                if ( $languageConverter->hasVariants() ) {
                        // findVariantLink will replace the link arg as well but we want to keep our original
                        // search string, use a copy in the $variantTerm var so that $term remains intact.
                        $variantTerm = $term;
                        $languageConverter->findVariantLink( $variantTerm, $title );
                }

                $showSuggestion = $title === null || !$title->isKnown();
                $engine->setShowSuggestion( $showSuggestion );

                $rewritten = $engine->replacePrefixes( $term );
                if ( $rewritten !== $term ) {
                        wfDeprecatedMsg( 'SearchEngine::replacePrefixes()  was overridden by ' .
                                get_class( $engine ) . ', this is deprecated since MediaWiki 1.32',
                                '1.32', false, false );
                }

                // fetch search results
                $titleMatches = $engine->searchTitle( $rewritten );
                $textMatches = $engine->searchText( $rewritten );

                $textStatus = null;
                if ( $textMatches instanceof Status ) {
                        $textStatus = $textMatches;
                        $textMatches = $textStatus->getValue();
                }

                // Get number of results
                $titleMatchesNum = $textMatchesNum = $numTitleMatches = $numTextMatches = 0;
                $approxTotalRes = false;
                if ( $titleMatches ) {
                        $titleMatchesNum = $titleMatches->numRows();
                        $numTitleMatches = $titleMatches->getTotalHits();
                        $approxTotalRes = $titleMatches->isApproximateTotalHits();
                }
                if ( $textMatches ) {
                        $textMatchesNum = $textMatches->numRows();
                        $numTextMatches = $textMatches->getTotalHits();
                        $approxTotalRes = $approxTotalRes || $textMatches->isApproximateTotalHits();
                        if ( $textMatchesNum > 0 ) {
                                $engine->augmentSearchResults( $textMatches );
                        }
                }
                $num = $titleMatchesNum + $textMatchesNum;
                $totalRes = $numTitleMatches + $numTextMatches;

                // start rendering the page
                $out->enableOOUI();
                $out->addHTML( $formWidget->render(
                        $this->profile, $term, $num, $totalRes, $approxTotalRes, $this->offset, $this->isPowerSearch(),
                        $widgetOptions
                ) );

                // did you mean... suggestions
                if ( $textMatches ) {
                        $dymWidget = new DidYouMeanWidget( $this );
                        $out->addHTML( $dymWidget->render( $term, $textMatches ) );
                }

                $hasSearchErrors = $textStatus && $textStatus->getMessages() !== [];
                $hasInlineIwResults = $textMatches &&
                        $textMatches->hasInterwikiResults( ISearchResultSet::INLINE_RESULTS );
                $hasSecondaryIwResults = $textMatches &&
                        $textMatches->hasInterwikiResults( ISearchResultSet::SECONDARY_RESULTS );

                $classNames = [ 'searchresults' ];
                if ( $hasSecondaryIwResults ) {
                        $classNames[] = 'mw-searchresults-has-iw';
                }
                if ( $this->offset > 0 ) {
                        $classNames[] = 'mw-searchresults-has-offset';
                }
                $out->addHTML( '<div class="' . implode( ' ', $classNames ) . '">' );

                $out->addHTML( '<div class="mw-search-results-info">' );

                if ( $hasSearchErrors || $this->loadStatus->getMessages() ) {
                        if ( $textStatus === null ) {
                                $textStatus = $this->loadStatus;
                        } else {
                                $textStatus->merge( $this->loadStatus );
                        }
                        [ $error, $warning ] = $textStatus->splitByErrorType();
                        if ( $error->getMessages() ) {
                                $out->addHTML( Html::errorBox(
                                        $error->getHTML( 'search-error' )
                                ) );
                        }
                        if ( $warning->getMessages() ) {
                                $out->addHTML( Html::warningBox(
                                        $warning->getHTML( 'search-warning' )
                                ) );
                        }
                }

                // If we have no results and have not already displayed an error message
                if ( $num === 0 && !$hasSearchErrors ) {
                        $out->wrapWikiMsg( "<p class=\"mw-search-nonefound\">\n$1</p>", [
                                $hasInlineIwResults ? 'search-nonefound-thiswiki' : 'search-nonefound',
                                wfEscapeWikiText( $term ),
                                $term
                        ] );
                }

                // Show the create link ahead
                $this->showCreateLink( $title, $num, $titleMatches, $textMatches );

                $this->getHookRunner()->onSpecialSearchResults( $term, $titleMatches, $textMatches );

                // Close <div class='mw-search-results-info'>
                $out->addHTML( '</div>' );

                // Although $num might be 0 there can still be secondary or inline
                // results to display.
                $linkRenderer = $this->getLinkRenderer();
                $mainResultWidget = new FullSearchResultWidget(
                        $this,
                        $linkRenderer,
                        $this->getHookContainer(),
                        $this->repoGroup,
                        $this->thumbnailProvider,
                        $this->userOptionsManager
                );

                $sidebarResultWidget = new InterwikiSearchResultWidget( $this, $linkRenderer );
                $sidebarResultsWidget = new InterwikiSearchResultSetWidget(
                        $this,
                        $sidebarResultWidget,
                        $linkRenderer,
                        $this->interwikiLookup,
                        $engine->getFeatureData( 'show-multimedia-search-results' )
                );

                $widget = new BasicSearchResultSetWidget( $this, $mainResultWidget, $sidebarResultsWidget );

                $out->addHTML( '<div class="mw-search-visualclear"></div>' );
                $this->prevNextLinks( $totalRes, $textMatches, $term, 'mw-search-pager-top', $out );

                $out->addHTML( $widget->render(
                        $term, $this->offset, $titleMatches, $textMatches
                ) );

                $out->addHTML( '<div class="mw-search-visualclear"></div>' );
                $this->prevNextLinks( $totalRes, $textMatches, $term, 'mw-search-pager-bottom', $out );

                // Close <div class='searchresults'>
                $out->addHTML( "</div>" );

                $this->getHookRunner()->onSpecialSearchResultsAppend( $this, $out, $term );
        }

        /**
         * @param Title|null $title
         * @param int $num The number of search results found
         * @param null|ISearchResultSet $titleMatches Results from title search
         * @param null|ISearchResultSet $textMatches Results from text search
         */
        protected function showCreateLink( $title, $num, $titleMatches, $textMatches ) {
                // show direct page/create link if applicable

                // Check DBkey !== '' in case of fragment link only.
                if ( $title === null || $title->getDBkey() === ''
                        || ( $titleMatches !== null && $titleMatches->searchContainedSyntax() )
                        || ( $textMatches !== null && $textMatches->searchContainedSyntax() )
                ) {
                        // invalid title
                        // preserve the paragraph for margins etc...
                        $this->getOutput()->addHTML( '<p></p>' );

                        return;
                }

                $messageName = 'searchmenu-new-nocreate';
                $linkClass = 'mw-search-createlink';

                if ( !$title->isExternal() ) {
                        if ( $title->isKnown() ) {
                                $messageName = 'searchmenu-exists';
                                $linkClass = 'mw-search-exists';
                        } elseif (
                                $this->contentHandlerFactory->getContentHandler( $title->getContentModel() )
                                        ->supportsDirectEditing()
                                && $this->getAuthority()->probablyCan( 'edit', $title )
                        ) {
                                $messageName = 'searchmenu-new';
                        }
                }

                $params = [
                        $messageName,
                        wfEscapeWikiText( $title->getPrefixedText() ),
                        Message::numParam( $num )
                ];
                $this->getHookRunner()->onSpecialSearchCreateLink( $title, $params );

                // Extensions using the hook might still return an empty $messageName
                // @phan-suppress-next-line PhanRedundantCondition Might be unset by hook
                if ( $messageName ) {
                        $this->getOutput()->wrapWikiMsg( "<p class=\"$linkClass\">\n$1</p>", $params );
                } else {
                        // preserve the paragraph for margins etc...
                        $this->getOutput()->addHTML( '<p></p>' );
                }
        }

        /**
         * Sets up everything for the HTML output page including styles, javascript,
         * page title, etc.
         *
         * @param string $term
         */
        protected function setupPage( $term ) {
                $out = $this->getOutput();

                $this->setHeaders();
                $this->outputHeader();
                // TODO: Is this true? The namespace remember uses a user token
                // on save.
                $out->getMetadata()->setPreventClickjacking( false );
                $this->addHelpLink( 'Help:Searching' );

                if ( strval( $term ) !== '' ) {
                        $out->setPageTitleMsg( $this->msg( 'searchresults' ) );
                        $out->setHTMLTitle( $this->msg( 'pagetitle' )
                                ->plaintextParams( $this->msg( 'searchresults-title' )->plaintextParams( $term )->text() )
                                ->inContentLanguage()->text()
                        );
                }

                if ( $this->mPrefix !== '' ) {
                        $subtitle = $this->msg( 'search-filter-title-prefix' )->plaintextParams( $this->mPrefix );
                        $params = $this->powerSearchOptions();
                        unset( $params['prefix'] );
                        $params += [
                                'search' => $term,
                                'fulltext' => 1,
                        ];

                        $subtitle .= ' (';
                        $subtitle .= Xml::element(
                                'a',
                                [
                                        'href' => $this->getPageTitle()->getLocalURL( $params ),
                                        'title' => $this->msg( 'search-filter-title-prefix-reset' )->text(),
                                ],
                                $this->msg( 'search-filter-title-prefix-reset' )->text()
                        );
                        $subtitle .= ')';
                        $out->setSubtitle( $subtitle );
                }

                $out->addJsConfigVars( [ 'searchTerm' => $term ] );
                $out->addModules( 'mediawiki.special.search' );
                $out->addModuleStyles( [
                        'mediawiki.special', 'mediawiki.special.search.styles',
                        'mediawiki.widgets.SearchInputWidget.styles',
                ] );
        }

        /**
         * Return true if current search is a power (advanced) search
         *
         * @return bool
         */
        protected function isPowerSearch() {
                return $this->profile === 'advanced';
        }

        /**
         * Extract "power search" namespace settings from the request object,
         * returning a list of index numbers to search.
         *
         * @param WebRequest &$request
         * @return array
         */
        protected function powerSearch( &$request ) {
                $arr = [];
                foreach ( $this->searchConfig->searchableNamespaces() as $ns => $name ) {
                        if ( $request->getCheck( 'ns' . $ns ) ) {
                                $arr[] = $ns;
                        }
                }

                return $arr;
        }

        /**
         * Reconstruct the 'power search' options for links
         * TODO: Instead of exposing this publicly, could we instead expose
         *  a function for creating search links?
         *
         * @return array
         */
        public function powerSearchOptions() {
                $opt = [];
                if ( $this->isPowerSearch() ) {
                        foreach ( $this->namespaces as $n ) {
                                $opt['ns' . $n] = 1;
                        }
                } else {
                        $opt['profile'] = $this->profile;
                }

                return $opt + $this->extraParams;
        }

        /**
         * Save namespace preferences when we're supposed to
         *
         * @return bool Whether we wrote something
         */
        protected function saveNamespaces() {
                $user = $this->getUser();
                $request = $this->getRequest();

                if ( $user->isRegistered() &&
                        $user->matchEditToken(
                                $request->getVal( 'nsRemember' ),
                                'searchnamespace',
                                $request
                        ) && !$this->readOnlyMode->isReadOnly()
                ) {
                        // Reset namespace preferences: namespaces are not searched
                        // when they're not mentioned in the URL parameters.
                        foreach ( $this->nsInfo->getValidNamespaces() as $n ) {
                                $this->userOptionsManager->setOption( $user, 'searchNs' . $n, false );
                        }
                        // The request parameters include all the namespaces to be searched.
                        // Even if they're the same as an existing profile, they're not eaten.
                        foreach ( $this->namespaces as $n ) {
                                $this->userOptionsManager->setOption( $user, 'searchNs' . $n, true );
                        }

                        DeferredUpdates::addCallableUpdate( static function () use ( $user ) {
                                $user->saveSettings();
                        } );

                        return true;
                }

                return false;
        }

        /**
         * @return array[]
         * @phan-return array<string,array{message:string,tooltip:string,namespaces:int|string|(int|string)[],namespace-messages?:string[]}>
         */
        protected function getSearchProfiles() {
                // Builds list of Search Types (profiles)
                $nsAllSet = array_keys( $this->searchConfig->searchableNamespaces() );
                $defaultNs = $this->searchConfig->defaultNamespaces();
                $profiles = [
                        'default' => [
                                'message' => 'searchprofile-articles',
                                'tooltip' => 'searchprofile-articles-tooltip',
                                'namespaces' => $defaultNs,
                                'namespace-messages' => $this->searchConfig->namespacesAsText(
                                        $defaultNs
                                ),
                        ],
                        'images' => [
                                'message' => 'searchprofile-images',
                                'tooltip' => 'searchprofile-images-tooltip',
                                'namespaces' => [ NS_FILE ],
                        ],
                        'all' => [
                                'message' => 'searchprofile-everything',
                                'tooltip' => 'searchprofile-everything-tooltip',
                                'namespaces' => $nsAllSet,
                        ],
                        'advanced' => [
                                'message' => 'searchprofile-advanced',
                                'tooltip' => 'searchprofile-advanced-tooltip',
                                'namespaces' => self::NAMESPACES_CURRENT,
                        ]
                ];

                $this->getHookRunner()->onSpecialSearchProfiles( $profiles );

                foreach ( $profiles as &$data ) {
                        if ( !is_array( $data['namespaces'] ) ) {
                                continue;
                        }
                        sort( $data['namespaces'] );
                }

                return $profiles;
        }

        /**
         * @since 1.18
         *
         * @return SearchEngine
         */
        public function getSearchEngine() {
                if ( $this->searchEngine === null ) {
                        $this->searchEngine = $this->searchEngineFactory->create( $this->searchEngineType );
                }

                return $this->searchEngine;
        }

        /**
         * Current search profile.
         * @return null|string
         */
        public function getProfile() {
                return $this->profile;
        }

        /**
         * Current namespaces.
         * @return array
         */
        public function getNamespaces() {
                return $this->namespaces;
        }

        /**
         * Users of hook SpecialSearchSetupEngine can use this to
         * add more params to links to not lose selection when
         * user navigates search results.
         * @since 1.18
         *
         * @param string $key
         * @param mixed $value
         */
        public function setExtraParam( $key, $value ) {
                $this->extraParams[$key] = $value;
        }

        /**
         * The prefix value send to Special:Search using the 'prefix' URI param
         * It means that the user is willing to search for pages whose titles start with
         * this prefix value.
         * (Used by the InputBox extension)
         *
         * @return string
         */
        public function getPrefix() {
                return $this->mPrefix;
        }

        /**
         * @param null|int $totalRes
         * @param null|ISearchResultSet $textMatches
         * @param string $term
         * @param string $class
         * @param OutputPage $out
         */
        private function prevNextLinks(
                ?int $totalRes,
                ?ISearchResultSet $textMatches,
                string $term,
                string $class,
                OutputPage $out
        ) {
                if ( $totalRes > $this->limit || $this->offset ) {
                        // Allow matches to define the correct offset, as interleaved
                        // AB testing may require a different next page offset.
                        if ( $textMatches && $textMatches->getOffset() !== null ) {
                                $offset = $textMatches->getOffset();
                        } else {
                                $offset = $this->offset;
                        }

                        // use the rewritten search term for subsequent page searches
                        $newSearchTerm = $term;
                        if ( $textMatches && $textMatches->hasRewrittenQuery() ) {
                                $newSearchTerm = $textMatches->getQueryAfterRewrite();
                        }

                        $prevNext =
                                // @phan-suppress-next-line PhanTypeMismatchArgumentNullable offset is not null
                                $this->buildPrevNextNavigation( $offset, $this->limit,
                                        $this->powerSearchOptions() + [ 'search' => $newSearchTerm ],
                                        $this->limit + $this->offset >= $totalRes );
                        $out->addHTML( "<div class='{$class}'>{$prevNext}</div>\n" );
                }
        }

        protected function getGroupName() {
                return 'pages';
        }
}

/**
 * Retain the old class name for backwards compatibility.
 * @deprecated since 1.41
 */
class_alias( SpecialSearch::class, 'SpecialSearch' );