User::isSafeToLoad() should return false if MW_NO_SESSION

[mediawiki.git] / includes / api / ApiOpenSearch.php

<?php
/**
 * Created on Oct 13, 2006
 *
 * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
 * Copyright © 2008 Brion Vibber <brion@wikimedia.org>
 * Copyright © 2014 Brad Jorsch <bjorsch@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
 */

/**
 * @ingroup API
 */
class ApiOpenSearch extends ApiBase {

        private $format = null;
        private $fm = null;

        /**
         * Get the output format
         *
         * @return string
         */
        protected function getFormat() {
                if ( $this->format === null ) {
                        $params = $this->extractRequestParams();
                        $format = $params['format'];

                        $allowedParams = $this->getAllowedParams();
                        if ( !in_array( $format, $allowedParams['format'][ApiBase::PARAM_TYPE] ) ) {
                                $format = $allowedParams['format'][ApiBase::PARAM_DFLT];
                        }

                        if ( substr( $format, -2 ) === 'fm' ) {
                                $this->format = substr( $format, 0, -2 );
                                $this->fm = 'fm';
                        } else {
                                $this->format = $format;
                                $this->fm = '';
                        }
                }
                return $this->format;
        }

        public function getCustomPrinter() {
                switch ( $this->getFormat() ) {
                        case 'json':
                                return new ApiOpenSearchFormatJson(
                                        $this->getMain(), $this->fm, $this->getParameter( 'warningsaserror' )
                                );

                        case 'xml':
                                $printer = $this->getMain()->createPrinterByName( 'xml' . $this->fm );
                                $printer->setRootElement( 'SearchSuggestion' );
                                return $printer;

                        default:
                                ApiBase::dieDebug( __METHOD__, "Unsupported format '{$this->getFormat()}'" );
                }
        }

        public function execute() {
                $params = $this->extractRequestParams();
                $search = $params['search'];
                $limit = $params['limit'];
                $namespaces = $params['namespace'];
                $suggest = $params['suggest'];

                if ( $params['redirects'] === null ) {
                        // Backwards compatibility, don't resolve for JSON.
                        $resolveRedir = $this->getFormat() !== 'json';
                } else {
                        $resolveRedir = $params['redirects'] === 'resolve';
                }

                $results = [];

                if ( !$suggest || $this->getConfig()->get( 'EnableOpenSearchSuggest' ) ) {
                        // Open search results may be stored for a very long time
                        $this->getMain()->setCacheMaxAge( $this->getConfig()->get( 'SearchSuggestCacheExpiry' ) );
                        $this->getMain()->setCacheMode( 'public' );
                        $this->search( $search, $limit, $namespaces, $resolveRedir, $results );

                        // Allow hooks to populate extracts and images
                        Hooks::run( 'ApiOpenSearchSuggest', [ &$results ] );

                        // Trim extracts, if necessary
                        $length = $this->getConfig()->get( 'OpenSearchDescriptionLength' );
                        foreach ( $results as &$r ) {
                                if ( is_string( $r['extract'] ) && !$r['extract trimmed'] ) {
                                        $r['extract'] = self::trimExtract( $r['extract'], $length );
                                }
                        }
                }

                // Populate result object
                $this->populateResult( $search, $results );
        }

        /**
         * Perform the search
         *
         * @param string $search Text to search
         * @param int $limit Maximum items to return
         * @param array $namespaces Namespaces to search
         * @param bool $resolveRedir Whether to resolve redirects
         * @param array &$results Put results here. Keys have to be integers.
         */
        protected function search( $search, $limit, $namespaces, $resolveRedir, &$results ) {

                $searchEngine = SearchEngine::create();
                $searchEngine->setLimitOffset( $limit );
                $searchEngine->setNamespaces( $namespaces );
                $titles = $searchEngine->extractTitles( $searchEngine->completionSearchWithVariants( $search ) );

                if ( !$titles ) {
                        return;
                }

                // Special pages need unique integer ids in the return list, so we just
                // assign them negative numbers because those won't clash with the
                // always positive articleIds that non-special pages get.
                $nextSpecialPageId = -1;

                if ( $resolveRedir ) {
                        // Query for redirects
                        $redirects = [];
                        $lb = new LinkBatch( $titles );
                        if ( !$lb->isEmpty() ) {
                                $db = $this->getDB();
                                $res = $db->select(
                                        [ 'page', 'redirect' ],
                                        [ 'page_namespace', 'page_title', 'rd_namespace', 'rd_title' ],
                                        [
                                                'rd_from = page_id',
                                                'rd_interwiki IS NULL OR rd_interwiki = ' . $db->addQuotes( '' ),
                                                $lb->constructSet( 'page', $db ),
                                        ],
                                        __METHOD__
                                );
                                foreach ( $res as $row ) {
                                        $redirects[$row->page_namespace][$row->page_title] =
                                                [ $row->rd_namespace, $row->rd_title ];
                                }
                        }

                        // Bypass any redirects
                        $seen = [];
                        foreach ( $titles as $title ) {
                                $ns = $title->getNamespace();
                                $dbkey = $title->getDBkey();
                                $from = null;
                                if ( isset( $redirects[$ns][$dbkey] ) ) {
                                        list( $ns, $dbkey ) = $redirects[$ns][$dbkey];
                                        $from = $title;
                                        $title = Title::makeTitle( $ns, $dbkey );
                                }
                                if ( !isset( $seen[$ns][$dbkey] ) ) {
                                        $seen[$ns][$dbkey] = true;
                                        $resultId = $title->getArticleID();
                                        if ( $resultId === 0 ) {
                                                $resultId = $nextSpecialPageId;
                                                $nextSpecialPageId -= 1;
                                        }
                                        $results[$resultId] = [
                                                'title' => $title,
                                                'redirect from' => $from,
                                                'extract' => false,
                                                'extract trimmed' => false,
                                                'image' => false,
                                                'url' => wfExpandUrl( $title->getFullURL(), PROTO_CURRENT ),
                                        ];
                                }
                        }
                } else {
                        foreach ( $titles as $title ) {
                                $resultId = $title->getArticleID();
                                if ( $resultId === 0 ) {
                                        $resultId = $nextSpecialPageId;
                                        $nextSpecialPageId -= 1;
                                }
                                $results[$resultId] = [
                                        'title' => $title,
                                        'redirect from' => null,
                                        'extract' => false,
                                        'extract trimmed' => false,
                                        'image' => false,
                                        'url' => wfExpandUrl( $title->getFullURL(), PROTO_CURRENT ),
                                ];
                        }
                }
        }

        /**
         * @param string $search
         * @param array &$results
         */
        protected function populateResult( $search, &$results ) {
                $result = $this->getResult();

                switch ( $this->getFormat() ) {
                        case 'json':
                                // http://www.opensearch.org/Specifications/OpenSearch/Extensions/Suggestions/1.1
                                $result->addArrayType( null, 'array' );
                                $result->addValue( null, 0, strval( $search ) );
                                $terms = [];
                                $descriptions = [];
                                $urls = [];
                                foreach ( $results as $r ) {
                                        $terms[] = $r['title']->getPrefixedText();
                                        $descriptions[] = strval( $r['extract'] );
                                        $urls[] = $r['url'];
                                }
                                $result->addValue( null, 1, $terms );
                                $result->addValue( null, 2, $descriptions );
                                $result->addValue( null, 3, $urls );
                                break;

                        case 'xml':
                                // http://msdn.microsoft.com/en-us/library/cc891508%28v=vs.85%29.aspx
                                $imageKeys = [
                                        'source' => true,
                                        'alt' => true,
                                        'width' => true,
                                        'height' => true,
                                        'align' => true,
                                ];
                                $items = [];
                                foreach ( $results as $r ) {
                                        $item = [
                                                'Text' => $r['title']->getPrefixedText(),
                                                'Url' => $r['url'],
                                        ];
                                        if ( is_string( $r['extract'] ) && $r['extract'] !== '' ) {
                                                $item['Description'] = $r['extract'];
                                        }
                                        if ( is_array( $r['image'] ) && isset( $r['image']['source'] ) ) {
                                                $item['Image'] = array_intersect_key( $r['image'], $imageKeys );
                                        }
                                        ApiResult::setSubelementsList( $item, array_keys( $item ) );
                                        $items[] = $item;
                                }
                                ApiResult::setIndexedTagName( $items, 'Item' );
                                $result->addValue( null, 'version', '2.0' );
                                $result->addValue( null, 'xmlns', 'http://opensearch.org/searchsuggest2' );
                                $result->addValue( null, 'Query', strval( $search ) );
                                $result->addSubelementsList( null, 'Query' );
                                $result->addValue( null, 'Section', $items );
                                break;

                        default:
                                ApiBase::dieDebug( __METHOD__, "Unsupported format '{$this->getFormat()}'" );
                }
        }

        public function getAllowedParams() {
                return [
                        'search' => null,
                        'limit' => [
                                ApiBase::PARAM_DFLT => $this->getConfig()->get( 'OpenSearchDefaultLimit' ),
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => 100,
                                ApiBase::PARAM_MAX2 => 100
                        ],
                        'namespace' => [
                                ApiBase::PARAM_DFLT => NS_MAIN,
                                ApiBase::PARAM_TYPE => 'namespace',
                                ApiBase::PARAM_ISMULTI => true
                        ],
                        'suggest' => false,
                        'redirects' => [
                                ApiBase::PARAM_TYPE => [ 'return', 'resolve' ],
                        ],
                        'format' => [
                                ApiBase::PARAM_DFLT => 'json',
                                ApiBase::PARAM_TYPE => [ 'json', 'jsonfm', 'xml', 'xmlfm' ],
                        ],
                        'warningsaserror' => false,
                ];
        }

        protected function getExamplesMessages() {
                return [
                        'action=opensearch&search=Te'
                                => 'apihelp-opensearch-example-te',
                ];
        }

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

        /**
         * Trim an extract to a sensible length.
         *
         * Adapted from Extension:OpenSearchXml, which adapted it from
         * Extension:ActiveAbstract.
         *
         * @param string $text
         * @param int $length Target length; actual result will continue to the end of a sentence.
         * @return string
         */
        public static function trimExtract( $text, $length ) {
                static $regex = null;

                if ( $regex === null ) {
                        $endchars = [
                                '([^\d])\.\s', '\!\s', '\?\s', // regular ASCII
                                '。', // full-width ideographic full-stop
                                '．', '！', '？', // double-width roman forms
                                '｡', // half-width ideographic full stop
                        ];
                        $endgroup = implode( '|', $endchars );
                        $end = "(?:$endgroup)";
                        $sentence = ".{{$length},}?$end+";
                        $regex = "/^($sentence)/u";
                }

                $matches = [];
                if ( preg_match( $regex, $text, $matches ) ) {
                        return trim( $matches[1] );
                } else {
                        // Just return the first line
                        $lines = explode( "\n", $text );
                        return trim( $lines[0] );
                }
        }

        /**
         * Fetch the template for a type.
         *
         * @param string $type MIME type
         * @return string
         * @throws MWException
         */
        public static function getOpenSearchTemplate( $type ) {
                global $wgOpenSearchTemplate, $wgCanonicalServer;

                if ( $wgOpenSearchTemplate && $type === 'application/x-suggestions+json' ) {
                        return $wgOpenSearchTemplate;
                }

                $ns = implode( '|', SearchEngine::defaultNamespaces() );
                if ( !$ns ) {
                        $ns = "0";
                }

                switch ( $type ) {
                        case 'application/x-suggestions+json':
                                return $wgCanonicalServer . wfScript( 'api' )
                                        . '?action=opensearch&search={searchTerms}&namespace=' . $ns;

                        case 'application/x-suggestions+xml':
                                return $wgCanonicalServer . wfScript( 'api' )
                                        . '?action=opensearch&format=xml&search={searchTerms}&namespace=' . $ns;

                        default:
                                throw new MWException( __METHOD__ . ": Unknown type '$type'" );
                }
        }
}

class ApiOpenSearchFormatJson extends ApiFormatJson {
        private $warningsAsError = false;

        public function __construct( ApiMain $main, $fm, $warningsAsError ) {
                parent::__construct( $main, "json$fm" );
                $this->warningsAsError = $warningsAsError;
        }

        public function execute() {
                if ( !$this->getResult()->getResultData( 'error' ) ) {
                        $result = $this->getResult();

                        // Ignore warnings or treat as errors, as requested
                        $warnings = $result->removeValue( 'warnings', null );
                        if ( $this->warningsAsError && $warnings ) {
                                $this->dieUsage(
                                        'Warnings cannot be represented in OpenSearch JSON format', 'warnings', 0,
                                        [ 'warnings' => $warnings ]
                                );
                        }

                        // Ignore any other unexpected keys (e.g. from $wgDebugToolbar)
                        $remove = array_keys( array_diff_key(
                                $result->getResultData(),
                                [ 0 => 'search', 1 => 'terms', 2 => 'descriptions', 3 => 'urls' ]
                        ) );
                        foreach ( $remove as $key ) {
                                $result->removeValue( $key, null );
                        }
                }

                parent::execute();
        }
}