wikimedia/mediawiki-extensions-Translate

<?php
declare( strict_types = 1 );

namespace MediaWiki\Extension\Translate\TtmServer;

use Elastica\Document;
use Elastica\ResultSet;
use MediaWiki\Extension\Translate\MessageLoading\MessageCollection;
use MediaWiki\Extension\Translate\MessageLoading\MessageDefinitions;
use MediaWiki\Extension\Translate\MessageLoading\MessageHandle;
use MediaWiki\Title\Title;

/**
 * Cross Language Translation Search.
 *
 * @license GPL-2.0-or-later
 * @ingroup TTMServer
 */
class CrossLanguageTranslationSearchQuery {
    private SearchableTtmServer $server;
    private array $params;
    private ?ResultSet $resultSet = null;
    private int $total = 0;
    private array $hl = [ '', '' ];

    public function __construct( array $params, SearchableTtmServer $server ) {
        $this->params = $params;
        $this->server = $server;
    }

    public function getDocuments(): array {
        $documents = [];
        $offset = $this->params['offset'];
        $limit = $this->params['limit'];

        $options = $this->params;
        $options['language'] = $this->params['sourcelanguage'];
        // Use a bigger limit that what was requested, since we are likely to throw away many
        // results in the local filtering step at extractMessages
        $options['limit'] = $limit * 10;
        // TODO: the real offset should be communicated to the frontend. It currently assumes
        // next offset is current offset + limit and previous one is current offset - limit.
        // It might be difficult to fix scrolling results backwards. For now we handle offset
        // locally.
        $options['offset'] = 0;

        // @phan-suppress-next-line PhanUndeclaredMethod
        $search = $this->server->createSearch( $this->params['query'], $options, $this->hl );
        $scroll = $search->scroll( '5s' );

        // Used for aggregations. Only the first scroll response has them.
        $this->resultSet = null;

        foreach ( $scroll as $resultSet ) {
            if ( !$this->resultSet ) {
                $this->resultSet = $resultSet;
                $this->total = $resultSet->getTotalHits();
            }

            $results = $this->extractMessages( $resultSet->getDocuments() );
            $documents = array_merge( $documents, $results );

            $count = count( $documents );

            if ( $count >= $offset + $limit ) {
                break;
            }
        }

        if ( !$this->resultSet ) {
            // No hits for documents, just set the result set.
            $this->resultSet = $scroll->current();
            $this->total = $scroll->current()->getTotalHits();
        }

        // clear was introduced in Elastica 5.3.1, but Elastica extension uses 5.3.0
        if ( is_callable( [ $scroll, 'clear' ] ) ) {
            $scroll->clear();
        }
        return array_slice( $documents, $offset, $limit );
    }

    /**
     * Extract messages from the documents and build message definitions.
     * Create a message collection from the definitions in the target language.
     * Filter the message collection to get filtered messages.
     * Slice messages according to limit and offset given.
     * @param Document[] $documents
     */
    private function extractMessages( array $documents ): array {
        $messages = $ret = [];

        $language = $this->params['language'];
        foreach ( $documents as $document ) {
            $data = $document->getData();

            // @phan-suppress-next-line PhanUndeclaredMethod
            if ( !$this->server->isLocalSuggestion( $data ) ) {
                continue;
            }

            $title = Title::newFromText( $data['localid'] );
            if ( !$title ) {
                continue;
            }

            $handle = new MessageHandle( $title );
            if ( !$handle->isValid() ) {
                continue;
            }

            $key = $title->getNamespace() . ':' . $title->getDBkey();
            $messages[$key] = $data['content'];
        }

        $definitions = new MessageDefinitions( $messages );
        $collection = MessageCollection::newFromDefinitions( $definitions, $language );

        $filter = $this->params['filter'];
        if ( $filter === 'untranslated' ) {
            $collection->filter( 'hastranslation', true );
        } elseif ( in_array( $filter, $this->getAvailableFilters() ) ) {
            $collection->filter( $filter, false );
        }

        if ( $filter === 'translated' || $filter === 'fuzzy' ) {
            $collection->loadTranslations();
        }

        foreach ( $collection->keys() as $messageKey => $titleValue ) {
            $title = Title::newFromLinkTarget( $titleValue );

            $result = [];
            $result['content'] = $messages[$messageKey];
            if ( $filter === 'translated' || $filter === 'fuzzy' ) {
                $result['content'] = $collection[$messageKey]->translation();
            }
            $handle = new MessageHandle( $title );
            $result['localid'] = $handle->getTitleForBase()->getPrefixedText();
            $result['language'] = $language;

            $ret[] = $result;
        }

        return $ret;
    }

    public function getAvailableFilters(): array {
        return [
            'translated',
            'fuzzy',
            'untranslated'
        ];
    }

    public function getTotalHits(): int {
        return $this->total;
    }

    public function getResultSet(): ResultSet {
        return $this->resultSet;
    }
}