wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Lib\Formatters;

use InvalidArgumentException;
use ValueFormatters\FormatterOptions;
use ValueFormatters\ValueFormatter;
use Wikibase\DataModel\Services\Lookup\LabelDescriptionLookup;
use Wikibase\DataModel\Services\Lookup\LanguageLabelDescriptionLookup;
use Wikibase\DataModel\Services\Lookup\TermLookup;
use Wikibase\Lib\Store\CachingFallbackLabelDescriptionLookup;
use Wikibase\Lib\Store\LanguageFallbackLabelDescriptionLookup;
use Wikibase\Lib\Store\RedirectResolvingLatestRevisionLookup;
use Wikibase\Lib\TermFallbackCache\TermFallbackCacheFacade;
use Wikibase\Lib\TermLanguageFallbackChain;

/**
 * Factory for LabelDescriptionLookup objects based on FormatterOptions.
 *
 * The LabelDescriptionLookup is created based on the values of the options
 * OPT_LANGUAGE_FALLBACK_CHAIN, and ValueFormatter::OPT_LANG:
 *
 * * If OPT_LANGUAGE_FALLBACK_CHAIN is set, a LanguageFallbackLabelDescriptionLookup will be created byed on
 *   the TermLanguageFallbackChain contained in that option.
 * * If ValueFormatter::OPT_LANG is set, a LanguageLabelDescriptionLookup is created
 * * If none of these options is set, an InvalidArgumentException is thrown.
 *
 * @license GPL-2.0-or-later
 * @author Daniel Kinzler
 */
class FormatterLabelDescriptionLookupFactory {

    public const OPT_LANGUAGE_FALLBACK_CHAIN = 'languages';

    /**
     * @var TermLookup
     */
    private $termLookup;

    /**
     * @var TermFallbackCacheFacade
     */
    private $termFallbackCache;

    /**
     * @var RedirectResolvingLatestRevisionLookup
     */
    private $redirectResolvingLatestRevisionLookup;

    public function __construct(
        TermLookup $termLookup,
        TermFallbackCacheFacade $cache,
        RedirectResolvingLatestRevisionLookup $redirectResolvingLatestRevisionLookup
    ) {
        $this->termLookup = $termLookup;
        $this->termFallbackCache = $cache;
        $this->redirectResolvingLatestRevisionLookup = $redirectResolvingLatestRevisionLookup;
    }

    /**
     * @param FormatterOptions $options
     *
     * @throws InvalidArgumentException
     * @return LabelDescriptionLookup
     */
    public function getLabelDescriptionLookup( FormatterOptions $options ) {
        if ( $options->hasOption( self::OPT_LANGUAGE_FALLBACK_CHAIN ) ) {
            return $this->newLanguageFallbackLabelDescriptionLookup( $options );
        } elseif ( $options->hasOption( ValueFormatter::OPT_LANG ) ) {
            return $this->newLanguageLabelDescriptionLookup( $options );
        } else {
            throw new InvalidArgumentException( 'OPT_LANG or OPT_LANGUAGE_FALLBACK_CHAIN, '
                . 'must be set in FormatterOptions.' );
        }
    }

    private function newLanguageFallbackLabelDescriptionLookup( FormatterOptions $options ) {
        $fallbackChain = $options->getOption( self::OPT_LANGUAGE_FALLBACK_CHAIN );

        if ( !( $fallbackChain instanceof TermLanguageFallbackChain ) ) {
            throw new InvalidArgumentException( 'OPT_LANGUAGE_FALLBACK_CHAIN must be used ' .
                'with an instance of TermLanguageFallbackChain.' );
        }

        return new CachingFallbackLabelDescriptionLookup(
            $this->termFallbackCache,
            $this->redirectResolvingLatestRevisionLookup,
            new LanguageFallbackLabelDescriptionLookup( $this->termLookup, $fallbackChain ),
            $fallbackChain
        );
    }

    private function newLanguageLabelDescriptionLookup( FormatterOptions $options ) {
        $languageCode = $options->getOption( ValueFormatter::OPT_LANG );

        if ( !is_string( $languageCode ) ) {
            throw new InvalidArgumentException( 'ValueFormatter::OPT_LANG must be a '
                . 'language code string.' );
        }

        return new LanguageLabelDescriptionLookup( $this->termLookup, $languageCode );
    }

}