<?php

/**
 * German Stemmer
 *
 * Lightweight suffix-based stemmer for German.
 *
 * @package ProRank\SEO\Modules\Content\InternalLinking\Parser\MultiLanguage\Languages
 * @since   1.0.0
 */

declare(strict_types=1);

namespace ProRank\SEO\Modules\Content\InternalLinking\Parser\MultiLanguage\Languages;

use ProRank\SEO\Modules\Content\InternalLinking\Parser\MultiLanguage\Stemmer;

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class GermanStemmer extends Stemmer {
    public function __construct() {
        parent::__construct('de');
    }

    public function stem(string $word): string {
        $word = $this->normalize($word);
        if (strlen($word) <= 3) {
            return $word;
        }

        $suffixes = [
            'lichkeiten', 'igkeiten', 'lichkeit', 'igkeit', 'schaften', 'schaft',
            'ungen', 'ung', 'heiten', 'heit', 'keit', 'chen', 'lein',
            'ern', 'ern', 'er', 'en', 'es', 'e', 'n', 's',
        ];

        foreach ($suffixes as $suffix) {
            if (str_ends_with($word, $suffix) && strlen($word) > strlen($suffix) + 2) {
                return substr($word, 0, -strlen($suffix));
            }
        }

        return $word;
    }
}
