PHP Spelling suggester function

spell-suggester.php

<?php

function get_suggestions($user_input)
{
    $pspell_link = pspell_new("en");
    $suggestions = pspell_suggest($pspell_link, $user_input);

    $lowest_distance = null;
    $most_relevant_words = [];

    foreach ($suggestions as $word) {
        $distance = levenshtein($user_input, $word);

        if (null === $lowest_distance) {
            $lowest_distance = $distance;
        }

        if ($lowest_distance >= $distance) {
            $lowest_distance = $distance;
            $most_relevant_words[] = $word;
        }
    }

    $most_similar = null;
    $most_similar_words = [];
    foreach ($most_relevant_words as $word) {
        $similarity = similar_text($user_input, $word);

        if (null == $most_similar) {
            $most_similar = $similarity;
        }

        if ($most_similar <= $similarity) {
            $most_similar_words[$similarity] = $word;
        }
    }

    return $most_similar_words;
}