MaidIB Text Similar

<?php
namespace App\Lib;

class Text {

    public function similar($text, $textSearch, $params = array('maxSymbols' => false, 'toTranslit' => false, 'lower' => false)) {
        $convert = $this->convertToSimilar($text, $textSearch, $params);
        similar_text($convert['text'], $convert['textSearch'], $percents);
        return $percents;
    }

    public function convertToSimilar($text, $textSearch, $params = array('maxSymbols' => false, 'toTranslit' => false, 'lower' => false)) {
        if(isset($params['maxSymbols']) and $params['maxSymbols'] !== false and $params['maxSymbols'] != 0 and $params['maxSymbols'] != null) {
            $text = mb_substr($text, 0, $params['maxSymbols']);
            $textSearch = mb_substr($textSearch, 0, $params['maxSymbols']);
        }
        if(isset($params['lower']) and ($params['lower'] === true or $params['lower'] == 1)) {
            $text = mb_strtolower($text);
            $textSearch = mb_strtolower($textSearch);
        }
        if(isset($params['toTranslit']) and ($params['toTranslit'] == true or $params['toTranslit'] == 1)) {
            if(!isset($params['lower']) or $params['lower'] === false or $params['lower'] == 0 or $params['lower'] == null) {
                $text = $this->toTranslit($text);
                $textSearch = $this->toTranslit($textSearch);
            } else {
                $text = $this->toTranslit($text, true, false);
                $textSearch = $this->toTranslit($textSearch, true, false);
            }
        }
        return ['text' => $text, 'textSearch' => $textSearch];
    }

    public function toTranslit($text, $lowerSymbols = true, $upperSymbols = true) {
        if($lowerSymbols == true) {
        $converterLower = array(
            'а' => 'a',   'б' => 'b',   'в' => 'v',
            'г' => 'g',   'д' => 'd',   'е' => 'e',
            'ё' => 'e',   'ж' => 'zh',  'з' => 'z',
            'и' => 'i',   'й' => 'y',   'к' => 'k',
            'л' => 'l',   'м' => 'm',   'н' => 'n',
            'о' => 'o',   'п' => 'p',   'р' => 'r',
            'с' => 's',   'т' => 't',   'у' => 'u',
            'ф' => 'f',   'х' => 'h',   'ц' => 'c',
            'ч' => 'ch',  'ш' => 'sh',  'щ' => 'sch',
            'ь' => '\'',  'ы' => 'y',   'ъ' => '\'',
            'э' => 'e',   'ю' => 'yu',  'я' => 'ya',
            );
        } else {
            $converterLower = array();
        }
        if($upperSymbols == true) {
            $converterUpper = array(
                'А' => 'A',   'Б' => 'B',   'В' => 'V',
                'Г' => 'G',   'Д' => 'D',   'Е' => 'E',
                'Ё' => 'E',   'Ж' => 'Zh',  'З' => 'Z',
                'И' => 'I',   'Й' => 'Y',   'К' => 'K',
                'Л' => 'L',   'М' => 'M',   'Н' => 'N',
                'О' => 'O',   'П' => 'P',   'Р' => 'R',
                'С' => 'S',   'Т' => 'T',   'У' => 'U',
                'Ф' => 'F',   'Х' => 'H',   'Ц' => 'C',
                'Ч' => 'Ch',  'Ш' => 'Sh',  'Щ' => 'Sch',
                'Ь' => '\'',  'Ы' => 'Y',   'Ъ' => '\'',
                'Э' => 'E',   'Ю' => 'Yu',  'Я' => 'Ya',
            );
        } else {
            $converterUpper = array();
        }
        $converter = array_merge($converterLower, $converterUpper);
        return strtr($text, $converter);
    }
}