Proper sanitizing for non-latin symbols in filenames

better_sanitizer.php

<?php
$app['upload'] = $app->share(
    $app->extend(
        'upload',
        function (\Sirius\Upload\Handler $uploadHandler) {
            $uploadHandler->setSanitizerCallback(
                function ($filename) {
                    $clean_name = $filename;


                    // from https://github.com/kohana/core/blob/3.3/master/utf8/transliterate_to_ascii.php
                    $utf8_lower_accents = [
                        'à' => 'a',  'ô' => 'o',  'ď' => 'd',  'ḟ' => 'f',  'ë' => 'e',  'š' => 's',  'ơ' => 'o',
                        'ß' => 'ss', 'ă' => 'a',  'ř' => 'r',  'ț' => 't',  'ň' => 'n',  'ā' => 'a',  'ķ' => 'k',
                        'ŝ' => 's',  'ỳ' => 'y',  'ņ' => 'n',  'ĺ' => 'l',  'ħ' => 'h',  'ṗ' => 'p',  'ó' => 'o',
                        'ú' => 'u',  'ě' => 'e',  'é' => 'e',  'ç' => 'c',  'ẁ' => 'w',  'ċ' => 'c',  'õ' => 'o',
                        'ṡ' => 's',  'ø' => 'o',  'ģ' => 'g',  'ŧ' => 't',  'ș' => 's',  'ė' => 'e',  'ĉ' => 'c',
                        'ś' => 's',  'î' => 'i',  'ű' => 'u',  'ć' => 'c',  'ę' => 'e',  'ŵ' => 'w',  'ṫ' => 't',
                        'ū' => 'u',  'č' => 'c',  'ö' => 'o',  'è' => 'e',  'ŷ' => 'y',  'ą' => 'a',  'ł' => 'l',
                        'ų' => 'u',  'ů' => 'u',  'ş' => 's',  'ğ' => 'g',  'ļ' => 'l',  'ƒ' => 'f',  'ž' => 'z',
                        'ẃ' => 'w',  'ḃ' => 'b',  'å' => 'a',  'ì' => 'i',  'ï' => 'i',  'ḋ' => 'd',  'ť' => 't',
                        'ŗ' => 'r',  'ä' => 'a',  'í' => 'i',  'ŕ' => 'r',  'ê' => 'e',  'ü' => 'u',  'ò' => 'o',
                        'ē' => 'e',  'ñ' => 'n',  'ń' => 'n',  'ĥ' => 'h',  'ĝ' => 'g',  'đ' => 'd',  'ĵ' => 'j',
                        'ÿ' => 'y',  'ũ' => 'u',  'ŭ' => 'u',  'ư' => 'u',  'ţ' => 't',  'ý' => 'y',  'ő' => 'o',
                        'â' => 'a',  'ľ' => 'l',  'ẅ' => 'w',  'ż' => 'z',  'ī' => 'i',  'ã' => 'a',  'ġ' => 'g',
                        'ṁ' => 'm',  'ō' => 'o',  'ĩ' => 'i',  'ù' => 'u',  'į' => 'i',  'ź' => 'z',  'á' => 'a',
                        'û' => 'u',  'þ' => 'th', 'ð' => 'dh', 'æ' => 'ae', 'µ' => 'u',  'ĕ' => 'e',  'ı' => 'i',
                    ];
                    $utf8_upper_accents = [
                        'À' => 'A',  'Ô' => 'O',  'Ď' => 'D',  'Ḟ' => 'F',  'Ë' => 'E',  'Š' => 'S',  'Ơ' => 'O',
                        'Ă' => 'A',  'Ř' => 'R',  'Ț' => 'T',  'Ň' => 'N',  'Ā' => 'A',  'Ķ' => 'K',  'Ĕ' => 'E',
                        'Ŝ' => 'S',  'Ỳ' => 'Y',  'Ņ' => 'N',  'Ĺ' => 'L',  'Ħ' => 'H',  'Ṗ' => 'P',  'Ó' => 'O',
                        'Ú' => 'U',  'Ě' => 'E',  'É' => 'E',  'Ç' => 'C',  'Ẁ' => 'W',  'Ċ' => 'C',  'Õ' => 'O',
                        'Ṡ' => 'S',  'Ø' => 'O',  'Ģ' => 'G',  'Ŧ' => 'T',  'Ș' => 'S',  'Ė' => 'E',  'Ĉ' => 'C',
                        'Ś' => 'S',  'Î' => 'I',  'Ű' => 'U',  'Ć' => 'C',  'Ę' => 'E',  'Ŵ' => 'W',  'Ṫ' => 'T',
                        'Ū' => 'U',  'Č' => 'C',  'Ö' => 'O',  'È' => 'E',  'Ŷ' => 'Y',  'Ą' => 'A',  'Ł' => 'L',
                        'Ų' => 'U',  'Ů' => 'U',  'Ş' => 'S',  'Ğ' => 'G',  'Ļ' => 'L',  'Ƒ' => 'F',  'Ž' => 'Z',
                        'Ẃ' => 'W',  'Ḃ' => 'B',  'Å' => 'A',  'Ì' => 'I',  'Ï' => 'I',  'Ḋ' => 'D',  'Ť' => 'T',
                        'Ŗ' => 'R',  'Ä' => 'A',  'Í' => 'I',  'Ŕ' => 'R',  'Ê' => 'E',  'Ü' => 'U',  'Ò' => 'O',
                        'Ē' => 'E',  'Ñ' => 'N',  'Ń' => 'N',  'Ĥ' => 'H',  'Ĝ' => 'G',  'Đ' => 'D',  'Ĵ' => 'J',
                        'Ÿ' => 'Y',  'Ũ' => 'U',  'Ŭ' => 'U',  'Ư' => 'U',  'Ţ' => 'T',  'Ý' => 'Y',  'Ő' => 'O',
                        'Â' => 'A',  'Ľ' => 'L',  'Ẅ' => 'W',  'Ż' => 'Z',  'Ī' => 'I',  'Ã' => 'A',  'Ġ' => 'G',
                        'Ṁ' => 'M',  'Ō' => 'O',  'Ĩ' => 'I',  'Ù' => 'U',  'Į' => 'I',  'Ź' => 'Z',  'Á' => 'A',
                        'Û' => 'U',  'Þ' => 'Th', 'Ð' => 'Dh', 'Æ' => 'Ae', 'İ' => 'I',
                    ];

                    $cyrillic    = [
                        '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',
                        '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',
                    ];

                    $clean_name = strtr($clean_name, $utf8_lower_accents);
                    $clean_name = strtr($clean_name, $utf8_upper_accents);
                    $clean_name = strtr($clean_name, $cyrillic);

                    // taken from \Sirius\Upload\Handler::sanitizeFileName
                    $clean_name = preg_replace('/[^A-Za-z0-9\.]+/', '_', $clean_name);

                    return $clean_name;
                }
            );

            return $uploadHandler;
        }
    )
);