<?php
/**
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/gpl-3.0.
 *
 * 2019 - 2023 https://://www.bananas-playground.net/projekt/selfpaste
 */

/**
 * a static helper class
 */
class Summoner {

    /**
     * validate the given string with the given type. Optional check the string
     * length
     *
     * @param string $input The string to check
     * @param string $mode How the string should be checked
     * @param int $limit If int given the string is checked for length
     *
     * @see http://de.php.net/manual/en/regexp.reference.unicode.php
     * http://www.sql-und-xml.de/unicode-database/#pc
     *
     * the pattern replaces all that is allowed. the correct result after
     * the replace should be empty, otherwise are there chars which are not
     * allowed
     *
     * @return bool
     */
    static function validate(string $input, string $mode='text', int $limit=0): bool {
        // check if we have input
        $input = trim($input);

        if($input == "") return false;

        $ret = false;

        switch ($mode) {
            case 'mail':
                if(filter_var($input,FILTER_VALIDATE_EMAIL) === $input) {
                    return true;
                }
                else {
                    return false;
                }
                break;

            case 'url':
                if(filter_var($input,FILTER_VALIDATE_URL) === $input) {
                    return true;
                }
                else {
                    return false;
                }
                break;

            case 'nospace':
                // text without any whitespace and special chars
                $pattern = '/[\p{L}\p{N}]/u';
                break;

            case 'nospaceP':
                // text without any whitespace and special chars
                // but with Punctuation other
                # http://www.sql-und-xml.de/unicode-database/po.html
                $pattern = '/[\p{L}\p{N}\p{Po}\-_]/u';
                break;

            case 'digit':
                // only numbers and digit
                // warning with negative numbers...
                $pattern = '/[\p{N}\-]/';
                break;

            case 'pageTitle':
                // text with whitespace and without special chars
                // but with Punctuation
                $pattern = '/[\p{L}\p{N}\p{Po}\p{Z}\s\-_]/u';
                break;

            # strange. the \p{M} is needed.. don't know why..
            case 'filename':
                $pattern = '/[\p{L}\p{N}\p{M}\-_\.\p{Zs}]/u';
                break;

            case 'text':
            default:
                $pattern = '/[\p{L}\p{N}\p{P}\p{S}\p{Z}\p{M}\s]/u';
        }

        $value = preg_replace($pattern, '', $input);

        if($value === "") {
            $ret = true;
        }

        if(!empty($limit)) {
            # isset starts with 0
            if(isset($input[$limit])) {
                # too long
                $ret = false;
            }
        }

        return $ret;
    }

    /**
     * Simple helper to detect the $_FILES upload status
     * Expects the error value from $_FILES['error']
     *
     * @param int $error
     * @return array
     */
    static function checkFileUploadStatus(int $error): array {
        $message = "Unknown upload error";
        $status = false;

        switch ($error) {
            case UPLOAD_ERR_OK:
                $message = "There is no error, the file uploaded with success.";
                $status = true;
            break;
            case UPLOAD_ERR_INI_SIZE:
                $message = "The uploaded file exceeds the upload_max_filesize directive in php.ini";
            break;
            case UPLOAD_ERR_FORM_SIZE:
                $message = "The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form";
            break;
            case UPLOAD_ERR_PARTIAL:
                $message = "The uploaded file was only partially uploaded";
            break;
            case UPLOAD_ERR_NO_FILE:
                $message = "No file was uploaded";
            break;
            case UPLOAD_ERR_NO_TMP_DIR:
                $message = "Missing a temporary folder";
            break;
            case UPLOAD_ERR_CANT_WRITE:
                $message = "Failed to write file to disk";
            break;
            case UPLOAD_ERR_EXTENSION:
                $message = "File upload stopped by extension";
            break;
        }

        return array(
            'message' => $message,
            'status' => $status
        );
    }

    /**
     * create a short string based on a integer
     *
     * @see https://www.jwz.org/base64-shortlinks/
     * @return string
     */
    static function b64sl_pack_id(string $id): string {
        $id = intval($id);
        $ida = ($id > 0xFFFFFFFF ? $id >> 32 : 0);	// 32 bit big endian, top
        $idb = ($id & 0xFFFFFFFF);			// 32 bit big endian, bottom
        $id = pack ('N', $ida) . pack ('N', $idb);
        $id = preg_replace('/^\000+/', '', "$id");	// omit high-order NUL bytes
        $id = base64_encode ($id);
        $id = str_replace ('+', '-', $id);		// encode URL-unsafe "+" "/"
        $id = str_replace ('/', '_', $id);
        $id = preg_replace ('/=+$/', '', $id);	// omit trailing padding bytes
        return $id;
    }

    /**
     * Decode a base64-encoded big-endian integer of up to 64 bits.
     *
     * @see https://www.jwz.org/base64-shortlinks/
     * @param string $id
     * @return int
     */
    static function b64sl_unpack_id(string $id): int {
        $id = str_replace ('-', '+', $id);		// decode URL-unsafe "+" "/"
        $id = str_replace ('_', '/', $id);
        $id = base64_decode ($id);
        while (strlen($id) < 8) { $id = "\000$id"; }	// pad with leading NULs
        $a = unpack ('N*', $id);			// 32 bit big endian
        $id = ($a[1] << 32) | $a[2];			// pack top and bottom word
        return $id;
    }

    /**
     * create based on the given string a path
     * each char in string is a dir
     * asdef -> a/s/d/e/f/
     *
     * @param string $string
     * @return string
     */
    static function forwardslashStringToPath(string $string): string {
        $ret = '';
        if(!empty($string)) {
            for ($i = 0; $i < strlen($string); $i++) {
                $ret .= $string[$i] . "/";
            }
        }
        return $ret;
    }
}