Convert numbers and strings into Shadok

Shadok.php

<?php
/**
 * Shadok 1.2
 * 
 * This class converts numbers and strings into Shadok.
 * Only for fun.
 * 
 * @changelog
 * 		1.2 - Support strings
 * 		1.1 - Add Shadok alphabet
 *		1.0 - First version (convert numbers)
 * 
 * @example Converts strings (only ASCII, without accents and special characters) :
 * 				Shadok::stringFromHuman('RSeon'); // BUBUGAZO BUBUGAMEU BUZOBUBU BUZOMEUMEU BUZOMEUZO
 * 				Shadok::stringToHuman('BUBUGAZO BUBUGAMEU BUZOBUBU BUZOMEUMEU BUZOMEUZO'); // RSeon
 * 
 * @example With Shadok alphabet :
 * 				Shadok::stringFromHuman('RSeon', true); // −−O⨼ −−O◿ −⨼−− −⨼◿◿ −⨼◿⨼
 * 				Shadok::stringToHuman('−−O⨼ −−O◿ −⨼−− −⨼◿◿ −⨼◿⨼'); // RSeon
 * 
 * @example Converts numbers (only integers) :
 * 				Shadok::numberFromHuman(2018); // BUMEUMEUZOGAZO
 * 				Shadok::numberToHuman('BUMEUMEUZOGAZO'); // 2018
 * 
 * @example With Shadok alphabet :
 * 				Shadok::numberFromHuman(2018, true); // −◿◿⨼O⨼
 * 				Shadok::numberToHuman('−◿◿⨼O⨼'); // 2018
 * 
 * @link https://www.dcode.fr/numeration-shadok
 * @link http://www.fil.univ-lille1.fr/~wegrzyno/portail/Info/Doc/HTML/tp_numeration_shadok.html
 */
class Shadok {
    
    protected static $base = ['GA', 'BU', 'ZO', 'MEU'];
    protected static $alphabet = ['O', '−', '⨼', '◿'];
    
    /**
     * Get alphabet [Human => Shadok] or [Shadok => Human]
     * 
     * @param bool
     * @return array
     */
    public static function getShadokAlphabet($reverse = false) {
        if($reverse) {
            return array_combine(self::$alphabet, self::$base);
        }
        return array_combine(self::$base, self::$alphabet);
    }
    
    /**
     * Convert Shadok string to Human
     * 
     * @param string
     * @return string
     */
    public static function stringToHuman($shadok) {
        $shadok = strtoupper(str_replace(' ', '', $shadok));
        $infos_number = self::_getShadokNumberInfos($shadok);
        $octets = [];
        $oi = 0;
        foreach($infos_number['matches'] as $i => $m) {
            if($i % 4 === 0) {
                ++$oi;
            }
            if(!isset($octets[$oi])) {
                $octets[$oi] = '';
            }
            $octets[$oi] .= $m;
        }
        
        $string = '';
        foreach($octets as $o) {
            $string .= chr(self::numberToHuman($o));
        }
        
        return $string;
    }
    
    /**
     * Convert human string to Shadok
     * 
     * @param string
     * @param bool  If true, uses Shadok alphabet
     * @return string
     */
    public static function stringFromHuman($string, $use_alphabet = false) {
        $ascii = unpack("C*", $string);
        $shadok = '';
        foreach($ascii as $ord) {
            $shadok .= self::numberFromHuman($ord, $use_alphabet) . ' ';
        }
        $shadok = substr($shadok, 0, -1);
        
        return $shadok;
    }
    
    /**
     * Convert Shadok number to human number.
     * 
     * @param string
     * @return int
     */
    public static function numberToHuman($shadok) {
        $shadok = strtoupper(str_replace(' ', '', $shadok));
        $infos_number = self::_getShadokNumberInfos($shadok);
        
        $tmp = array_reverse($infos_number['matches']);
        $number = 0;
        $base = $infos_number['use_alphabet'] ? self::$alphabet : self::$base;
        foreach($tmp as $i => $letter) {
            $number += (array_search($letter, $base)) * 4**$i;
        }
        
        return $number;
    }
    
    /**
     * Convert human number (base 10) to Shadok number
     * 
     * @param int
     * @param bool  If true, uses Shadok alphabet
     * @return string
     */
    public static function numberFromHuman($number, $use_alphabet = false) {
        if(!is_int($number)) {
            throw new Exception('Please use real number');
        }
        $tmp = str_split(base_convert($number, 10, 4));
        $shadok = '';
        $base = $use_alphabet ? self::$alphabet : self::$base;
        foreach($tmp as $i => $n) {
            $shadok .= $base[$n];
        }
        
        return $shadok;
    }
    
    /**
     * Get infos from shadok number (each character and if uses Shadok alphabet)
     *
     * @param string
     * @return array
     */
    protected static function _getShadokNumberInfos($string) {
        preg_match_all('/GA|BU|ZO|MEU/', $string, $matches);
        $use_alphabet = false;
        if(!isset($matches[0]) || empty($matches[0])) {
	        preg_match_all('/O|−|⨼|◿/', $string, $matches);
	        if(!isset($matches[0]) || empty($matches[0])) {
	            throw new Exception('Please use shadok numbers ('.implode(' ', self::$base).' or '.implode(' ', self::$alphabet).')');
	        }
	        $use_alphabet = true;
        }
        
        return [
            'matches' => $matches[0],
            'use_alphabet' => $use_alphabet
        ];
    }
}