Sort File by Extension Inside Folder Using PHP

sort.php

<?php
$folder = __DIR__."/experimen/";
$moved_folder = __DIR__."/hasil/";
$extensions = [
    "gambar" => ["jpg","png", "jpeg", "JPG", "svg"],
    "video" => ["mkv", "mp4"],
    "musik" => ["mp3"],
    "document" => ["pdf","txt","xls", "epub", "docx", "xlsb"],
    "compressed" => ["rar","zip", "tar.gz"],
    "programming" => ["php", "py", "sql", "js", "html", "htm", "map", "phar"],
    "windows_installer" => ["exe"],
    "installer" => ["deb", "bin", "run"],
    "shell" => ["sh"],
    "vpn" => ["ovpn"],
    "flash" => ["swf"],
    "java" => ["jar", "java", "javac"],
    "other" => [""]
];

function cek_folder($dir){
    if(!file_exists($dir)){
        mkdir($dir);
    }
}
function generate_insensitive($ext){
    $text = "";
    $length_string = strlen($ext);
    for($i=0; $i<$length_string; $i++){
        $text .= "[";
        $text .= strtolower($ext[$i]);
        $text .= strtoupper($ext[$i]);
        $text .= "]";
    }
    return $text;
}

function glob_recursive($pattern, $flags = 0){
    $files = glob($pattern, $flags);
    foreach (glob(dirname($pattern).'/*', GLOB_ONLYDIR|GLOB_NOSORT) as $dir)
    {
        $files = array_merge($files, glob_recursive($dir.'/'.basename($pattern), $flags));
    }
    return $files;
}
foreach($extensions as $key => $extension){
    $moved_folder_new = $moved_folder.$key.'/';
    cek_folder($moved_folder_new);
    array_map(function($ext) use ($folder, $moved_folder_new, $key){
        $ext = generate_insensitive($ext);
        $files = glob_recursive($folder."*.".$ext);
        if($key == "other"){
            $files = glob_recursive($folder."*");
        }
        foreach($files as $file){
            if(!is_file($file)){
                continue;
            }
	    echo "Moving ".$file." to ".$moved_folder_new.basename($file)."\n";
            rename($file, $moved_folder_new.basename($file));
        }
    },$extension);
}