PHP - Displaying directory folders in random order - php

Question

The code works perfectly. Just don't know how to get it to display the content randomly without using Jquery.
Got it to display a random image from the current directory, but not sure how to get the directory to display randomly.
$dir = 'img/series_thumbnail/';
$dh = opendir($dir);
while (($fileName = readdir($dh)) !== false) {
if (!in_array($fileName, array('.', '..'))) {
$images = glob($dir . $fileName . '/*.{jpg,jpeg,png,gif}', GLOB_BRACE);
$imgMax = count($images)-1;
$imgNum = rand(0, $imgMax);
$imgUrl = $images[$imgNum];
echo '<li>';
echo '<img src="' . $imgUrl . '"/>';
echo '<div class="info"><p>' . $fileName . '</p></div>';
echo '</li>';
}
}
Thank you.
EDIT
Figured it out! Thanks for your help everyone.
$dir = glob("img/series_thumbnail/*", GLOB_ONLYDIR);
shuffle($dir);
foreach ($dir as $folder) {
if (!in_array($folder, array(".", ".."))) {
$folderName = basename($folder).PHP_EOL;
$images = glob($folder . "/*.{jpg,jpeg,png,gif}", GLOB_BRACE);
shuffle($images);
echo "<li>";
echo '<img src="' . $images[0] . '"/>';
echo "<div class='info'><p>" . $folderName . "</p></div>";
echo "</li>";
}
}

Answer 1

If you want to display a single random image from each directory, with the directories in random order, you can use this code:
$dir = 'img/series_thumbnail/';
$directories = glob("$dir*", GLOB_ONLYDIR);
shuffle($directories);
foreach ($directories as $directory) {
$images = glob($dir . $directory. '/*.{jpg,jpeg,png,gif}', GLOB_BRACE);
$imgMax = count($images)-1;
$imgNum = rand(0, $imgMax);
$imgUrl = $images[$imgNum];
echo '<li>';
echo '<img src="' . $imgUrl . '"/>';
echo '<div class="info"><p>' . $fileName . '</p></div>';
echo '</li>';
}