<?php

$topdir = 'Fable';
$dirs = listDir($topdir, true);

foreach ($dirs as $dir) {
    $files = listDir($topdir . DIRECTORY_SEPARATOR . $dir);
    sort($files);
    $total = count($files);
    $portion = floor($total / 10);

    createAdditionals($dir, $topdir);

    $start = $dir - 1;
    foreach ($files as $k => $file) {
        $addon = '';
        if (!($k % $portion)) {
            $start++;

        }
        if ($start < 100) {
            $addon = '0';
        } else {
            $addon = '';
        }

        $from = $topdir . DIRECTORY_SEPARATOR . $dir . DIRECTORY_SEPARATOR . $file;
        $to = $topdir . DIRECTORY_SEPARATOR . $addon . $start . DIRECTORY_SEPARATOR . $file;

        if ($from != $to) {
            rename($from, $to);
        }
    }
}

function createAdditionals($dir, $topdir)
{
    if (substr($dir, -1, 1) == '0') {
        for ($i = (int) $dir; $i < $dir + 10; $i++) {
            if ($i < 100) {
                $addon = '0';
            } else {
                $addon = '';
            }
            if (!file_exists($topdir . DIRECTORY_SEPARATOR . $addon . $i)) {
                mkdir($topdir . DIRECTORY_SEPARATOR . $addon . $i, 0755);
            }
        }
    }
}

function listDir($path, $onlyTop = false)
{
    $dirs = [];
    if ($handle = opendir($path)) {
        while (false !== ($entry = readdir($handle))) {
            if ($entry != '.' && $entry != '..') {
                if ($onlyTop) {
                    if (substr($entry, -1, 1) != '0') {
                        continue;
                    }
                }
                $dirs[] = $entry;
            }

        }
        closedir($handle);
    }
    return $dirs;
}