upload_timetable/upload_timetable.php

<?php 
/**
 * upload-timetable
 *
 * @package    upload_timetable
 * @copyright  2020 Raphael Dannecker <raphael.dannecker@steinbeisschule-reutlingen.de>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

require_once dirname(__FILE__) . '/vendor/autoload.php';
require_once('config.php');

$MoodleRest = new MoodleRest($config['url'], $config['token']);

if (file_exists ($config['hashfile'])) {
  $hashfile = file_get_contents($config['hashfile']);
  $hashes = (array) json_decode($hashfile);
} else $hashes = array();

$untis_data = array('files' => array());
foreach($config['files'] as $file) {
  $content = file_get_contents($file['file']);
  $hash = md5($content);
  if (! array_key_exists($file['name'],$hashes) || $hashes[$file['name']] != $hash)
    $untis_data['files'][] = array('name' => $file['name'], 'content' => base64_encode($content));
  $hashes[$file['name']] = $hash;
}

if (count($untis_data['files'])) {
  $result = $MoodleRest->request('mod_timetable_update', $untis_data, MoodleRest::METHOD_POST);
  print_r($result);
  if (true) {
    $hashfile = fopen($config['hashfile'],'w');
    fwrite($hashfile, json_encode($hashes, JSON_FORCE_OBJECT));
    fclose($hashfile);
  }
} else {
  echo "Nothing to do\n";
}