<?php
/*!
 * Copyright Anucha Puangpaka
 * Contact anucha.ppk@icloud.com 062-479-9836
 */

$token = (isset($_GET['token']) && preg_match('/^[0-9a-f]{8}$/', $_GET['token'])) ? $_GET['token'] : false;

if (!$token) {
  $token = sprintf('%08x', crc32(microtime()));
}

$quadrant = ceil(date_create()->format('s') / 15);
$previousQuadrant = $quadrant - 1 < 1 ? 4 : $quadrant - 1;
$key = 'anucha_'.$quadrant;
$previousKey = 'anucha_'.$previousQuadrant;

$current = apc_fetch($key);
$previous = apc_fetch($previousKey);

if (!is_array($current)) {
  $current = array();
}

if (!is_array($previous)) {
  $previous = array();
}

if (count($current) < 250 && !in_array($token, $current)) {
  $current[] = $token;
  apc_store($key, $current, 31);
}

$output = array(
  'usersOnline' => count($current) > 250 ? '250+' : count(array_unique(array_merge($current, $previous))),
  'token' => $token,
);

header('Content-Type: application/json');
print json_encode($output);
exit;
?>