- Refactors and fixes issues identified during code review

lib/Cron/CronHelper.php

@@ -0,0 +1,67 @@
+<?php
+namespace MailPoet\Cron;
+
+use MailPoet\Models\Setting;
+use MailPoet\Util\Security;
+
+if(!defined('ABSPATH')) exit;
+
+class CronHelper {
+  static function createDaemon($token) {
+    $daemon = array(
+      'status' => 'starting',
+      'counter' => 0,
+      'token' => $token
+    );
+    self::saveDaemon($daemon);
+    return $daemon;
+  }
+
+  static function getDaemon() {
+    return Setting::getValue('cron_daemon');
+  }
+
+  static function saveDaemon($daemon) {
+    $daemon['updated_at'] = time();
+    return Setting::setValue(
+      'cron_daemon',
+      $daemon
+    );
+  }
+
+  static function createToken() {
+    return Security::generateRandomString();
+  }
+
+  static function accessDaemon($token) {
+    $payload = serialize(array('token' => $token));
+    $url = '/?mailpoet-api&section=queue&action=run&request_payload=' .
+      base64_encode($payload);
+    $args = array(
+      'timeout' => 1,
+      'user-agent' => 'MailPoet (www.mailpoet.com) Cron'
+    );
+    $result = wp_remote_get(
+      self::getSiteUrl() . $url,
+      $args
+    );
+    return wp_remote_retrieve_body($result);
+  }
+
+  private static function getSiteUrl() {
+    // additional check for some sites running on a virtual machine or behind
+    // proxy where there could be different ports (e.g., host:8080 => guest:80)
+
+    // if the site URL does not contain a port, return the URL
+    if(!preg_match('!^https?://.*?:\d+!', site_url())) return site_url();
+    preg_match('!://(?P<host>.*?):(?P<port>\d+)!', site_url(), $server);
+    // connect to the URL with port
+    $fp = @fsockopen($server['host'], $server['port'], $errno, $errstr, 1);
+    if($fp) return site_url();
+    // connect to the URL without port
+    $fp = @fsockopen($server['host'], $server['port'], $errno, $errstr, 1);
+    if($fp) return preg_replace('!(?=:\d+):\d+!', '$1', site_url());
+    // throw an error if all connection attempts failed
+    throw new \Exception(__('Site URL is unreachable.'));
+  }
+}