Trigger action scheduler runner immediately when starting sending

When users click send email in UI, they need to wait a minute or more to
see some emails started going out.

This commit adds additional trigger into sending queue API.
If emails is set to send it triggers Action Scheduler immediately.
Users will get immediate feedback that emails are sending.
[MAILPOET-4274]

mailpoet/lib/API/JSON/v1/SendingQueue.php

@@ -6,6 +6,8 @@ use MailPoet\API\JSON\Endpoint as APIEndpoint;
 use MailPoet\API\JSON\Error as APIError;
 use MailPoet\API\JSON\Response;
 use MailPoet\Config\AccessControl;
+use MailPoet\Cron\CronTrigger;
+use MailPoet\Cron\DaemonActionSchedulerRunner;
 use MailPoet\Cron\Triggers\WordPress;
 use MailPoet\Entities\NewsletterEntity;
 use MailPoet\Entities\ScheduledTaskEntity;
@@ -19,6 +21,7 @@ use MailPoet\Newsletter\Scheduler\Scheduler;
 use MailPoet\Newsletter\Sending\ScheduledTasksRepository;
 use MailPoet\Newsletter\Sending\SendingQueuesRepository;
 use MailPoet\Segments\SubscribersFinder;
+use MailPoet\Settings\SettingsController;
 use MailPoet\Tasks\Sending as SendingTask;
 use MailPoet\Util\License\Features\Subscribers as SubscribersFeature;
 
@@ -47,10 +50,16 @@ class SendingQueue extends APIEndpoint {
 
   /** @var NewsletterValidator */
   private $newsletterValidator;
-  
+
   /** @var Scheduler */
   private $scheduler;
 
+  /** @var SettingsController */
+  private $settings;
+
+  /** @var DaemonActionSchedulerRunner */
+  private $actionSchedulerRunner;
+
   public function __construct(
     SubscribersFeature $subscribersFeature,
     NewslettersRepository $newsletterRepository,
@@ -59,6 +68,8 @@ class SendingQueue extends APIEndpoint {
     ScheduledTasksRepository $scheduledTasksRepository,
     MailerFactory $mailerFactory,
     Scheduler $scheduler,
+    SettingsController $settings,
+    DaemonActionSchedulerRunner $actionSchedulerRunner,
     NewsletterValidator $newsletterValidator
   ) {
     $this->subscribersFeature = $subscribersFeature;
@@ -68,6 +79,8 @@ class SendingQueue extends APIEndpoint {
     $this->scheduledTasksRepository = $scheduledTasksRepository;
     $this->mailerFactory = $mailerFactory;
     $this->scheduler = $scheduler;
+    $this->settings = $settings;
+    $this->actionSchedulerRunner = $actionSchedulerRunner;
     $this->newsletterValidator = $newsletterValidator;
   }
 
@@ -172,6 +185,7 @@ class SendingQueue extends APIEndpoint {
     if (!empty($errors)) {
       return $this->errorResponse($errors);
     } else {
+      $this->triggerSending($newsletterEntity);
       return $this->successResponse(
         $newsletter->getQueue()->asArray()
       );
@@ -224,6 +238,7 @@ class SendingQueue extends APIEndpoint {
         ]);
       } else {
         $this->sendingQueuesRepository->resume($queue);
+        $this->triggerSending($newsletter);
         return $this->successResponse();
       }
     } else {
@@ -232,4 +247,17 @@ class SendingQueue extends APIEndpoint {
       ]);
     }
   }
+
+  /**
+   * In case the newsletter was switched to sending trigger the background job immediately.
+   * This is done so that user immediately sees that email is sending and doesn't have to wait on WP Cron to start it.
+   */
+  private function triggerSending(NewsletterEntity $newsletter): void {
+    if (
+      $newsletter->getStatus() === NewsletterEntity::STATUS_SENDING
+      && $this->settings->get('cron_trigger.method') === CronTrigger::METHOD_ACTION_SCHEDULER
+    ) {
+      $this->actionSchedulerRunner->trigger();
+    }
+  }
 }