Add "core" automation integration & implement wait action

The "core" integration will provide triggers, actions, and subjects
that are not specific to any 3rd party integration.

[MAILPOET-4136]

mailpoet/lib/Automation/Engine/Control/ActionScheduler.php

@@ -12,4 +12,8 @@ class ActionScheduler {
   public function schedule(int $timestamp, string $hook, array $args = []): int {
     return as_schedule_single_action($timestamp, $hook, $args, self::GROUP_ID);
   }
+
+  public function hasScheduledAction(string $hook, array $args = []): bool {
+    return as_has_scheduled_action($hook, $args, self::GROUP_ID);
+  }
 }

mailpoet/lib/Automation/Engine/Control/StepRunner.php

@@ -82,6 +82,12 @@ class StepRunner {
       throw Exceptions::workflowNotFound($workflowRun->getWorkflowId());
     }
 
+    // complete workflow run
+    if (!$stepId) {
+      $this->workflowRunStorage->updateStatus($workflowRunId, WorkflowRun::STATUS_COMPLETE);
+      return;
+    }
+
     $step = $workflow->getStep($stepId);
     if (!$step) {
       throw Exceptions::workflowStepNotFound($stepId);
@@ -94,19 +100,21 @@ class StepRunner {
       throw new InvalidStateException();
     }
 
-    // enqueue next step / complete workflow
-    $nextStepId = $step->getNextStepId();
-    if ($nextStepId) {
-      $this->actionScheduler->enqueue(Hooks::WORKFLOW_STEP, [
+    $nextStepArgs = [
       [
         'workflow_run_id' => $workflowRunId,
-          'step_id' => $nextStepId,
+        'step_id' => $step->getNextStepId(),
       ],
-      ]);
-    } else {
-      $this->workflowRunStorage->updateStatus($workflowRunId, WorkflowRun::STATUS_COMPLETE);
+    ];
+
+    // next step scheduled by action
+    if ($this->actionScheduler->hasScheduledAction(Hooks::WORKFLOW_STEP, $nextStepArgs)) {
+      return;
     }
 
+    // enqueue next step
+    $this->actionScheduler->enqueue(Hooks::WORKFLOW_STEP, $nextStepArgs);
+
     // TODO: allow long-running steps (that are not done here yet)
   }
 }

mailpoet/lib/Automation/Engine/Engine.php

@@ -6,11 +6,15 @@ use MailPoet\Automation\Engine\API\API;
 use MailPoet\Automation\Engine\Control\StepRunner;
 use MailPoet\Automation\Engine\Control\TriggerHandler;
 use MailPoet\Automation\Engine\Storage\WorkflowStorage;
+use MailPoet\Automation\Integrations\Core\CoreIntegration;
 
 class Engine {
   /** @var API */
   private $api;
 
+  /** @var CoreIntegration */
+  private $coreIntegration;
+
   /** @var Registry */
   private $registry;
 
@@ -28,6 +32,7 @@ class Engine {
 
   public function __construct(
     API $api,
+    CoreIntegration $coreIntegration,
     Registry $registry,
     StepRunner $stepRunner,
     TriggerHandler $triggerHandler,
@@ -35,6 +40,7 @@ class Engine {
     WorkflowStorage $workflowStorage
   ) {
     $this->api = $api;
+    $this->coreIntegration = $coreIntegration;
     $this->registry = $registry;
     $this->stepRunner = $stepRunner;
     $this->triggerHandler = $triggerHandler;
@@ -50,6 +56,7 @@ class Engine {
     $this->stepRunner->initialize();
     $this->triggerHandler->initialize();
 
+    $this->coreIntegration->register($this->registry);
     $this->wordPress->doAction(Hooks::INITIALIZE, [$this->registry]);
     $this->registerActiveTriggerHooks();
   }

mailpoet/lib/Automation/Integrations/Core/Actions/WaitAction.php

@@ -0,0 +1,40 @@
+<?php declare(strict_types = 1);
+
+namespace MailPoet\Automation\Integrations\Core\Actions;
+
+use MailPoet\Automation\Engine\Control\ActionScheduler;
+use MailPoet\Automation\Engine\Hooks;
+use MailPoet\Automation\Engine\Workflows\Action;
+use MailPoet\Automation\Engine\Workflows\Step;
+use MailPoet\Automation\Engine\Workflows\Workflow;
+use MailPoet\Automation\Engine\Workflows\WorkflowRun;
+
+class WaitAction implements Action {
+  /** @var ActionScheduler */
+  private $actionScheduler;
+
+  public function __construct(
+    ActionScheduler $actionScheduler
+  ) {
+    $this->actionScheduler = $actionScheduler;
+  }
+
+  public function getKey(): string {
+    return 'core:wait';
+  }
+
+  public function getName(): string {
+    return __('Wait', 'mailpoet');
+  }
+
+  public function run(Workflow $workflow, WorkflowRun $workflowRun, Step $step): void {
+    $this->actionScheduler->schedule(time() + $step->getArgs()['seconds'], Hooks::WORKFLOW_STEP, [
+      [
+        'workflow_run_id' => $workflowRun->getId(),
+        'step_id' => $step->getNextStepId(),
+      ],
+    ]);
+
+    // TODO: call a step complete ($id) hook instead?
+  }
+}

mailpoet/lib/Automation/Integrations/Core/CoreIntegration.php

@@ -0,0 +1,22 @@
+<?php declare(strict_types = 1);
+
+namespace MailPoet\Automation\Integrations\Core;
+
+use MailPoet\Automation\Engine\Integration;
+use MailPoet\Automation\Engine\Registry;
+use MailPoet\Automation\Integrations\Core\Actions\WaitAction;
+
+class CoreIntegration implements Integration {
+  /** @var WaitAction */
+  private $waitAction;
+
+  public function __construct(
+    WaitAction $waitAction
+  ) {
+    $this->waitAction = $waitAction;
+  }
+
+  public function register(Registry $registry): void {
+    $registry->addAction($this->waitAction);
+  }
+}

mailpoet/lib/DI/ContainerConfigurator.php

@@ -118,6 +118,9 @@ class ContainerConfigurator implements IContainerConfigurator {
     $container->autowire(\MailPoet\Automation\Engine\Storage\WorkflowRunStorage::class)->setPublic(true);
     $container->autowire(\MailPoet\Automation\Engine\Storage\WorkflowStorage::class)->setPublic(true);
     $container->autowire(\MailPoet\Automation\Engine\WordPress::class)->setPublic(true);
+    // Automation - core integration
+    $container->autowire(\MailPoet\Automation\Integrations\Core\Actions\WaitAction::class)->setPublic(true);
+    $container->autowire(\MailPoet\Automation\Integrations\Core\CoreIntegration::class)->setPublic(true);
     // Automation - MailPoet integration
     $container->autowire(\MailPoet\Automation\Integrations\MailPoet\MailPoetIntegration::class)->setPublic(true);
     $container->autowire(\MailPoet\Automation\Integrations\MailPoet\Subjects\SegmentSubject::class)->setPublic(true);