Refactor initialization of the email editor

This changes how the editor is initialized. The integration initialization class
doesn't get the engine class anymore, but integration is initialized via
mailpoet_email_editor_initialized action triggered from the engine.

This allows multiple integrations to hook into the engine.
[MAILPOET-5540]

mailpoet/lib/Config/Initializer.php

@@ -11,7 +11,8 @@ use MailPoet\Automation\Integrations\MailPoet\MailPoetIntegration;
 use MailPoet\Automation\Integrations\WooCommerce\WooCommerceIntegration;
 use MailPoet\Cron\CronTrigger;
 use MailPoet\Cron\DaemonActionSchedulerRunner;
-use MailPoet\EmailEditor\Integrations\MailPoet\EmailEditor;
+use MailPoet\EmailEditor\Engine\EmailEditor;
+use MailPoet\EmailEditor\Integrations\MailPoet\EmailEditor as MailpoetEmailEditorIntegration;
 use MailPoet\InvalidStateException;
 use MailPoet\Migrator\Cli as MigratorCli;
 use MailPoet\PostEditorBlocks\PostEditorBlock;
@@ -122,6 +123,9 @@ class Initializer {
   /** @var EmailEditor */
   private $emailEditor;
 
+  /** @var MailpoetEmailEditorIntegration */
+  private $mailpoetEmailEditorIntegration;
+
   /** @var Url */
   private $urlHelper;
 
@@ -160,6 +164,7 @@ class Initializer {
     PersonalDataExporters $personalDataExporters,
     DaemonActionSchedulerRunner $actionSchedulerRunner,
     EmailEditor $emailEditor,
+    MailpoetEmailEditorIntegration $mailpoetEmailEditorIntegration,
     Url $urlHelper
   ) {
     $this->rendererFactory = $rendererFactory;
@@ -192,6 +197,7 @@ class Initializer {
     $this->personalDataExporters = $personalDataExporters;
     $this->actionSchedulerRunner = $actionSchedulerRunner;
     $this->emailEditor = $emailEditor;
+    $this->mailpoetEmailEditorIntegration = $mailpoetEmailEditorIntegration;
     $this->urlHelper = $urlHelper;
   }
 
@@ -273,6 +279,11 @@ class Initializer {
       'multisiteDropTables',
     ]);
 
+    $this->wpFunctions->addFilter('mailpoet_email_editor_initialized', [
+      $this->mailpoetEmailEditorIntegration,
+      'initialize',
+    ]);
+
     WPFunctions::get()->addAction(AutomationHooks::INITIALIZE, [
       $this->automationMailPoetIntegration,
       'register',

mailpoet/lib/EmailEditor/Engine/EmailEditor.php

@@ -22,10 +22,11 @@ class EmailEditor {
   }
 
   public function initialize(): void {
-    $this->registerEmailPostTypes();
     add_filter('allowed_block_types_all', [$this, 'setAllowedBlocksInEmails'], 100, 2);
     add_filter('enqueue_block_editor_assets', [$this, 'cleanupBlockEditorAssets'], ~PHP_INT_MAX);
     add_filter('block_editor_settings_all', [$this, 'updateBlockEditorSettings'], 100, 2);
+    do_action('mailpoet_email_editor_initialized');
+    $this->registerEmailPostTypes();
   }
 
   /**

mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailEditor.php

@@ -3,7 +3,6 @@
 namespace MailPoet\EmailEditor\Integrations\MailPoet;
 
 use MailPoet\Config\Env;
-use MailPoet\EmailEditor\Engine\EmailEditor as CoreEmailEditor;
 use MailPoet\Entities\NewsletterEntity;
 use MailPoet\Features\FeaturesController;
 use MailPoet\Newsletter\NewslettersRepository;
@@ -12,9 +11,6 @@ use MailPoet\WP\Functions as WPFunctions;
 class EmailEditor {
   const MAILPOET_EMAIL_POST_TYPE = 'mailpoet_email';
 
-  /** @var \MailPoet\EmailEditor\Engine\EmailEditor */
-  private $coreEmailEditor;
-
   /** @var WPFunctions */
   private $wp;
 
@@ -28,13 +24,11 @@ class EmailEditor {
   private $emailApiController;
 
   public function __construct(
-    CoreEmailEditor $coreEmailEditor,
     WPFunctions $wp,
     FeaturesController $featuresController,
     NewslettersRepository $newsletterRepository,
     EmailApiController $emailApiController
   ) {
-    $this->coreEmailEditor = $coreEmailEditor;
     $this->wp = $wp;
     $this->featuresController = $featuresController;
     $this->newsletterRepository = $newsletterRepository;
@@ -50,7 +44,6 @@ class EmailEditor {
     $this->wp->addFilter('save_post', [$this, 'onEmailSave'], 10, 2);
     $this->wp->addAction('enqueue_block_editor_assets', [$this, 'enqueueAssets']);
     $this->extendEmailPostApi();
-    $this->coreEmailEditor->initialize();
   }
 
   public function addEmailPostType(array $postTypes): array {

mailpoet/tests/integration/EmailEditor/Integration/MailPoet/EmailEditorTest.php

@@ -27,6 +27,7 @@ class EmailEditorTest extends \MailPoetTest {
 
   public function testItRegistersMailPoetEmailPostType() {
     $this->emailEditor->initialize();
+    $this->diContainer->get(\MailPoet\EmailEditor\Engine\EmailEditor::class)->initialize();
     $postTypes = get_post_types();
     $this->assertArrayHasKey('mailpoet_email', $postTypes);
   }