Add CTAs to daily emails

Add a daily email CTA node type and reference field to attach a CTA to a
daily email.

Also update the RSS feed view to include the referenced body field
value.

modules/opd_daily_emails/opd_daily_emails.module

@@ -4,8 +4,54 @@ declare(strict_types=1);
 
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\node\NodeInterface;
+use Drupal\opd_daily_emails\Ctas;
+use Drupal\opd_daily_emails\DailyEmail;
 use Drupal\opd_daily_emails\DailyEmailNodeRepository;
 
+/**
+ * Implements hook_entity_bundle_info_alter().
+ *
+ * @param array<non-empty-string, array{class: non-empty-string}> $bundles
+ */
+function opd_daily_emails_entity_bundle_info_alter(array &$bundles): void {
+  if (isset($bundles['node'])) {
+    $bundles['node'][DailyEmail::NODE_TYPE]['class'] = DailyEmail::class;
+  }
+}
+
+/**
+ * Implements hook_entity_presave().
+ */
+function opd_daily_emails_entity_presave(Drupal\Core\Entity\EntityInterface $entity): void {
+  if (!$entity instanceof DailyEmail) {
+    return;
+  }
+
+  if (!$entity->isNew()) {
+    return;
+  }
+
+  if ($entity->get('field_daily_email_cta')->getValue() !== []) {
+    return;
+  }
+
+  $nodeStorage = \Drupal::entityTypeManager()->getStorage('node');
+  $query = $nodeStorage->getQuery();
+  $query->condition('status', NodeInterface::PUBLISHED);
+  $query->condition('type', 'daily_email_cta');
+  $query->accessCheck();
+  $ctaNodes = $nodeStorage->loadMultiple($query->execute());
+
+  $ctas = Ctas::fromNodes($ctaNodes);
+
+  if ($ctas->isEmpty()) {
+    return;
+  }
+
+  $entity->set('field_daily_email_cta', $ctas->getRandomCta());
+}
+
 /**
  * Implements hook_token_info().
  *

modules/opd_daily_emails/src/Ctas.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\opd_daily_emails;
+
+use Drupal\node\NodeInterface;
+use Webmozart\Assert\Assert;
+
+final class Ctas {
+
+  public function isEmpty(): bool {
+    return empty($this->ctas);
+  }
+
+  public function getRandomCta(): NodeInterface {
+    return $this->ctas[array_rand($this->ctas)];
+  }
+
+  /**
+   * @param list<NodeInterface> $nodes
+   */
+  public static function fromNodes(array $nodes): self {
+    return new self($nodes);
+  }
+
+  /**
+   * @param list<NodeInterface> $ctas
+   */
+  private function __construct(
+    private array $ctas,
+  ) {
+    Assert::allIsInstanceOf($ctas, NodeInterface::class);
+  }
+
+}

modules/opd_daily_emails/src/DailyEmail.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\opd_daily_emails;
+
+use Drupal\node\Entity\Node;
+use Drupal\node\NodeInterface;
+
+final class DailyEmail extends Node implements NodeInterface {
+
+  public const NODE_TYPE = 'daily_email';
+
+}

modules/opd_daily_emails/tests/src/Functional/CallToActionTest.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\opd_daily_emails\Functional;
+
+use weitzman\DrupalTestTraits\ExistingSiteBase;
+
+final class CallToActionTest extends ExistingSiteBase {
+
+  public function test_saving_an_email_node_without_a_cta_will_populate_one(): void {
+    $cta = $this->createNode([
+      'type' => 'daily_email_cta',
+    ]);
+
+    $email = $this->createNode([
+      'field_daily_email_cta' => NULL,
+      'type' => 'daily_email',
+    ]);
+
+    $this->assertNotEmpty($email->get('field_daily_email_cta')->getValue());
+
+    // TODO: assert the returned text.
+  }
+
+  public function test_saving_an_email_node_with_a_cta_will_keep_the_same_cta(): void {
+    $cta = $this->createNode([
+      'type' => 'daily_email_cta',
+    ]);
+
+    $email = $this->createNode([
+      'field_daily_email_cta' => $cta,
+      'type' => 'daily_email',
+    ]);
+
+    $email->set('title', 'Updated');
+    $email->save();
+
+    $this->assertSame(
+      actual: $email->get('field_daily_email_cta')->getValue()[0]['target_id'],
+      expected: $cta->id(),
+    );
+  }
+
+}