Pre-populate the next podcast episode number

modules/opd_podcast/opd_podcast.module

@@ -2,12 +2,26 @@
 
 declare(strict_types=1);
 
+use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\BubbleableMetadata;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 use Drupal\node\NodeInterface;
+use Drupal\opd_podcast\Action\GetNextPodcastEpisodeNumber;
 use Drupal\opd_podcast\Episode;
 use Drupal\opd_podcast\Guest;
 
+/**
+ * Implements hook_form_FORM_ID_alter().
+ *
+ * @param array{} $form
+ */
+function opd_podcast_form_node_podcast_episode_form_alter(array &$form, FormStateInterface $formState): void {
+  $nextEpisodeNumber = \Drupal::service(GetNextPodcastEpisodeNumber::class);
+  assert($nextEpisodeNumber instanceof GetNextPodcastEpisodeNumber);
+
+  $form['field_episode_number']['widget'][0]['value']['#default_value'] = $nextEpisodeNumber();
+}
+
 /**
  * Implements hook_entity_bundle_info_alter().
  *

modules/opd_podcast/opd_podcast.services.yml

@@ -0,0 +1,5 @@
+services:
+  Drupal\opd_podcast\Action\GetNextPodcastEpisodeNumber:
+    autowire: true
+  Drupal\opd_podcast\Repository\PodcastNodeRepository:
+    autowire: true

modules/opd_podcast/src/Action/GetNextPodcastEpisodeNumber.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\opd_podcast\Action;
+
+use Drupal\opd_podcast\Repository\PodcastNodeRepository;
+
+readonly final class GetNextPodcastEpisodeNumber {
+
+  public function __construct(private PodcastNodeRepository $repository) {
+  }
+
+  public function __invoke(): int {
+    $episodes = $this->repository->getPublished();
+
+    return count($episodes) + 1;
+  }
+
+}

modules/opd_podcast/src/Repository/PodcastNodeRepository.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\opd_podcast\Repository;
+
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\node\NodeInterface;
+use Drupal\node\NodeStorageInterface;
+
+readonly final class PodcastNodeRepository {
+
+  private NodeStorageInterface $nodeStorage;
+
+  public function __construct(EntityTypeManagerInterface $entityTypeManager) {
+    $this->nodeStorage = $entityTypeManager->getStorage('node');
+  }
+
+  /**
+   * @return list<NodeInterface>
+   */
+  public function getPublished(): array {
+    $query = $this->nodeStorage->getQuery();
+    $query->accessCheck();
+    $query->condition('status', NodeInterface::PUBLISHED);
+    $query->condition('type', 'podcast_episode');
+
+    $nodeIds = $query->execute();
+
+    return $this->nodeStorage->loadMultiple($nodeIds);
+  }
+
+}

todo.txt

@@ -12,7 +12,6 @@ Podcast:
 - Link field for episode links.
 - Quotes and talking points in episodes.
 - Add copyright statement to podcast episodes.
-- Pre-populate the episode number to a default value based on the number of nodes.
 
 Testimonials: