namespace Drupal\my_module\Plugin\Block;

use Drupal\Core\Block\BlockBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\block_content\Entity\BlockContent;
use Drupal\Core\Language\LanguageManagerInterface;

/**
* Provides embed a custom block to an any region.
*
* @Block(
*   id = "my_module_block_custom_content_block",
*   admin_label = @Translation("Embed custom block content"), //ラベル名：埋込ブロックコンテンツ
*   category = @Translation("My Module")
* )
*/
class EmbedCustomBlockContentBlock extends BlockBase implements ContainerFactoryPluginInterface {

  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;

  /**
   * Language manager.
   *
   * @var \Drupal\Core\Language\LanguageManagerInterface
   */
  protected $languageManager;

  /**
   * Constructs a new EntityView.
   *
   * @param array $configuration
   *   A configuration array containing information about the plugin instance.
   * @param string $plugin_id
   *   The plugin ID for the plugin instance.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   The language manager.
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, LanguageManagerInterface $language_manager) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);

    $this->entityTypeManager = $entity_type_manager;
    $this->languageManager = $language_manager;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager'),
      $container->get('language_manager')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    return [
      'custom_block_machine_name' => '',
      'custom_block_view_mode' => 'default',
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function blockForm($form, FormStateInterface $form_state) {
    $form['custom_block_machine_name'] = [
      '#title' => $this->t('Machine name for a custom block content'),
      '#type' => 'textfield',
      '#description' => $this->t("Please set a machine name of a custom block."),
      '#default_value' => $this->configuration['custom_block_machine_name'],
      '#required' => TRUE,
      '#placeholder' => t('ex) unique_machine_name'),
    ];

    $node_view_modes = \Drupal::service('entity_display.repository')->getViewModes('block_content');
    $node_view_modes_options = ['' => $this->t('-Select-')];
    foreach ($node_view_modes as $key => $view_mode) {
      $node_view_modes_options[$key] = $view_mode['label'];
    }
    $form['custom_block_view_mode'] = [
      '#title' => $this->t('View mode'),
      '#type' => 'select',
      '#options' => $node_view_modes_options,
      '#description' => $this->t("Please select a view mode of the Embed Content."),
      '#default_value' => $this->configuration['custom_block_view_mode'],
      '#required' => FALSE,
      '#placeholder' => t('ex) default'),
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function blockSubmit($form, FormStateInterface $form_state) {
    $this->configuration['custom_block_machine_name'] = $form_state->getValue('custom_block_machine_name');
    $this->configuration['custom_block_view_mode'] = $form_state->getValue('custom_block_view_mode');
  }

  /**
   * Builds the renderable array for this Entity Embed display plugin.
   *
   * @return array
   *   A renderable array representing the content of the embedded entity.
   */
  public function build() {
    $build = [];
    $machine_name = $this->configuration['custom_block_machine_name'];
    if ($machine_name) {
      $query = $this->entityTypeManager->getStorage('block_content')->getQuery();
      $query->condition('type', 'basic');
      $query->condition('field_machine_name', $machine_name);
      $bids = $query->execute();
    }
    else {
      return $build;
    }

    if ($block_contents = BlockContent::loadMultiple($bids)) {
      $view_mode = $this->configuration['custom_block_view_mode'] ?? 'default';
      $langcode = $this->languageManager->getCurrentLanguage()->getId();
      $render_controller = $this->entityTypeManager->getViewBuilder('block_content');
      $build['content'] = $render_controller->viewMultiple($block_contents, $view_mode, $langcode);
    }

    return $build;
  }

}