class TaxonomyHooks

class TaxonomyHooks {
  use StringTranslationTrait;
  
  /**
   * Implements hook_help().
   */
  public function help($route_name, RouteMatchInterface $route_match) : ?string {
    switch ($route_name) {
      case 'help.page.taxonomy':
        $field_ui_url = \Drupal::moduleHandler()->moduleExists('field_ui') ? Url::fromRoute('help.page', [
          'name' => 'field_ui',
        ])->toString() : '#';
        $output = '';
        $output .= '<h2>' . $this->t('About') . '</h2>';
        $output .= '<p>' . $this->t('The Taxonomy module allows users who have permission to create and edit content to categorize (tag) content of that type. Users who have the <em>Administer vocabularies and terms</em> <a href=":permissions" title="Taxonomy module permissions">permission</a> can add <em>vocabularies</em> that contain a set of related <em>terms</em>. The terms in a vocabulary can either be pre-set by an administrator or built gradually as content is added and edited. Terms may be organized hierarchically if desired.', [
          ':permissions' => Url::fromRoute('user.admin_permissions.module', [
            'modules' => 'taxonomy',
          ])->toString(),
        ]) . '</p>';
        $output .= '<p>' . $this->t('For more information, see the <a href=":taxonomy">online documentation for the Taxonomy module</a>.', [
          ':taxonomy' => 'https://www.drupal.org/docs/8/core/modules/taxonomy',
        ]) . '</p>';
        $output .= '<h2>' . $this->t('Uses') . '</h2>';
        $output .= '<dl>';
        $output .= '<dt>' . $this->t('Managing vocabularies') . '</dt>';
        $output .= '<dd>' . $this->t('Users who have the <em>Administer vocabularies and terms</em> permission can add and edit vocabularies from the <a href=":taxonomy_admin">Taxonomy administration page</a>. Vocabularies can be deleted from their <em>Edit vocabulary</em> page. Users with the <em>Taxonomy term: Administer fields</em> permission may add additional fields for terms in that vocabulary using the <a href=":field_ui">Field UI module</a>.', [
          ':taxonomy_admin' => Url::fromRoute('entity.taxonomy_vocabulary.collection')->toString(),
          ':field_ui' => $field_ui_url,
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Managing terms') . '</dt>';
        $output .= '<dd>' . $this->t('Users who have the <em>Administer vocabularies and terms</em> permission or the <em>Edit terms</em> permission for a particular vocabulary can add, edit, and organize the terms in a vocabulary from a vocabulary\'s term listing page, which can be accessed by going to the <a href=":taxonomy_admin">Taxonomy administration page</a> and clicking <em>List terms</em> in the <em>Operations</em> column. Users must have the <em>Administer vocabularies and terms</em> permission or the <em>Delete terms</em> permission for a particular vocabulary to delete terms.', [
          ':taxonomy_admin' => Url::fromRoute('entity.taxonomy_vocabulary.collection')->toString(),
        ]) . ' </dd>';
        $output .= '<dt>' . $this->t('Classifying entity content') . '</dt>';
        $output .= '<dd>' . $this->t('A user with the <em>Administer fields</em> permission for a certain entity type may add <em>Taxonomy term</em> reference fields to the entity type, which will allow entities to be classified using taxonomy terms. See the <a href=":entity_reference">Entity Reference help</a> for more information about reference fields. See the <a href=":field">Field module help</a> and the <a href=":field_ui">Field UI help</a> pages for general information on fields and how to create and manage them.', [
          ':field_ui' => $field_ui_url,
          ':field' => Url::fromRoute('help.page', [
            'name' => 'field',
          ])->toString(),
          ':entity_reference' => Url::fromRoute('help.page', [
            'name' => 'entity_reference',
          ])->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Adding new terms during content creation') . '</dt>';
        $output .= '<dd>' . $this->t("Allowing users to add new terms gradually builds a vocabulary as content is added and edited. Users can add new terms if either of the two <em>Autocomplete</em> widgets is chosen for the Taxonomy term reference field in the <em>Manage form display</em> page for the field. You will also need to enable the <em>Create referenced entities if they don't already exist</em> option, and restrict the field to one vocabulary.") . '</dd>';
        $output .= '<dt>' . $this->t('Configuring displays and form displays') . '</dt>';
        $output .= '<dd>' . $this->t('See the <a href=":entity_reference">Entity Reference help</a> page for the field widgets and formatters that can be configured for any reference field on the <em>Manage display</em> and <em>Manage form display</em> pages. Taxonomy additionally provides an <em>RSS category</em> formatter that displays nothing when the entity item is displayed as HTML, but displays an RSS category instead of a list when the entity item is displayed in an RSS feed.', [
          ':entity_reference' => Url::fromRoute('help.page', [
            'name' => 'entity_reference',
          ])->toString(),
        ]) . '</li>';
        $output .= '</ul>';
        $output .= '</dd>';
        $output .= '</dl>';
        return $output;
      case 'entity.taxonomy_vocabulary.collection':
        $output = '<p>' . $this->t('Taxonomy is for categorizing content. Terms are grouped into vocabularies. For example, a vocabulary called "Fruit" would contain the terms "Apple" and "Banana".') . '</p>';
        return $output;
    }
    return NULL;
  }
  
  /**
   * Implements hook_local_tasks_alter().
   *
   * @todo Evaluate removing as part of https://www.drupal.org/node/2358923.
   */
  public function localTasksAlter(&$local_tasks) : void {
    $local_task_key = 'config_translation.local_tasks:entity.taxonomy_vocabulary.config_translation_overview';
    if (isset($local_tasks[$local_task_key])) {
      // The config_translation module expects the base route to be
      // entity.taxonomy_vocabulary.edit_form like it is for other configuration
      // entities. Taxonomy uses the overview_form as the base route.
      $local_tasks[$local_task_key]['base_route'] = 'entity.taxonomy_vocabulary.overview_form';
    }
  }
  
  /**
   * Implements hook_entity_operation().
   */
  public function entityOperation(EntityInterface $term) : array {
    $operations = [];
    if ($term instanceof Term && $term->access('create')) {
      $operations['add-child'] = [
        'title' => $this->t('Add child'),
        'weight' => 10,
        'url' => Url::fromRoute('entity.taxonomy_term.add_form', [
          'taxonomy_vocabulary' => $term->bundle(),
        ], [
          'query' => [
            'parent' => $term->id(),
          ],
        ]),
      ];
    }
    return $operations;
  }
  
  /**
   * @defgroup taxonomy_index Taxonomy indexing
   * @{
   * Functions to maintain taxonomy indexing.
   *
   * Taxonomy uses default field storage to store canonical relationships
   * between terms and fieldable entities. However its most common use case
   * requires listing all content associated with a term or group of terms
   * sorted by creation date. To avoid slow queries due to joining across
   * multiple node and field tables with various conditions and order by
   * criteria, we maintain a denormalized table with all relationships between
   * terms, published nodes and common sort criteria such as status, sticky and
   * created. When using other field storage engines or alternative methods of
   * denormalizing this data you should set the
   * taxonomy.settings:maintain_index_table to '0' to avoid unnecessary writes
   * in SQL.
   */
  
  /**
   * Implements hook_ENTITY_TYPE_insert() for node entities.
   */
  public function nodeInsert(EntityInterface $node) : void {
    // Add taxonomy index entries for the node.
    $this->buildNodeIndex($node);
  }
  
  /**
   * Implements hook_ENTITY_TYPE_update() for node entities.
   */
  public function nodeUpdate(EntityInterface $node) : void {
    // If we're not dealing with the default revision of the node, do not make
    // any change to the taxonomy index.
    if (!$node->isDefaultRevision()) {
      return;
    }
    $this->deleteNodeIndex($node);
    $this->buildNodeIndex($node);
  }
  
  /**
   * Implements hook_ENTITY_TYPE_predelete() for node entities.
   */
  public function nodePredelete(EntityInterface $node) : void {
    // Clean up the {taxonomy_index} table when nodes are deleted.
    $this->deleteNodeIndex($node);
  }
  
  /**
   * Implements hook_ENTITY_TYPE_delete() for taxonomy_term entities.
   */
  public function taxonomyTermDelete(Term $term) : void {
    if (\Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
      // Clean up the {taxonomy_index} table when terms are deleted.
      \Drupal::database()->delete('taxonomy_index')
        ->condition('tid', $term->id())
        ->execute();
    }
  }
  // phpcs:ignore Drupal.Commenting.InlineComment.DocBlock
  
  /**
   * @addtogroup taxonomy_index
   * @{
   */
  
  /**
   * Builds and inserts taxonomy index entries for a given node.
   *
   * The index lists all terms that are related to a given node entity, and is
   * therefore maintained at the entity level.
   *
   * @param \Drupal\node\NodeInterface $node
   *   The node entity.
   */
  protected function buildNodeIndex(NodeInterface $node) : void {
    // We maintain a denormalized table of term/node relationships, containing
    // only data for current, published nodes.
    if (!\Drupal::config('taxonomy.settings')->get('maintain_index_table') || !\Drupal::entityTypeManager()->getStorage('node') instanceof SqlContentEntityStorage) {
      return;
    }
    $status = $node->isPublished();
    $sticky = (int) $node->isSticky();
    // We only maintain the taxonomy index for published nodes.
    if ($status && $node->isDefaultRevision()) {
      // Collect a unique list of all the term IDs from all node fields.
      $tid_all = [];
      $entity_reference_class = 'Drupal\\Core\\Field\\Plugin\\Field\\FieldType\\EntityReferenceItem';
      foreach ($node->getFieldDefinitions() as $field) {
        $field_name = $field->getName();
        $class = $field->getItemDefinition()
          ->getClass();
        $is_entity_reference_class = $class === $entity_reference_class || is_subclass_of($class, $entity_reference_class);
        if ($is_entity_reference_class && $field->getSetting('target_type') == 'taxonomy_term') {
          foreach ($node->getTranslationLanguages() as $language) {
            foreach ($node->getTranslation($language->getId())->{$field_name} as $item) {
              if (!$item->isEmpty()) {
                $tid_all[$item->target_id] = $item->target_id;
              }
            }
          }
        }
      }
      // Insert index entries for all the node's terms.
      if (!empty($tid_all)) {
        $connection = \Drupal::database();
        foreach ($tid_all as $tid) {
          $connection->merge('taxonomy_index')
            ->keys([
            'nid' => $node->id(),
            'tid' => $tid,
            'status' => $node->isPublished(),
          ])
            ->fields([
            'sticky' => $sticky,
            'created' => $node->getCreatedTime(),
          ])
            ->execute();
        }
      }
    }
  }
  
  /**
   * Deletes taxonomy index entries for a given node.
   *
   * @param \Drupal\Core\Entity\EntityInterface $node
   *   The node entity.
   */
  protected function deleteNodeIndex(EntityInterface $node) : void {
    if (\Drupal::config('taxonomy.settings')->get('maintain_index_table')) {
      \Drupal::database()->delete('taxonomy_index')
        ->condition('nid', $node->id())
        ->execute();
    }
  }
  // phpcs:ignore Drupal.Commenting.InlineComment.DocBlock
  
  /**
   * @} End of "addtogroup taxonomy_index".
   */

}