Delete and manipulate drupal entities in hook_update_N().

hook_update_delete_content()

<?php

/**
 * Reset fields from dev.
 *
 * @param $sandbox
 */
function loom_solr_multisite_update_8010(&$sandbox) {
  /** @var MultisiteSearchService $multisite */
  $multisite = Drupal::service('loom.solr_multisite.utility');
  _loom_solr_multi_dev_reset($multisite);
}


/**
 * Add facet fields with config.
 *
 * @param $sandbox
 */
function loom_solr_multisite_update_8011(&$sandbox) {
  \Drupal::service('config.installer')->installDefaultConfig('module', 'loom_solr_multisite');
}

/**
 * Add facet fields.
 *
 * @param $sandbox
 */
function loom_solr_multisite_update_8011(&$sandbox) {
  /** @var MultisiteSearchService $multisite */
  $multisite = Drupal::service('loom.solr_multisite.utility');

  // Add field storage.
  _loom_add_field_storage($multisite::FACET_FIELD_TYPE, $multisite);
  _loom_add_field_storage($multisite::FACET_FIELD_LANG, $multisite);

  // Add field config.
  foreach($multisite->getIndexedTypes() as $content_type) {
    $field_name = $multisite::FACET_FIELD_TYPE;
    $label = 'Multisearch facet: type';
    $description = 'Facet id: <b>multisearch_facet_type</b>.';
    $settings = [];
    _loom_add_field_config($field_name, $content_type, $label, $description, $settings, $multisite);

    $field_name = $multisite::FACET_FIELD_LANG;
    $label = 'Multisearch facet: language';
    $description = 'Facet id: <b>multisearch_facet_lang</b>.';
    $settings = [];
//    $settings = [
//      'handler' => 'default',
//      'handler_settings' => [],
//      ];
    _loom_add_field_config($field_name, $content_type, $label, $description, $settings, $multisite);
  }
}

/**
 * @param $field_name
 * @param $multisite
 *
 */
function _loom_add_field_storage($field_name, $multisite) {
  if (!FieldStorageConfig::loadByName('node', $field_name)) {
    try {
      $field_storage = FieldStorageConfig::create([
        'field_name' => $field_name,
        'type' => 'string',
        'entity_type' => 'node',
        'cardinality' => 1,
      ]);
      if ($field_storage->save()) {
        $message = sprintf('Successfully added field storage: %s.', $field_name);
        $multisite->logger->notice($message);
      }
    }
    catch (EntityStorageException $exception) {
      $message = sprintf('There was a problem creating field: %s with exception: %s', $field_name, $exception->getMessage());
      $multisite->logger->error($message);
    }
  }
}

/**
 * @param string $field_name
 * @param string $content_type
 * @param string $label
 * @param string $description
 * @param array $settings
 * @param MultisiteSearchService $multisite
 */
function _loom_add_field_config($field_name, $content_type, $label, $description, $settings, $multisite) {
  if (FieldConfig::loadByName('node', $content_type, $field_name)) {
    $message = sprintf('Field %s already exists on content type %s', $field_name, $content_type);
    $multisite->logger->notice($message);
  }
  else {
    try {
      $field = FieldConfig::create([
        'field_name' => $field_name,
        'entity_type' => 'node',
        'bundle' => $content_type,
        'label' => $label,
        'description' => $description,
        'settings' => $settings,
      ]);
      if ($field->save()) {
        $message = sprintf('Successfully added field: %s on content type: %s', $field_name, $content_type);
        $multisite->logger->notice($message);
      }
    }
    catch (EntityStorageException $exception) {
      $message = sprintf('There was a problem creating field: %s on content types "%s" with exception: %s', $field_name, $content_type, $exception->getMessage());
      $multisite->logger->error($message);
    }
  }
}

/**
 * @param MultisiteSearchService $multisite
 */
function _loom_solr_multi_dev_reset($multisite) {

  _loom_delete_field($multisite::FACET_FIELD_KEY_TYPE, $multisite);
  _loom_delete_field($multisite::FACET_FIELD_KEY_LANG, $multisite);
  _loom_delete_field($multisite::FACET_FIELD_TYPE, $multisite);
  _loom_delete_field($multisite::FACET_FIELD_LANG, $multisite);

  _loom_delete_vocab($multisite::FACET_ID_TYPE, $multisite);
  _loom_delete_vocab($multisite::FACET_ID_LANG, $multisite);

  $table = sprintf('node__%s', $multisite::FACET_FIELD_KEY_TYPE);
  _loom_delete_field_table($table, $multisite);
  $table = sprintf('node_revision__%s', $multisite::FACET_FIELD_KEY_TYPE);
  _loom_delete_field_table($table, $multisite);

  $table = sprintf('node__%s', $multisite::FACET_FIELD_KEY_LANG);
  _loom_delete_field_table($table, $multisite);
  $table = sprintf('node_revision__%s', $multisite::FACET_FIELD_KEY_LANG);
  _loom_delete_field_table($table, $multisite);

  $table = sprintf('node__%s', $multisite::FACET_FIELD_TYPE);
  _loom_delete_field_table($table, $multisite);
  $table = sprintf('node_revision__%s', $multisite::FACET_FIELD_TYPE);
  _loom_delete_field_table($table, $multisite);

  $table = sprintf('node__%s', $multisite::FACET_FIELD_LANG);
  _loom_delete_field_table($table, $multisite);
  $table = sprintf('node_revision__%s', $multisite::FACET_FIELD_LANG);
  _loom_delete_field_table($table, $multisite);

};

/**
 * @param string $table
 * @param MultisiteSearchService $multisite
 */
function _loom_delete_field_table($table, $multisite) {
  $connection = Drupal::database();
  try {
    $connection->schema()->dropTable($table);
    $message = sprintf('Successfully emptied truncated table: %s', $table);
    $multisite->logger->notice($message);
  }
  catch (\Drupal\Core\Database\DatabaseExceptionWrapper $exception) {
    $message = sprintf('Unable to delete table: %s', $table);
    $multisite->logger->warning($message);
  }
}

/**
 * @param string $field_name
 * @param $multisite
 */
function _loom_delete_field($field_name, $multisite) {
  $types = $multisite->getIndexedTypes();
  foreach ($types as $type) {
    if ($field = FieldConfig::loadByName('node', $type, $field_name)) {
      try {
        $field->delete();
        $message = sprintf('Deleted field %s on %s.', $field_name, $type);
        $multisite->logger->notice($message);
      }
      catch (Exception $exception) {}
    };
  }
  if ($field_storage = FieldStorageConfig::loadByName('node', $field_name)) {
    try {
      $field_storage->delete();
      $message = sprintf('Field storage %s was deleted.', $field_name);
      $multisite->logger->notice($message);
    }
    catch (Exception $exception) {}
  }
};

/**
 * @param $vid
 * @param MultisiteSearchService $multisite
 */
function _loom_delete_vocab($vid, $multisite) {
  try {
    $termStorage = $multisite->etm->getStorage('taxonomy_term');
    $termStorage->delete($termStorage->loadByProperties(['vid' => $vid]));
    $message = sprintf('Deleted terms for: %s.', $vid);
    $multisite->logger->notice($message);
  }
  catch (Exception $exception) {}
  try {
    $vocabStorage = $multisite->etm->getStorage('taxonomy_vocabulary');
    $vocabStorage->delete($vocabStorage->loadByProperties(['vid' => $vid]));
    $message = sprintf('Deleted vocab: %s.', $vid);
    $multisite->logger->notice($message);
  }
  catch (Exception $exception) {}
}