class ViewsUIController

class ViewsUIController extends ControllerBase {
  
  /**
   * Stores the Views data cache object.
   *
   * @var \Drupal\views\ViewsData
   */
  protected $viewsData;
  
  /**
   * Constructs a new \Drupal\views_ui\Controller\ViewsUIController object.
   *
   * @param \Drupal\views\ViewsData $views_data
   *   The Views data cache object.
   */
  public function __construct(ViewsData $views_data) {
    $this->viewsData = $views_data;
  }
  
  /**
   * Lists all instances of fields on any views.
   *
   * @return array
   *   The Views fields report page.
   */
  public function reportFields() {
    $views = $this->entityTypeManager()
      ->getStorage('view')
      ->loadMultiple();
    // Fetch all fieldapi fields which are used in views
    // Therefore search in all views, displays and handler-types.
    $fields = [];
    $handler_types = ViewExecutable::getHandlerTypes();
    foreach ($views as $view) {
      $executable = $view->getExecutable();
      $executable->initDisplay();
      foreach ($executable->displayHandlers as $display_id => $display) {
        if ($executable->setDisplay($display_id)) {
          foreach ($handler_types as $type => $info) {
            foreach ($executable->getHandlers($type, $display_id) as $item) {
              $table_data = $this->viewsData
                ->get($item['table']);
              if (isset($table_data[$item['field']]) && isset($table_data[$item['field']][$type]) && ($field_data = $table_data[$item['field']][$type])) {
                // The final check that we have a fieldapi field now.
                if (isset($field_data['field_name'])) {
                  $fields[$field_data['field_name']][$view->id()] = $view->id();
                }
              }
            }
          }
        }
      }
    }
    $header = [
      $this->t('Field name'),
      $this->t('Used in'),
    ];
    $rows = [];
    foreach ($fields as $field_name => $views) {
      $rows[$field_name]['data'][0]['data']['#plain_text'] = $field_name;
      foreach ($views as $view) {
        $rows[$field_name]['data'][1][] = Link::fromTextAndUrl($view, new Url('entity.view.edit_form', [
          'view' => $view,
        ]))->toString();
      }
      $item_list = [
        '#theme' => 'item_list',
        '#items' => $rows[$field_name]['data'][1],
        '#context' => [
          'list_style' => 'comma-list',
        ],
      ];
      $rows[$field_name]['data'][1] = [
        'data' => $item_list,
      ];
    }
    // Sort rows by field name.
    ksort($rows);
    $output = [
      '#type' => 'table',
      '#header' => $header,
      '#rows' => $rows,
      '#empty' => $this->t('No fields have been used in views yet.'),
    ];
    return $output;
  }
  
  /**
   * Lists all plugins and what enabled Views use them.
   *
   * @return array
   *   The Views plugins report page.
   */
  public function reportPlugins() {
    $rows = Views::pluginList();
    foreach ($rows as &$row) {
      $views = [];
      // Link each view name to the view itself.
      foreach ($row['views'] as $view) {
        $views[] = Link::fromTextAndUrl($view, new Url('entity.view.edit_form', [
          'view' => $view,
        ]))->toString();
      }
      unset($row['views']);
      $row['views']['data'] = [
        '#theme' => 'item_list',
        '#items' => $views,
        '#context' => [
          'list_style' => 'comma-list',
        ],
      ];
    }
    // Sort rows by field name.
    ksort($rows);
    return [
      '#type' => 'table',
      '#header' => [
        $this->t('Type'),
        $this->t('Name'),
        $this->t('Provided by'),
        $this->t('Used in'),
      ],
      '#rows' => $rows,
      '#empty' => $this->t('There are no enabled views.'),
    ];
  }
  
  /**
   * Calls a method on a view and reloads the listing page.
   *
   * @param \Drupal\views\ViewEntityInterface $view
   *   The view being acted upon.
   * @param string $op
   *   The operation to perform, e.g., 'enable' or 'disable'.
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The current request.
   *
   * @return \Drupal\Core\Ajax\AjaxResponse|\Symfony\Component\HttpFoundation\RedirectResponse
   *   Either returns a rebuilt listing page as an AJAX response, or redirects
   *   back to the listing page.
   */
  public function ajaxOperation(ViewEntityInterface $view, $op, Request $request) {
    // Perform the operation.
    $view->{$op}()
      ->save();
    // If the request is via AJAX, return the rendered list as JSON.
    if ($request->request
      ->get('js')) {
      $list = $this->entityTypeManager()
        ->getListBuilder('view')
        ->render();
      $response = new AjaxResponse();
      $response->addCommand(new ReplaceCommand('#views-entity-list', $list));
      return $response;
    }
    // Otherwise, redirect back to the page.
    return $this->redirect('entity.view.collection');
  }
  
  /**
   * Menu callback for Views tag autocompletion.
   *
   * Like other autocomplete functions, this function inspects the 'q' query
   * parameter for the string to use to search for suggestions.
   *
   * @return \Symfony\Component\HttpFoundation\JsonResponse
   *   A JSON response containing the autocomplete suggestions for Views tags.
   */
  public function autocompleteTag(Request $request) {
    $matches = [];
    $string = $request->query
      ->get('q');
    // Get matches from default views.
    $views = $this->entityTypeManager()
      ->getStorage('view')
      ->loadMultiple();
    // Keep track of previously processed tags so they can be skipped.
    $tags = [];
    foreach ($views as $view) {
      $view_tag = $view->get('tag');
      foreach (Tags::explode($view_tag) as $tag) {
        if ($tag && !in_array($tag, $tags, TRUE)) {
          $tags[] = $tag;
          if (mb_stripos($tag, $string) !== FALSE) {
            $matches[] = [
              'value' => $tag,
              'label' => Html::escape($tag),
            ];
            if (count($matches) >= 10) {
              break 2;

            }
          }
        }
      }
    }
    return new JsonResponse($matches);
  }
  
  /**
   * Returns the form to edit a view.
   *
   * @param \Drupal\views_ui\ViewUI $view
   *   The view to be edited.
   * @param string|null $display_id
   *   (optional) The display ID being edited. Defaults to NULL, which will load
   *   the first available display.
   *
   * @return array
   *   An array containing the Views edit and preview forms.
   */
  public function edit(ViewUI $view, $display_id = NULL) {
    $name = $view->label();
    $data = $this->viewsData
      ->get($view->get('base_table'));
    if (isset($data['table']['base']['title'])) {
      $name .= ' (' . $data['table']['base']['title'] . ')';
    }
    $build['#title'] = $name;
    $build['edit'] = $this->entityFormBuilder()
      ->getForm($view, 'edit', [
      'display_id' => $display_id,
    ]);
    $build['preview'] = $this->entityFormBuilder()
      ->getForm($view, 'preview', [
      'display_id' => $display_id,
    ]);
    return $build;
  }

}