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;
    }

}