class SearchController

class SearchController extends ControllerBase {
    
    /**
     * The search page repository.
     *
     * @var \Drupal\search\SearchPageRepositoryInterface
     */
    protected $searchPageRepository;
    
    /**
     * A logger instance.
     *
     * @var \Psr\Log\LoggerInterface
     */
    protected $logger;
    
    /**
     * The renderer.
     *
     * @var \Drupal\Core\Render\RendererInterface
     */
    protected $renderer;
    
    /**
     * Constructs a new search controller.
     *
     * @param \Drupal\search\SearchPageRepositoryInterface $search_page_repository
     *   The search page repository.
     * @param \Drupal\Core\Render\RendererInterface $renderer
     *   The renderer.
     */
    public function __construct(SearchPageRepositoryInterface $search_page_repository, RendererInterface $renderer) {
        $this->searchPageRepository = $search_page_repository;
        $this->logger = $this->getLogger('search');
        $this->renderer = $renderer;
    }
    
    /**
     * Creates a render array for the search page.
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The request object.
     * @param \Drupal\search\SearchPageInterface $entity
     *   The search page entity.
     *
     * @return array
     *   The search form and search results build array.
     */
    public function view(Request $request, SearchPageInterface $entity) {
        $build = [];
        $plugin = $entity->getPlugin();
        // Build the form first, because it may redirect during the submit,
        // and we don't want to build the results based on last time's request.
        $build['#cache']['contexts'][] = 'url.query_args:keys';
        if ($request->query
            ->has('keys')) {
            $keys = trim($request->query
                ->get('keys'));
            $plugin->setSearch($keys, $request->query
                ->all(), $request->attributes
                ->all());
        }
        $build['#title'] = $plugin->suggestedTitle();
        $build['search_form'] = $this->formBuilder()
            ->getForm(SearchPageForm::class, $entity);
        // Build search results, if keywords or other search parameters are in the
        // GET parameters. Note that we need to try the search if 'keys' is in
        // there at all, vs. being empty, due to advanced search.
        $results = [];
        if ($request->query
            ->has('keys')) {
            if ($plugin->isSearchExecutable()) {
                // Log the search.
                if ($this->config('search.settings')
                    ->get('logging')) {
                    $this->logger
                        ->info('Searched %type for %keys.', [
                        '%keys' => $keys,
                        '%type' => $entity->label(),
                    ]);
                }
                // Collect the search results.
                $results = $plugin->buildResults();
            }
            else {
                // The search not being executable means that no keywords or other
                // conditions were entered.
                $this->messenger()
                    ->addError($this->t('Enter some keywords.'));
            }
        }
        if (count($results)) {
            $build['search_results_title'] = [
                '#markup' => '<h2>' . $this->t('Search results') . '</h2>',
            ];
        }
        $build['search_results'] = [
            '#theme' => [
                'item_list__search_results__' . $plugin->getPluginId(),
                'item_list__search_results',
            ],
            '#items' => $results,
            '#empty' => [
                '#type' => 'html_tag',
                '#tag' => 'em',
                '#value' => $this->t('Your search yielded no results.'),
            ],
            '#list_type' => 'ol',
            '#context' => [
                'plugin' => $plugin->getPluginId(),
            ],
        ];
        $this->renderer
            ->addCacheableDependency($build, $entity);
        if ($plugin instanceof CacheableDependencyInterface) {
            $this->renderer
                ->addCacheableDependency($build, $plugin);
        }
        // If this plugin uses a search index, then also add the cache tag tracking
        // that search index, so that cached search result pages are invalidated
        // when necessary.
        if ($plugin->getType()) {
            $build['search_results']['#cache']['tags'][] = 'search_index';
            $build['search_results']['#cache']['tags'][] = 'search_index:' . $plugin->getType();
        }
        $build['pager'] = [
            '#type' => 'pager',
        ];
        return $build;
    }
    
    /**
     * Creates a render array for the search help page.
     *
     * @param \Drupal\search\SearchPageInterface $entity
     *   The search page entity.
     *
     * @return array
     *   The search help page.
     */
    public function searchHelp(SearchPageInterface $entity) {
        $build = [];
        $build['search_help'] = $entity->getPlugin()
            ->getHelp();
        return $build;
    }
    
    /**
     * Redirects to a search page.
     *
     * This is used to redirect from /search to the default search page.
     *
     * @param \Drupal\search\SearchPageInterface $entity
     *   The search page entity.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *   A redirect to the search page.
     */
    public function redirectSearchPage(SearchPageInterface $entity) {
        return $this->redirect('search.view_' . $entity->id());
    }
    
    /**
     * Route title callback.
     *
     * @param \Drupal\search\SearchPageInterface $search_page
     *   The search page entity.
     *
     * @return string
     *   The title for the search page edit form.
     */
    public function editTitle(SearchPageInterface $search_page) {
        return $this->t('Edit %label search page', [
            '%label' => $search_page->label(),
        ]);
    }
    
    /**
     * Performs an operation on the search page entity.
     *
     * @param \Drupal\search\SearchPageInterface $search_page
     *   The search page entity.
     * @param string $op
     *   The operation to perform, usually 'enable' or 'disable'.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *   A redirect back to the search settings page.
     */
    public function performOperation(SearchPageInterface $search_page, $op) {
        $search_page->{$op}()
            ->save();
        if ($op == 'enable') {
            $this->messenger()
                ->addStatus($this->t('The %label search page has been enabled.', [
                '%label' => $search_page->label(),
            ]));
        }
        elseif ($op == 'disable') {
            $this->messenger()
                ->addStatus($this->t('The %label search page has been disabled.', [
                '%label' => $search_page->label(),
            ]));
        }
        $url = $search_page->toUrl('collection');
        return $this->redirect($url->getRouteName(), $url->getRouteParameters(), $url->getOptions());
    }
    
    /**
     * Sets the search page as the default.
     *
     * @param \Drupal\search\SearchPageInterface $search_page
     *   The search page entity.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *   A redirect to the search settings page.
     */
    public function setAsDefault(SearchPageInterface $search_page) {
        // Set the default page to this search page.
        $this->searchPageRepository
            ->setDefaultSearchPage($search_page);
        $this->messenger()
            ->addStatus($this->t('The default search page is now %label. Be sure to check the ordering of your search pages.', [
            '%label' => $search_page->label(),
        ]));
        return $this->redirect('entity.search_page.collection');
    }

}