class NodeTestHooks

class NodeTestHooks {
    
    /**
     * Implements hook_ENTITY_TYPE_view() for node entities.
     */
    public function nodeView(array &$build, NodeInterface $node, EntityViewDisplayInterface $display, $view_mode) {
        if ($node->isNew()) {
            return;
        }
        if ($view_mode == 'rss') {
            // Add RSS elements and namespaces when building the RSS feed.
            $node->rss_elements[] = [
                'key' => 'testElement',
                'value' => t('Value of testElement RSS element for node @nid.', [
                    '@nid' => $node->id(),
                ]),
            ];
            // Add content that should be displayed only in the RSS feed.
            $build['extra_feed_content'] = [
                '#markup' => '<p>' . t('Extra data that should appear only in the RSS feed for node @nid.', [
                    '@nid' => $node->id(),
                ]) . '</p>',
                '#weight' => 10,
            ];
        }
        if ($view_mode != 'rss') {
            // Add content that should NOT be displayed in the RSS feed.
            $build['extra_non_feed_content'] = [
                '#markup' => '<p>' . t('Extra data that should appear everywhere except the RSS feed for node @nid.', [
                    '@nid' => $node->id(),
                ]) . '</p>',
            ];
        }
    }
    
    /**
     * Implements hook_ENTITY_TYPE_build_defaults_alter() for node entities.
     */
    public function nodeBuildDefaultsAlter(array &$build, NodeInterface &$node, $view_mode = 'full') {
        if ($view_mode == 'rss') {
            $node->rss_namespaces['xmlns:test'] = 'http://example.com/test-namespace';
        }
    }
    
    /**
     * Implements hook_node_grants().
     */
    public function nodeGrants(AccountInterface $account, $operation) {
        // Give everyone full grants so we don't break other node tests.
        // Our node access tests asserts three realms of access.
        // See testGrantAlter().
        return [
            'test_article_realm' => [
                1,
            ],
            'test_page_realm' => [
                1,
            ],
            'test_alter_realm' => [
                2,
            ],
        ];
    }
    
    /**
     * Implements hook_node_access_records().
     */
    public function nodeAccessRecords(NodeInterface $node) {
        // Return nothing when testing for empty responses.
        if (!empty($node->disable_node_access)) {
            return;
        }
        $grants = [];
        if ($node->getType() == 'article') {
            // Create grant in arbitrary article_realm for article nodes.
            $grants[] = [
                'realm' => 'test_article_realm',
                'gid' => 1,
                'grant_view' => 1,
                'grant_update' => 0,
                'grant_delete' => 0,
            ];
        }
        elseif ($node->getType() == 'page') {
            // Create grant in arbitrary page_realm for page nodes.
            $grants[] = [
                'realm' => 'test_page_realm',
                'gid' => 1,
                'grant_view' => 1,
                'grant_update' => 0,
                'grant_delete' => 0,
            ];
        }
        return $grants;
    }
    
    /**
     * Implements hook_node_access_records_alter().
     */
    public function nodeAccessRecordsAlter(&$grants, NodeInterface $node) {
        if (!empty($grants)) {
            foreach ($grants as $key => $grant) {
                // Alter grant from test_page_realm to test_alter_realm and modify the gid.
                if ($grant['realm'] == 'test_page_realm' && $node->isPromoted()) {
                    $grants[$key]['realm'] = 'test_alter_realm';
                    $grants[$key]['gid'] = 2;
                }
            }
        }
    }
    
    /**
     * Implements hook_node_grants_alter().
     */
    public function nodeGrantsAlter(&$grants, AccountInterface $account, $operation) {
        // Return an empty array of grants to prove that we can alter by reference.
        $grants = [];
    }
    
    /**
     * Implements hook_ENTITY_TYPE_presave() for node entities.
     */
    public function nodePresave(NodeInterface $node) {
        if ($node->getTitle() == 'testing_node_presave') {
            // Sun, 19 Nov 1978 05:00:00 GMT
            $node->setCreatedTime(280299600);
            // Drupal 1.0 release.
            $node->changed = 979534800;
        }
        // Determine changes.
        if (!empty($node->original) && $node->original
            ->getTitle() == 'test_changes') {
            if ($node->original
                ->getTitle() != $node->getTitle()) {
                $node->title->value .= '_presave';
            }
        }
    }
    
    /**
     * Implements hook_ENTITY_TYPE_update() for node entities.
     */
    public function nodeUpdate(NodeInterface $node) {
        // Determine changes on update.
        if (!empty($node->original) && $node->original
            ->getTitle() == 'test_changes') {
            if ($node->original
                ->getTitle() != $node->getTitle()) {
                $node->title->value .= '_update';
            }
        }
    }
    
    /**
     * Implements hook_entity_view_mode_alter().
     */
    public function entityViewModeAlter(&$view_mode, EntityInterface $entity) {
        // Only alter the view mode if we are on the test callback.
        $change_view_mode = \Drupal::state()->get('node_test_change_view_mode', '');
        if ($change_view_mode) {
            $view_mode = $change_view_mode;
        }
    }
    
    /**
     * Implements hook_ENTITY_TYPE_insert() for node entities.
     *
     * This tests saving a node on node insert.
     *
     * @see \Drupal\node\Tests\NodeSaveTest::testNodeSaveOnInsert()
     */
    public function nodeInsert(NodeInterface $node) {
        // Set the node title to the node ID and save.
        if ($node->getTitle() == 'new') {
            $node->setTitle('Node ' . $node->id());
            $node->setNewRevision(FALSE);
            $node->save();
        }
    }
    
    /**
     * Implements hook_form_alter().
     */
    public function formAlter(&$form, FormStateInterface $form_state, $form_id) : void {
        if (!$form_state->get('node_test_form_alter')) {
            \Drupal::messenger()->addStatus('Storage is not set');
            $form_state->set('node_test_form_alter', TRUE);
        }
        else {
            \Drupal::messenger()->addStatus('Storage is set');
        }
    }

}