class ViewsViewsHooks

class ViewsViewsHooks {
    
    /**
     * Implements hook_views_data().
     */
    public function viewsData() {
        $data['views']['table']['group'] = t('Global');
        $data['views']['table']['join'] = [
            '#global' => [],
        ];
        $data['views']['random'] = [
            'title' => t('Random'),
            'help' => t('Randomize the display order.'),
            'sort' => [
                'id' => 'random',
            ],
        ];
        $data['views']['null'] = [
            'title' => t('Null'),
            'help' => t('Allow a contextual filter value to be ignored. The query will not be altered by this contextual filter value. Can be used when contextual filter values come from the URL, and a part of the URL needs to be ignored.'),
            'argument' => [
                'id' => 'null',
            ],
        ];
        $data['views']['nothing'] = [
            'title' => t('Custom text'),
            'help' => t('Provide custom text or link.'),
            'field' => [
                'id' => 'custom',
                'click sortable' => FALSE,
            ],
        ];
        $data['views']['counter'] = [
            'title' => t('View result counter'),
            'help' => t('Displays the actual position of the view result'),
            'field' => [
                'id' => 'counter',
            ],
        ];
        $data['views']['area'] = [
            'title' => t('Text area'),
            'help' => t('Provide markup for the area using any available text format.'),
            'area' => [
                'id' => 'text',
            ],
        ];
        $data['views']['area_text_custom'] = [
            'title' => t('Unfiltered text'),
            'help' => t('Provide markup for the area with minimal filtering.'),
            'area' => [
                'id' => 'text_custom',
            ],
        ];
        $data['views']['title'] = [
            'title' => t('Title override'),
            'help' => t('Override the default view title for this view. This is useful to display an alternative title when a view is empty.'),
            'area' => [
                'id' => 'title',
                'sub_type' => 'empty',
            ],
        ];
        $data['views']['view'] = [
            'title' => t('View area'),
            'help' => t('Insert a view inside an area.'),
            'area' => [
                'id' => 'view',
            ],
        ];
        $data['views']['result'] = [
            'title' => t('Result summary'),
            'help' => t('Shows result summary, for example the items per page.'),
            'area' => [
                'id' => 'result',
            ],
        ];
        $data['views']['messages'] = [
            'title' => t('Messages'),
            'help' => t('Displays messages in an area.'),
            'area' => [
                'id' => 'messages',
            ],
        ];
        $data['views']['http_status_code'] = [
            'title' => t('Response status code'),
            'help' => t('Alter the HTTP response status code used by this view, mostly helpful for empty results.'),
            'area' => [
                'id' => 'http_status_code',
            ],
        ];
        $data['views']['combine'] = [
            'title' => t('Combine fields filter'),
            'help' => t('Combine multiple fields together and search by them.'),
            'filter' => [
                'id' => 'combine',
            ],
        ];
        $data['views']['dropbutton'] = [
            'title' => t('Dropbutton'),
            'help' => t('Display fields in a dropbutton.'),
            'field' => [
                'id' => 'dropbutton',
            ],
        ];
        $data['views']['display_link'] = [
            'title' => t('Link to display'),
            'help' => t('Displays a link to a path-based display of this view while keeping the filter criteria, sort criteria, pager settings and contextual filters.'),
            'area' => [
                'id' => 'display_link',
            ],
        ];
        // Registers an entity area handler per entity type.
        foreach (\Drupal::entityTypeManager()->getDefinitions() as $entity_type_id => $entity_type) {
            // Excludes entity types, which cannot be rendered.
            if ($entity_type->hasViewBuilderClass()) {
                $label = $entity_type->getLabel();
                $data['views']['entity_' . $entity_type_id] = [
                    'title' => t('Rendered entity - @label', [
                        '@label' => $label,
                    ]),
                    'help' => t('Displays a rendered @label entity in an area.', [
                        '@label' => $label,
                    ]),
                    'area' => [
                        'entity_type' => $entity_type_id,
                        'id' => 'entity',
                    ],
                ];
            }
        }
        // Registers an action bulk form per entity.
        foreach (\Drupal::entityTypeManager()->getDefinitions() as $entity_type => $entity_info) {
            $actions = array_filter(\Drupal::entityTypeManager()->getStorage('action')
                ->loadMultiple(), function (ActionConfigEntityInterface $action) use ($entity_type) {
                return $action->getType() == $entity_type;
            });
            if (empty($actions)) {
                continue;
            }
            $data[$entity_info->getBaseTable()][$entity_type . '_bulk_form'] = [
                'title' => t('Bulk update'),
                'help' => t('Allows users to apply an action to one or more items.'),
                'field' => [
                    'id' => 'bulk_form',
                ],
            ];
        }
        // Registers views data for the entity itself.
        foreach (\Drupal::entityTypeManager()->getDefinitions() as $entity_type_id => $entity_type) {
            if ($entity_type->hasHandlerClass('views_data')) {
                
                /** @var \Drupal\views\EntityViewsDataInterface $views_data */
                $views_data = \Drupal::entityTypeManager()->getHandler($entity_type_id, 'views_data');
                $data = NestedArray::mergeDeep($data, $views_data->getViewsData());
            }
        }
        // Field modules can implement hook_field_views_data() to override the default
        // behavior for adding fields.
        $module_handler = \Drupal::moduleHandler();
        $entity_type_manager = \Drupal::entityTypeManager();
        if ($entity_type_manager->hasDefinition('field_storage_config')) {
            
            /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
            foreach ($entity_type_manager->getStorage('field_storage_config')
                ->loadMultiple() as $field_storage) {
                if (_views_field_get_entity_type_storage($field_storage)) {
                    $provider = $field_storage->getTypeProvider();
                    $result = (array) $module_handler->invoke($provider === 'core' ? 'views' : $provider, 'field_views_data', [
                        $field_storage,
                    ]);
                    if (empty($result)) {
                        $result = views_field_default_views_data($field_storage);
                    }
                    $module_handler->alter('field_views_data', $result, $field_storage);
                    if (is_array($result)) {
                        $data = NestedArray::mergeDeep($result, $data);
                    }
                }
            }
        }
        return $data;
    }
    
    /**
     * Implements hook_views_data_alter().
     *
     * Field modules can implement hook_field_views_data_views_data_alter() to
     * alter the views data on a per field basis. This is weirdly named so as
     * not to conflict with the \Drupal::moduleHandler()->alter('field_views_data')
     * in views_views_data().
     */
    public function viewsDataAlter(&$data) {
        $entity_type_manager = \Drupal::entityTypeManager();
        if (!$entity_type_manager->hasDefinition('field_storage_config')) {
            return;
        }
        
        /** @var \Drupal\field\FieldStorageConfigInterface $field_storage */
        foreach ($entity_type_manager->getStorage('field_storage_config')
            ->loadMultiple() as $field_storage) {
            if (_views_field_get_entity_type_storage($field_storage)) {
                \Drupal::moduleHandler()->invoke($field_storage->getTypeProvider(), 'field_views_data_views_data_alter', [
                    &$data,
                    $field_storage,
                ]);
            }
        }
    }
    
    /**
     * Implements hook_field_views_data().
     *
     * The function implements the hook on behalf of 'core' because it adds a
     * relationship and a reverse relationship to entity_reference field type, which
     * is provided by core. This function also provides an argument plugin for
     * entity_reference fields that handles title token replacement.
     */
    public function fieldViewsData(FieldStorageConfigInterface $field_storage) {
        $data = views_field_default_views_data($field_storage);
        // The code below only deals with the Entity reference field type.
        if ($field_storage->getType() != 'entity_reference') {
            return $data;
        }
        $entity_type_manager = \Drupal::entityTypeManager();
        $entity_type_id = $field_storage->getTargetEntityTypeId();
        
        /** @var \Drupal\Core\Entity\Sql\DefaultTableMapping $table_mapping */
        $table_mapping = $entity_type_manager->getStorage($entity_type_id)
            ->getTableMapping();
        foreach ($data as $table_name => $table_data) {
            // Add a relationship to the target entity type.
            $target_entity_type_id = $field_storage->getSetting('target_type');
            $target_entity_type = $entity_type_manager->getDefinition($target_entity_type_id);
            $entity_type_id = $field_storage->getTargetEntityTypeId();
            $entity_type = $entity_type_manager->getDefinition($entity_type_id);
            $target_base_table = $target_entity_type->getDataTable() ?: $target_entity_type->getBaseTable();
            $field_name = $field_storage->getName();
            if ($target_entity_type instanceof ContentEntityTypeInterface) {
                // Provide a relationship for the entity type with the entity reference
                // field.
                $args = [
                    '@label' => $target_entity_type->getLabel(),
                    '@field_name' => $field_name,
                ];
                $data[$table_name][$field_name]['relationship'] = [
                    'title' => t('@label referenced from @field_name', $args),
                    'label' => t('@field_name: @label', $args),
                    'group' => $entity_type->getLabel(),
                    'help' => t('Appears in: @bundles.', [
                        '@bundles' => implode(', ', $field_storage->getBundles()),
                    ]),
                    'id' => 'standard',
                    'base' => $target_base_table,
                    'entity type' => $target_entity_type_id,
                    'base field' => $target_entity_type->getKey('id'),
                    'relationship field' => $field_name . '_target_id',
                ];
                // Provide a reverse relationship for the entity type that is referenced by
                // the field.
                $args['@entity'] = $entity_type->getLabel();
                $args['@label'] = $target_entity_type->getSingularLabel();
                $pseudo_field_name = 'reverse__' . $entity_type_id . '__' . $field_name;
                $data[$target_base_table][$pseudo_field_name]['relationship'] = [
                    'title' => t('@entity using @field_name', $args),
                    'label' => t('@field_name', [
                        '@field_name' => $field_name,
                    ]),
                    'group' => $target_entity_type->getLabel(),
                    'help' => t('Relate each @entity with a @field_name set to the @label.', $args),
                    'id' => 'entity_reverse',
                    'base' => $entity_type->getDataTable() ?: $entity_type->getBaseTable(),
                    'entity_type' => $entity_type_id,
                    'base field' => $entity_type->getKey('id'),
                    'field_name' => $field_name,
                    'field table' => $table_mapping->getDedicatedDataTableName($field_storage),
                    'field field' => $field_name . '_target_id',
                    'join_extra' => [
                        [
                            'field' => 'deleted',
                            'value' => 0,
                            'numeric' => TRUE,
                        ],
                    ],
                ];
            }
            // Provide an argument plugin that has a meaningful titleQuery()
            // implementation getting the entity label.
            $data[$table_name][$field_name . '_target_id']['argument']['id'] = 'entity_target_id';
            $data[$table_name][$field_name . '_target_id']['argument']['target_entity_type_id'] = $target_entity_type_id;
        }
        return $data;
    }

}