class ViewsConfigUpdater

class ViewsConfigUpdater implements ContainerInjectionInterface {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity field manager.
     *
     * @var \Drupal\Core\Entity\EntityFieldManagerInterface
     */
    protected $entityFieldManager;
    
    /**
     * The typed config manager.
     *
     * @var \Drupal\Core\Config\TypedConfigManagerInterface
     */
    protected $typedConfigManager;
    
    /**
     * The views data service.
     *
     * @var \Drupal\views\ViewsData
     */
    protected $viewsData;
    
    /**
     * An array of helper data for the multivalue base field update.
     *
     * @var array
     */
    protected $multivalueBaseFieldsUpdateTableInfo;
    
    /**
     * ViewsConfigUpdater constructor.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
     *   The entity field manager.
     * @param \Drupal\Core\Config\TypedConfigManagerInterface $typed_config_manager
     *   The typed config manager.
     * @param \Drupal\views\ViewsData $views_data
     *   The views data service.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $entity_field_manager, TypedConfigManagerInterface $typed_config_manager, ViewsData $views_data) {
        $this->entityTypeManager = $entity_type_manager;
        $this->entityFieldManager = $entity_field_manager;
        $this->typedConfigManager = $typed_config_manager;
        $this->viewsData = $views_data;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity_type.manager'), $container->get('entity_field.manager'), $container->get('config.typed'), $container->get('views.views_data'));
    }
    
    /**
     * Performs all required updates.
     *
     * @param \Drupal\views\ViewEntityInterface $view
     *   The View to update.
     *
     * @return bool
     *   Whether the view was updated.
     */
    public function updateAll(ViewEntityInterface $view) {
        return $this->processDisplayHandlers($view, FALSE, function (&$handler, $handler_type, $key, $display_id) use ($view) {
            $changed = FALSE;
            if ($this->processEntityLinkUrlHandler($handler, $handler_type)) {
                $changed = TRUE;
            }
            if ($this->processOperatorDefaultsHandler($handler, $handler_type)) {
                $changed = TRUE;
            }
            if ($this->processMultivalueBaseFieldHandler($handler, $handler_type, $key, $display_id, $view)) {
                $changed = TRUE;
            }
            return $changed;
        });
    }
    
    /**
     * Processes all display handlers.
     *
     * @param \Drupal\views\ViewEntityInterface $view
     *   The View to update.
     * @param bool $return_on_changed
     *   Whether processing should stop after a change is detected.
     * @param callable $handler_processor
     *   A callback performing the actual update.
     *
     * @return bool
     *   Whether the view was updated.
     */
    protected function processDisplayHandlers(ViewEntityInterface $view, $return_on_changed, callable $handler_processor) {
        $changed = FALSE;
        $displays = $view->get('display');
        $handler_types = [
            'field',
            'argument',
            'sort',
            'relationship',
            'filter',
        ];
        foreach ($displays as $display_id => &$display) {
            foreach ($handler_types as $handler_type) {
                $handler_type_plural = $handler_type . 's';
                if (!empty($display['display_options'][$handler_type_plural])) {
                    foreach ($display['display_options'][$handler_type_plural] as $key => &$handler) {
                        if ($handler_processor($handler, $handler_type, $key, $display_id)) {
                            $changed = TRUE;
                            if ($return_on_changed) {
                                return $changed;
                            }
                        }
                    }
                }
            }
        }
        if ($changed) {
            $view->set('display', $displays);
        }
        return $changed;
    }
    
    /**
     * Add additional settings to the entity link field.
     *
     * @param \Drupal\views\ViewEntityInterface $view
     *   The View to update.
     *
     * @return bool
     *   Whether the view was updated.
     */
    public function needsEntityLinkUrlUpdate(ViewEntityInterface $view) {
        return $this->processDisplayHandlers($view, TRUE, function (&$handler, $handler_type) {
            return $this->processEntityLinkUrlHandler($handler, $handler_type);
        });
    }
    
    /**
     * Processes entity link URL fields.
     *
     * @param array $handler
     *   A display handler.
     * @param string $handler_type
     *   The handler type.
     *
     * @return bool
     *   Whether the handler was updated.
     */
    protected function processEntityLinkUrlHandler(array &$handler, $handler_type) {
        $changed = FALSE;
        if ($handler_type === 'field') {
            if (isset($handler['plugin_id']) && $handler['plugin_id'] === 'entity_link') {
                // Add any missing settings for entity_link.
                if (!isset($handler['output_url_as_text'])) {
                    $handler['output_url_as_text'] = FALSE;
                    $changed = TRUE;
                }
                if (!isset($handler['absolute'])) {
                    $handler['absolute'] = FALSE;
                    $changed = TRUE;
                }
            }
            elseif (isset($handler['plugin_id']) && $handler['plugin_id'] === 'node_path') {
                // Convert the use of node_path to entity_link.
                $handler['plugin_id'] = 'entity_link';
                $handler['field'] = 'view_node';
                $handler['output_url_as_text'] = TRUE;
                $changed = TRUE;
            }
        }
        return $changed;
    }
    
    /**
     * Add additional settings to the entity link field.
     *
     * @param \Drupal\views\ViewEntityInterface $view
     *   The View to update.
     *
     * @return bool
     *   Whether the view was updated.
     */
    public function needsOperatorDefaultsUpdate(ViewEntityInterface $view) {
        return $this->processDisplayHandlers($view, TRUE, function (&$handler, $handler_type) {
            return $this->processOperatorDefaultsHandler($handler, $handler_type);
        });
    }
    
    /**
     * Processes operator defaults.
     *
     * @param array $handler
     *   A display handler.
     * @param string $handler_type
     *   The handler type.
     *
     * @return bool
     *   Whether the handler was updated.
     */
    protected function processOperatorDefaultsHandler(array &$handler, $handler_type) {
        $changed = FALSE;
        if ($handler_type === 'filter') {
            if (!isset($handler['expose']['operator_limit_selection'])) {
                $handler['expose']['operator_limit_selection'] = FALSE;
                $changed = TRUE;
            }
            if (!isset($handler['expose']['operator_list'])) {
                $handler['expose']['operator_list'] = [];
                $changed = TRUE;
            }
        }
        return $changed;
    }
    
    /**
     * Update field names for multi-value base fields.
     *
     * @param \Drupal\views\ViewEntityInterface $view
     *   The View to update.
     *
     * @return bool
     *   Whether the view was updated.
     */
    public function needsMultivalueBaseFieldUpdate(ViewEntityInterface $view) {
        if ($this->getMultivalueBaseFieldUpdateTableInfo()) {
            return $this->processDisplayHandlers($view, TRUE, function (&$handler, $handler_type, $key, $display_id) use ($view) {
                return $this->processMultivalueBaseFieldHandler($handler, $handler_type, $key, $display_id, $view);
            });
        }
        return FALSE;
    }
    
    /**
     * Returns the multivalue base fields update table info.
     *
     * @return array
     *   An array of multivalue base field info.
     */
    protected function getMultivalueBaseFieldUpdateTableInfo() {
        $table_info =& $this->multivalueBaseFieldsUpdateTableInfo;
        if (!isset($table_info)) {
            $table_info = [];
            foreach ($this->entityTypeManager
                ->getDefinitions() as $entity_type_id => $entity_type) {
                if ($entity_type->hasHandlerClass('views_data') && $entity_type->entityClassImplements(FieldableEntityInterface::class)) {
                    $base_field_definitions = $this->entityFieldManager
                        ->getBaseFieldDefinitions($entity_type_id);
                    $entity_storage = $this->entityTypeManager
                        ->getStorage($entity_type_id);
                    $table_mapping = $entity_storage->getTableMapping($base_field_definitions);
                    if (!$table_mapping instanceof DefaultTableMapping) {
                        continue;
                    }
                    foreach ($base_field_definitions as $field_name => $base_field_definition) {
                        $base_field_storage_definition = $base_field_definition->getFieldStorageDefinition();
                        // Skip single value and custom storage base fields.
                        if (!$base_field_storage_definition->isMultiple() || $base_field_storage_definition->hasCustomStorage()) {
                            continue;
                        }
                        // Get the actual table, as well as the column for the main property
                        // name, so we can perform an update on the views in
                        // ::updateFieldNamesForMultivalueBaseFields().
                        $table_name = $table_mapping->getFieldTableName($field_name);
                        $main_property_name = $base_field_storage_definition->getMainPropertyName();
                        $table_info[$table_name][$field_name] = $table_mapping->getFieldColumnName($base_field_storage_definition, $main_property_name);
                    }
                }
            }
        }
        return $table_info;
    }
    
    /**
     * Processes handlers affected by the multivalue base field update.
     *
     * @param array $handler
     *   A display handler.
     * @param string $handler_type
     *   The handler type.
     * @param string $key
     *   The handler key.
     * @param string $display_id
     *   The handler display ID.
     * @param \Drupal\views\ViewEntityInterface $view
     *   The view being updated.
     *
     * @return bool
     *   Whether the handler was updated.
     */
    protected function processMultivalueBaseFieldHandler(array &$handler, $handler_type, $key, $display_id, ViewEntityInterface $view) {
        $changed = FALSE;
        // If there are no multivalue base fields we have nothing to do.
        $table_info = $this->getMultivalueBaseFieldUpdateTableInfo();
        if (!$table_info) {
            return $changed;
        }
        // Only if the wrong field name is set do we process the field. It
        // could already be using the correct field. Like "user__roles" vs
        // "roles_target_id".
        if (isset($handler['table']) && isset($table_info[$handler['table']]) && isset($table_info[$handler['table']][$handler['field']])) {
            $changed = TRUE;
            $original_field_name = $handler['field'];
            $handler['field'] = $table_info[$handler['table']][$original_field_name];
            $handler['plugin_id'] = $this->viewsData
                ->get($handler['table'])[$table_info[$handler['table']][$original_field_name]][$handler_type]['id'];
            // Retrieve type data information about the handler to clean it up
            // reliably. We need to manually create a typed view rather than
            // instantiating the current one, as the schema will be affected by the
            // updated values.
            $id = 'views.view.' . $view->id();
            $path_to_handler = "display.{$display_id}.display_options.{$handler_type}s.{$key}";
            $view_config = $view->toArray();
            $keys = explode('.', $path_to_handler);
            NestedArray::setValue($view_config, $keys, $handler);
            
            /** @var \Drupal\Core\Config\Schema\TypedConfigInterface $typed_view */
            $typed_view = $this->typedConfigManager
                ->createFromNameAndData($id, $view_config);
            
            /** @var \Drupal\Core\Config\Schema\ArrayElement $typed_handler */
            $typed_handler = $typed_view->get($path_to_handler);
            // Filter values we want to convert from a string to an array.
            if ($handler_type === 'filter' && $typed_handler->get('value') instanceof ArrayElement && is_string($handler['value'])) {
                // An empty string cast to an array is an array with one element.
                if ($handler['value'] === '') {
                    $handler['value'] = [];
                }
                else {
                    $handler['value'] = (array) $handler['value'];
                }
                $handler['operator'] = $this->mapOperatorFromSingleToMultiple($handler['operator']);
            }
            // For all the other fields we try to determine the fields using config
            // schema and remove everything not being defined in the new handler.
            foreach (array_keys($handler) as $handler_key) {
                if (!isset($typed_handler->getDataDefinition()['mapping'][$handler_key])) {
                    unset($handler[$handler_key]);
                }
            }
        }
        return $changed;
    }
    
    /**
     * Maps a single operator to a multiple one, if possible.
     *
     * @param string $single_operator
     *   A single operator.
     *
     * @return string
     *   A multiple operator or the original one if no mapping was available.
     */
    protected function mapOperatorFromSingleToMultiple($single_operator) {
        switch ($single_operator) {
            case '=':
                return 'or';
            case '!=':
                return 'not';
            default:
                return $single_operator;
        }
    }

}