class Tid

class Tid extends ArgumentDefaultPluginBase implements CacheableDependencyInterface {
    
    /**
     * The route match.
     *
     * @var \Drupal\Core\Routing\RouteMatchInterface
     */
    protected $routeMatch;
    
    /**
     * The vocabulary storage.
     *
     * @var \Drupal\taxonomy\VocabularyStorageInterface
     */
    protected $vocabularyStorage;
    
    /**
     * Constructs a new Tid instance.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.   *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The route match.
     * @param \Drupal\taxonomy\VocabularyStorageInterface $vocabulary_storage
     *   The vocabulary storage.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, RouteMatchInterface $route_match, VocabularyStorageInterface $vocabulary_storage) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->routeMatch = $route_match;
        $this->vocabularyStorage = $vocabulary_storage;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('current_route_match'), $container->get('entity_type.manager')
            ->getStorage('taxonomy_vocabulary'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
        parent::init($view, $display, $options);
        // @todo Remove the legacy code.
        // Convert legacy vids option to machine name vocabularies.
        if (!empty($this->options['vids'])) {
            $vocabularies = taxonomy_vocabulary_get_names();
            foreach ($this->options['vids'] as $vid) {
                if (isset($vocabularies[$vid], $vocabularies[$vid]->machine_name)) {
                    $this->options['vocabularies'][$vocabularies[$vid]->machine_name] = $vocabularies[$vid]->machine_name;
                }
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    protected function defineOptions() {
        $options = parent::defineOptions();
        $options['term_page'] = [
            'default' => TRUE,
        ];
        $options['node'] = [
            'default' => FALSE,
        ];
        $options['anyall'] = [
            'default' => ',',
        ];
        $options['limit'] = [
            'default' => FALSE,
        ];
        $options['vids'] = [
            'default' => [],
        ];
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildOptionsForm(&$form, FormStateInterface $form_state) {
        $form['term_page'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Load default filter from term page'),
            '#default_value' => $this->options['term_page'],
        ];
        $form['node'] = [
            '#type' => 'checkbox',
            '#title' => $this->t("Load default filter from node page, that's good for related taxonomy blocks"),
            '#default_value' => $this->options['node'],
        ];
        $form['limit'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Limit terms by vocabulary'),
            '#default_value' => $this->options['limit'],
            '#states' => [
                'visible' => [
                    ':input[name="options[argument_default][taxonomy_tid][node]"]' => [
                        'checked' => TRUE,
                    ],
                ],
            ],
        ];
        $options = [];
        $vocabularies = $this->vocabularyStorage
            ->loadMultiple();
        foreach ($vocabularies as $voc) {
            $options[$voc->id()] = $voc->label();
        }
        $form['vids'] = [
            '#type' => 'checkboxes',
            '#title' => $this->t('Vocabularies'),
            '#options' => $options,
            '#default_value' => $this->options['vids'],
            '#states' => [
                'visible' => [
                    ':input[name="options[argument_default][taxonomy_tid][limit]"]' => [
                        'checked' => TRUE,
                    ],
                    ':input[name="options[argument_default][taxonomy_tid][node]"]' => [
                        'checked' => TRUE,
                    ],
                ],
            ],
        ];
        $form['anyall'] = [
            '#type' => 'radios',
            '#title' => $this->t('Multiple-value handling'),
            '#default_value' => $this->options['anyall'],
            '#options' => [
                ',' => $this->t('Filter to items that share all terms'),
                '+' => $this->t('Filter to items that share any term'),
            ],
            '#states' => [
                'visible' => [
                    ':input[name="options[argument_default][taxonomy_tid][node]"]' => [
                        'checked' => TRUE,
                    ],
                ],
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitOptionsForm(&$form, FormStateInterface $form_state, &$options = []) {
        // Filter unselected items so we don't unnecessarily store giant arrays.
        $options['vids'] = array_filter($options['vids']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getArgument() {
        // Load default argument from taxonomy page.
        if (!empty($this->options['term_page'])) {
            if (($taxonomy_term = $this->routeMatch
                ->getParameter('taxonomy_term')) && $taxonomy_term instanceof TermInterface) {
                return $taxonomy_term->id();
            }
        }
        // Load default argument from node.
        if (!empty($this->options['node'])) {
            // Just check, if a node could be detected.
            if (($node = $this->routeMatch
                ->getParameter('node')) && $node instanceof NodeInterface) {
                $taxonomy = [];
                foreach ($node->getFieldDefinitions() as $field) {
                    if ($field->getType() == 'entity_reference' && $field->getSetting('target_type') == 'taxonomy_term') {
                        $taxonomy_terms = $node->{$field->getName()}
                            ->referencedEntities();
                        
                        /** @var \Drupal\taxonomy\TermInterface $taxonomy_term */
                        foreach ($taxonomy_terms as $taxonomy_term) {
                            $taxonomy[$taxonomy_term->id()] = $taxonomy_term->bundle();
                        }
                    }
                }
                if (!empty($this->options['limit'])) {
                    $tids = [];
                    // filter by vocabulary
                    foreach ($taxonomy as $tid => $vocab) {
                        if (!empty($this->options['vids'][$vocab])) {
                            $tids[] = $tid;
                        }
                    }
                    return implode($this->options['anyall'], $tids);
                }
                else {
                    return implode($this->options['anyall'], array_keys($taxonomy));
                }
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheMaxAge() {
        return Cache::PERMANENT;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheContexts() {
        return [
            'url',
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function calculateDependencies() {
        $dependencies = parent::calculateDependencies();
        foreach ($this->vocabularyStorage
            ->loadMultiple(array_keys($this->options['vids'])) as $vocabulary) {
            $dependencies[$vocabulary->getConfigDependencyKey()][] = $vocabulary->getConfigDependencyName();
        }
        return $dependencies;
    }

}