class ResolverRelationshipConfigure

abstract class ResolverRelationshipConfigure extends FormBase {
    
    /**
     * @var \Drupal\Core\TempStore\SharedTempStoreFactory
     */
    protected $tempstore;
    
    /**
     * @var string
     */
    protected $tempstore_id;
    
    /**
     * @var string
     */
    protected $machine_name;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('tempstore.shared'));
    }
    
    /**
     * Configure Relationships Resolver form.
     *
     * @param \Drupal\Core\TempStore\SharedTempStoreFactory $tempstore
     *   Tempstore Factory.
     */
    public function __construct(SharedTempStoreFactory $tempstore) {
        $this->tempstore = $tempstore;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'ctools_context_configure';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, $context = NULL, $tempstore_id = NULL, $machine_name = NULL) {
        $this->tempstore_id = $tempstore_id;
        $this->machine_name = $machine_name;
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        if (is_numeric($context)) {
            $id = $context;
            $contexts = $this->getContexts($cached_values);
            $context = $contexts[$id]['context'];
            $label = $contexts[$id]['label'];
            $machine_name = $contexts[$id]['machine_name'];
            $description = $contexts[$id]['description'];
            // Conditionally set this form element so that we can update or add.
            $form['id'] = [
                '#type' => 'value',
                '#value' => $id,
            ];
        }
        else {
            $label = '';
            $machine_name = '';
            $description = '';
        }
        $form['#attached']['library'][] = 'core/drupal.dialog.ajax';
        $form['context'] = [
            '#type' => 'value',
            '#value' => $context,
        ];
        $form['label'] = [
            '#type' => 'textfield',
            '#title' => $this->t('Label'),
            '#default_value' => $label,
            '#required' => TRUE,
        ];
        $form['machine_name'] = [
            '#type' => 'textfield',
            '#title' => $this->t('Machine Name'),
            '#default_value' => $machine_name,
            '#required' => TRUE,
        ];
        $form['description'] = [
            '#type' => 'textarea',
            '#title' => $this->t('Description'),
            '#default_value' => $description,
        ];
        $form['submit'] = [
            '#type' => 'submit',
            '#value' => $this->t('Save'),
            '#ajax' => [
                'callback' => [
                    $this,
                    'ajaxSave',
                ],
            ],
        ];
        return $form;
    }
    
    /**
     * Configuration Form Validator.
     *
     * @param array $form
     *   The Drupal Form.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The Form State.
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
        $machine_name = $form_state->getValue('machine_name');
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        foreach ($this->getContexts($cached_values) as $id => $context) {
            if ($context['machine_name'] == $machine_name) {
                $form_state->setError($form['machine_name'], $this->t('That machine name is in use by another context definition.'));
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        $contexts = $this->getContexts($cached_values);
        $context = [
            'context' => $form_state->getValue('context'),
            'label' => $form_state->getValue('label'),
            'machine_name' => $form_state->getValue('machine_name'),
            'description' => $form_state->getValue('description'),
        ];
        if ($form_state->hasValue('id')) {
            $contexts[$form_state->getValue('id')] = $context;
        }
        else {
            $contexts[] = $context;
        }
        $cached_values = $this->setContexts($cached_values, $contexts);
        $this->tempstore
            ->get($this->tempstore_id)
            ->set($this->machine_name, $cached_values);
        [
            $route_name,
            $route_parameters,
        ] = $this->getParentRouteInfo($cached_values);
        $form_state->setRedirect($route_name, $route_parameters);
    }
    
    /**
     * Ajax Save Method.
     *
     * @param array $form
     *   Drupal Form.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   Form State.
     *
     * @return \Drupal\Core\Ajax\AjaxResponse
     *   The ajax data in the response.
     */
    public function ajaxSave(array &$form, FormStateInterface $form_state) {
        $response = new AjaxResponse();
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        [
            $route_name,
            $route_parameters,
        ] = $this->getParentRouteInfo($cached_values);
        $url = Url::fromRoute($route_name, $route_parameters);
        $response->addCommand(new RedirectCommand($url->toString()));
        $response->addCommand(new CloseModalDialogCommand());
        return $response;
    }
    
    /**
     * Document the route name and parameters for redirect after submission.
     *
     * @param $cached_values
     *
     * @return array
     *   In the format of
     *   return ['route.name', ['machine_name' => $this->machine_name, 'step' => 'step_name]];
     */
    protected abstract function getParentRouteInfo($cached_values);
    
    /**
     * Custom logic for retrieving the contexts array from cached_values.
     *
     * @param $cached_values
     *
     * @return array
     */
    protected abstract function getContexts($cached_values);
    
    /**
     * Custom logic for setting the contexts array in cached_values.
     *
     * @param $cached_values
     *
     * @param $contexts
     *   The contexts to set within the cached values.
     *
     * @return mixed
     *   Return the $cached_values
     */
    protected abstract function setContexts($cached_values, $contexts);

}