class RequiredContextDelete

abstract class RequiredContextDelete extends ConfirmFormBase {
    
    /**
     * Creates a shared temporary storage for a collection.
     *
     * @var \Drupal\Core\TempStore\SharedTempStoreFactory
     */
    protected $tempstore;
    
    /**
     * The temporary id storage.
     *
     * @var string
     */
    // @codingStandardsIgnoreLine
    protected $tempstore_id;
    
    /**
     * The machine name.
     *
     * @var string
     */
    // @codingStandardsIgnoreLine
    protected $machine_name;
    
    /**
     * The id.
     *
     * @var int
     */
    protected $id;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('tempstore.shared'));
    }
    
    /**
     * The constructor.
     *
     * @param \Drupal\Core\TempStore\SharedTempStoreFactory $tempstore
     *   The shared temporary storage.
     */
    public function __construct(SharedTempStoreFactory $tempstore) {
        $this->tempstore = $tempstore;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'ctools_required_context_delete';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, $id = NULL, $tempstore_id = NULL, $machine_name = NULL) {
        $this->tempstore_id = $tempstore_id;
        $this->machine_name = $machine_name;
        $this->id = $id;
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        $form['#title'] = $this->getQuestion($id, $cached_values);
        $form['#attributes']['class'][] = 'confirmation';
        $form['description'] = [
            '#markup' => $this->getDescription(),
        ];
        $form[$this->getFormName()] = [
            '#type' => 'hidden',
            '#value' => 1,
        ];
        // By default, render the form using theme_confirm_form().
        if (!isset($form['#theme'])) {
            $form['#theme'] = 'confirm_form';
        }
        $form['actions'] = [
            '#type' => 'actions',
        ];
        $form['actions'] += $this->actions($form, $form_state);
        return $form;
    }
    
    /**
     * {@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);
        unset($contexts[$this->id]);
        $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);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getQuestion($id = NULL, $cached_values = NULL) {
        $context = $this->getContexts($cached_values)[$id];
        return $this->t('Are you sure you want to delete the @label context?', [
            '@label' => $context['label'],
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDescription() {
        return $this->t('This action cannot be undone.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormName() {
        return 'confirm';
    }
    
    /**
     * Provides the action buttons for submitting this form.
     */
    protected function actions(array $form, FormStateInterface $form_state) {
        return [
            'submit' => [
                '#type' => 'submit',
                '#value' => $this->getConfirmText(),
                '#validate' => [
                    [
                        $this,
                        'validate',
                    ],
                ],
                '#submit' => [
                    [
                        $this,
                        'submitForm',
                    ],
                ],
            ],
            'cancel' => ConfirmFormHelper::buildCancelLink($this, $this->getRequest()),
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelUrl() {
        $cached_values = $this->tempstore
            ->get($this->tempstore_id)
            ->get($this->machine_name);
        [
            $route_name,
            $route_parameters,
        ] = $this->getParentRouteInfo($cached_values);
        return new Url($route_name, $route_parameters);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfirmText() {
        return $this->t('Delete');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelText() {
        return $this->t('Cancel');
    }
    
    /**
     * Document the route name and parameters for redirect after submission.
     *
     * @param mixed $cached_values
     *   The 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 mixed $cached_values
     *   The cache values.
     *
     * @return array
     *   Return an array.
     */
    protected abstract function getContexts($cached_values);
    
    /**
     * Custom logic for setting the contexts array in cached_values.
     *
     * @param mixed $cached_values
     *   The cache values.
     * @param mixed $contexts
     *   The contexts to set within the cached values.
     *
     * @return mixed
     *   Return the $cached_values
     */
    protected abstract function setContexts($cached_values, $contexts);

}