class DevelopmentSettingsForm

class DevelopmentSettingsForm extends FormBase {
    
    /**
     * Constructs a new development settings form.
     *
     * @param \Drupal\Core\KeyValueStore\KeyValueFactoryInterface $keyValueFactory
     *   The key value factory.
     * @param \Drupal\Core\DrupalKernelInterface $kernel
     *   The Drupal kernel.
     */
    public function __construct(KeyValueFactoryInterface $keyValueFactory, DrupalKernelInterface $kernel) {
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        $instance = new static($container->get('keyvalue'), $container->get('kernel'));
        $instance->setMessenger($container->get('messenger'));
        return $instance;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'development_settings_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $development_settings = $this->keyValueFactory
            ->get('development_settings');
        $form['description'] = [
            '#plain_text' => $this->t('These settings should only be enabled on development environments and never on production.'),
        ];
        $twig_debug = $development_settings->get('twig_debug', FALSE);
        $twig_cache_disable = $development_settings->get('twig_cache_disable', FALSE);
        $twig_development_state_conditions = [
            'input[data-drupal-selector="edit-twig-development-mode"]' => [
                'checked' => TRUE,
            ],
        ];
        $form['disable_rendered_output_cache_bins'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Do not cache markup'),
            '#description' => $this->t('Disables render cache, dynamic page cache, and page cache.'),
            '#default_value' => $development_settings->get('disable_rendered_output_cache_bins', FALSE),
        ];
        $form['twig_development_mode'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Twig development mode'),
            '#description' => $this->t('Exposes Twig development settings.'),
            '#default_value' => $twig_debug || $twig_cache_disable,
        ];
        $form['twig_development'] = [
            '#type' => 'fieldset',
            '#title' => $this->t('Twig development mode'),
            '#states' => [
                'visible' => $twig_development_state_conditions,
            ],
        ];
        $form['twig_development']['twig_debug'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Twig debug mode'),
            '#description' => $this->t("Provides Twig's <code>dump()</code> function for debugging, outputs template suggestions to HTML comments, and automatically recompile Twig templates after changes."),
            '#default_value' => $twig_debug,
        ];
        $form['twig_development']['twig_cache_disable'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Disable Twig cache'),
            '#description' => $this->t('Twig templates are not cached and are always compiled when rendered.'),
            '#default_value' => $twig_cache_disable,
        ];
        if (!$twig_debug && !$twig_cache_disable) {
            $form['twig_development']['twig_debug']['#states'] = [
                'checked' => $twig_development_state_conditions,
            ];
            $form['twig_development']['twig_cache_disable']['#states'] = [
                'checked' => $twig_development_state_conditions,
            ];
        }
        $form['actions']['#type'] = 'actions';
        $form['actions']['submit'] = [
            '#type' => 'submit',
            '#value' => $this->t('Save settings'),
            '#button_type' => 'primary',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $development_settings = $this->keyValueFactory
            ->get('development_settings');
        $disable_rendered_output_cache_bins_previous = $development_settings->get('disable_rendered_output_cache_bins', FALSE);
        $disable_rendered_output_cache_bins = (bool) $form_state->getValue('disable_rendered_output_cache_bins');
        if ($disable_rendered_output_cache_bins) {
            $development_settings->set('disable_rendered_output_cache_bins', TRUE);
        }
        else {
            $development_settings->delete('disable_rendered_output_cache_bins');
        }
        $twig_development_mode = (bool) $form_state->getValue('twig_development_mode');
        $twig_development_previous = $development_settings->getMultiple([
            'twig_debug',
            'twig_cache_disable',
        ]);
        $twig_development = [
            'twig_debug' => (bool) $form_state->getValue('twig_debug'),
            'twig_cache_disable' => (bool) $form_state->getValue('twig_cache_disable'),
        ];
        if ($twig_development_mode) {
            $invalidate_container = $twig_development_previous !== $twig_development;
            $development_settings->setMultiple($twig_development);
        }
        else {
            $invalidate_container = TRUE;
            $development_settings->deleteMultiple(array_keys($twig_development));
        }
        if ($invalidate_container || $disable_rendered_output_cache_bins_previous !== $disable_rendered_output_cache_bins) {
            $this->kernel
                ->invalidateContainer();
        }
        $this->messenger()
            ->addStatus($this->t('The settings have been saved.'));
    }

}