class ContentLanguageSettingsForm

class ContentLanguageSettingsForm extends FormBase {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity bundle info.
     *
     * @var \Drupal\Core\Entity\EntityTypeBundleInfoInterface
     */
    protected $entityTypeBundleInfo;
    
    /**
     * If this validator can handle multiple arguments.
     *
     * @var bool
     */
    protected $multipleCapable = TRUE;
    
    /**
     * The module handler.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * Constructs an \Drupal\views\Plugin\views\argument_validator\Entity object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
     *   The entity type bundle info.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info, ModuleHandlerInterface $module_handler) {
        $this->entityTypeManager = $entity_type_manager;
        $this->entityTypeBundleInfo = $entity_type_bundle_info;
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity_type.manager'), $container->get('entity_type.bundle.info'), $container->get('module_handler'));
    }
    
    /**
     * The _title_callback for the language.content_settings_page route.
     *
     * @return \Drupal\Core\StringTranslation\TranslatableMarkup
     *   The page title.
     */
    public function getTitle() : string {
        if ($this->moduleHandler
            ->moduleExists('content_translation')) {
            return $this->t('Content language and translation');
        }
        else {
            return $this->t('Content language');
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'language_content_settings_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $entity_types = $this->entityTypeManager
            ->getDefinitions();
        $labels = [];
        $default = [];
        $bundles = $this->entityTypeBundleInfo
            ->getAllBundleInfo();
        $language_configuration = [];
        foreach ($entity_types as $entity_type_id => $entity_type) {
            if (!$entity_type instanceof ContentEntityTypeInterface || !$entity_type->hasKey('langcode') || !isset($bundles[$entity_type_id])) {
                continue;
            }
            $labels[$entity_type_id] = $entity_type->getLabel() ?: $entity_type_id;
            $default[$entity_type_id] = FALSE;
            // Check whether we have any custom setting.
            foreach ($bundles[$entity_type_id] as $bundle => $bundle_info) {
                $config = ContentLanguageSettings::loadByEntityTypeBundle($entity_type_id, $bundle);
                if (!$config->isDefaultConfiguration()) {
                    $default[$entity_type_id] = $entity_type_id;
                }
                $language_configuration[$entity_type_id][$bundle] = $config;
            }
        }
        asort($labels);
        $form = [
            '#labels' => $labels,
            '#attached' => [
                'library' => [
                    'language/drupal.language.admin',
                ],
            ],
            '#attributes' => [
                'class' => 'language-content-settings-form',
            ],
        ];
        $form['entity_types'] = [
            '#title' => $this->t('Custom language settings'),
            '#type' => 'checkboxes',
            '#options' => $labels,
            '#default_value' => $default,
        ];
        $form['settings'] = [
            '#tree' => TRUE,
        ];
        foreach ($labels as $entity_type_id => $label) {
            $entity_type = $entity_types[$entity_type_id];
            $form['settings'][$entity_type_id] = [
                '#title' => $label,
                '#type' => 'details',
                '#entity_type' => $entity_type_id,
                '#theme' => 'language_content_settings_table',
                '#bundle_label' => $entity_type->getBundleLabel() ?: $label,
                '#states' => [
                    'visible' => [
                        ':input[name="entity_types[' . $entity_type_id . ']"]' => [
                            'checked' => TRUE,
                        ],
                    ],
                ],
            ];
            foreach ($bundles[$entity_type_id] as $bundle => $bundle_info) {
                $form['settings'][$entity_type_id][$bundle]['settings'] = [
                    '#type' => 'item',
                    '#label' => $bundle_info['label'],
                    'language' => [
                        '#type' => 'language_configuration',
                        '#entity_information' => [
                            'entity_type' => $entity_type_id,
                            'bundle' => $bundle,
                        ],
                        '#default_value' => $language_configuration[$entity_type_id][$bundle],
                    ],
                ];
            }
        }
        $form['actions']['#type'] = 'actions';
        $form['actions']['submit'] = [
            '#type' => 'submit',
            '#value' => $this->t('Save configuration'),
            '#button_type' => 'primary',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $entity_types = $form_state->getValue('entity_types');
        foreach ($form_state->getValue('settings') as $entity_type => $entity_settings) {
            foreach ($entity_settings as $bundle => $bundle_settings) {
                $config = ContentLanguageSettings::loadByEntityTypeBundle($entity_type, $bundle);
                if (empty($entity_types[$entity_type])) {
                    $bundle_settings['settings']['language']['language_alterable'] = FALSE;
                }
                $config->setDefaultLangcode($bundle_settings['settings']['language']['langcode'])
                    ->setLanguageAlterable($bundle_settings['settings']['language']['language_alterable'])
                    ->save();
            }
        }
        $this->messenger()
            ->addStatus($this->t('Settings successfully updated.'));
    }

}