<?php

/**
 * @file
 * Workaround for core bugs in display of entity title.
 */

// EntityViewController::buildTitle creates problems, see https://www.drupal.org/node/2941208.
// It runs as a pre_render hook, difficult to alter it, see comment below for explanation.
// Solution found was to override the _controller for routes using a route enhancer service.
//
// Sequence of events.
// 1) Building
// - EntityViewController::view
// - EntityViewBuilder::view
// - hook_entity_build_defaults_alter: can add OWN_entity_pre_render but Core
//   pre_render not available to alter
// 2) Rendering
// - pre_render
//   - OWN_entity_pre_render: too late to alter Core pre_render; no built fields to hook
//   - EntityViewBuilder::build
//     - hook_entity_view_display_alter XXXX ideal place, except can't detect whether the entity is on its own page
//     - hook_entity_prepare_view XXXX acts on entities
//     - EntityViewDisplay::buildMultiple formatter builds the output, so after this it's too late to swap to a different formatter
//     - hook_entity_display_build_alter
//     - hook_entity_view, hook_entity_view_alter
//   - EntityViewController::buildTitle
//     - title field: #pre_render, template_preprocess_field, hook_preprocess_field
// - preprocess
//   - node: #pre_render, template_preprocess_node, hook_preprocess_node
//   - field: #pre_render, template_preprocess_field, hook_preprocess_field.

/**
 * Implements hook_entity_view_display_alter().
 */
// function manage_display_entity_view_display_alter(EntityViewDisplayInterface $display, array $context) {
//   $label_field = Drupal::entityTypeManager()->getDefinition($context['entity_type'])->getKey('label');
//   $options = [
//     'label' => 'hidden',
//     'type' => 'basic_string',
//   ];
//   $display->setComponent($label_field, $options);
// }

/**
 * Implements hook_entity_view().
 */
// function manage_display_entity_view(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, $view_mode) {
//   if ($entity instanceof FieldableEntityInterface) {
//     $label_field = $entity->getEntityType()->getKey('label');
//     if (isset($build[$label_field])) {
//       $build[$label_field]['#pre_render'][] = 'manage_display_title_pre_render';
//       @todo If want to keep the field in the entity.
//       Requires a change to EntityViewController::buildTitle
//       $build['#built_page_title'] = TRUE;
//       @todo If also want to hide title block.
//       But loses metadata - better to prevent only title block.
//       $build['#title'] = '';
//       ??$build['#title'] = new HtmlEscapedText($entity->label());
//     }
//   }
// }

/**
 * Implements hook_theme().
 */
function manage_display_fix_title_theme() {
  return [
    'entity_page_title' => [
      'variables' => [
        'attributes' => [],
        'title' => NULL,
        'entity' => NULL,
        'view_mode' => NULL,
      ],
    ],
  ];
}

/**
 * Implements hook_preprocess_HOOK() for entity_page_title.
 * On behalf of quickedit.module.
 */
function quickedit_preprocess_entity_page_title(&$variables) {
  $variables['#cache']['contexts'][] = 'user.permissions';
  $entity = $variables['entity'];
  if (!\Drupal::currentUser()->hasPermission('access in-place editing') || !$entity->isLatestRevision()) {
    return;
  }

  $label_field = $entity->getEntityType()->getKey('label');
  $variables['attributes']['data-quickedit-field-id'] = $entity->getEntityTypeId() . '/' . $entity->id() . '/' . $label_field . '/' . $entity->language()->getId() . '/' . $variables['view_mode'];
}