<?php

namespace Drupal\media\Hook;

use Drupal\Core\Access\AccessResultInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\views\ViewExecutable;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Field\FieldTypeCategoryManagerInterface;
use Drupal\Core\Access\AccessResult;
use Drupal\field\FieldConfigInterface;
use Drupal\Core\Session\AccountInterface;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Url;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Hook\Attribute\Hook;

/**
 * Hook implementations for media.
 */
class MediaHooks {

  use StringTranslationTrait;

  /**
   * Implements hook_help().
   */
  #[Hook('help')]
  public function help($route_name, RouteMatchInterface $route_match): ?string {
    switch ($route_name) {
      case 'help.page.media':
        $output = '<h2>' . $this->t('About') . '</h2>';
        $output .= '<p>' . $this->t('The Media module manages the creation, editing, deletion, settings, and display of media. Items are typically images, documents, slideshows, YouTube videos, tweets, Instagram photos, etc. You can reference media items from any other content on your site. For more information, see the <a href=":media">online documentation for the Media module</a>.', [':media' => 'https://www.drupal.org/docs/8/core/modules/media']) . '</p>';
        $output .= '<h2>' . $this->t('Uses') . '</h2>';
        $output .= '<dl>';
        $output .= '<dt>' . $this->t('Creating media items') . '</dt>';
        $output .= '<dd>' . $this->t('When a new media item is created, the Media module records basic information about it, including the author, date of creation, and the <a href=":media-type">media type</a>. It also manages the <em>publishing options</em>, which define whether or not the item is published. Default settings can be configured for each type of media on your site.', [
          ':media-type' => Url::fromRoute('entity.media_type.collection')->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Listing media items') . '</dt>';
        $output .= '<dd>' . $this->t('Media items are listed at the <a href=":media-collection">media administration page</a>.', [
          ':media-collection' => Url::fromRoute('entity.media.collection')->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Creating custom media types') . '</dt>';
        $output .= '<dd>' . $this->t('The Media module gives users with the <em>Administer media types</em> permission the ability to <a href=":media-new">create new media types</a> in addition to the default ones already configured. Each media type has an associated media source (such as the image source) which support thumbnail generation and metadata extraction. Fields managed by the <a href=":field">Field module</a> may be added for storing that metadata, such as width and height, as well as any other associated values.', [
          ':media-new' => Url::fromRoute('entity.media_type.add_form')->toString(),
          ':field' => Url::fromRoute('help.page', [
            'name' => 'field',
          ])->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Creating revisions') . '</dt>';
        $output .= '<dd>' . $this->t('The Media module also enables you to create multiple versions of any media item, and revert to older versions using the <em>Revision information</em> settings.') . '</dd>';
        $output .= '<dt>' . $this->t('User permissions') . '</dt>';
        $output .= '<dd>' . $this->t('The Media module makes a number of permissions available, which can be set by role on the <a href=":permissions">permissions page</a>.', [
          ':permissions' => Url::fromRoute('user.admin_permissions.module', [
            'modules' => 'media',
          ])->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Adding media to other content') . '</dt>';
        $output .= '<dd>' . $this->t('Users with permission to administer content types can add media support by adding a media reference field to the content type on the content type administration page. (The same is true of block types, taxonomy terms, user profiles, and other content that supports fields.) A media reference field can refer to any configured media type. It is possible to allow multiple media types in the same field.') . '</dd>';
        $output .= '</dl>';
        $output .= '<h2>' . $this->t('Differences between Media, File, and Image reference fields') . '</h2>';
        $output .= '<p>' . $this->t('<em>Media</em> reference fields offer several advantages over basic <em>File</em> and <em>Image</em> references:') . '</p>';
        $output .= '<ul>';
        $output .= '<li>' . $this->t('Media reference fields can reference multiple media types in the same field.') . '</li>';
        $output .= '<li>' . $this->t('Fields can also be added to media types themselves, which means that custom metadata like descriptions and taxonomy tags can be added for the referenced media. (Basic file and image fields do not support this.)') . '</li>';
        $output .= '<li>' . $this->t('Media types for audio and video files are provided by default, so there is no need for additional configuration to upload these media.') . '</li>';
        $output .= '<li>' . $this->t('Contributed or custom projects can provide additional media sources (such as third-party websites, Twitter, etc.).') . '</li>';
        $output .= '<li>' . $this->t('Existing media items can be reused on any other content items with a media reference field.') . '</li>';
        $output .= '</ul>';
        $output .= '<p>' . $this->t('Use <em>Media</em> reference fields for most files, images, audio, videos, and remote media. Use <em>File</em> or <em>Image</em> reference fields when creating your own media types, or for legacy files and images created before installing the Media module.') . '</p>';
        return $output;
    }
    return NULL;
  }

  /**
   * Implements hook_entity_access().
   */
  #[Hook('entity_access')]
  public function entityAccess(EntityInterface $entity, $operation, AccountInterface $account): AccessResultInterface {
    if ($operation === 'delete' && $entity instanceof FieldConfigInterface && $entity->getTargetEntityTypeId() === 'media') {
      /** @var \Drupal\media\MediaTypeInterface $media_type */
      $media_type = \Drupal::entityTypeManager()->getStorage('media_type')->load($entity->getTargetBundle());
      return AccessResult::forbiddenIf($entity->id() === 'media.' . $media_type->id() . '.' . $media_type->getSource()->getConfiguration()['source_field']);
    }
    return AccessResult::neutral();
  }

  /**
   * Implements hook_field_ui_preconfigured_options_alter().
   */
  #[Hook('field_ui_preconfigured_options_alter')]
  public function fieldUiPreconfiguredOptionsAlter(array &$options, $field_type): void {
    // If the field is not an "entity_reference"-based field, bail out.
    /** @var \Drupal\Core\Field\FieldTypePluginManager $field_type_manager */
    $field_type_manager = \Drupal::service('plugin.manager.field.field_type');
    $class = $field_type_manager->getPluginClass($field_type);
    if (!is_a($class, 'Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem', TRUE)) {
      return;
    }
    // Set the default formatter for media in entity reference fields to be the
    // "Rendered entity" formatter.
    if (!empty($options['media'])) {
      $options['media']['description'] = $this->t('Upload new media or select existing one');
      $options['media']['weight'] = -25;
      $options['media']['category'] = FieldTypeCategoryManagerInterface::FALLBACK_CATEGORY;
      $options['media']['entity_view_display']['type'] = 'entity_reference_entity_view';
    }
  }

  /**
   * Provides help text to choose between File and Media reference fields.
   *
   * @return string|\Drupal\Core\StringTranslation\TranslatableMarkup
   *   A suggestion of when to use Media fields instead of File or Image fields.
   */
  protected function fileMediaHelpText(): string|TranslatableMarkup {
    $help_text = $this->t('Use <em>Media</em> reference fields for most files, images, audio, videos, and remote media. Use <em>File</em> or <em>Image</em> reference fields when creating your own media types, or for legacy files and images created before installing the Media module.');
    if (\Drupal::moduleHandler()->moduleExists('help')) {
      $help_text .= ' ' . $this->t('For more information, see the <a href="@help_url">Media help page</a>.', [
        '@help_url' => Url::fromRoute('help.page', [
          'name' => 'media',
        ])->toString(),
      ]);
    }
    return $help_text;
  }

  /**
   * Implements hook_form_FORM_ID_alter().
   */
  #[Hook('form_field_ui_field_storage_add_form_alter')]
  public function formFieldUiFieldStorageAddFormAlter(&$form, FormStateInterface $form_state, $form_id) : void {
    // Provide some help text to aid users decide whether they need a Media,
    // File, or Image reference field.
    if ($form_state->getStorage()['field_type'] === 'field_ui:entity_reference:media') {
      $form['field_options_wrapper']['description_wrapper'] = [
        '#type' => 'item',
        '#markup' => $this->fileMediaHelpText(),
      ];
    }
  }

  /**
   * Implements hook_field_widget_complete_form_alter().
   */
  #[Hook('field_widget_complete_form_alter')]
  public function fieldWidgetCompleteFormAlter(array &$field_widget_complete_form, FormStateInterface $form_state, array $context): void {
    $elements =& $field_widget_complete_form['widget'];
    // Do not alter the default settings form.
    if ($context['default']) {
      return;
    }
    // Only act on entity reference fields that reference media.
    $field_type = $context['items']->getFieldDefinition()->getType();
    $target_type = $context['items']->getFieldDefinition()->getFieldStorageDefinition()->getSetting('target_type');
    if ($field_type !== 'entity_reference' || $target_type !== 'media') {
      return;
    }
    // Autocomplete widgets need different help text than options widgets.
    $widget_plugin_id = $context['widget']->getPluginId();
    if (in_array($widget_plugin_id, ['entity_reference_autocomplete', 'entity_reference_autocomplete_tags'])) {
      $is_autocomplete = TRUE;
    }
    else {
      // @todo We can't yet properly alter non-autocomplete fields. Resolve this
      //   in https://www.drupal.org/node/2943020 and remove this condition.
      return;
    }
    $elements['#media_help'] = [];
    // Retrieve the media bundle list and add information for the user based on
    // which bundles are available to be created or referenced.
    $settings = $context['items']->getFieldDefinition()->getSetting('handler_settings');
    $allowed_bundles = !empty($settings['target_bundles']) ? $settings['target_bundles'] : [];
    $add_url = $this->addUrl($allowed_bundles);
    if ($add_url) {
      $elements['#media_help']['#media_add_help'] = $this->t('Create your media on the <a href=":add_page" target="_blank">media add page</a> (opens a new window), then add it by name to the field below.', [':add_page' => $add_url]);
    }
    $elements['#theme'] = 'media_reference_help';
    // @todo \Drupal\Core\Field\FieldPreprocess::preprocessFieldMultipleValueForm()
    //   assumes this key exists, but it does not exist in the case of a single
    //   widget that accepts multiple values. This is for some reason necessary
    //   to use our template for the entity_autocomplete_tags widget.
    //   Research and resolve this in https://www.drupal.org/node/2943020.
    if (empty($elements['#cardinality_multiple'])) {
      $elements['#cardinality_multiple'] = NULL;
    }
    // Use the title set on the element if it exists, otherwise fall back to the
    // field label.
    $elements['#media_help']['#original_label'] = $elements['#title'] ?? $context['items']->getFieldDefinition()->getLabel();
    // Customize the label for the field widget.
    // @todo Research a better approach https://www.drupal.org/node/2943024.
    $use_existing_label = $this->t('Use existing media');
    if (!empty($elements[0]['target_id']['#title'])) {
      $elements[0]['target_id']['#title'] = $use_existing_label;
    }
    if (!empty($elements['#title'])) {
      $elements['#title'] = $use_existing_label;
    }
    if (!empty($elements['target_id']['#title'])) {
      $elements['target_id']['#title'] = $use_existing_label;
    }
    // This help text is only relevant for autocomplete widgets. When the user
    // is presented with options, they don't need to type anything or know what
    // types of media are allowed.
    if ($is_autocomplete) {
      $elements['#media_help']['#media_list_help'] = $this->t('Type part of the media name.');
      $overview_url = Url::fromRoute('entity.media.collection');
      if ($overview_url->access()) {
        $elements['#media_help']['#media_list_link'] = $this->t('See the <a href=":list_url" target="_blank">media list</a> (opens a new window) to help locate media.', [':list_url' => $overview_url->toString()]);
      }
      $bundle_labels = array_intersect_key(\Drupal::service('entity_type.bundle.info')->getBundleLabels('media'), $allowed_bundles);
      $elements['#media_help']['#allowed_types_help'] = $this->t('Allowed media types: %types', ['%types' => implode(", ", $bundle_labels)]);
    }
  }

  /**
   * Implements hook_entity_type_alter().
   */
  #[Hook('entity_type_alter')]
  public function entityTypeAlter(array &$entity_types) : void {
    if (\Drupal::config('media.settings')->get('standalone_url')) {
      /** @var \Drupal\Core\Entity\ContentEntityTypeInterface $entity_type */
      $entity_type = $entity_types['media'];
      $entity_type->setLinkTemplate('canonical', '/media/{media}');
    }
  }

  /**
   * Implements hook_form_FORM_ID_alter().
   */
  #[Hook('form_filter_format_edit_form_alter')]
  public function formFilterFormatEditFormAlter(array &$form, FormStateInterface $form_state, $form_id) : void {
    // Add an additional validate callback so we can ensure the order of filters
    // is correct, this is not necessary when using ckeditor5 since allowed tags
    // are added automatically by CKEditor 5. The validator would conflict with
    // the automatic addition of those allowed tags.
    if ($form_state->getValue('editor') !== 'ckeditor5') {
      $form['#validate'][] = self::class . ':formatEditFormValidate';
    }
  }

  /**
   * Implements hook_form_FORM_ID_alter().
   */
  #[Hook('form_filter_format_add_form_alter')]
  public function formFilterFormatAddFormAlter(array &$form, FormStateInterface $form_state, $form_id) : void {
    // Add an additional validate callback so we can ensure the order of filters
    // is correct, this is not necessary when using ckeditor5 since allowed tags
    // are added automatically by CKEditor 5. The validator would conflict with
    // the automatic addition of those allowed tags.
    if ($form_state->getValue('editor') !== 'ckeditor5') {
      $form['#validate'][] = self::class . ':formatEditFormValidate';
    }
  }

  /**
   * Implements hook_field_widget_single_element_form_alter().
   */
  #[Hook('field_widget_single_element_form_alter')]
  public function fieldWidgetSingleElementFormAlter(&$element, FormStateInterface $form_state, $context): void {
    // Add an attribute so that text editors plugins can pass the host entity's
    // language, allowing it to present entities in the same language.
    if (!empty($element['#type']) && $element['#type'] == 'text_format') {
      $element['#attributes']['data-media-embed-host-entity-langcode'] = $context['items']->getLangcode();
    }
  }

  /**
   * Implements hook_views_query_substitutions().
   */
  #[Hook('views_query_substitutions')]
  public function viewsQuerySubstitutions(ViewExecutable $view): array {
    $account = \Drupal::currentUser();
    return [
      '***VIEW_OWN_UNPUBLISHED_MEDIA***' => (int) $account->hasPermission('view own unpublished media'),
      '***ADMINISTER_MEDIA***' => (int) $account->hasPermission('administer media'),
    ];
  }

  /**
   * Implements hook_field_type_category_info_alter().
   */
  #[Hook('field_type_category_info_alter')]
  public function fieldTypeCategoryInfoAlter(&$definitions): void {
    // The `media` field type belongs in the `general` category, so the
    // libraries need to be attached using an alter hook.
    $definitions[FieldTypeCategoryManagerInterface::FALLBACK_CATEGORY]['libraries'][] = 'media/drupal.media-icon';

    // Provide some help text to aid users decide whether they need a Media,
    // File, or Image reference field.
    if (!empty($definitions['file_upload'])) {
      $existing_summary = $definitions['file_upload']['summary'] ?? '';
      $definitions['file_upload']['summary'] = empty($existing_summary)
        ? $this->fileMediaHelpText()
        : $existing_summary . ' ' . $this->fileMediaHelpText();
    }
  }

  /**
   * Returns the appropriate URL to add media for the current user.
   *
   * @todo Remove in https://www.drupal.org/project/drupal/issues/2938116
   *
   * @param string[] $allowed_bundles
   *   An array of bundles that should be checked for create access.
   *
   * @return string|false
   *   The URL to add media, or FALSE if the user cannot create any media.
   *
   * @internal
   *   This function is internal and may be removed in a minor release.
   */
  protected function addUrl(array $allowed_bundles): string|false {
    $access_handler = \Drupal::entityTypeManager()->getAccessControlHandler('media');
    $create_bundles = array_filter($allowed_bundles, [$access_handler, 'createAccess']);

    // Add a section about how to create media if the user has access to do so.
    if (count($create_bundles) === 1) {
      return Url::fromRoute('entity.media.add_form', ['media_type' => reset($create_bundles)])->toString();
    }
    elseif (count($create_bundles) > 1) {
      return Url::fromRoute('entity.media.add_page')->toString();
    }

    return FALSE;
  }

  /**
   * Validate callback to ensure filter order and allowed_html are compatible.
   */
  public function formatEditFormValidate(array $form, FormStateInterface $form_state): void {
    if ($form_state->getTriggeringElement()['#name'] !== 'op') {
      return;
    }

    $allowed_html_path = [
      'filters',
      'filter_html',
      'settings',
      'allowed_html',
    ];

    $filter_html_settings_path = [
      'filters',
      'filter_html',
      'settings',
    ];

    $filter_html_enabled = $form_state->getValue([
      'filters',
      'filter_html',
      'status',
    ]);

    $media_embed_enabled = $form_state->getValue([
      'filters',
      'media_embed',
      'status',
    ]);

    if (!$media_embed_enabled) {
      return;
    }

    $get_filter_label = function ($filter_plugin_id) use ($form) {
      return (string) $form['filters']['order'][$filter_plugin_id]['filter']['#markup'];
    };

    if ($filter_html_enabled && $form_state->getValue($allowed_html_path)) {
      /** @var \Drupal\filter\Entity\FilterFormat $filter_format */
      $filter_format = $form_state->getFormObject()->getEntity();

      $filter_html = clone $filter_format->filters()->get('filter_html');
      $filter_html->setConfiguration(['settings' => $form_state->getValue($filter_html_settings_path)]);
      $restrictions = $filter_html->getHTMLRestrictions();
      $allowed = $restrictions['allowed'];

      // Require `<drupal-media>` HTML tag if filter_html is enabled.
      if (!isset($allowed['drupal-media'])) {
        $form_state->setError($form['filters']['settings']['filter_html']['allowed_html'], $this->t('The %media-embed-filter-label filter requires <code>&lt;drupal-media&gt;</code> among the allowed HTML tags.', [
          '%media-embed-filter-label' => $get_filter_label('media_embed'),
        ]));
      }
      else {
        $required_attributes = [
          'data-entity-type',
          'data-entity-uuid',
        ];

        // If there are no attributes, the allowed item is set to FALSE,
        // otherwise, it is set to an array.
        if ($allowed['drupal-media'] === FALSE) {
          $missing_attributes = $required_attributes;
        }
        else {
          $missing_attributes = array_diff($required_attributes, array_keys($allowed['drupal-media']));
        }

        if ($missing_attributes) {
          $form_state->setError($form['filters']['settings']['filter_html']['allowed_html'], $this->t('The <code>&lt;drupal-media&gt;</code> tag in the allowed HTML tags is missing the following attributes: <code>%list</code>.', [
            '%list' => implode(', ', $missing_attributes),
          ]));
        }
      }
    }

    $filters = $form_state->getValue('filters');

    // The "media_embed" filter must run after "filter_align", "filter_caption",
    // and "filter_html_image_secure".
    $precedents = [
      'filter_align',
      'filter_caption',
      'filter_html_image_secure',
    ];

    $error_filters = [];
    foreach ($precedents as $filter_name) {
      // A filter that should run before media embed filter.
      $precedent = $filters[$filter_name];

      if (empty($precedent['status']) || !isset($precedent['weight'])) {
        continue;
      }

      if ($precedent['weight'] >= $filters['media_embed']['weight']) {
        $error_filters[$filter_name] = $get_filter_label($filter_name);
      }
    }

    if (!empty($error_filters)) {
      $error_message = \Drupal::translation()->formatPlural(
        count($error_filters),
        'The %media-embed-filter-label filter needs to be placed after the %filter filter.',
        'The %media-embed-filter-label filter needs to be placed after the following filters: %filters.',
        [
          '%media-embed-filter-label' => $get_filter_label('media_embed'),
          '%filter' => reset($error_filters),
          '%filters' => implode(', ', $error_filters),
        ]
      );

      $form_state->setErrorByName('filters', $error_message);
    }
  }

}
