<?php

namespace Drupal\media_library\Plugin\views\field;

use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\CloseDialogCommand;
use Drupal\Core\Ajax\InvokeCommand;
use Drupal\Core\Form\FormBuilderInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
use Drupal\views\Plugin\views\field\FieldPluginBase;
use Drupal\views\Render\ViewsRenderPipelineMarkup;
use Drupal\views\ResultRow;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;

/**
 * Defines a field that outputs a checkbox and form for selecting media.
 *
 * @ViewsField("media_library_select_form")
 *
 * @internal
 */
class MediaLibrarySelectForm extends FieldPluginBase {

  /**
   * {@inheritdoc}
   */
  public function getValue(ResultRow $row, $field = NULL) {
    return '<!--form-item-' . $this->options['id'] . '--' . $row->index . '-->';
  }

  /**
   * {@inheritdoc}
   */
  public function render(ResultRow $values) {
    return ViewsRenderPipelineMarkup::create($this->getValue($values));
  }

  /**
   * Form constructor for the media library select form.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function viewsForm(array &$form, FormStateInterface $form_state) {
    // Only add the bulk form options and buttons if there are results.
    if (empty($this->view->result)) {
      return;
    }

    // Render checkboxes for all rows.
    $form[$this->options['id']]['#tree'] = TRUE;
    foreach ($this->view->result as $row_index => $row) {
      $entity = $this->getEntity($row);
      $form[$this->options['id']][$row_index] = [
        '#type' => 'checkbox',
        '#title' => $this->t('Select @label', [
          '@label' => $entity->label(),
        ]),
        '#title_display' => 'invisible',
        '#return_value' => $entity->id(),
      ];
    }

    // @todo Remove in https://www.drupal.org/project/drupal/issues/2504115
    // Currently the default URL for all AJAX form elements is the current URL,
    // not the form action. This causes bugs when this form is rendered from an
    // AJAX path like /views/ajax, which cannot process AJAX form submits.
    $url = parse_url($form['#action'], PHP_URL_PATH);
    $query = \Drupal::request()->query->all();
    $query[FormBuilderInterface::AJAX_FORM_REQUEST] = TRUE;
    $form['actions']['submit']['#ajax'] = [
      'url' => Url::fromUserInput($url),
      'options' => [
        'query' => $query,
      ],
      'callback' => [static::class, 'updateWidget'],
    ];

    $form['actions']['submit']['#value'] = $this->t('Select media');
    $form['actions']['submit']['#field_id'] = $this->options['id'];
  }

  /**
   * Submit handler for the media library select form.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   *
   * @return \Drupal\Core\Ajax\AjaxResponse
   *   A command to send the selection to the current field widget.
   */
  public static function updateWidget(array &$form, FormStateInterface $form_state) {
    $widget_id = \Drupal::request()->query->get('media_library_widget_id');
    if (!$widget_id || !is_string($widget_id)) {
      throw new BadRequestHttpException('The "media_library_widget_id" query parameter is required and must be a string.');
    }
    $field_id = $form_state->getTriggeringElement()['#field_id'];
    $selected = array_values(array_filter($form_state->getValue($field_id, [])));
    // Pass the selection to the field widget based on the current widget ID.
    return (new AjaxResponse())
      ->addCommand(new InvokeCommand("[data-media-library-widget-value=\"$widget_id\"]", 'val', [implode(',', $selected)]))
      ->addCommand(new InvokeCommand("[data-media-library-widget-update=\"$widget_id\"]", 'trigger', ['mousedown']))
      ->addCommand(new CloseDialogCommand());
  }

  /**
   * {@inheritdoc}
   */
  public function viewsFormValidate(array &$form, FormStateInterface $form_state) {
    $selected = array_filter($form_state->getValue($this->options['id']));
    if (empty($selected)) {
      $form_state->setErrorByName('', $this->t('No items selected.'));
    }
  }

  /**
   * {@inheritdoc}
   */
  public function clickSortable() {
    return FALSE;
  }

}