<?php

namespace Drupal\views\Controller;

use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Ajax\ReplaceCommand;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\EventSubscriber\AjaxResponseSubscriber;
use Drupal\Core\EventSubscriber\MainContentViewSubscriber;
use Drupal\Core\Form\FormBuilderInterface;
use Drupal\Core\Path\CurrentPathStack;
use Drupal\Core\Render\BubbleableMetadata;
use Drupal\Core\Render\RenderContext;
use Drupal\Core\Render\RendererInterface;
use Drupal\Core\Routing\RedirectDestinationInterface;
use Drupal\views\Ajax\ScrollTopCommand;
use Drupal\views\Ajax\ViewAjaxResponse;
use Drupal\views\ViewExecutableFactory;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;

/**
 * Defines a controller to load a view via AJAX.
 */
class ViewAjaxController implements ContainerInjectionInterface {

  /**
   * The entity storage for views.
   *
   * @var \Drupal\Core\Entity\EntityStorageInterface
   */
  protected $storage;

  /**
   * The factory to load a view executable with.
   *
   * @var \Drupal\views\ViewExecutableFactory
   */
  protected $executableFactory;

  /**
   * The renderer.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;

  /**
   * The current path.
   *
   * @var \Drupal\Core\Path\CurrentPathStack
   */
  protected $currentPath;

  /**
   * The redirect destination.
   *
   * @var \Drupal\Core\Routing\RedirectDestinationInterface
   */
  protected $redirectDestination;

  /**
   * Constructs a ViewAjaxController object.
   *
   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
   *   The entity storage for views.
   * @param \Drupal\views\ViewExecutableFactory $executable_factory
   *   The factory to load a view executable with.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer.
   * @param \Drupal\Core\Path\CurrentPathStack $current_path
   *   The current path.
   * @param \Drupal\Core\Routing\RedirectDestinationInterface $redirect_destination
   *   The redirect destination.
   */
  public function __construct(EntityStorageInterface $storage, ViewExecutableFactory $executable_factory, RendererInterface $renderer, CurrentPathStack $current_path, RedirectDestinationInterface $redirect_destination) {
    $this->storage = $storage;
    $this->executableFactory = $executable_factory;
    $this->renderer = $renderer;
    $this->currentPath = $current_path;
    $this->redirectDestination = $redirect_destination;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('entity.manager')->getStorage('view'),
      $container->get('views.executable'),
      $container->get('renderer'),
      $container->get('path.current'),
      $container->get('redirect.destination')
    );
  }

  /**
   * Loads and renders a view via AJAX.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The current request object.
   *
   * @return \Drupal\views\Ajax\ViewAjaxResponse
   *  The view response as ajax response.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
   *   Thrown when the view was not found.
   */
  public function ajaxView(Request $request) {
    $name = $request->request->get('view_name');
    $display_id = $request->request->get('view_display_id');
    if (isset($name) && isset($display_id)) {
      $args = $request->request->get('view_args');
      $args = isset($args) && $args !== '' ? explode('/', $args) : array();

      // Arguments can be empty, make sure they are passed on as NULL so that
      // argument validation is not triggered.
      $args = array_map(function ($arg) {
        return ($arg == '' ? NULL : $arg);
      }, $args);

      $path = $request->request->get('view_path');
      $dom_id = $request->request->get('view_dom_id');
      $dom_id = isset($dom_id) ? preg_replace('/[^a-zA-Z0-9_-]+/', '-', $dom_id) : NULL;
      $pager_element = $request->request->get('pager_element');
      $pager_element = isset($pager_element) ? intval($pager_element) : NULL;

      $response = new ViewAjaxResponse();

      // Remove all of this stuff from the query of the request so it doesn't
      // end up in pagers and tablesort URLs.
      foreach (array('view_name', 'view_display_id', 'view_args', 'view_path', 'view_dom_id', 'pager_element', 'view_base_path', AjaxResponseSubscriber::AJAX_REQUEST_PARAMETER) as $key) {
        $request->query->remove($key);
        $request->request->remove($key);
      }

      // Load the view.
      if (!$entity = $this->storage->load($name)) {
        throw new NotFoundHttpException();
      }
      $view = $this->executableFactory->get($entity);
      if ($view && $view->access($display_id)) {
        $response->setView($view);
        // Fix the current path for paging.
        if (!empty($path)) {
          $this->currentPath->setPath('/' . $path, $request);
        }

        // Add all POST data, because AJAX is always a post and many things,
        // such as tablesorts, exposed filters and paging assume GET.
        $request_all = $request->request->all();
        $query_all = $request->query->all();
        $request->query->replace($request_all + $query_all);

        // Overwrite the destination.
        // @see the redirect.destination service.
        $origin_destination = $path;

        // Remove some special parameters you never want to have part of the
        // destination query.
        $used_query_parameters = $request->query->all();
        // @todo Remove this parsing once these are removed from the request in
        //   https://www.drupal.org/node/2504709.
        unset($used_query_parameters[FormBuilderInterface::AJAX_FORM_REQUEST], $used_query_parameters[MainContentViewSubscriber::WRAPPER_FORMAT], $used_query_parameters['ajax_page_state']);

        $query = UrlHelper::buildQuery($used_query_parameters);
        if ($query != '') {
          $origin_destination .= '?' . $query;
        }
        $this->redirectDestination->set($origin_destination);

        // Override the display's pager_element with the one actually used.
        if (isset($pager_element)) {
          $response->addCommand(new ScrollTopCommand(".js-view-dom-id-$dom_id"));
          $view->displayHandlers->get($display_id)->setOption('pager_element', $pager_element);
        }
        // Reuse the same DOM id so it matches that in drupalSettings.
        $view->dom_id = $dom_id;

        $context = new RenderContext();
        $preview = $this->renderer->executeInRenderContext($context, function() use ($view, $display_id, $args) {
          return $view->preview($display_id, $args);
        });
        if (!$context->isEmpty()) {
          $bubbleable_metadata = $context->pop();
          BubbleableMetadata::createFromRenderArray($preview)
            ->merge($bubbleable_metadata)
            ->applyTo($preview);
        }
        $response->addCommand(new ReplaceCommand(".js-view-dom-id-$dom_id", $preview));

        return $response;
      }
      else {
        throw new AccessDeniedHttpException();
      }
    }
    else {
      throw new NotFoundHttpException();
    }
  }

}
