<?php

/**
 * Contains hook implementations for the metatag_views module.
 */

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\views\ViewEntityInterface;
use Drupal\views\ViewExecutable;
use Drupal\views\Views;

/**
 * Gets the metatags of a specific view, if set.
 *
 * @param mixed $view
 *   The view id, view config entity or view executable.
 * @param string $display
 *   The display id. If empty uses the preselected display if $view is a
 *   ViewExecutable, otherwise the default display.
 *
 * @return array|null
 *   The metatags if set, null otherwise.
 */
function metatag_get_view_tags($view, $display_id = NULL) {
  if (empty($view)) {
    return;
  }
  if ($view instanceof ViewEntityInterface) {
    $view = $view->getExecutable();
  }
  elseif (is_string($view)) {
    $view = Views::getView($view);
  }
  if (!$view instanceof ViewExecutable) {
    return;
  }
  $view->setDisplay($display_id);

  // And get the list of extenders for this display.
  $extenders = $view->getDisplay()->getExtenders();
  if (!isset($extenders['metatag_display_extender'])) {
    // If the id of the plugin is not in the list then something is wrong.
    return;
  }

  // Retrieve the metatag settings from the extender.
  return $extenders['metatag_display_extender']->getMetatags();
}

/**
 * Implements hook_metatags_alter().
 */
function metatag_views_metatags_alter(&$metatags, $context) {
  if (!$context['entity'] instanceof ViewEntityInterface) {
    return;
  }

  $view = $context['entity']->getExecutable();
  // If display_id is not available, will default to Master display.
  $display_id = \Drupal::routeMatch()->getParameter('display_id');
  if ($tags = metatag_get_view_tags($view, $display_id)) {
    // Apply view overrides.
    $metatags = array_merge($metatags, $tags);
  }
}

/**
 * Implements hook_metatag_route_entity().
 */
function metatag_views_metatag_route_entity(RouteMatchInterface $route_match) {
  if ($view_id = $route_match->getParameter('view_id')) {
    $entity = \Drupal::entityTypeManager()->getStorage('view')->load($view_id);
    return $entity;
  }
}