<?php

/**
 * @file
 * Find node paths on menu item creation via autocomplete.
 *
 * This is a shameless clone of
 * http://drupal.org/project/mpac
 * by stBorchert
 */

/**
 * Implements hook_menu().
 *
 * @return array
 *   An array of menu items.
 */
function me_path_autocomplete_menu() {
  $items = array();

  $items['mepac/autocomplete'] = array(
    'title' => 'Menu path autocomplete',
    'description' => 'Autocomplete callback for menu path autocomplete',
    /* @see me_path_autocomplete() */
    'page callback' => 'me_path_autocomplete',
    'access callback' => 'user_access',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK,
  );

  return $items;
}

/**
 * Page callback for 'mepac/autocomplete'.
 *
 * Finds nodes and URL aliases based on title.
 * Sets a http header, and prints json output.
 *
 * @param string $string
 *   Title of element to find.
 *
 * @see mpac_autocomplete()
 */
function me_path_autocomplete($string = NULL) {
  $args = func_get_args();
  /** @noinspection SuspiciousAssignmentsInspection */
  $string = implode('/', $args);

  $matches = _me_path_autocomplete_get_matches($string);

  drupal_json_output($matches);
}

/**
 * @param string $string
 *
 * @return string[]
 */
function _me_path_autocomplete_get_matches($string) {
  $string = strtolower($string);

  // @todo Do we need to filter this?
  // See https://www.drupal.org/node/2785261 in mpac issue queue.
  # $title = filter_xss_admin($string);

  $matches = _me_path_autocomplete_get_matches_for_placeholders($string);

  if ($string === '') {
    return $matches;
  }

  $like_placeholder = (strlen($string) > 3) ? "%" . db_like($string) . "%" : db_like($string) . "%";

  $matches += _me_path_autocomplete_get_matches_for_nodes($like_placeholder);
  $matches += _me_path_autocomplete_get_matches_for_aliases($like_placeholder);

  return $matches;
}

/**
 * @param string $string
 *
 * @return string[]
 *
 * @see _mpac_get_matches_for_nodes()
 */
function _me_path_autocomplete_get_matches_for_placeholders($string) {

  $matches = array();
  /* @see hook_menu_editor_placeholders() */
  foreach (module_invoke_all('menu_editor_placeholders') as $placeholder_code => $placeholder_path) {
    if ($string === '' || false !== strpos($placeholder_code, $string)) {
      $matches[$placeholder_code] = htmlentities($placeholder_code);
    }
  }

  return $matches;
}

/**
 * @param string $like_placeholder
 *
 * @return string[]
 *
 * @see _mpac_get_matches_for_nodes()
 */
function _me_path_autocomplete_get_matches_for_nodes($like_placeholder) {

  $q = db_select('node', 'n');
  $q->fields('n');
  $q->condition('title', $like_placeholder, 'LIKE');
  $q->range(0, 8);

  $matches = array();
  foreach ($q->execute() as $node) {
    // Add node path and title to list.
    if (node_access('view', $node) && $node->status) {
      $node_title = check_plain($node->title);
      $nid = $node->nid;
      $lang = $node->language !== LANGUAGE_NONE ? ($node->language . ': ') : '';
      $matches['node/'. $node->nid] = $lang . "$node_title [nid:$nid]";
    }
  }

  return $matches;
}

/**
 * @param string $like_placeholder
 *
 * @return string[]
 *
 * @see _mpac_get_matches_for_aliases()
 */
function _me_path_autocomplete_get_matches_for_aliases($like_placeholder) {

  if (!module_exists('path')) {
    return array();
  }

  // Get a list of all URL aliases where the destination matches the given
  // string.
  $q = db_select('url_alias');
  $q->fields('url_alias');
  $q->condition('alias', $like_placeholder, 'LIKE');
  $q->range(0, 8);

  $matches = array();
  foreach ($q->execute() as $alias) {
    // Add alias source and destination to list (and add a special marker to
    // the item).
    $lang = $alias->language !== LANGUAGE_NONE ? ($alias->language . ': ') : '';
    $src = check_plain($alias->source);
    $dst = check_plain($alias->alias);
    $matches[$alias->source] = $lang . "$dst | $src";
  }

  return $matches;
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Change path field to autocomplete field.
 *
 * @param array $form
 * @param array $form_state
 */
function me_path_autocomplete_form_menu_editor_overview_form_alter(array &$form, array &$form_state) {
  foreach (element_children($form) as $element_key) {
    $form[$element_key]['link_path']['#autocomplete_path'] = 'mepac/autocomplete';
  }
}