text: <?php
  // This file is part of Moodle - http://moodle.org/
  //
  // Moodle is free software: you can redistribute it and/or modify
  // it under the terms of the GNU General Public License as published by
  // the Free Software Foundation, either version 3 of the License, or
  // (at your option) any later version.
  //
  // Moodle is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  // GNU General Public License for more details.
  //
  // You should have received a copy of the GNU General Public License
  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  
  /**
   * The forum module trait with additional generator helpers.
   *
   * @package    mod_forum
   * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
   */
  
  defined('MOODLE_INTERNAL') || die();
  
  trait mod_forum_tests_generator_trait {
  
      /**
       * Helper to create the required number of users in the specified course.
       * Users are enrolled as students by default.
       *
       * @param   stdClass $course The course object
       * @param   integer $count The number of users to create
       * @param   string  $role The role to assign users as
       * @return  array The users created
       */
      protected function helper_create_users($course, $count, $role = null) {
          $users = array();
  
          for ($i = 0; $i < $count; $i++) {
              $user = $this->getDataGenerator()->create_user();
              $this->getDataGenerator()->enrol_user($user->id, $course->id, $role);
              $users[] = $user;
          }
  
          return $users;
      }
  
      /**
       * Create a new discussion and post within the specified forum, as the
       * specified author.
       *
       * @param stdClass $forum The forum to post in
       * @param stdClass $author The author to post as
       * @param array $fields any other fields in discussion (name, message, messageformat, ...)
       * @return array An array containing the discussion object, and the post object
       */
      protected function helper_post_to_forum($forum, $author, $fields = array()) {
          global $DB;
          $generator = $this->getDataGenerator()->get_plugin_generator('mod_forum');
  
          // Create a discussion in the forum, and then add a post to that discussion.
          $record = (object)$fields;
          $record->course = $forum->course;
          $record->userid = $author->id;
          $record->forum = $forum->id;
          $discussion = $generator->create_discussion($record);
  
          // Retrieve the post which was created by create_discussion.
          $post = $DB->get_record('forum_posts', array('discussion' => $discussion->id));
  
          return [$discussion, $post];
      }
  
      /**
       * Update the post time for the specified post by $factor.
       *
       * @param stdClass $post The post to update
       * @param int $factor The amount to update by
       */
      protected function helper_update_post_time($post, $factor) {
          global $DB;
  
          // Update the post to have a created in the past.
          $DB->set_field('forum_posts', 'created', $post->created + $factor, array('id' => $post->id));
      }
  
      /**
       * Update the subscription time for the specified user/discussion by $factor.
       *
       * @param stdClass $user The user to update
       * @param stdClass $discussion The discussion to update for this user
       * @param int $factor The amount to update by
       */
      protected function helper_update_subscription_time($user, $discussion, $factor) {
          global $DB;
  
          $sub = $DB->get_record('forum_discussion_subs', array('userid' => $user->id, 'discussion' => $discussion->id));
  
          // Update the subscription to have a preference in the past.
          $DB->set_field('forum_discussion_subs', 'preference', $sub->preference + $factor, array('id' => $sub->id));
      }
  
      /**
       * Create a new post within an existing discussion, as the specified author.
       *
       * @param stdClass $forum The forum to post in
       * @param stdClass $discussion The discussion to post in
       * @param stdClass $author The author to post as
       * @param array $options Additional options to pass to `create_post`
       * @return stdClass The forum post
       */
      protected function helper_post_to_discussion($forum, $discussion, $author, array $options = []) {
          global $DB;
  
          $generator = $this->getDataGenerator()->get_plugin_generator('mod_forum');
  
          // Add a post to the discussion.
          $strre = get_string('re', 'forum');
          $record = array_merge([
              'course' => $forum->course,
              'subject' => "{$strre} {$discussion->subject}",
              'userid' => $author->id,
              'forum' => $forum->id,
              'discussion' => $discussion->id,
              'mailnow' => 1,
          ], $options);
  
          $post = $generator->create_post((object) $record);
  
          return $post;
      }
  
      /**
       * Create a new post within an existing discussion, as the specified author.
       *
       * @param stdClass $parent The post being replied to
       * @param stdClass $author The author to post as
       * @param array $options Additional options to pass to `create_post`
       * @return stdClass The forum post
       */
      protected function helper_reply_to_post($parent, $author, array $options = []) {
          global $DB;
  
          $generator = $this->getDataGenerator()->get_plugin_generator('mod_forum');
  
          // Add a post to the discussion.
          $strre = get_string('re', 'forum');
          $record = (object) array_merge([
              'discussion' => $parent->discussion,
              'parent' => $parent->id,
              'userid' => $author->id,
              'mailnow' => 1,
              'subject' => $strre . ' ' . $parent->subject,
          ], $options);
  
          $post = $generator->create_post($record);
  
          return $post;
      }
  
      /**
       * Gets the role id from it's shortname.
       *
       * @param   string $roleshortname
       * @return  int
       */
      protected function get_role_id($roleshortname) {
          global $DB;
  
          return $DB->get_field('role', 'id', ['shortname' => $roleshortname]);
      }
  }
  