class DblogHooks

class DblogHooks {
  use StringTranslationTrait;
  
  /**
   * Implements hook_help().
   */
  public function help($route_name, RouteMatchInterface $route_match) : ?string {
    switch ($route_name) {
      case 'help.page.dblog':
        $output = '';
        $output .= '<h2>' . $this->t('About') . '</h2>';
        $output .= '<p>' . $this->t('The Database Logging module logs system events in the Drupal database. For more information, see the <a href=":dblog">online documentation for the Database Logging module</a>.', [
          ':dblog' => 'https://www.drupal.org/documentation/modules/dblog',
        ]) . '</p>';
        $output .= '<h2>' . $this->t('Uses') . '</h2>';
        $output .= '<dl>';
        $output .= '<dt>' . $this->t('Monitoring your site') . '</dt>';
        $output .= '<dd>' . $this->t('The Database Logging module allows you to view an event log on the <a href=":dblog">Recent log messages</a> page. The log is a chronological list of recorded events containing usage data, performance data, errors, warnings and operational information. Administrators should check the log on a regular basis to ensure their site is working properly.', [
          ':dblog' => Url::fromRoute('dblog.overview')->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('Debugging site problems') . '</dt>';
        $output .= '<dd>' . $this->t('In case of errors or problems with the site, the <a href=":dblog">Recent log messages</a> page can be useful for debugging, since it shows the sequence of events. The log messages include usage information, warnings, and errors.', [
          ':dblog' => Url::fromRoute('dblog.overview')->toString(),
        ]) . '</dd>';
        $output .= '<dt>' . $this->t('This log is not persistent') . '</dt>';
        $output .= '<dd>' . $this->t('The Database Logging module logs may be cleared by administrators and automated cron tasks, so they should not be used for <a href=":audit_trail_wiki">forensic logging</a>. For forensic purposes, use the Syslog module.', [
          ':audit_trail_wiki' => 'https://en.wikipedia.org/wiki/Audit_trail',
        ]) . '</dd>';
        $output .= '</dl>';
        return $output;
      case 'dblog.overview':
        return '<p>' . $this->t('The Database Logging module logs system events in the Drupal database. Monitor your site or debug site problems on this page.') . '</p>';
    }
    return NULL;
  }
  
  /**
   * Implements hook_menu_links_discovered_alter().
   */
  public function menuLinksDiscoveredAlter(&$links) : void {
    if (\Drupal::moduleHandler()->moduleExists('search')) {
      $links['dblog.search'] = [
        'title' => new TranslatableMarkup('Top search phrases'),
        'route_name' => 'dblog.search',
        'description' => new TranslatableMarkup('View most popular search phrases.'),
        'parent' => 'system.admin_reports',
      ];
    }
  }
  
  /**
   * Implements hook_cron().
   *
   * Controls the size of the log table, paring it to 'dblog_row_limit'
   * messages.
   */
  public function cron() : void {
    // Cleanup the watchdog table.
    $row_limit = \Drupal::config('dblog.settings')->get('row_limit');
    // For row limit n, get the wid of the nth row in descending wid order.
    // Counting the most recent n rows avoids issues with wid number sequences,
    // e.g. auto_increment value > 1 or rows deleted directly from the table.
    if ($row_limit > 0) {
      $connection = \Drupal::database();
      $min_row = $connection->select('watchdog', 'w')
        ->fields('w', [
        'wid',
      ])
        ->orderBy('wid', 'DESC')
        ->range($row_limit - 1, 1)
        ->execute()
        ->fetchField();
      // Delete all table entries older than the nth row, if nth row was found.
      if ($min_row) {
        $connection->delete('watchdog')
          ->condition('wid', $min_row, '<')
          ->execute();
      }
    }
  }
  
  /**
   * Implements hook_form_FORM_ID_alter() for system_logging_settings().
   */
  public function formSystemLoggingSettingsAlter(&$form, FormStateInterface $form_state) : void {
    $row_limits = [
      100,
      1000,
      10000,
      100000,
      1000000,
    ];
    $form['dblog_row_limit'] = [
      '#type' => 'select',
      '#title' => $this->t('Database log messages to keep'),
      '#config_target' => 'dblog.settings:row_limit',
      '#options' => [
        0 => $this->t('All'),
      ] + array_combine($row_limits, $row_limits),
      '#description' => $this->t('The maximum number of messages to keep in the database log. Requires a <a href=":cron">cron maintenance task</a>.', [
        ':cron' => Url::fromRoute('system.status')->toString(),
      ]),
    ];
  }
  
  /**
   * Implements hook_views_pre_render().
   */
  public function viewsPreRender(ViewExecutable $view) : void {
    if (isset($view) && $view->storage
      ->get('base_table') == 'watchdog') {
      $view->element['#attached']['library'][] = 'dblog/drupal.dblog';
    }
  }

}