class DblogHooks

class DblogHooks {
    
    /**
     * Implements hook_help().
     */
    public function help($route_name, RouteMatchInterface $route_match) {
        switch ($route_name) {
            case 'help.page.dblog':
                $output = '';
                $output .= '<h2>' . t('About') . '</h2>';
                $output .= '<p>' . 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>' . t('Uses') . '</h2>';
                $output .= '<dl>';
                $output .= '<dt>' . t('Monitoring your site') . '</dt>';
                $output .= '<dd>' . 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>' . t('Debugging site problems') . '</dt>';
                $output .= '<dd>' . 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>' . t('This log is not persistent') . '</dt>';
                $output .= '<dd>' . 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>' . t('The Database Logging module logs system events in the Drupal database. Monitor your site or debug site problems on this page.') . '</p>';
        }
    }
    
    /**
     * 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,
        ];
        $form['dblog_row_limit'] = [
            '#type' => 'select',
            '#title' => t('Database log messages to keep'),
            '#config_target' => 'dblog.settings:row_limit',
            '#options' => [
                0 => t('All'),
            ] + array_combine($row_limits, $row_limits),
            '#description' => 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 $view) {
        if (isset($view) && $view->storage
            ->get('base_table') == 'watchdog') {
            $view->element['#attached']['library'][] = 'dblog/drupal.dblog';
        }
    }

}