class DbLogController

class DbLogController extends ControllerBase {
    
    /**
     * The database service.
     *
     * @var \Drupal\Core\Database\Connection
     */
    protected $database;
    
    /**
     * The module handler service.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * The date formatter service.
     *
     * @var \Drupal\Core\Datetime\DateFormatterInterface
     */
    protected $dateFormatter;
    
    /**
     * The form builder service.
     *
     * @var \Drupal\Core\Form\FormBuilderInterface
     */
    protected $formBuilder;
    
    /**
     * The user storage.
     *
     * @var \Drupal\user\UserStorageInterface
     */
    protected $userStorage;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('database'), $container->get('module_handler'), $container->get('date.formatter'), $container->get('form_builder'));
    }
    
    /**
     * Constructs a DbLogController object.
     *
     * @param \Drupal\Core\Database\Connection $database
     *   A database connection.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   A module handler.
     * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
     *   The date formatter service.
     * @param \Drupal\Core\Form\FormBuilderInterface $form_builder
     *   The form builder service.
     */
    public function __construct(Connection $database, ModuleHandlerInterface $module_handler, DateFormatterInterface $date_formatter, FormBuilderInterface $form_builder) {
        $this->database = $database;
        $this->moduleHandler = $module_handler;
        $this->dateFormatter = $date_formatter;
        $this->formBuilder = $form_builder;
        $this->userStorage = $this->entityTypeManager()
            ->getStorage('user');
    }
    
    /**
     * Gets an array of log level classes.
     *
     * @return array
     *   An array of log level classes.
     */
    public static function getLogLevelClassMap() {
        return [
            RfcLogLevel::DEBUG => 'dblog-debug',
            RfcLogLevel::INFO => 'dblog-info',
            RfcLogLevel::NOTICE => 'dblog-notice',
            RfcLogLevel::WARNING => 'dblog-warning',
            RfcLogLevel::ERROR => 'dblog-error',
            RfcLogLevel::CRITICAL => 'dblog-critical',
            RfcLogLevel::ALERT => 'dblog-alert',
            RfcLogLevel::EMERGENCY => 'dblog-emergency',
        ];
    }
    
    /**
     * Displays a listing of database log messages.
     *
     * Messages are truncated at 56 chars.
     * Full-length messages can be viewed on the message details page.
     *
     * @return array
     *   A render array as expected by
     *   \Drupal\Core\Render\RendererInterface::render().
     *
     * @see Drupal\dblog\Form\DblogClearLogConfirmForm
     * @see Drupal\dblog\Controller\DbLogController::eventDetails()
     */
    public function overview() {
        $filter = $this->buildFilterQuery();
        $rows = [];
        $classes = static::getLogLevelClassMap();
        $this->moduleHandler
            ->loadInclude('dblog', 'admin.inc');
        $build['dblog_filter_form'] = $this->formBuilder
            ->getForm('Drupal\\dblog\\Form\\DblogFilterForm');
        $header = [
            // Icon column.
'',
            [
                'data' => $this->t('Type'),
                'field' => 'w.type',
                'class' => [
                    RESPONSIVE_PRIORITY_MEDIUM,
                ],
            ],
            [
                'data' => $this->t('Date'),
                'field' => 'w.wid',
                'sort' => 'desc',
                'class' => [
                    RESPONSIVE_PRIORITY_LOW,
                ],
            ],
            $this->t('Message'),
            [
                'data' => $this->t('User'),
                'field' => 'ufd.name',
                'class' => [
                    RESPONSIVE_PRIORITY_MEDIUM,
                ],
            ],
            [
                'data' => $this->t('Operations'),
                'class' => [
                    RESPONSIVE_PRIORITY_LOW,
                ],
            ],
        ];
        $query = $this->database
            ->select('watchdog', 'w')
            ->extend('\\Drupal\\Core\\Database\\Query\\PagerSelectExtender')
            ->extend('\\Drupal\\Core\\Database\\Query\\TableSortExtender');
        $query->fields('w', [
            'wid',
            'uid',
            'severity',
            'type',
            'timestamp',
            'message',
            'variables',
            'link',
        ]);
        $query->leftJoin('users_field_data', 'ufd', 'w.uid = ufd.uid');
        if (!empty($filter['where'])) {
            $query->where($filter['where'], $filter['args']);
        }
        $result = $query->limit(50)
            ->orderByHeader($header)
            ->execute();
        foreach ($result as $dblog) {
            $message = $this->formatMessage($dblog);
            if ($message && isset($dblog->wid)) {
                $title = Unicode::truncate(Html::decodeEntities(strip_tags($message)), 256, TRUE, TRUE);
                $log_text = Unicode::truncate($title, 56, TRUE, TRUE);
                // The link generator will escape any unsafe HTML entities in the final
                // text.
                $message = Link::fromTextAndUrl($log_text, new Url('dblog.event', [
                    'event_id' => $dblog->wid,
                ], [
                    'attributes' => [
                        // Provide a title for the link for useful hover hints. The
                        // Attribute object will escape any unsafe HTML entities in the
                        // final text.
'title' => $title,
                    ],
                ]))
                    ->toString();
            }
            $username = [
                '#theme' => 'username',
                '#account' => $this->userStorage
                    ->load($dblog->uid),
            ];
            $rows[] = [
                'data' => [
                    // Cells.
[
                        'class' => [
                            'icon',
                        ],
                    ],
                    $this->t($dblog->type),
                    $this->dateFormatter
                        ->format($dblog->timestamp, 'short'),
                    $message,
                    [
                        'data' => $username,
                    ],
                    [
                        'data' => [
                            '#markup' => $dblog->link,
                        ],
                    ],
                ],
                // Attributes for table row.
'class' => [
                    Html::getClass('dblog-' . $dblog->type),
                    $classes[$dblog->severity],
                ],
            ];
        }
        $build['dblog_table'] = [
            '#type' => 'table',
            '#header' => $header,
            '#rows' => $rows,
            '#attributes' => [
                'id' => 'admin-dblog',
                'class' => [
                    'admin-dblog',
                ],
            ],
            '#empty' => $this->t('No log messages available.'),
            '#attached' => [
                'library' => [
                    'dblog/drupal.dblog',
                ],
            ],
        ];
        $build['dblog_pager'] = [
            '#type' => 'pager',
        ];
        return $build;
    }
    
    /**
     * Displays details about a specific database log message.
     *
     * @param int $event_id
     *   Unique ID of the database log message.
     *
     * @return array
     *   If the ID is located in the Database Logging table, a build array in the
     *   format expected by \Drupal\Core\Render\RendererInterface::render().
     *
     * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
     *   If no event found for the given ID.
     */
    public function eventDetails($event_id) {
        $dblog = $this->database
            ->query('SELECT w.*, u.uid FROM {watchdog} w LEFT JOIN {users} u ON u.uid = w.uid WHERE w.wid = :id', [
            ':id' => $event_id,
        ])
            ->fetchObject();
        if (empty($dblog)) {
            throw new NotFoundHttpException();
        }
        $build = [];
        $severity = RfcLogLevel::getLevels();
        $message = $this->formatMessage($dblog);
        $username = [
            '#theme' => 'username',
            '#account' => $dblog->uid ? $this->userStorage
                ->load($dblog->uid) : User::getAnonymousUser(),
        ];
        $rows = [
            [
                [
                    'data' => $this->t('Type'),
                    'header' => TRUE,
                ],
                $this->t($dblog->type),
            ],
            [
                [
                    'data' => $this->t('Date'),
                    'header' => TRUE,
                ],
                $this->dateFormatter
                    ->format($dblog->timestamp, 'long'),
            ],
            [
                [
                    'data' => $this->t('User'),
                    'header' => TRUE,
                ],
                [
                    'data' => $username,
                ],
            ],
            [
                [
                    'data' => $this->t('Location'),
                    'header' => TRUE,
                ],
                $this->createLink($dblog->location),
            ],
            [
                [
                    'data' => $this->t('Referrer'),
                    'header' => TRUE,
                ],
                $this->createLink($dblog->referer),
            ],
            [
                [
                    'data' => $this->t('Message'),
                    'header' => TRUE,
                ],
                $message,
            ],
            [
                [
                    'data' => $this->t('Severity'),
                    'header' => TRUE,
                ],
                $severity[$dblog->severity],
            ],
            [
                [
                    'data' => $this->t('Hostname'),
                    'header' => TRUE,
                ],
                $dblog->hostname,
            ],
            [
                [
                    'data' => $this->t('Operations'),
                    'header' => TRUE,
                ],
                [
                    'data' => [
                        '#markup' => $dblog->link,
                    ],
                ],
            ],
        ];
        $build['dblog_table'] = [
            '#type' => 'table',
            '#rows' => $rows,
            '#attributes' => [
                'class' => [
                    'dblog-event',
                ],
            ],
            '#attached' => [
                'library' => [
                    'dblog/drupal.dblog',
                ],
            ],
        ];
        return $build;
    }
    
    /**
     * Builds a query for database log administration filters based on session.
     *
     * @return array|null
     *   An associative array with keys 'where' and 'args' or NULL if there were
     *   no filters set.
     */
    protected function buildFilterQuery() {
        if (empty($_SESSION['dblog_overview_filter'])) {
            return;
        }
        $this->moduleHandler
            ->loadInclude('dblog', 'admin.inc');
        $filters = dblog_filters();
        // Build query.
        $where = $args = [];
        foreach ($_SESSION['dblog_overview_filter'] as $key => $filter) {
            $filter_where = [];
            foreach ($filter as $value) {
                $filter_where[] = $filters[$key]['where'];
                $args[] = $value;
            }
            if (!empty($filter_where)) {
                $where[] = '(' . implode(' OR ', $filter_where) . ')';
            }
        }
        $where = !empty($where) ? implode(' AND ', $where) : '';
        return [
            'where' => $where,
            'args' => $args,
        ];
    }
    
    /**
     * Formats a database log message.
     *
     * @param object $row
     *   The record from the watchdog table. The object properties are: wid, uid,
     *   severity, type, timestamp, message, variables, link, name.
     *
     * @return string|\Drupal\Core\StringTranslation\TranslatableMarkup|false
     *   The formatted log message or FALSE if the message or variables properties
     *   are not set.
     */
    public function formatMessage($row) {
        // Check for required properties.
        if (isset($row->message, $row->variables)) {
            $variables = @unserialize($row->variables);
            // Messages without variables or user specified text.
            if ($variables === NULL) {
                $message = Xss::filterAdmin($row->message);
            }
            elseif (!is_array($variables)) {
                $message = $this->t('Log data is corrupted and cannot be unserialized: @message', [
                    '@message' => Xss::filterAdmin($row->message),
                ]);
            }
            else {
                // Ensure backtrace strings are properly formatted.
                if (isset($variables['@backtrace_string'])) {
                    $variables['@backtrace_string'] = new FormattableMarkup('<pre class="backtrace">@backtrace_string</pre>', $variables);
                }
                $message = $this->t(Xss::filterAdmin($row->message), $variables);
            }
        }
        else {
            $message = FALSE;
        }
        return $message;
    }
    
    /**
     * Creates a Link object if the provided URI is valid.
     *
     * @param string|null $uri
     *   The uri string to convert into link if valid.
     *
     * @return \Drupal\Core\Link|string|null
     *   Return a Link object if the uri can be converted as a link. In case of
     *   empty uri or invalid, fallback to the provided $uri.
     */
    protected function createLink($uri) {
        if (UrlHelper::isValid($uri, TRUE)) {
            return new Link($uri, Url::fromUri($uri));
        }
        return $uri;
    }
    
    /**
     * Shows the most frequent log messages of a given event type.
     *
     * Messages are not truncated on this page because events detailed herein do
     * not have links to a detailed view.
     *
     * @param string $type
     *   Type of database log events to display (e.g., 'search').
     *
     * @return array
     *   A build array in the format expected by
     *   \Drupal\Core\Render\RendererInterface::render().
     */
    public function topLogMessages($type) {
        $header = [
            [
                'data' => $this->t('Count'),
                'field' => 'count',
                'sort' => 'desc',
            ],
            [
                'data' => $this->t('Message'),
                'field' => 'message',
            ],
        ];
        $count_query = $this->database
            ->select('watchdog');
        $count_query->addExpression('COUNT(DISTINCT(message))');
        $count_query->condition('type', $type);
        $query = $this->database
            ->select('watchdog', 'w')
            ->extend('\\Drupal\\Core\\Database\\Query\\PagerSelectExtender')
            ->extend('\\Drupal\\Core\\Database\\Query\\TableSortExtender');
        $query->addExpression('COUNT(wid)', 'count');
        $query = $query->fields('w', [
            'message',
            'variables',
        ])
            ->condition('w.type', $type)
            ->groupBy('message')
            ->groupBy('variables')
            ->limit(30)
            ->orderByHeader($header);
        $query->setCountQuery($count_query);
        $result = $query->execute();
        $rows = [];
        foreach ($result as $dblog) {
            if ($message = $this->formatMessage($dblog)) {
                $rows[] = [
                    $dblog->count,
                    $message,
                ];
            }
        }
        $build['dblog_top_table'] = [
            '#type' => 'table',
            '#header' => $header,
            '#rows' => $rows,
            '#empty' => $this->t('No log messages available.'),
            '#attached' => [
                'library' => [
                    'dblog/drupal.dblog',
                ],
            ],
        ];
        $build['dblog_top_pager'] = [
            '#type' => 'pager',
        ];
        return $build;
    }

}