class NodeStatisticsDatabaseStorage

class NodeStatisticsDatabaseStorage implements StatisticsStorageInterface {
    
    /**
     * The database connection used.
     *
     * @var \Drupal\Core\Database\Connection
     */
    protected $connection;
    
    /**
     * The state service.
     *
     * @var \Drupal\Core\State\StateInterface
     */
    protected $state;
    
    /**
     * The request stack.
     *
     * @var \Symfony\Component\HttpFoundation\RequestStack
     */
    protected $requestStack;
    
    /**
     * Constructs the statistics storage.
     *
     * @param \Drupal\Core\Database\Connection $connection
     *   The database connection for the node view storage.
     * @param \Drupal\Core\State\StateInterface $state
     *   The state service.
     * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
     *   The request stack.
     */
    public function __construct(Connection $connection, StateInterface $state, RequestStack $request_stack) {
        $this->connection = $connection;
        $this->state = $state;
        $this->requestStack = $request_stack;
    }
    
    /**
     * {@inheritdoc}
     */
    public function recordView($id) {
        return (bool) $this->connection
            ->merge('node_counter')
            ->key('nid', $id)
            ->fields([
            'daycount' => 1,
            'totalcount' => 1,
            'timestamp' => $this->getRequestTime(),
        ])
            ->expression('daycount', '[daycount] + 1')
            ->expression('totalcount', '[totalcount] + 1')
            ->execute();
    }
    
    /**
     * {@inheritdoc}
     */
    public function fetchViews($ids) {
        $views = $this->connection
            ->select('node_counter', 'nc')
            ->fields('nc', [
            'totalcount',
            'daycount',
            'timestamp',
        ])
            ->condition('nid', $ids, 'IN')
            ->execute()
            ->fetchAll();
        foreach ($views as $id => $view) {
            $views[$id] = new StatisticsViewsResult($view->totalcount, $view->daycount, $view->timestamp);
        }
        return $views;
    }
    
    /**
     * {@inheritdoc}
     */
    public function fetchView($id) {
        $views = $this->fetchViews([
            $id,
        ]);
        return reset($views);
    }
    
    /**
     * {@inheritdoc}
     */
    public function fetchAll($order = 'totalcount', $limit = 5) {
        assert(in_array($order, [
            'totalcount',
            'daycount',
            'timestamp',
        ]), "Invalid order argument.");
        return $this->connection
            ->select('node_counter', 'nc')
            ->fields('nc', [
            'nid',
        ])
            ->orderBy($order, 'DESC')
            ->range(0, $limit)
            ->execute()
            ->fetchCol();
    }
    
    /**
     * {@inheritdoc}
     */
    public function deleteViews($id) {
        return (bool) $this->connection
            ->delete('node_counter')
            ->condition('nid', $id)
            ->execute();
    }
    
    /**
     * {@inheritdoc}
     */
    public function resetDayCount() {
        $statistics_timestamp = $this->state
            ->get('statistics.day_timestamp', 0);
        if ($this->getRequestTime() - $statistics_timestamp >= 86400) {
            $this->state
                ->set('statistics.day_timestamp', $this->getRequestTime());
            $this->connection
                ->update('node_counter')
                ->fields([
                'daycount' => 0,
            ])
                ->execute();
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function maxTotalCount() {
        $query = $this->connection
            ->select('node_counter', 'nc');
        $query->addExpression('MAX([totalcount])');
        $max_total_count = (int) $query->execute()
            ->fetchField();
        return $max_total_count;
    }
    
    /**
     * Get current request time.
     *
     * @return int
     *   Unix timestamp for current server request time.
     */
    protected function getRequestTime() {
        return $this->requestStack
            ->getCurrentRequest()->server
            ->get('REQUEST_TIME');
    }

}