<?php
  
  namespace Guzzle\Http;
  
  use Guzzle\Common\Event;
  use Guzzle\Common\HasDispatcherInterface;
  use Symfony\Component\EventDispatcher\EventDispatcher;
  use Symfony\Component\EventDispatcher\EventSubscriberInterface;
  use Symfony\Component\EventDispatcher\EventDispatcherInterface;
  
  /**
   * EntityBody decorator that emits events for read and write methods
   */
  class IoEmittingEntityBody extends AbstractEntityBodyDecorator implements HasDispatcherInterface
  {
      /** @var EventDispatcherInterface */
      protected $eventDispatcher;
  
      public static function getAllEvents()
      {
          return array('body.read', 'body.write');
      }
  
      /**
       * {@inheritdoc}
       * @codeCoverageIgnore
       */
      public function setEventDispatcher(EventDispatcherInterface $eventDispatcher)
      {
          $this->eventDispatcher = $eventDispatcher;
  
          return $this;
      }
  
      public function getEventDispatcher()
      {
          if (!$this->eventDispatcher) {
              $this->eventDispatcher = new EventDispatcher();
          }
  
          return $this->eventDispatcher;
      }
  
      public function dispatch($eventName, array $context = array())
      {
          $this->getEventDispatcher()->dispatch($eventName, new Event($context));
      }
  
      /**
       * {@inheritdoc}
       * @codeCoverageIgnore
       */
      public function addSubscriber(EventSubscriberInterface $subscriber)
      {
          $this->getEventDispatcher()->addSubscriber($subscriber);
  
          return $this;
      }
  
      public function read($length)
      {
          $event = array(
              'body'   => $this,
              'length' => $length,
              'read'   => $this->body->read($length)
          );
          $this->dispatch('body.read', $event);
  
          return $event['read'];
      }
  
      public function write($string)
      {
          $event = array(
              'body'   => $this,
              'write'  => $string,
              'result' => $this->body->write($string)
          );
          $this->dispatch('body.write', $event);
  
          return $event['result'];
      }
  }