<?php

/*

 * This file is part of SwiftMailer.

 * (c) 2004-2009 Chris Corbyn

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

/**

 * The EventDispatcher which handles the event dispatching layer.

 * 

 * @package Swift

 * @subpackage Events

 * @author Chris Corbyn

 */

class Swift_Events_SimpleEventDispatcher implements Swift_Events_EventDispatcher

{

  /** A map of event types to their associated listener types */

  private $_eventMap = array();

  /** Event listeners bound to this dispatcher */

  private $_listeners = array();

  /** Listeners queued to have an Event bubbled up the stack to them */

  private $_bubbleQueue = array();

  /**

   * Create a new EventDispatcher.

   */

  public function __construct()

  {

    $this->_eventMap = array(

      'Swift_Events_CommandEvent' => 'Swift_Events_CommandListener',

      'Swift_Events_ResponseEvent' => 'Swift_Events_ResponseListener',

      'Swift_Events_SendEvent' => 'Swift_Events_SendListener',

      'Swift_Events_TransportChangeEvent' => 'Swift_Events_TransportChangeListener',

      'Swift_Events_TransportExceptionEvent' => 'Swift_Events_TransportExceptionListener'

      );

  }

  /**

   * Create a new SendEvent for $source and $message.

   * 

   * @param Swift_Transport $source

   * @param Swift_Mime_Message

   * @return Swift_Events_SendEvent

   */

  public function createSendEvent(Swift_Transport $source,

    Swift_Mime_Message $message)

  {

    return new Swift_Events_SendEvent($source, $message);

  }

  /**

   * Create a new CommandEvent for $source and $command.

   * 

   * @param Swift_Transport $source

   * @param string $command That will be executed

   * @param array $successCodes That are needed

   * @return Swift_Events_CommandEvent

   */

  public function createCommandEvent(Swift_Transport $source,

    $command, $successCodes = array())

  {

    return new Swift_Events_CommandEvent($source, $command, $successCodes);

  }

  /**

   * Create a new ResponseEvent for $source and $response.

   * 

   * @param Swift_Transport $source

   * @param string $response

   * @param boolean $valid If the response is valid

   * @return Swift_Events_ResponseEvent

   */

  public function createResponseEvent(Swift_Transport $source,

    $response, $valid)

  {

    return new Swift_Events_ResponseEvent($source, $response, $valid);

  }

  /**

   * Create a new TransportChangeEvent for $source.

   * 

   * @param Swift_Transport $source

   * @return Swift_Events_TransportChangeEvent

   */

  public function createTransportChangeEvent(Swift_Transport $source)

  {

    return new Swift_Events_TransportChangeEvent($source);

  }

  /**

   * Create a new TransportExceptionEvent for $source.

   * 

   * @param Swift_Transport $source

   * @param Swift_TransportException $ex

   * @return Swift_Events_TransportExceptionEvent

   */

  public function createTransportExceptionEvent(Swift_Transport $source,

    Swift_TransportException $ex)

  {

    return new Swift_Events_TransportExceptionEvent($source, $ex);

  }

  /**

   * Bind an event listener to this dispatcher.

   * 

   * @param Swift_Events_EventListener $listener

   */

  public function bindEventListener(Swift_Events_EventListener $listener)

  {

    foreach ($this->_listeners as $l)

    {

      //Already loaded

      if ($l === $listener)

      {

        return;

      }

    }

    $this->_listeners[] = $listener;

  }

  /**

   * Dispatch the given Event to all suitable listeners.

   * 

   * @param Swift_Events_EventObject $evt

   * @param string $target method

   */

  public function dispatchEvent(Swift_Events_EventObject $evt, $target)

  {

    $this->_prepareBubbleQueue($evt);

    $this->_bubble($evt, $target);

  }

  // -- Private methods

  /** Queue listeners on a stack ready for $evt to be bubbled up it */

  private function _prepareBubbleQueue(Swift_Events_EventObject $evt)

  {

    $this->_bubbleQueue = array();

    $evtClass = get_class($evt);

    foreach ($this->_listeners as $listener)

    {

      if (array_key_exists($evtClass, $this->_eventMap)

        && ($listener instanceof $this->_eventMap[$evtClass]))

      {

        $this->_bubbleQueue[] = $listener;

      }

    }

  }

  /** Bubble $evt up the stack calling $target() on each listener */

  private function _bubble(Swift_Events_EventObject $evt, $target)

  {

    if (!$evt->bubbleCancelled() && $listener = array_shift($this->_bubbleQueue))

    {

      $listener->$target($evt);

      $this->_bubble($evt, $target);

    }

  }

}