<?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.

 */

/**

 * Contains a list of redundant Transports so when one fails, the next is used.

 * @package Swift

 * @subpackage Transport

 * @author Chris Corbyn

 */

class Swift_Transport_FailoverTransport

  extends Swift_Transport_LoadBalancedTransport

{

  /**

   * Registered transport curently used.

   * @var Swift_Transport

   * @access private

   */

  private $_currentTransport;

  /**

   * Creates a new FailoverTransport.

   */

  public function __construct()

  {

    parent::__construct();

  }

  /**

   * Send the given Message.

   * Recipient/sender data will be retreived from the Message API.

   * The return value is the number of recipients who were accepted for delivery.

   * @param Swift_Mime_Message $message

   * @param string[] &$failedRecipients to collect failures by-reference

   * @return int

   */

  public function send(Swift_Mime_Message $message, &$failedRecipients = null)

  {

    $maxTransports = count($this->_transports);

    $sent = 0;

    for ($i = 0; $i < $maxTransports

      && $transport = $this->_getNextTransport(); ++$i)

    {

      try

      {

        if (!$transport->isStarted())

        {

          $transport->start();

        }

        return $transport->send($message, $failedRecipients);

      }

      catch (Swift_TransportException $e)

      {

        $this->_killCurrentTransport();

      }

    }

    if (count($this->_transports) == 0)

    {

      throw new Swift_TransportException(

        'All Transports in FailoverTransport failed, or no Transports available'

        );

    }

    return $sent;

  }

  // -- Protected methods

  protected function _getNextTransport()

  {

    if (!isset($this->_currentTransport))

    {

      $this->_currentTransport = parent::_getNextTransport();

    }

    return $this->_currentTransport;

  }

  protected function _killCurrentTransport()

  {

    $this->_currentTransport = null;

    parent::_killCurrentTransport();

  }

}