<?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.

 */

/**

 * Makes sure a connection to a POP3 host has been established prior to connecting to SMTP.

 * 

 * @package Swift

 * @subpackage Plugins

 * 

 * @author Chris Corbyn

 */

class Swift_Plugins_PopBeforeSmtpPlugin

  implements Swift_Events_TransportChangeListener, Swift_Plugins_Pop_Pop3Connection

{

  /** A delegate connection to use (mostly a test hook) */

  private $_connection;

  /** Hostname of the POP3 server */

  private $_host;

  /** Port number to connect on */

  private $_port;

  /** Encryption type to use (if any) */

  private $_crypto;

  /** Username to use (if any) */

  private $_username;

  /** Password to use (if any) */

  private $_password;

  /** Established connection via TCP socket */

  private $_socket;

  /** Connect timeout in seconds */

  private $_timeout = 10;

  /** SMTP Transport to bind to */

  private $_transport;

  /**

   * Create a new PopBeforeSmtpPlugin for $host and $port.

   * 

   * @param string $host

   * @param int $port

   * @param string $cypto as "tls" or "ssl"

   */

  public function __construct($host, $port = 110, $crypto = null)

  {

    $this->_host = $host;

    $this->_port = $port;

    $this->_crypto = $crypto;

  }

  /**

   * Create a new PopBeforeSmtpPlugin for $host and $port.

   * 

   * @param string $host

   * @param int $port

   * @param string $cypto as "tls" or "ssl"

   * 

   * @return Swift_Plugins_PopBeforeSmtpPlugin

   */

  public static function newInstance($host, $port = 110, $crypto = null)

  {

    return new self($host, $port, $crypto);

  }

  /**

   * Set a Pop3Connection to delegate to instead of connecting directly.

   * 

   * @param Swift_Plugins_Pop_Pop3Connection $connection

   */

  public function setConnection(Swift_Plugins_Pop_Pop3Connection $connection)

  {

    $this->_connection = $connection;

    return $this;

  }

  /**

   * Bind this plugin to a specific SMTP transport instance.

   * 

   * @param Swift_Transport

   */

  public function bindSmtp(Swift_Transport $smtp)

  {

    $this->_transport = $smtp;

  }

  /**

   * Set the connection timeout in seconds (default 10).

   * 

   * @param int $timeout

   */

  public function setTimeout($timeout)

  {

    $this->_timeout = (int) $timeout;

    return $this;

  }

  /**

   * Set the username to use when connecting (if needed).

   * 

   * @param string $username

   */

  public function setUsername($username)

  {

    $this->_username = $username;

    return $this;

  }

  /**

   * Set the password to use when connecting (if needed).

   * 

   * @param string $password

   */

  public function setPassword($password)

  {

    $this->_password = $password;

    return $this;

  }

  /**

   * Connect to the POP3 host and authenticate.

   * 

   * @throws Swift_Plugins_Pop_Pop3Exception if connection fails

   */

  public function connect()

  {

    if (isset($this->_connection))

    {

      $this->_connection->connect();

    }

    else

    {

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

      {

        if (!$socket = fsockopen(

          $this->_getHostString(), $this->_port, $errno, $errstr, $this->_timeout))

        {

          throw new Swift_Plugins_Pop_Pop3Exception(

            sprintf('Failed to connect to POP3 host [%s]: %s', $this->_host, $errstr)

          );

        }

        $this->_socket = $socket;

        if (false === $greeting = fgets($this->_socket))

        {

          throw new Swift_Plugins_Pop_Pop3Exception(

            sprintf('Failed to connect to POP3 host [%s]', trim($greeting))

          );

        }

        $this->_assertOk($greeting);

        if ($this->_username)

        {

          $this->_command(sprintf("USER %s\r\n", $this->_username));

          $this->_command(sprintf("PASS %s\r\n", $this->_password));

        }

      }

    }

  }

  /**

   * Disconnect from the POP3 host.

   */

  public function disconnect()

  {

    if (isset($this->_connection))

    {

      $this->_connection->disconnect();

    }

    else

    {

      $this->_command("QUIT\r\n");

      if (!fclose($this->_socket))

      {

        throw new Swift_Plugins_Pop_Pop3Exception(

          sprintf('POP3 host [%s] connection could not be stopped', $this->_host)

        );

      }

      $this->_socket = null;

    }

  }

  /**

   * Invoked just before a Transport is started.

   * 

   * @param Swift_Events_TransportChangeEvent $evt

   */

  public function beforeTransportStarted(Swift_Events_TransportChangeEvent $evt)

  {

    if (isset($this->_transport))

    {

      if ($this->_transport !== $evt->getTransport())

      {

        return;

      }

    }

    $this->connect();

    $this->disconnect();

  }

  /**

   * Not used.

   */

  public function transportStarted(Swift_Events_TransportChangeEvent $evt)

  {

  }

  /**

   * Not used.

   */

  public function beforeTransportStopped(Swift_Events_TransportChangeEvent $evt)

  {

  }

  /**

   * Not used.

   */

  public function transportStopped(Swift_Events_TransportChangeEvent $evt)

  {

  }

  // -- Private Methods

  private function _command($command)

  {

    if (!fwrite($this->_socket, $command))

    {

      throw new Swift_Plugins_Pop_Pop3Exception(

        sprintf('Failed to write command [%s] to POP3 host', trim($command))

      );

    }

    if (false === $response = fgets($this->_socket))

    {

      throw new Swift_Plugins_Pop_Pop3Exception(

        sprintf('Failed to read from POP3 host after command [%s]', trim($command))

      );

    }

    $this->_assertOk($response);

    return $response;

  }

  private function _assertOk($response)

  {

    if (substr($response, 0, 3) != '+OK')

    {

      throw new Swift_Plugins_Pop_Pop3Exception(

        sprintf('POP3 command failed [%s]', trim($response))

      );

    }

  }

  private function _getHostString()

  {

    $host = $this->_host;

    switch (strtolower($this->_crypto))

    {

      case 'ssl':

        $host = 'ssl://' . $host;

        break;

      case 'tls':

        $host = 'tls://' . $host;

        break;

    }

    return $host;

  }

}