<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Mail

 * @subpackage Protocol

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Abstract.php 22602 2010-07-16 22:37:31Z freak $

 */

/**

 * @see Zend_Validate

 */

require_once 'Zend/Validate.php';

/**

 * @see Zend_Validate_Hostname

 */

require_once 'Zend/Validate/Hostname.php';

/**

 * Zend_Mail_Protocol_Abstract

 *

 * Provides low-level methods for concrete adapters to communicate with a remote mail server and track requests and responses.

 *

 * @category   Zend

 * @package    Zend_Mail

 * @subpackage Protocol

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Abstract.php 22602 2010-07-16 22:37:31Z freak $

 * @todo Implement proxy settings

 */

abstract class Zend_Mail_Protocol_Abstract

{

    /**

     * Mail default EOL string

     */

    const EOL = "\r\n";

    /**

     * Default timeout in seconds for initiating session

     */

    const TIMEOUT_CONNECTION = 30;

    /**

     * Maximum of the transaction log

     * @var integer

     */

    protected $_maximumLog = 64;

    /**

     * Hostname or IP address of remote server

     * @var string

     */

    protected $_host;

    /**

     * Port number of connection

     * @var integer

     */

    protected $_port;

    /**

     * Instance of Zend_Validate to check hostnames

     * @var Zend_Validate

     */

    protected $_validHost;

    /**

     * Socket connection resource

     * @var resource

     */

    protected $_socket;

    /**

     * Last request sent to server

     * @var string

     */

    protected $_request;

    /**

     * Array of server responses to last request

     * @var array

     */

    protected $_response;

    /**

     * String template for parsing server responses using sscanf (default: 3 digit code and response string)

     * @var resource

     * @deprecated Since 1.10.3

     */

    protected $_template = '%d%s';

    /**

     * Log of mail requests and server responses for a session

     * @var array

     */

    private $_log = array();

    /**

     * Constructor.

     *

     * @param  string  $host OPTIONAL Hostname of remote connection (default: 127.0.0.1)

     * @param  integer $port OPTIONAL Port number (default: null)

     * @throws Zend_Mail_Protocol_Exception

     * @return void

     */

    public function __construct($host = '127.0.0.1', $port = null)

    {

        $this->_validHost = new Zend_Validate();

        $this->_validHost->addValidator(new Zend_Validate_Hostname(Zend_Validate_Hostname::ALLOW_ALL));

        if (!$this->_validHost->isValid($host)) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception(join(', ', $this->_validHost->getMessages()));

        }

        $this->_host = $host;

        $this->_port = $port;

    }

    /**

     * Class destructor to cleanup open resources

     *

     * @return void

     */

    public function __destruct()

    {

        $this->_disconnect();

    }

    /**

     * Set the maximum log size 

     * 

     * @param integer $maximumLog Maximum log size

     * @return void

     */

    public function setMaximumLog($maximumLog)

    {

        $this->_maximumLog = (int) $maximumLog;

    }

    /**

     * Get the maximum log size 

     * 

     * @return int the maximum log size

     */

    public function getMaximumLog()

    {

        return $this->_maximumLog;

    }

    /**

     * Create a connection to the remote host

     *

     * Concrete adapters for this class will implement their own unique connect scripts, using the _connect() method to create the socket resource.

     */

    abstract public function connect();

    /**

     * Retrieve the last client request

     *

     * @return string

     */

    public function getRequest()

    {

        return $this->_request;

    }

    /**

     * Retrieve the last server response

     *

     * @return array

     */

    public function getResponse()

    {

        return $this->_response;

    }

    /**

     * Retrieve the transaction log

     *

     * @return string

     */

    public function getLog()

    {

        return implode('', $this->_log);

    }

    /**

     * Reset the transaction log

     *

     * @return void

     */

    public function resetLog()

    {

        $this->_log = array();

    }

    /**

     * Add the transaction log

     *

     * @param  string new transaction

     * @return void

     */

    protected function _addLog($value)

    {

        if ($this->_maximumLog >= 0 && count($this->_log) >= $this->_maximumLog) {

            array_shift($this->_log);

        }

        $this->_log[] = $value;

    }

    /**

     * Connect to the server using the supplied transport and target

     *

     * An example $remote string may be 'tcp://mail.example.com:25' or 'ssh://hostname.com:2222'

     *

     * @param  string $remote Remote

     * @throws Zend_Mail_Protocol_Exception

     * @return boolean

     */

    protected function _connect($remote)

    {

        $errorNum = 0;

        $errorStr = '';

        // open connection

        $this->_socket = @stream_socket_client($remote, $errorNum, $errorStr, self::TIMEOUT_CONNECTION);

        if ($this->_socket === false) {

            if ($errorNum == 0) {

                $errorStr = 'Could not open socket';

            }

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception($errorStr);

        }

        if (($result = stream_set_timeout($this->_socket, self::TIMEOUT_CONNECTION)) === false) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception('Could not set stream timeout');

        }

        return $result;

    }

    /**

     * Disconnect from remote host and free resource

     *

     * @return void

     */

    protected function _disconnect()

    {

        if (is_resource($this->_socket)) {

            fclose($this->_socket);

        }

    }

    /**

     * Send the given request followed by a LINEEND to the server.

     *

     * @param  string $request

     * @throws Zend_Mail_Protocol_Exception

     * @return integer|boolean Number of bytes written to remote host

     */

    protected function _send($request)

    {

        if (!is_resource($this->_socket)) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception('No connection has been established to ' . $this->_host);

        }

        $this->_request = $request;

        $result = fwrite($this->_socket, $request . self::EOL);

        // Save request to internal log

        $this->_addLog($request . self::EOL);

        if ($result === false) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception('Could not send request to ' . $this->_host);

        }

        return $result;

    }

    /**

     * Get a line from the stream.

     *

     * @var    integer $timeout Per-request timeout value if applicable

     * @throws Zend_Mail_Protocol_Exception

     * @return string

     */

    protected function _receive($timeout = null)

    {

        if (!is_resource($this->_socket)) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception('No connection has been established to ' . $this->_host);

        }

        // Adapters may wish to supply per-commend timeouts according to appropriate RFC

        if ($timeout !== null) {

           stream_set_timeout($this->_socket, $timeout);

        }

        // Retrieve response

        $reponse = fgets($this->_socket, 1024);

        // Save request to internal log

        $this->_addLog($reponse);

        // Check meta data to ensure connection is still valid

        $info = stream_get_meta_data($this->_socket);

        if (!empty($info['timed_out'])) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception($this->_host . ' has timed out');

        }

        if ($reponse === false) {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception('Could not read from ' . $this->_host);

        }

        return $reponse;

    }

    /**

     * Parse server response for successful codes

     *

     * Read the response from the stream and check for expected return code.

     * Throws a Zend_Mail_Protocol_Exception if an unexpected code is returned.

     *

     * @param  string|array $code One or more codes that indicate a successful response

     * @throws Zend_Mail_Protocol_Exception

     * @return string Last line of response string

     */

    protected function _expect($code, $timeout = null)

    {

        $this->_response = array();

        $cmd  = '';

        $more = '';

        $msg  = '';

        $errMsg = '';

        if (!is_array($code)) {

            $code = array($code);

        }

        do {

            $this->_response[] = $result = $this->_receive($timeout);

            list($cmd, $more, $msg) = preg_split('/([\s-]+)/', $result, 2, PREG_SPLIT_DELIM_CAPTURE);

            if ($errMsg !== '') {

                $errMsg .= ' ' . $msg;

            } elseif ($cmd === null || !in_array($cmd, $code)) {

                $errMsg =  $msg;

            }

        } while (strpos($more, '-') === 0); // The '-' message prefix indicates an information string instead of a response string.

        if ($errMsg !== '') {

            /**

             * @see Zend_Mail_Protocol_Exception

             */

            require_once 'Zend/Mail/Protocol/Exception.php';

            throw new Zend_Mail_Protocol_Exception($errMsg);

        }

        return $msg;

    }

}