<?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_TimeSync

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

 * @version    $Id: TimeSync.php 20096 2010-01-06 02:05:09Z bkarwin $

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

 */

/**

 * Zend_Date

 */

require_once 'Zend/Date.php';

/**

 * @category   Zend

 * @package    Zend_TimeSync

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

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

 */

class Zend_TimeSync implements IteratorAggregate

{

    /**

     * Set the default timeserver protocol to "Ntp". This will be called

     * when no protocol is specified

     */

    const DEFAULT_PROTOCOL = 'Ntp';

    /**

     * Contains array of timeserver objects

     *

     * @var array

     */

    protected $_timeservers = array();

    /**

     * Holds a reference to the timeserver that is currently being used

     *

     * @var object

     */

    protected $_current;

    /**

     * Allowed timeserver schemes

     *

     * @var array

     */

    protected $_allowedSchemes = array(

        'Ntp',

        'Sntp'

    );

    /**

     * Configuration array, set using the constructor or using

     * ::setOptions() or ::setOption()

     *

     * @var array

     */

    public static $options = array(

        'timeout' => 1

    );

    /**

     * Zend_TimeSync constructor

     *

     * @param  string|array $target - OPTIONAL single timeserver, or an array of timeservers.

     * @param  string       $alias  - OPTIONAL an alias for this timeserver

     * @return  object

     */

    public function __construct($target = null, $alias = null)

    {

        if ($target !== null) {

            $this->addServer($target, $alias);

        }

    }

    /**

     * getIterator() - return an iteratable object for use in foreach and the like,

     * this completes the IteratorAggregate interface

     *

     * @return ArrayObject

     */

    public function getIterator()

    {

        return new ArrayObject($this->_timeservers);

    }

    /**

     * Add a timeserver or multiple timeservers

     *

     * Server should be a single string representation of a timeserver,

     * or a structured array listing multiple timeservers.

     *

     * If you provide an array of timeservers in the $target variable,

     * $alias will be ignored. you can enter these as the array key

     * in the provided array, which should be structured as follows:

     *

     * <code>

     * $example = array(

     *   'server_a' => 'ntp://127.0.0.1',

     *   'server_b' => 'ntp://127.0.0.1:123',

     *   'server_c' => 'ntp://[2000:364:234::2.5]',

     *   'server_d' => 'ntp://[2000:364:234::2.5]:123'

     * );

     * </code>

     *

     * If no port number has been suplied, the default matching port

     * number will be used.

     *

     * Supported protocols are:

     * - ntp

     * - sntp

     *

     * @param  string|array $target - Single timeserver, or an array of timeservers.

     * @param  string       $alias  - OPTIONAL an alias for this timeserver

     * @throws Zend_TimeSync_Exception

     */

    public function addServer($target, $alias = null)

    {

        if (is_array($target)) {

            foreach ($target as $key => $server) {

                $this->_addServer($server, $key);

            }

        } else {

            $this->_addServer($target, $alias);

        }

    }

    /**

     * Sets the value for the given options

     *

     * This will replace any currently defined options.

     *

     * @param   array $options - An array of options to be set

     */

    public static function setOptions(array $options)

    {

        foreach ($options as $key => $value) {

            Zend_TimeSync::$options[$key] = $value;

        }

    }

    /**

     * Marks a nameserver as current

     *

     * @param   string|integer $alias - The alias from the timeserver to set as current

     * @throws  Zend_TimeSync_Exception

     */

    public function setServer($alias)

    {

        if (isset($this->_timeservers[$alias]) === true) {

            $this->_current = $this->_timeservers[$alias];

        } else {

            require_once 'Zend/TimeSync/Exception.php';

            throw new Zend_TimeSync_Exception("'$alias' does not point to valid timeserver");

        }

    }

    /**

     * Returns the value to the option

     *

     * @param   string $key - The option's identifier

     * @return  mixed

     * @throws  Zend_TimeSync_Exception

     */

    public static function getOptions($key = null)

    {

        if ($key == null) {

            return Zend_TimeSync::$options;

        }

        if (isset(Zend_TimeSync::$options[$key]) === true) {

            return Zend_TimeSync::$options[$key];

        } else {

            require_once 'Zend/TimeSync/Exception.php';

            throw new Zend_TimeSync_Exception("'$key' does not point to valid option");

        }

    }

    /**

     * Return a specified timeserver by alias

     * If no alias is given it will return the current timeserver

     *

     * @param   string|integer $alias - The alias from the timeserver to return

     * @return  object

     * @throws  Zend_TimeSync_Exception

     */

    public function getServer($alias = null)

    {

        if ($alias === null) {

            if (isset($this->_current) && $this->_current !== false) {

                return $this->_current;

            } else {

                require_once 'Zend/TimeSync/Exception.php';

                throw new Zend_TimeSync_Exception('there is no timeserver set');

            }

        }

        if (isset($this->_timeservers[$alias]) === true) {

            return $this->_timeservers[$alias];

        } else {

            require_once 'Zend/TimeSync/Exception.php';

            throw new Zend_TimeSync_Exception("'$alias' does not point to valid timeserver");

        }

    }

    /**

     * Returns information sent/returned from the current timeserver

     *

     * @return  array

     */

    public function getInfo()

    {

        return $this->getServer()->getInfo();

    }

    /**

     * Query the timeserver list using the fallback mechanism

     *

     * If there are multiple servers listed, this method will act as a

     * facade and will try to return the date from the first server that

     * returns a valid result.

     *

     * @param   $locale - OPTIONAL locale

     * @return  object

     * @throws  Zend_TimeSync_Exception

     */

    public function getDate($locale = null)

    {

        require_once 'Zend/TimeSync/Exception.php';

        foreach ($this->_timeservers as $alias => $server) {

            $this->_current = $server;

            try {

                return $server->getDate($locale);

            } catch (Zend_TimeSync_Exception $e) {

                if (!isset($masterException)) {

                    $masterException = new Zend_TimeSync_Exception('all timeservers are bogus');

                }

                $masterException->addException($e);

            }

        }

        throw $masterException;

    }

    /**

     * Adds a timeserver object to the timeserver list

     *

     * @param  string|array $target   - Single timeserver, or an array of timeservers.

     * @param  string       $alias    - An alias for this timeserver

     */

    protected function _addServer($target, $alias)

    {

        if ($pos = strpos($target, '://')) {

            $protocol = substr($target, 0, $pos);

            $adress = substr($target, $pos + 3);

        } else {

            $adress = $target;

            $protocol = self::DEFAULT_PROTOCOL;

        }

        if ($pos = strrpos($adress, ':')) {

            $posbr = strpos($adress, ']');

            if ($posbr and ($pos > $posbr)) {

                $port = substr($adress, $pos + 1);

                $adress = substr($adress, 0, $pos);

            } else if (!$posbr and $pos) {

                $port = substr($adress, $pos + 1);

                $adress = substr($adress, 0, $pos);

            } else {

                $port = null;

            }

        } else {

            $port = null;

        }

        $protocol = ucfirst(strtolower($protocol));

        if (!in_array($protocol, $this->_allowedSchemes)) {

            require_once 'Zend/TimeSync/Exception.php';

            throw new Zend_TimeSync_Exception("'$protocol' is not a supported protocol");

        }

        $className = 'Zend_TimeSync_' . $protocol;

        if (!class_exists($className)) {

            require_once 'Zend/Loader.php';

            Zend_Loader::loadClass($className);

        }

        $timeServerObj = new $className($adress, $port);

        $this->_timeservers[$alias] = $timeServerObj;

    }

}