<?php
/**
 * A NetworkPackage class. This class implements the Deliverable class because
 * all network packages should be deliverable to other nodes. It further
 * provides methods for reading raw content from template engines and feeding it
 * to the stacker for undeclared packages.
 *
 * The factory method requires you to provide a compressor class (which must
 * implement the Compressor interface). If you don't want any compression (not
 * adviceable due to increased network load), please use the NullCompressor
 * class and encode it with BASE64 for a more error-free transfer over the
 * Internet.
 *
 * For performance reasons, this class should only be instantiated once and then
 * used as a "pipe-through" class.
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 Hub Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.ship-simu.org
 * @todo		Needs to add functionality for handling the object's type
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
class NetworkPackage extends BaseFrameworkSystem implements Deliverable, Registerable {
	/**
	 * Package mask for compressing package data
	 */
	const PACKAGE_MASK = '%s:%s:%s';

	/**
	 * Stacker name for "undeclared" packages
	 */
	const STACKER_NAME_UNDECLARED = 'undeclared';

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// We need to initialize a stack here for our packages even those
		// which have no recipient address and stamp... ;-)
		$stackerInstance = ObjectFactory::createObjectByConfiguredName('package_stacker_class');

		// At last, set it in this class
		$this->setStackerInstance($stackerInstance);
	}

	/**
	 * Creates an instance of this class
	 *
	 * @param	$compressorInstance		A Compressor instance for compressing the content
	 * @return	$packageInstance		An instance of a Deliverable class
	 */
	public final static function createNetworkPackage (Compressor $compressorInstance) {
		// Get new instance
		$packageInstance = new NetworkPackage();

		// Now set the compressor instance if set
		if ($compressorInstance instanceof Compressor) {
			// Okay, set it
			$packageInstance->setCompressorInstance($compressorInstance);
		} // END - if

		// Return the prepared instance
		return $packageInstance;
	}

	/**
	 * "Enqueues" raw content into this delivery class by reading the raw content
	 * from given template instance and pushing it on the 'undeclared' stack.
	 *
	 * @param	$helperInstance		A BaseHubHelper instance
	 * @return	void
	 */
	public function enqueueRawDataFromTemplate (BaseHubHelper $helperInstance) {
		// Get the raw content ...
		$content = $helperInstance->getTemplateInstance()->getRawTemplateData();

		// ... and compress it
		$content = $this->getCompressorInstance()->compressStream($content);

		// Add magic in front of it and hash behind it, including BASE64 encoding
		$content = sprintf(self::PACKAGE_MASK,
			$this->getCompressorInstance()->getCompressorExtension(),
			base64_encode($content),
			crc32($content) // @TODO Not so good, but needs to be fast!
		);

		// Now prepare the temporary array and push it on the 'undeclared' stack including a call-back helper instance
		$this->getStackerInstance()->pushNamed(self::STACKER_NAME_UNDECLARED, array(
			'sender'    => $helperInstance->getNodeInstance()->getSessionId(),
			'recipient' => null,
			'content'   => $content,
			'callback'  => $helperInstance
		));
	}
}

// [EOF]
?>