<?php
/**
 * A Package tags 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
 *
 * 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 PackageTags extends BaseTags implements Tagable {
	// Exception codes
	const EXCEPTION_INVALID_TAG = 0x160;

	/**
	 * Last found protocol
	 */
	private $lastProtocol = 'invalid';

	/**
	 * Last found recipient type
	 */
	private $lastRecipientType = 'invalid';

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

		// Init the object registry
		$this->initObjectRegistry();
	}

	/**
	 * Creates an instance of this class
	 *
	 * @return	$tagsInstance	An instance of a Tagable class
	 */
	public final static function createPackageTags () {
		// Get new instance
		$tagsInstance = new PackageTags();

		// Return the prepared instance
		return $tagsInstance;
	}

	/**
	 * Loads the XML file (our "object registry") and saves an instance for faster re-use
	 *
	 * @return	void
	 */
	private function initObjectRegistry () {
		// Output debug message
		$this->debugOutput('TAGS: Initializing object registry - START');

		// Get the application instance
		$appInstance = Registry::getRegistry()->getInstance('app');

		// Get a XML template instance
		$templateInstance = ObjectFactory::createObjectByConfiguredName('object_registry_template_class', array($appInstance));

		// Disable language support
		$templateInstance->enableLanguageSupport(false);

		/*
		 * Enable compacting/rewriting of the  XML to save bandwidth from XML
		 * comments. This is expensive and should be avoided in general.
		 */
		$templateInstance->enableXmlCompacting();

		// Set it for later use
		$this->setTemplateInstance($templateInstance);

		// Read the XML file
		$this->getTemplateInstance()->loadObjectRegistryTemplate('object_registry');

		// Render the XML content
		$this->getTemplateInstance()->renderXmlContent();

		// Output debug message
		$this->debugOutput('TAGS: Initializing object registry - FINISHED');
	}

	/**
	 * Extracts the tags from given package data
	 *
	 * @param	$packageData	Raw package data
	 * @return	void
	 */
	private function extractTagsFromPackageData (array $packageData) {
		/*
		 * We take a look at the tags (in most cases only one is needed) so
		 * first we need the content data splitted up into all it's parts.
		 */
		$contentData = explode(NetworkPackage::PACKAGE_MASK_SEPERATOR, $packageData['content']);

		// Get the tags and store them locally
		$this->setTags(explode(NetworkPackage::PACKAGE_TAGS_SEPERATOR, $contentData[NetworkPackage::INDEX_TAGS]));
	}

	/**
	 * Verifies all tags by looking them up in an XML file. This method is
	 * the key method to make sure only known objects are being distributed and
	 * shared over the whole hub-network. So if the "tag" (let's better say
	 * object type) isn't found in that XML the package won't be distributed.
	 *
	 * @return	void
	 * @throws	InvalidTagException		If a provided tag from the package data is invalid
	 */
	private function verifyAllTags () {
		// Get the registry
		$objectRegistryInstance = ObjectFactory::createObjectByConfiguredName('object_type_registry_class');

		// "Walk" over all tags
		foreach ($this->getTags() as $tag) {
			// Get an array from this tag
			$entry = $objectRegistryInstance->getArrayFromKey($tag);

			// If the array is empty, the entry is invalid!
			if (count($entry) == 0) {
				// Invalid entry found
				throw new InvalidTagException(array($this, $tag), self::EXCEPTION_INVALID_TAG);
			} // END - if

			// Now save the last discovered protocol/recipient type
			$this->lastProtocol      = $entry['object-protocol'];
			$this->lastRecipientType = $entry['object-recipient-type'];
		} // END - foreach
	}

	/**
	 * Chooses the right protocol from given package data
	 *
	 * @param	$packageData	Raw package data
	 * @return	$protocolName	Name of the choosen procotol
	 */
	public function chooseProtocolFromPackageData (array $packageData) {
		// Extract the tags
		$this->extractTagsFromPackageData($packageData);

		// Now we need to verify every single tag
		$this->verifyAllTags();

		// Use the last found protocol for transmission
		$protocolName = $this->lastProtocol;

		// Return it
		return $protocolName;
	}

	/**
	 * Checks wether the given package data is accepted by the listener
	 *
	 * @param	$packageData		Raw package data
	 * @param	$listenerInstance	A Listenable instance
	 * @return	$accepts			Wether it is accepted
	 */
	public function ifPackageDataIsAcceptedByListener (array $packageData, Listenable $listenerInstance) {
		// Extract the tags
		$this->extractTagsFromPackageData($packageData);

		// Now we need to verify every single tag
		$this->verifyAllTags();

		// Now simply check it out
		$accepts = (($this->lastRecipientType == $listenerInstance->getListenerType()) && ($listenerInstance->getListenerType() != 'invalid'));

		// And return the result
		return $accepts;
	}
}

// [EOF]
?>