<?php
/**
 * A socket discovery class
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 Core 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 PackageSocketDiscovery extends BaseDiscovery implements DiscoverableSocket, Registerable {
	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Create an instance of this class
	 *
	 * @return	$discoveryInstance	An instance of this discovery class
	 */
	public final static function createPackageSocketDiscovery () {
		// Get an instance of this class
		$discoveryInstance = new PackageSocketDiscovery();

		// Output debug message
		$discoveryInstance->debugOutput('SOCKET-DISCOVERY: Initialized.');

		// Return the prepared instance
		return $discoveryInstance;
	}

	/**
	 * Tries to dicover the right listener instance
	 *
	 * @param	$protocolName		Protocol name
	 * @param	$packageData		Raw package data
	 * @return	$listenerInstance	An instance of a Listenable instance or null
	 */
	public function discoverListenerInstance ($protocolName, array $packageData) {
		/*
		 * Get the listener pool instance, we need to lookup the matching
		 * listener->poolInstance chain there.
		 */
		$poolInstance = Registry::getRegistry()->getInstance('node')->getListenerPoolInstance();

		// Init listener instance
		$listenerInstance = null;

		/*
		 * Now we need to choose again. It is wether we are speaking with a hub
		 * or with a client. So just handle it over to all listeners in this
		 * pool.
		 */
		foreach ($poolInstance->getPoolEntriesInstance()->getArrayFromGroup($protocolName) as $listenerInstance) {
			// Does the listener want that package?
			if ($listenerInstance->ifListenerAcceptsPackageData($packageData)) {
				// This listener likes our package data, so abort here
				break;
			} // END - if
		} // END - foreach

		// Return it
		return $listenerInstance;
	}

	/**
	 * Tries to discover the right socket for given package data and returns a
	 * matching socket resource for that protocol.
	 *
	 * @param	$packageData		Raw package data array
	 * @return	$socketResource		A valid socket resource
	 * @throws	NoListGroupException	If the procol group is not found in peer list
	 */
	public function discoverSocket (array $packageData) {
		// First we need a tags instance
		$tagsInstance = PackageTagsFactory::createPackageTagsInstance();

		/*
		 * We need to decide here which socket (TCP or UDP) should be used for
		 * the actual data transmission. In this process we will find out if
		 * the recipient of this package has already a known (registered) socket
		 * and if so we can re-use it. If there is no socket registered, we try
		 * to make a new connection (TCP or UDP) to the given IP:port.
		 */
		$protocolName = $tagsInstance->chooseProtocolFromPackageData($packageData);

		// Get the listener instance
		$listenerInstance = $this->discoverListenerInstance($protocolName, $packageData);

		// If there is no listener who wants to have that package, we simply drop it here
		if (is_null($listenerInstance)) {
			// @TODO We may need some locking here
			// Abort with no resource
			return false;
		} // END - if

		/*
		 * Now we have the listener instance, we can determine the right
		 * resource to continue. The first step is to get the attached pool
		 * instance and pass over the whole package data to get the right
		 * socket.
		 */
		$socketResource = $listenerInstance->getPoolInstance()->getSocketFromPackageData($packageData);

		// Is it false, the recipient isn't known to us and we have no connection to it
		if (!is_resource($socketResource)) {
			// Create a new socket resource
			$socketResource = SocketFactory::createSocketFromPackageData($packageData, $protocolName);
		} // END - if

		// And return it
		return $socketResource;
	}
}

// [EOF]
?>