<?php
/**
 * A class for making socket connections to other hubs including the master hub
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0
 * @copyright	Copyright(c) 2007, 2008 Roland Haeder, this is free software
 * @license		GNU GPL 3.0 or any newer version
 *
 * 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 HubConnector extends BaseFrameworkSystem {
	/**
	 * The socket we shall use for communication
	 */
	private $socketResource = null;

	/**
	 * The peer instance (HubPeer class)
	 */
	private $peerInstance = null;

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

		// Set description
		$this->setObjectDescription("Hub-Connector");

		// Set unique ID
		$this->createUniqueID();

		// Tidy up a little
		$this->removeSystemArray();
		$this->removeNumberFormaters();
	}

	/**
	 * Creates an instance based on the (IP) address and port number of this
	 * class. Next it tries to connect to the specified peer and communicates
	 * to it over a socket
	 *
	 * @param		$address				The peer's IP address
	 * @param		$port				The peer's port number
	 * @param		$hubInstance			An instance of a HubCoreLoop class
	 * @return	$connector			An instance of this class
	 * @throws	HubHelloException		If HELLO retries reached maximum
	 */
	public final static function createHubConnectorByAddressPort ($address, $port, HubCoreLoop $hubInstance) {
		// Get a new instance of this class
		$connector = new HubConnector();

		// Connect to the given address and IP number
		$connector->aquireConnectionToAddress($address, $port);

		// Message to console
		$hubInstance->getOutputInstance()->output(sprintf("[%s] Sending %s request to hub %s:%d...",
			__METHOD__,
			$connector->getConfigInstance()->readConfig("hub_peer_hello"),
			$address,
			$port
		));

		// Get a HubPeer instance
		$peerInstance = HubPeer::createHubPeerBySocket($connector->getSocketResource(), $hubInstance);

		// Send a HELLO to the master hub
		$helloed = 0; $retries = 0;
		while (!$peerInstance->ifHelloReplied()) {
			// Within timeout?
			if ((time() - $helloed) >= $connector->getConfigInstance()->readConfig("hub_hello_timeout")) {
				// Send HELLOs out in periodic times
				$peerInstance->sendMessage($connector->getConfigInstance()->readConfig("hub_peer_hello"));
				$helloed = time(); $retries++;
				if ($retries == $connector->getConfigInstance()->readConfig("hub_hello_retires")) {
					// Maximum retries reached
					throw new HubHelloException(
						array(
							'this'	=> $connector,
							'peer'	=> $peerInstance
						), HubCoreLoop::EXCEPTION_HELLO_TIMED_OUT
					);
				}
			} // END - if
		} // END - while

		// Set the peer instance
		$connector->setPeerInstance($peerInstance);

		// Return the instance
		return $connector;
	}

	/**
	 * Aquires a socket link to a specified IP address and port number. It
	 * throws subclasses of SocketException-s if the peer is down or not
	 * responding. If the connection is up it writes it's resource into
	 * the attribute $socketResource and waits for incoming data packages.
	 *
	 * @param		$address				The peer's IP address
	 * @param		$port				The peer's port number
	 * @return	void
	 * @throws	SocketCreationException	If creation of the socket wents wrong
	 * @throws	SocketConnectException	If the connection was not established
	 */
	public function aquireConnectionToAddress ($address, $port) {
		// Create a socket for binding to the address
		$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

		// Was it a success?
		if (!is_resource($socket)) {
			// This fails! :(
			throw new SocketCreationException(
				array(
					'this' => $this,
					'code' => socket_last_error()
				), HubCoreLoop::EXCEPTION_SOCKET_PROBLEM
			);
		} // END - fi

		// Now connect to the peer
		if (@socket_connect($socket, $address, $port) === false) {
			// Something wents wrong!
			throw new SocketConnectException (
				array(
					'this'	=> $this,
					'code'	=> socket_last_error()
				), HubCoreLoop::EXCEPTION_SOCKET_PROBLEM
			);
		} // END - if

		// Set non-blocking mode
		@socket_set_nonblock($socket);

		// Set the socket
		$this->socketResource = $socket;
	}

	/**
	 * Getter for current socket
	 *
	 * @return	$socketResource	The current socket resource or null if not set
	 */
	public final function getSocketResource() {
		return $this->socketResource;
	}

	/**
	 * Setter for a HubPeer instance
	 *
	 * @param		$peerInstance		An instance of a HubPeer class
	 * @return	void
	 */
	public final function setPeerInstance (HubPeer $peerInstance) {
		$this->peerInstance = $peerInstance;
	}

	/**
	 * Handles any incoming master requests
	 *
	 * @return	void
	 */
	public function handleMasterRequests () {
		// Just ask the peer instance
		$command = $this->peerInstance->handleMasterRequests();
	}

} // END - class
?>