<?php
/**
 * A general hub system class
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 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 BaseHubSystem extends BaseFrameworkSystem {
	// Exception codes
	const EXCEPTION_UNSUPPORTED_ERROR_HANDLER  = 0x900;
	const EXCEPTION_CHUNK_ALREADY_ASSEMBLED    = 0x901;
	const EXCEPTION_ANNOUNCEMENT_NOT_ACCEPTED  = 0x902;
	const EXCEPTION_INVALID_CONNECTION_TYPE    = 0x903;
	const EXCEPTION_ANNOUNCEMENT_NOT_ATTEMPTED = 0x904;

	// Message status codes
	const MESSAGE_STATUS_CODE_OKAY = 'OKAY';

	/**
	 * Separator for all bootstrap node entries
	 */
	const BOOTSTRAP_NODES_SEPARATOR = ';';

	/**
	 * An instance of a node
	 */
	private $nodeInstance = NULL;

	/**
	 * An instance of a cruncher
	 */
	private $cruncherInstance = NULL;

	/**
	 * Listener instance
	 */
	private $listenerInstance = NULL;

	/**
	 * A network package handler instance
	 */
	private $packageInstance = NULL;

	/**
	 * A Receivable instance
	 */
	private $receiverInstance = NULL;

	/**
	 * State instance
	 */
	private $stateInstance = NULL;

	/**
	 * Listener pool instance
	 */
	private $listenerPoolInstance = NULL;

	/**
	 * Fragmenter instance
	 */
	private $fragmenterInstance = NULL;

	/**
	 * Decoder instance
	 */
	private $decoderInstance = NULL;

	/**
	 * Assembler instance
	 */
	private $assemblerInstance = NULL;

	/**
	 * Protected constructor
	 *
	 * @param	$className	Name of the class
	 * @return	void
	 */
	protected function __construct ($className) {
		// Call parent constructor
		parent::__construct($className);
	}

	/**
	 * Getter for node instance
	 *
	 * @return	$nodeInstance	An instance of a node node
	 */
	public final function getNodeInstance () {
		return $this->nodeInstance;
	}

	/**
	 * Setter for node instance
	 *
	 * @param	$nodeInstance	An instance of a node node
	 * @return	void
	 */
	protected final function setNodeInstance (NodeHelper $nodeInstance) {
		$this->nodeInstance = $nodeInstance;
	}

	/**
	 * Getter for cruncher instance
	 *
	 * @return	$cruncherInstance	An instance of a cruncher cruncher
	 */
	public final function getCruncherInstance () {
		return $this->cruncherInstance;
	}

	/**
	 * Setter for cruncher instance
	 *
	 * @param	$cruncherInstance	An instance of a cruncher cruncher
	 * @return	void
	 */
	protected final function setCruncherInstance (CruncherHelper $cruncherInstance) {
		$this->cruncherInstance = $cruncherInstance;
	}

	/**
	 * Setter for listener instance
	 *
	 * @param	$listenerInstance	A Listenable instance
	 * @return	void
	 */
	protected final function setListenerInstance (Listenable $listenerInstance) {
		$this->listenerInstance = $listenerInstance;
	}

	/**
	 * Getter for listener instance
	 *
	 * @return	$listenerInstance	A Listenable instance
	 */
	protected final function getListenerInstance () {
		return $this->listenerInstance;
	}

	/**
	 * Setter for network package handler instance
	 *
	 * @param	$packageInstance	The network package instance we shall set
	 * @return	void
	 */
	protected final function setPackageInstance (Deliverable $packageInstance) {
		$this->packageInstance = $packageInstance;
	}

	/**
	 * Getter for network package handler instance
	 *
	 * @return	$packageInstance	The network package handler instance we shall set
	 */
	protected final function getPackageInstance () {
		return $this->packageInstance;
	}

	/**
	 * Setter for receiver instance
	 *
	 * @param	$receiverInstance	A Receivable instance we shall set
	 * @return	void
	 */
	protected final function setReceiverInstance (Receivable $receiverInstance) {
		$this->receiverInstance = $receiverInstance;
	}

	/**
	 * Getter for receiver instance
	 *
	 * @return	$receiverInstance	A Receivable instance we shall get
	 */
	protected final function getReceiverInstance () {
		return $this->receiverInstance;
	}

	/**
	 * Setter for state instance
	 *
	 * @param	$stateInstance	A Stateable instance
	 * @return	void
	 */
	public final function setStateInstance (Stateable $stateInstance) {
		$this->stateInstance = $stateInstance;
	}

	/**
	 * Getter for state instance
	 *
	 * @return	$stateInstance	A Stateable instance
	 */
	public final function getStateInstance () {
		return $this->stateInstance;
	}

	/**
	 * Setter for listener pool instance
	 *
	 * @param	$listenerPoolInstance	The new listener pool instance
	 * @return	void
	 */
	protected final function setListenerPoolInstance (PoolableListener $listenerPoolInstance) {
		$this->listenerPoolInstance = $listenerPoolInstance;
	}

	/**
	 * Getter for listener pool instance
	 *
	 * @return	$listenerPoolInstance	Our current listener pool instance
	 */
	public final function getListenerPoolInstance () {
		return $this->listenerPoolInstance;
	}

	/**
	 * Setter for fragmenter instance
	 *
	 * @param	$fragmenterInstance		A Fragmentable instance
	 * @return	void
	 */
	protected final function setFragmenterInstance (Fragmentable $fragmenterInstance) {
		$this->fragmenterInstance = $fragmenterInstance;
	}

	/**
	 * Getter for fragmenter instance
	 *
	 * @return	$fragmenterInstance		A Fragmentable instance
	 */
	protected final function getFragmenterInstance () {
		return $this->fragmenterInstance;
	}

	/**
	 * Setter for decoder instance
	 *
	 * @param	$decoderInstance	A Decodeable instance
	 * @return	void
	 */
	protected final function setDecoderInstance (Decodeable $decoderInstance) {
		$this->decoderInstance = $decoderInstance;
	}

	/**
	 * Getter for decoder instance
	 *
	 * @return	$decoderInstance	A Decodeable instance
	 */
	protected final function getDecoderInstance () {
		return $this->decoderInstance;
	}

	/**
	 * Setter for assembler instance
	 *
	 * @param	$assemblerInstance	A Decodeable instance
	 * @return	void
	 */
	protected final function setAssemblerInstance (Assembler $assemblerInstance) {
		$this->assemblerInstance = $assemblerInstance;
	}

	/**
	 * Getter for assembler instance
	 *
	 * @return	$assemblerInstance	A Decodeable instance
	 */
	protected final function getAssemblerInstance () {
		return $this->assemblerInstance;
	}

	/**
	 * Setter for node id
	 *
	 * @param	$nodeId		The new node id
	 * @return	void
	 */
	protected final function setNodeId ($nodeId) {
		// Set it config now
		$this->getConfigInstance()->setConfigEntry('node_id', (string) $nodeId);
	}

	/**
	 * Getter for node id
	 *
	 * @return	$nodeId		Current node id
	 */
	public final function getNodeId () {
		// Get it from config
		return $this->getConfigInstance()->getConfigEntry('node_id');
	}

	/**
	 * Setter for private key
	 *
	 * @param	$privateKey		The new private key
	 * @return	void
	 */
	protected final function setPrivateKey ($privateKey) {
		// Set it config now
		$this->getConfigInstance()->setConfigEntry('private_key', (string) $privateKey);
	}

	/**
	 * Getter for private key
	 *
	 * @return	$privateKey		Current private key
	 */
	public final function getPrivateKey () {
		// Get it from config
		return $this->getConfigInstance()->getConfigEntry('private_key');
	}

	/**
	 * Setter for private key hash
	 *
	 * @param	$privateKeyHash		The new private key hash
	 * @return	void
	 */
	protected final function setPrivateKeyHash ($privateKeyHash) {
		// Set it config now
		$this->getConfigInstance()->setConfigEntry('private_key_hash', (string) $privateKeyHash);
	}

	/**
	 * Getter for private key hash
	 *
	 * @return	$privateKeyHash		Current private key hash
	 */
	public final function getPrivateKeyHash () {
		// Get it from config
		return $this->getConfigInstance()->getConfigEntry('private_key_hash');
	}

	/**
	 * Setter for session id
	 *
	 * @param	$sessionId		The new session id
	 * @return	void
	 */
	protected final function setSessionId ($sessionId) {
		$this->getConfigInstance()->setConfigEntry('session_id', (string) $sessionId);
	}

	/**
	 * Getter for session id
	 *
	 * @return	$sessionId		Current session id
	 */
	public final function getSessionId () {
		return $this->getConfigInstance()->getConfigEntry('session_id');
	}

	/**
	 * Constructs a callable method name from given socket error code. If the
	 * method is not found, a generic one is used.
	 *
	 * @param	$errorCode		Error code from socket_last_error()
	 * @return	$handlerName	Call-back method name for the error handler
	 * @throws	UnsupportedSocketErrorHandlerException If the error handler is not implemented
	 */
	protected function getSocketErrorHandlerFromCode ($errorCode) {
		// Create a name from translated error code
		$handlerName = 'socketError' . $this->convertToClassName($this->translateSocketErrorCodeToName($errorCode)) . 'Handler';

		// Is the call-back method there?
		if (!method_exists($this, $handlerName)) {
			// Please implement this
			throw new UnsupportedSocketErrorHandlerException(array($this, $handlerName, $errorCode), self::EXCEPTION_UNSUPPORTED_ERROR_HANDLER);
		} // END - if

		// Return it
		return $handlerName;
	}

	/**
	 * Handles socket error for given socket resource and peer data. This method
	 * validates $socketResource if it is a valid resource (see is_resource())
	 * but assumes valid data in array $recipientData, except that
	 * count($recipientData) is always 2.
	 *
	 * @param	$method				Value of __METHOD__ from calling method
	 * @param	$line				Value of __LINE__ from calling method
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	InvalidSocketException	If $socketResource is no socket resource
	 * @throws	NoSocketErrorDetectedException	If socket_last_error() gives zero back
	 */
	protected final function handleSocketError ($method, $line, $socketResource, array $recipientData) {
		// This method handles only socket resources
		if (!is_resource($socketResource)) {
			// No resource, abort here
			throw new InvalidSocketException(array($this, $socketResource), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if

		// Check count of array, should be two
		assert(count($recipientData) == 2);

		// Get error code for first validation (0 is not an error)
		$errorCode = socket_last_error($socketResource);

		// If the error code is zero, someone called this method without an error
		if ($errorCode == 0) {
			// No error detected (or previously cleared outside this method)
			throw new NoSocketErrorDetectedException(array($this, $socketResource), BaseListener::EXCEPTION_NO_SOCKET_ERROR);
		} // END - if

		// Get handler (method) name
		$handlerName = $this->getSocketErrorHandlerFromCode($errorCode);

		// Call-back the error handler method
		call_user_func_array(array($this, $handlerName), array($socketResource, $recipientData));

		// Finally clear the error because it has been handled
		socket_clear_error($socketResource);
	}

	/**
	 * Checks whether the final (last) chunk is valid
	 *
	 * @param	$chunks		An array with chunks and (hopefully) a valid final chunk
	 * @return	$isValid	Whether the final (last) chunk is valid
	 */
	protected function isValidFinalChunk (array $chunks) {
		// Default is all fine
		$isValid = true;

		// Split the (possible) EOP chunk
		$chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunks[count($chunks) - 1]);

		// Make sure chunks with only 3 elements are parsed (for details see ChunkHandler)
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('eopChunk=' . $chunks[count($chunks) - 1] . ',chunkSplits=' . print_r($chunkSplits,true));
		assert(count($chunkSplits) == 3);

		// Validate final chunk
		if (substr($chunkSplits[ChunkHandler::CHUNK_SPLITS_INDEX_RAW_DATA], 0, strlen(PackageFragmenter::END_OF_PACKAGE_IDENTIFIER)) != PackageFragmenter::END_OF_PACKAGE_IDENTIFIER) {
			// Not fine
			$isValid = false;
		} elseif (substr_count($chunkSplits[ChunkHandler::CHUNK_SPLITS_INDEX_RAW_DATA], PackageFragmenter::CHUNK_HASH_SEPARATOR) != 1) {
			// CHUNK_HASH_SEPARATOR shall only be found once
			$isValid = false;
		}

		// Return status
		return $isValid;
	}

	/**
	 * Translates socket error codes into our own internal names which can be
	 * used for call-backs.
	 *
	 * @param	$errorCode	The error code from socket_last_error() to be translated
	 * @return	$errorName	The translated name (all lower-case, with underlines)
	 */
	public function translateSocketErrorCodeToName ($errorCode) {
		// Nothing bad happened by default
		$errorName = BaseRawDataHandler::SOCKET_CONNECTED;

		// Is the code a number, then we have to change it
		switch ($errorCode) {
			case 0: // Silently ignored, the socket is connected
				break;

			case 11:  // "Resource temporary unavailable"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_RESOURCE_UNAVAILABLE;
				break;

			case 107: // "Transport end-point not connected"
			case 134: // On some (?) systems for 'transport end-point not connected'
				// @TODO On some systems it is 134, on some 107?
				$errorName = BaseRawDataHandler::SOCKET_ERROR_TRANSPORT_ENDPOINT;
				break;

			case 110: // "Connection timed out"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_CONNECTION_TIMED_OUT;
				break;

			case 111: // "Connection refused"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_CONNECTION_REFUSED;
				break;

			case 113: // "No route to host"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_NO_ROUTE_TO_HOST;
				break;

			case 114: // "Operation already in progress"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_OPERATION_ALREADY_PROGRESS;
				break;

			case 115: // "Operation now in progress"
				$errorName = BaseRawDataHandler::SOCKET_ERROR_OPERATION_IN_PROGRESS;
				break;

			default: // Everything else <> 0
				// Unhandled error code detected, so first debug it because we may want to handle it like the others
				self::createDebugInstance(__CLASS__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] UNKNOWN ERROR CODE = ' . $errorCode . ', MESSAGE = ' . socket_strerror($errorCode));

				// Change it only in this class
				$errorName = BaseRawDataHandler::SOCKET_ERROR_UNKNOWN;
				break;
		}

		// Return translated name
		return $errorName;
	}

	/**
	 * Shuts down a given socket resource. This method does only ease calling
	 * the right visitor.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @return	void
	 */
	public function shutdownSocket ($socketResource) {
		// Debug message
		self::createDebugInstance(__CLASS__)->debugOutput('HUB-SYSTEM: Shutting down socket resource ' . $socketResource . ' with state ' . $this->getPrintableState() . ' ...');

		// Set socket resource
		$this->setSocketResource($socketResource);

		// Get a visitor instance
		$visitorInstance = ObjectFactory::createObjectByConfiguredName('shutdown_socket_visitor_class');

		// Debug output
		self::createDebugInstance(__CLASS__)->debugOutput('HUB-SYSTEM:' . $this->__toString() . ': visitorInstance=' . $visitorInstance->__toString());

		// Call the visitor
		$this->accept($visitorInstance);
	}

	/**
	 * Half-shuts down a given socket resource. This method does only ease calling
	 * an other visitor than shutdownSocket() does.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @return	void
	 */
	public function halfShutdownSocket ($socketResource) {
		// Debug message
		self::createDebugInstance(__CLASS__)->debugOutput('HUB-SYSTEM: Half-shutting down socket resource ' . $socketResource . ' with state ' . $this->getPrintableState() . ' ...');

		// Set socket resource
		$this->setSocketResource($socketResource);

		// Get a visitor instance
		$visitorInstance = ObjectFactory::createObjectByConfiguredName('half_shutdown_socket_visitor_class');

		// Debug output
		self::createDebugInstance(__CLASS__)->debugOutput('HUB-SYSTEM:' . $this->__toString() . ': visitorInstance=' . $visitorInstance->__toString());

		// Call the visitor
		$this->accept($visitorInstance);
	}

	/**
	 * "Getter" for a printable state name
	 *
	 * @return	$stateName	Name of the node's state in a printable format
	 */
	public final function getPrintableState () {
		// Default is 'null'
		$stateName = 'null';

		// Get the state instance
		$stateInstance = $this->getStateInstance();

		// Is it an instance of Stateable?
		if ($stateInstance instanceof Stateable) {
			// Then use that state name
			$stateName = $stateInstance->getStateName();
		} // END - if

		// Return result
		return $stateName;
	}
}

// [EOF]
?>