<?php
/**
 * A general ConnectionHelper class
 *
 * @author		Roland Haeder <webmaster@shipsimu.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.shipsimu.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 BaseConnectionHelper extends BaseHubSystemHelper implements Registerable, ProtocolHandler {
	// Exception codes
	const EXCEPTION_UNSUPPORTED_ERROR_HANDLER = 0x9100;

	/**
	 * Connection type 'incoming'
	 */
	const CONNECTION_TYPE_INCOMING = 'incoming';

	/**
	 * Connection type 'outgoing'
	 */
	const CONNECTION_TYPE_OUTGOING = 'outgoing';

	/**
	 * Connection type 'server'
	 */
	const CONNECTION_TYPE_SERVER   = 'server';

	/**
	 * Protocol used
	 */
	private $protocol = 'invalid';

	/**
	 * Port number used
	 */
	private $port = 0;

	/**
	 * (IP) Adress used
	 */
	private $address = 0;

	/**
	 * Sent data in bytes
	 */
	private $sentData = 0;

	/**
	 * Whether this connection is initialized
	 */
	private $isInitialized = FALSE;

	/**
	 * Whether this connection is shutted down
	 */
	private $shuttedDown = FALSE;

	/**
	 * Currently queued chunks
	 */
	private $queuedChunks = array();

	/**
	 * Current final hash
	 */
	private $currentFinalHash = '';

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

		// Init state which sets the state to 'init'
		$this->initState();

		// Initialize output stream
		$streamInstance = ObjectFactory::createObjectByConfiguredName('node_raw_data_output_stream_class');

		// And add it to this connection helper
		$this->setOutputStreamInstance($streamInstance);

		// Get package instance from factory
		$packageInstance = NetworkPackageFactory::createNetworkPackageInstance();

		// ... and set it here
		$this->setPackageInstance($packageInstance);

		// Register this connection helper
		Registry::getRegistry()->addInstance('connection', $this);

		// Get the fragmenter instance
		$fragmenterInstance = FragmenterFactory::createFragmenterInstance('package');

		// Set it here
		$this->setFragmenterInstance($fragmenterInstance);
	}

	/**
	 * Getter for real class name, overwrites generic method and is final
	 *
	 * @return	$class	Name of this class
	 */
	public final function __toString () {
		// Class name representation
		$class = self::getConnectionClassName($this->getAddress(), $this->getPort(), parent::__toString());

		// Return it
		return $class;
	}

	/**
	 * Getter for port number to satify ProtocolHandler
	 *
	 * @return	$port	The port number
	 */
	public final function getPort () {
		return $this->port;
	}

	/**
	 * Setter for port number to satify ProtocolHandler
	 *
	 * @param	$port	The port number
	 * @return	void
	 */
	protected final function setPort ($port) {
		$this->port = $port;
	}

	/**
	 * Getter for protocol
	 *
	 * @return	$protocol	Used protocol
	 */
	public final function getProtocol () {
		return $this->protocol;
	}

	/**
	 * Setter for protocol
	 *
	 * @param	$protocol	Used protocol
	 * @return	void
	 */
	protected final function setProtocol ($protocol) {
		$this->protocol = $protocol;
	}

	/**
	 * Getter for IP address
	 *
	 * @return	$address	The IP address
	 */
	public final function getAddress () {
		return $this->address;
	}

	/**
	 * Setter for IP address
	 *
	 * @param	$address	The IP address
	 * @return	void
	 */
	protected final function setAddress ($address) {
		$this->address = $address;
	}

	/**
	 * Initializes the current connection
	 *
	 * @return	void
	 * @throws	SocketOptionException	If setting any socket option fails
	 */
	protected function initConnection () {
		// Get socket resource
		$socketResource = $this->getSocketResource();

		// Set the option to reuse the port
		if (!socket_set_option($socketResource, SOL_SOCKET, SO_REUSEADDR, 1)) {
			// Handle this socket error with a faked recipientData array
			$this->handleSocketError(__METHOD__, __LINE__, $socketResource, array('0.0.0.0', '0'));

			// And throw again
			// @TODO Move this to the socket error handler
			throw new SocketOptionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if

		/*
		 * Set socket to non-blocking mode before trying to establish a link to
		 * it. This is now the default behaviour for all connection helpers who
		 * call initConnection(); .
		 */
		if (!socket_set_nonblock($socketResource)) {
			// Handle this socket error with a faked recipientData array
			$helperInstance->handleSocketError(__METHOD__, __LINE__, $socketResource, array('0.0.0.0', '0'));

			// And throw again
			throw new SocketOptionException(array($helperInstance, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if

		// Last step: mark connection as initialized
		$this->isInitialized = TRUE;
	}

	/**
	 * Attempts to connect to a peer by given IP number and port from a valid
	 * recipientData array with currently configured timeout.
	 *
	 * @param	$recipientData	A valid recipient data array, 0=IP; 1=PORT
	 * @return	$isConnected	Whether the connection went fine
	 * @see		Please see http://de.php.net/manual/en/function.socket-connect.php#84465 for original code
	 * @todo	Rewrite the while() loop to a iterator to not let the software stay very long here
	 */
	protected function connectToPeerByRecipientData (array $recipientData) {
		// Only call this if the connection is initialized by initConnection()
		assert($this->isInitialized === TRUE);

		// Get current time
		$time = time();

		// "Cache" socket resource and timeout config
		$socketResource = $this->getSocketResource();
		$timeout = $this->getConfigInstance()->getConfigEntry('socket_timeout_seconds');

		// Debug output
		self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Trying to connect to ' . $recipientData[0] . ':' . $recipientData[1] . ' with socketResource[' . gettype($socketResource) . ']=' . $socketResource . ' ...');

		// Try to connect until it is connected
		while ($isConnected = !@socket_connect($socketResource, $recipientData[0], $recipientData[1])) {
			// Get last socket error
			$socketError = socket_last_error($socketResource);

			// Skip any errors which may happen on non-blocking connections
			if (($socketError == SOCKET_EINPROGRESS) || ($socketError == SOCKET_EALREADY)) {
				// Now, is that attempt within parameters?
				if ((time() - $time) >= $timeout) {
					// Didn't work within timeout
					$isConnected = FALSE;
					break;
				} // END - if

				// Sleep about one second
				$this->idle(1000);
			} elseif ($socketError != 0) {
				// Stop on everything else pronto
				$isConnected = FALSE;
				break;
			}
		} // END - while

		// Is the peer connected?
		if ($isConnected === TRUE) {
			// Connection is fully established here, so change the state.
			PeerStateFactory::createPeerStateInstanceByName('connected', $this);
		} else {
			/*
			 * There was a problem connecting to the peer (this state is a meta
			 * state until the error handler has found the real cause).
			 */
			PeerStateFactory::createPeerStateInstanceByName('problem', $this);
		}

		// Return status
		return $isConnected;
	}

	/**
	 * Static "getter" for this connection class' name
	 *
	 * @param	$address	IP address
	 * @param	$port		Port number
	 * @param	$className	Original class name
	 * @return	$class		Expanded class name
	 */
	public static function getConnectionClassName ($address, $port, $className) {
		// Construct it
		$class = $address . ':' . $port . ':' . $className;

		// ... and return it
		return $class;
	}

	/**
	 * Initializes the peer's state which sets it to 'init'
	 *
	 * @return	void
	 */
	private function initState() {
		// Get the state factory and create the initial state.
		PeerStateFactory::createPeerStateInstanceByName('init', $this);
	}

	/**
	 * "Getter" for raw data from a package array. A fragmenter is used which
	 * will returns us only so many raw data which fits into the back buffer.
	 * The rest is being held in a back-buffer and waits there for the next
	 * cycle and while be then sent.
	 *
	 * This method does 2 simple steps:
	 * 1) Request a chunk from set fragmenter instance
	 * 2) Finally return the chunk (array) to the caller
	 *
	 * @param	$packageData	Raw package data array
	 * @return	$chunkData		Raw data chunk
	 */
	private function getRawDataFromPackageArray (array $packageData) {
		// Debug message
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: currentFinalHash=' . $this->currentFinalHash);

		// Make sure the final hash is set
		assert((is_string($this->currentFinalHash)) && (!empty($this->currentFinalHash)));

		// Get the next raw data chunk from the fragmenter
		$rawDataChunk = $this->getFragmenterInstance()->getNextRawDataChunk($this->currentFinalHash);

		// Debug message
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: rawDataChunk=' . print_r($rawDataChunk, TRUE));

		// Get chunk hashes and chunk data
		$chunkHashes = array_keys($rawDataChunk);
		$chunkData   = array_values($rawDataChunk);

		// Is the required data there?
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: chunkHashes[]=' . count($chunkHashes) . ',chunkData[]=' . count($chunkData));
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('chunkData='.print_r($chunkData, TRUE));
		if ((isset($chunkHashes[0])) && (isset($chunkData[0]))) {
			// Remember this chunk as queued
			$this->queuedChunks[$chunkHashes[0]] = $chunkData[0];

			// Return the raw data
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Returning ' . strlen($chunkData[0]) . ' bytes from ' . __METHOD__ . ' ...');
			return $chunkData[0];
		} else {
			// Return zero string
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Returning zero bytes from ' . __METHOD__ . '!');
			return '';
		}
	}

	/**
	 * "Accept" a visitor by simply calling it back
	 *
	 * @param	$visitorInstance	A Visitor instance
	 * @return	void
	 */
	protected final function accept (Visitor $visitorInstance) {
		// Just call the visitor
		$visitorInstance->visitConnectionHelper($this);
	}

	/**
	 * Sends raw package data to the recipient
	 *
	 * @param	$packageData		Raw package data
	 * @return	void
	 * @throws	InvalidSocketException	If we got a problem with this socket
	 */
	public function sendRawPackageData (array $packageData) {
		// The helper's state must be 'connected'
		$this->getStateInstance()->validatePeerStateConnected();

		// Implode the package data array and fragement the resulting string, returns the final hash
		$finalHash = $this->getFragmenterInstance()->fragmentPackageArray($packageData, $this);

		// Is the final hash set?
		if ($finalHash !== TRUE) {
			// Debug message
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Setting finalHash=' . $finalHash . ',currentFinalHash[' . gettype($this->currentFinalHash) . ']=' . $this->currentFinalHash);

			// Set final hash
			$this->currentFinalHash = $finalHash;
		} // END - if

		// Reset serial number
		$this->getFragmenterInstance()->resetSerialNumber($this->currentFinalHash);

		// Init variables
		$rawData        = '';
		$dataStream     = ' ';

		// Fill sending buffer with data
		while (strlen($dataStream) > 0) {
			// Debug message
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: packageData=' . print_r($packageData, TRUE));

			// Convert the package data array to a raw data stream
			$dataStream = $this->getRawDataFromPackageArray($packageData);
			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Adding ' . strlen($dataStream) . ' bytes to the sending buffer ...');
			$rawData .= $dataStream;
		} // END - while

		// Nothing to sent is bad news, so assert on it
		assert(strlen($rawData) > 0);

		// Calculate buffer size
		$bufferSize = $this->getConfigInstance()->getConfigEntry($this->getProtocol() . '_buffer_length');

		// Encode the raw data with our output-stream
		$encodedData = $this->getOutputStreamInstance()->streamData($rawData);

		// Debug message
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('HELPER[' . __METHOD__ . ':' . __LINE__ . ']: socketResource[]=' . gettype($this->getSocketResource()) . PHP_EOL);

		// Init array
		$encodedDataArray = array(
			NetworkPackage::RAW_FINAL_HASH_INDEX   => $this->currentFinalHash,
			NetworkPackage::RAW_ENCODED_DATA_INDEX => $encodedData,
			NetworkPackage::RAW_SENT_BYTES_INDEX   => 0,
			NetworkPackage::RAW_SOCKET_INDEX       => $this->getSocketResource(),
			NetworkPackage::RAW_BUFFER_SIZE_INDEX  => $bufferSize,
			NetworkPackage::RAW_DIFF_INDEX         => 0
		);

		// Calculate difference
		$diff = $encodedDataArray[NetworkPackage::RAW_BUFFER_SIZE_INDEX] - strlen($encodedDataArray[NetworkPackage::RAW_ENCODED_DATA_INDEX]);

		// Push raw data to the package's outgoing stack
		$this->getPackageInstance()->getStackerInstance()->pushNamed(NetworkPackage::STACKER_NAME_OUTGOING_STREAM, $encodedDataArray);
	}

	/**
	 * Marks this connection as shutted down
	 *
	 * @return	void
	 */
	protected final function markConnectionShuttedDown () {
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: ' . $this->__toString() . ' has been marked as shutted down');
		$this->shuttedDown = TRUE;

		// And remove the (now invalid) socket
		$this->setSocketResource(FALSE);
	}

	/**
	 * Getter for shuttedDown
	 *
	 * @return	$shuttedDown	Whether this connection is shutted down
	 */
	public final function isShuttedDown () {
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: ' . $this->__toString() . ',shuttedDown=' . intval($this->shuttedDown));
		return $this->shuttedDown;
	}

	// ************************************************************************
	//                 Socket error handler call-back methods
	// ************************************************************************

	/**
	 * Handles socket error 'connection timed out', but does not clear it for
	 * later debugging purposes.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorConnectionTimedOutHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Shutdown this socket
		$this->shutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket error 'resource temporary unavailable', but does not
	 * clear it for later debugging purposes.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorResourceUnavailableHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Shutdown this socket
		$this->shutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket error 'connection refused', but does not clear it for
	 * later debugging purposes.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorConnectionRefusedHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Shutdown this socket
		$this->shutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket error 'no route to host', but does not clear it for later
	 * debugging purposes.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorNoRouteToHostHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Shutdown this socket
		$this->shutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket error 'operation already in progress' which happens in
	 * method connectToPeerByRecipientData() on timed out connection
	 * attempts.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorOperationAlreadyProgressHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Half-shutdown this socket (see there for difference to shutdownSocket())
		$this->halfShutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket error 'connection reset by peer', but does not clear it for
	 * later debugging purposes.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 * @throws	SocketConnectionException	The connection attempts fails with a time-out
	 */
	protected function socketErrorConnectionResetByPeerHandler ($socketResource, array $recipientData) {
		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Get error message
		$errorMessage = socket_strerror($socketError);

		// Shutdown this socket
		$this->shutdownSocket($socketResource);

		// Throw it again
		throw new SocketConnectionException(array($this, $socketResource, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
	}

	/**
	 * Handles socket "error" 'operation now in progress' which can be safely
	 * passed on with non-blocking connections.
	 *
	 * @param	$socketResource		A valid socket resource
	 * @param	$recipientData		An array with two elements: 0=IP number, 1=port number
	 * @return	void
	 */
	protected function socketErrorOperationInProgressHandler ($socketResource, array $recipientData) {
		self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Operation is now in progress, this is usual for non-blocking connections and is no bug.');
	}
}

// [EOF]
?>