<?php
/**
 * A TCP connection helper class
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Hub Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.shipsimu.org
 * @todo		Find an interface for hub helper
 *
 * 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 TcpConnectionHelper extends BaseIpV4ConnectionHelper implements ConnectionHelper {
	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Set protocol
		$this->setProtocolName('tcp');
	}

	/**
	 * Creates a half-connected socket resource ("connection") for given
	 * recipient in package data. After you called this method you still need to
	 * connect to the other node.
	 *
	 * @param	$packageData		Raw package data
	 * @return	$socketResource		Socket resource
	 * @throws	SocketCreationException		If the socket could not be created
	 * @throws	SocketOptionException		If a socket option could not be set
	 * @throws	SocketConnectionException	If a connection could not be opened
	 * @todo	$errorCode/-Message are now in handleSocketError()'s call-back methods
	 */
	public static function createConnectionFromPackageData (array $packageData) {
		// Create an instance
		$helperInstance = new TcpConnectionHelper();

		// Create a socket instance
		$socketResource = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

		// Is the socket resource valid?
		if (!is_resource($socketResource)) {
			/*
			 * Something bad happened, calling handleSocketError() is not
			 * possible here because that method would throw an
			 * InvalidSocketException back.
			 */
			throw new SocketCreationException(array($helperInstance, gettype($socketResource)), BaseListener::EXCEPTION_SOCKET_CREATION_FAILED);
		} // END - if

		// Get socket error code for verification
		$socketError = socket_last_error($socketResource);

		// Check if there was an error else
		if ($socketError > 0) {
			// Handle this socket error with a faked recipientData array
			$helperInstance->handleSocketError(__METHOD__, __LINE__, $socketResource, array('0.0.0.0', '0'));

			// Then throw again
			throw new SocketCreationException(array($helperInstance, gettype($socketResource), $socketError, socket_strerror($socketError)), BaseListener::EXCEPTION_SOCKET_CREATION_FAILED);
		} // END - if

		// Debug message
		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Setting socket resource ... (' . gettype($socketResource) . ')');

		// Set the resource
		$helperInstance->setSocketResource($socketResource);

		// Init connection
		$helperInstance->initConnection();

		// @TODO The whole resolving part should be moved out and made more configurable
		// Init recipient data
		$unlData = array();

		// Try to solve the recipient
		try {
			// Get protocol handler back from package data
			$handlerInstance = ProtocolHandlerFactory::createProtocolHandlerFromPackageData($packageData);

			// Get UNL data
			$unlData = $handlerInstance->getUniversalNodeLocatorDataArray();

			// Make sure it is a valid Universal Node Locator array (3 elements)
			assert(isset($unlData[UniversalNodeLocator::UNL_PART_PROTOCOL]));
			assert(isset($unlData[UniversalNodeLocator::UNL_PART_ADDRESS]));
			assert(isset($unlData[UniversalNodeLocator::UNL_PART_PORT]));

			// Set handler instance
			$helperInstance->setHandlerInstance($handlerInstance);
		} catch (NoValidHostnameException $e) {
			// Debug message
			self::createDebugInstance(__CLASS__)->debugOutput('CONNECTION-HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Failed to resolve ' . $packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT] . ':' . $e->getMessage());

			// Is the recipient equal as configured IP
			if (substr($packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT], 0, strlen($helperInstance->getConfigInstance()->getConfigEntry('external_address'))) == $helperInstance->getConfigInstance()->getConfigEntry('external_address')) {
				// This may connect to shipsimu.org and requests 'ip.php' which will return our external IP address
				$unlData[UniversalNodeLocator::UNL_PART_ADDRESS] = HubTools::determineExternalAddress();

				// Do we have ip:port match?
				// @TODO Rewrite this test for UNLs
				if (strpos($packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT], ':') === FALSE) {
					// No ip:port!
					$helperInstance->debugInstance($packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT] . ' does not contain ":". Please fix this.');
				} // END - if

				// "explode" the ip:port, so index 1 will be the port number
				// @TODO Rewrite this test for UNLs
				$recipientArray = explode(':', $packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT]);

				// Add the port
				$unlData[UniversalNodeLocator::UNL_PART_PORT] = $recipientArray[UniversalNodeLocator::UNL_PART_PORT];
			} else {
				// It doesn't match, we need to take care of this later
				$helperInstance->debugInstance($packageData[NetworkPackage::PACKAGE_DATA_RECIPIENT] . '!=' . $helperInstance->getConfigInstance()->getConfigEntry('external_address'));
			}
		}

		// Set address and maybe port
		$helperInstance->setAddress($unlData[UniversalNodeLocator::UNL_PART_ADDRESS]);
		$helperInstance->setConnectionPort($unlData[UniversalNodeLocator::UNL_PART_PORT]);

		// Now connect to it
		if (!$helperInstance->connectToPeerByUnlData($unlData)) {
			// Handle socket error
			$helperInstance->handleSocketError(__METHOD__, __LINE__, $socketResource, $unlData);
		} // END - if

		// Okay, that should be it. Return it...
		return $socketResource;
	}

	/**
	 * Do the shutdown sequence for this connection helper
	 *
	 * @return	void
	 * @throws	SocketShutdownException		If the current socket could not be shut down
	 * @todo	We may want to implement a filter for ease notification of other objects like our pool
	 */
	public function doShutdown () {
		// Debug message
		self::createDebugInstance(__CLASS__)->debugOutput('HELPER[' . __METHOD__ . ':' . __LINE__ . ']: Shutting down socket resource ' . $this->getSocketResource());

		// Clear any previous errors
		socket_clear_error($this->getSocketResource());

		// Call the shutdown function on the currently set socket
		if (!socket_shutdown($this->getSocketResource())) {
			// Could not shutdown socket, this is fine if e.g. the other side is not connected, so analyse it
			if (socket_last_error($this->getSocketResource()) != 107) {
				// Something bad happened while we shutdown a socket
				throw new SocketShutdownException($this, BaseListener::EXCEPTION_INVALID_SOCKET);
			} // END - if
		} // END - if

		// Try to make blocking IO for socket_close()
		socket_set_block($this->getSocketResource());

		// Drop all data (don't sent any on socket closure)
		socket_set_option($this->getSocketResource(), SOL_SOCKET, SO_LINGER, array('l_onoff' => 1, 'l_linger' => 0));

		// Finally close socket to free some resources
		socket_close($this->getSocketResource());

		// Mark this connection as shutted down
		$this->markConnectionShuttedDown();
	}
}

// [EOF]
?>