<?php
/**
 * A TCP network package handler
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009, 2010 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 TcpNetworkPackageHandler extends BaseNetworkPackageHandler implements Networkable {
	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Set handler name
		$this->setHandlerName('tcp');
	}

	/**
	 * Creates an instance of this class
	 *
	 * @return	$handlerInstance	An instance of a Networkable class
	 */
	public final static function createTcpNetworkPackageHandler () {
		// Get new instance
		$handlerInstance = new TcpNetworkPackageHandler();

		// Initialize new resolver instance
		$resolverInstance = ObjectFactory::createObjectByConfiguredName('network_state_resolver_class');

		// Set it in this class
		$handlerInstance->setResolverInstance($resolverInstance);

		// Return the prepared instance
		return $handlerInstance;
	}

	/**
	 * Verifies the package data itself (only rudymentary check)
	 *
	 * @param	$rawData	Raw package data (as string
	 * @return	$isValid	Wether the package data is valid
	 */
	private function isPackageDataValid ($rawData) {
		// Default is not valid
		$isValid = false;

		// Convert it back into an array
		$packageData = explode(NetworkPackage::PACKAGE_DATA_SEPERATOR, $rawData);

		// This should be at least three entries: sender|recipient|raw data
		if (count($packageData) < 3) {
			// Not enougth fields in $packageData!
			$this->setErrorCode(self::PACKAGE_ERROR_INCOMPLETE_DATA);
		} elseif (count(explode(NetworkPackage::PACKAGE_MASK_SEPERATOR, $packageData[NetworkPackage::INDEX_PACKAGE_CONTENT])) < 2) {
			// Not entougth fields in content
			$this->setErrorCode(self::PACKAGE_ERROR_INVALID_CONTENT);
		} elseif (!$this->ifRecipientMatchesOwnAddress($packageData)) {
			// Field 'recipient' doesn't match our address, this must always be the case
			$this->setErrorCode(self::PACKAGE_ERROR_RECIPIENT_MISMATCH);
		} else {
			// This check went fine...
			$isValid = true;
		}

		// Return the result
		return $isValid;
	}

	/**
	 * Processes a package from given resource. This is mostly useful for TCP
	 * package handling and is implemented in the TcpListener class
	 *
	 * @param	$resource	A valid resource identifier
	 * @return	void
	 * @throws	InvalidResourceException	If the given resource is invalid
	 * @todo	~10% done
	 */
	public function processResourcePackage ($resource) {
		// Check the resource
		if (!is_resource($resource)) {
			// Throw an exception
			throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
		} // END - if

		// Init package data array
		$packageData = array();

		// Reset error code to unhandled
		$this->setErrorCode(self::SOCKET_ERROR_UNHANDLED);

		// Debug message
		$this->debugOutput('HANDLER: Handling TCP package from peer ' . $resource);

		// Read the raw data from socket
		$rawData = socket_read($resource, $this->getConfigInstance()->getConfigEntry('tcp_buffer_length'), PHP_NORMAL_READ);

		// Is it valid?
		if (($rawData === false) || (socket_last_error($resource) > 0)) {
			// Network error or connection lost
			$this->setErrorCode(socket_last_error($resource));
		} elseif (empty($rawData)) {
			// The peer did send nothing to us
			$this->setErrorCode(self::SOCKET_ERROR_EMPTY_DATA);
		} elseif (!$this->isPackageDataValid($rawData)) {
			// Invalid package data
			if ($this->getErrorCode() == self::SOCKET_ERROR_UNHANDLED) {
				// Set it to PACKAGE_ERROR_INVALID_DATA, because SOCKET_ERROR_UNHANDLED should not be used
				$this->setErrorCode(self::PACKAGE_ERROR_INVALID_DATA);
			} // END - if
		} else {
			// Prepare the package data
			$packageData = explode(NetworkPackage::PACKAGE_DATA_SEPERATOR, $rawData);

			// Low-level checks are all green
			$this->setErrorCode(self::PACKAGE_LEVEL_CHECK_OKAY);
		}

		// Get a state from the resolver for this package
		$stateInstance = $this->getResolverInstance()->resolveStateByPackage($this, $packageData);
		die('UNFINISHED:'.$stateInstance->__toString());
	}
}

// [EOF]
?>