<?php
/**
 * A file-based socket listener
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2016 Core 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 SocketFileListener extends BaseListener implements Listenable {
	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Set the protocol to file
		$this->setProtocolName('file');
	}

	/**
	 * Creates an instance of this class
	 *
	 * @return	$listenerInstance	An instance a prepared listener class
	 */
	public final static function createSocketFileListener () {
		// Get new instance
		$listenerInstance = new SocketFileListener();

		// Return the prepared instance
		return $listenerInstance;
	}

	/**
	 * Initializes the listener by setting up the required socket server
	 *
	 * @return	void
	 */
	public function initListener() {
		// Init socket
		$mainSocket = socket_create(AF_UNIX, SOCK_STREAM, 0);

		// Is the socket resource valid?
		if (!is_resource($mainSocket)) {
			// Something bad happened
			throw new InvalidSocketException(array($this, $mainSocket), BaseListener::EXCEPTION_INVALID_SOCKET);
		} // END - if

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

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

		// Create file name
		$socketFile = self::createTempPathForFile($this->getConfigInstance()->getConfigEntry('ipc_socket_file_name'));

		// Debug message
		self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: socketFile=' . $socketFile . ' ...');

		// File name must not be empty
		assert(!empty($socketFile));

		// Is the file there?
		if ((self::isReachableFilePath($socketFile)) && (file_exists($socketFile))) {
			// Old socket found
			self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: WARNING: Old socket at ' . $socketFile . ' found. Will not start.');

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

			// Quit here
			exit;
		} // END - if

		// Debug message
		self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: Binding to ' . $socketFile . ' ...');

		// Try to bind to it
		if (!socket_bind($mainSocket, $socketFile)) {
			// Handle error here
			$this->handleSocketError(__METHOD__, __LINE__, $mainSocket, array($socketFile, '0'));
			/*
			// Get socket error code for verification
			$socketError = socket_last_error($mainSocket);

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

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

			// And throw again
			throw new InvalidSocketException(array($this, $mainSocket, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
			*/
		} // END - if

		// Start listen for connections
		self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: Listening for connections.');
		if (!socket_listen($mainSocket)) {
			// Handle this socket error with a faked recipientData array
			$this->handleSocketError(__METHOD__, __LINE__, $mainSocket, array($socketFile, '0'));
			/*
			// Get socket error code for verification
			$socketError = socket_last_error($mainSocket);

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

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

			// And throw again
			throw new InvalidSocketException(array($this, $mainSocket, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
			*/
		} // END - if

		// Now, we want non-blocking mode
		self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: Setting non-blocking mode.');
		if (!socket_set_nonblock($mainSocket)) {
			// Handle this socket error with a faked recipientData array
			$this->handleSocketError(__METHOD__, __LINE__, $mainSocket, array($socketFile, '0'));
			/*
			// Get socket error code for verification
			$socketError = socket_last_error($mainSocket);

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

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

			// And throw again
			throw new InvalidSocketException(array($this, $mainSocket, $socketError, $errorMessage), BaseListener::EXCEPTION_INVALID_SOCKET);
			*/
		} // END - if

		// Set the main socket
		$this->registerServerSocketResource($mainSocket);

		// Initialize the peer pool instance
		$poolInstance = ObjectFactory::createObjectByConfiguredName('application_pool_class', array($this));

		// Add main socket
		$poolInstance->addPeer($mainSocket, BaseConnectionHelper::CONNECTION_TYPE_SERVER);

		// And add it to this listener
		$this->setPoolInstance($poolInstance);

		// Initialize iterator for listening on packages
		$iteratorInstance = ObjectFactory::createObjectByConfiguredName('socket_listen_iterator_class', array($poolInstance->getPoolEntriesInstance()));

		// Rewind it and remember it in this class
		$iteratorInstance->rewind();
		$this->setIteratorInstance($iteratorInstance);

		// Initialize the raw data handler
		$handlerInstance = ObjectFactory::createObjectByConfiguredName('socket_raw_data_handler_class');

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

		// Output message
		self::createDebugInstance(__CLASS__)->debugOutput('SOCKET-FILE-LISTENER[' . __METHOD__ . ':' . __LINE__ . ']: Socket listener now ready on socket ' . $socketFile . ' for service.');
	}

	/**
	 * "Listens" for incoming network packages
	 *
	 * @return	void
	 */
	public function doListen() {
		// Call super method
		$this->doListenSocketSelect('');
	}

	/**
	 * Checks whether the listener would accept the given package data array
	 *
	 * @param	$packageData	Raw package data
	 * @return	$accepts		Whether this listener does accept
	 */
	public function ifListenerAcceptsPackageData (array $packageData) {
		$this->partialStub('Need to implement this method.');
	}

	/**
	 * Monitors incoming raw data from the handler and transfers it to the
	 * given receiver instance.
	 *
	 * @return	void
	 */
	public function monitorIncomingRawData () {
		$this->partialStub('Need to implement this method.');
	}

}