<?php
/**
 * A local query connector 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
 * @todo		Find an interface for: handleAllQueries()
 *
 * 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 LocalQueryConnector extends BaseQueryConnector implements Connectable, Visitable {
	/**
	 * The query class instance
	 */
	private $queryInstance = NULL;

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);

		// Init query instance
		$this->queryInstance = ObjectFactory::createObjectByConfiguredName('local_query_class');
	}

	/**
	 * Creates an instance of this query connector class
	 *
	 * @param	$nodeInstance		An instance of a node
	 * @return	$connectorInstance	An instance of this query connector class
	 */
	public static final function createLocalQueryConnector (NodeHelper $nodeInstance) {
		// Create the instance
		$connectorInstance = new LocalQueryConnector();

		// Set the node instance
		$connectorInstance->setNodeInstance($nodeInstance);

		// Get a list instance
		$listInstance = ObjectFactory::createObjectByConfiguredName('local_query_list_class');

		// Set it in the connector
		$connectorInstance->setListInstance($listInstance);

		// Prepare iterator instance
		$iteratorInstance = $listInstance->getListIterator();

		// Set it, too
		$connectorInstance->setIteratorInstance($iteratorInstance);

		// Finally return the connector
		return $connectorInstance;
	}

	/**
	 * Handles the in the list avaiable query (current) and hands it over to the
	 * query processor instance
	 *
	 * @return	void
	 * @TODO	0% done: Unfinished work here
	 */
	private function handleCurrentQuery () {
		// Is there a query available?
		if (!$this->getIteratorInstance()->valid()) {
			// Simply abort here
			return;
		} // END - if

		// Get the current query
		$currentQuery = $this->getIteratorInstance()->current();

		// Only while construction, else it would output to much!
		/* DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CONNECTOR: Handling query ' . $currentQuery);
	}

	/**
	 * Accepts the visitor to process the visit "request"
	 *
	 * @param	$visitorInstance	An instance of a Visitor class
	 * @return	void
	 */
	public function accept (Visitor $visitorInstance) {
		// Visit the query connector
		$visitorInstance->visitQueryConnector($this);

		// Visit the query as well
		$this->queryInstance->accept($visitorInstance);
	}

	/**
	 * Handles all pending queries. This method should be called by the
	 * ActiveTaskVisitor class and should use an iterator on all pending
	 * queries.
	 *
	 * @return	void
	 */
	public function handlePending () {
		// Should we rewind?
		if (!$this->getIteratorInstance()->valid()) {
			// Rewind to the beginning for next loop
			$this->getIteratorInstance()->rewind();

			// Still not valid?
			if ($this->getIteratorInstance()->valid()) {
				/*
				 * Then silently abort here because the queue is empty and to
				 * save some calls.
				 */
				return;
			} // END - if
		} // END - if

		// Try to execute the task
		$this->handleCurrentQuery();

		// Go to next entry
		$this->getIteratorInstance()->next();
	}
}

// [EOF]
?>