<?php
/**
 * Middleware class for selecting the right compressor channel
 *
 * @author		Roland Haeder <webmaster@ship-simu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, this is free software
 * @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 CompressorChannel extends BaseMiddleware implements Registerable {
	/**
	 * Real compressor instance
	 */
	private $compressor = null;

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

	/**
	 * Create a new compressor channel based a given base directory where
	 * we shall look for compressor classes
	 *
	 * @param	$baseDir	Directory which holds our compressor classes
	 * @return	$cInstance	A prepared instance of this class
	 */
	public final static function createCompressorChannel ($baseDir) {
		// Get new instance
		$cInstance = new CompressorChannel();

		// Is the compressor handler set?
		if (
			   (is_null($cInstance->getCompressor()))
			|| (!is_object($cInstance->getCompressor()))
			|| (!method_exists($cInstance->getCompressor(), 'compressStream'))
			|| (!method_exists($cInstance->getCompressor(), 'decompressStream'))
		) {
			// Get a directory pointer
			$dirPointer = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($baseDir);

			// Read all directories but no sub directories
			while ($dir = $dirPointer->readDirectoryExcept(array("..", ".", ".htaccess", ".svn"))) {
				// Is this a class file?
				if ((substr($dir, 0, 6) == "class_") && (substr($dir, -4, 4) == ".php")) {
					// Get the compressor's name. That's why you must name
					// your files like your classes and also that's why you
					// must keep on class in one file.
					$className = substr($dir, 6, -4);

					// Get an instance from our object factory
					$tempInstance = ObjectFactory::createObjectByName($className);

					// Set the compressor
					$cInstance->setCompressor($tempInstance);

					// No more searches required because we have found a valid compressor stream
					break;
				} // END - if
			} // END - while

			// Close the directory
			$dirPointer->closeDirectory();
		} // END - if

		// Check again if there is a compressor
		if (
			   (is_null($cInstance->getCompressor()))
			|| (!is_object($cInstance->getCompressor()))
			|| (!method_exists($cInstance->getCompressor(), 'compressStream'))
			|| (!method_exists($cInstance->getCompressor(), 'decompressStream'))
		) {
			// Set the null compressor handler. This should not be configureable!
			$cInstance->setCompressor(ObjectFactory::createObjectByName('NullCompressor'));
		} // END - if

		// Return the compressor instance
		return $cInstance;
	}

	/**
	 * Getter for compressor instance
	 *
	 * @return	$compressor	The compressor instance
	 */
	public final function getCompressor () {
		return $this->compressor;
	}

	/**
	 * Setter for compressor
	 *
	 * @param		$compressorInstance	The compressor instance we shall use
	 * @return	void
	 */
	public final function setCompressor (Compressor $compressorInstance) {
		$this->compressor = $compressorInstance;
	}

	/**
	 * Getter for the file extension of the current compressor
	 */
	public final function getCompressorExtension () {
		// Get compressor extension from current compressor
		return $this->getCompressor()->getCompressorExtension();
	}
}

// [EOF]
?>