<?php
/**
 * Kompressor-Auswahl Klasse
 *
 * @author		Roland Haeder <webmaster@mxchange.org>
 * @version		0.3.0
 * @copyright	Copyright(c) 2007, 2008 Roland Haeder, this is free software
 * @license		GNU GPL 3.0 or any newer version
 * @link 		http://www.mxchange.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 {
	// Output handler instance
	private $compressor = null;

	// Public constructor
	private function __construct () {
		// Call parent constructor!
		parent::constructor(__CLASS__);

		// Set description
		$this->setPartDescr("Komprimierungshandler");

		// Create an unique ID
		$this->createUniqueID();
	}

	// Create a new compressor channel based a given compression handler
	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 = $dirPointer->readDirectoryExcept(array("..", ".", ".htaccess"))) {
				// Is this a class file?
				if ((substr($dir, 0, 6) == "class_") && (substr($dir, -4, 4) == $cInstance->getConfigInstance()->readConfig("php_extension"))) {
					// 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.
					$class = substr($dir, 6, -4);

					// Create eval command
					$eval = sprintf("\$tempInstance = %s::create%s();",
						$class,
						$class
					);

					// Debug message
					if ((defined('DEBUG_EVAL')) || (defined('DEBUG_ALL'))) $cInstance->getDebugInstance()->output(sprintf("[%s:] Konstruierte PHP-Anweisung: <pre><em>%s</em></pre><br />\n",
						$cInstance->__toString(),
						htmlentities($eval)
					));

					// Run it. This will create an instance to the current class
					eval($eval);

					// Is the instance valid? We have the stream handler here
					if ((!is_null($tempInstance)) && (method_exists($tempInstance, 'compressStream')) && (method_exists($tempInstance, 'decompressStream'))) {
						// Okay, this handler is valid
						$cInstance->setCompressor($tempInstance);

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

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

		// 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
			$cInstance->setCompressor(NullCompressor::createNullCompressor());
		}

		// 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]
?>