<?php
/**
 * This class loads class include files with a specific prefix and suffix
 *
 * @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/>.
 *
 * ----------------------------------
 * 1.2
 *  - ClassLoader rewritten to PHP SPL's own RecursiveIteratorIterator class
 * 1.1
 *  - loadClasses rewritten to fix some notices
 * 1.0
 *  - Initial release
 * ----------------------------------
 */
class ClassLoader {
	/**
	 * Configuration array
	 */
	private $cfg = array();

	/**
	 * Array with all classes
	 */
	private $classes = array();

	/**
	 * Suffix with extension for all class files
	 */
	private $prefix = "class_";

	/**
	 * Suffix with extension for all class files
	 */
	private $suffix = ".php";

	/**
	 * Length of the suffix. Will be overwritten later.
	 */
	private $suffixLen = 0;

	/**
	 * Length of the prefix. Will be overwritten later.
	 */
	private $prefixLen = 0;

	/**
	 * A list for directory names (no leading/trailing slashes!) which not be scanned by the path scanner
	 * @see	scanLocalPath
	 */
	private $ignoreList = array();

	/**
	 * Debug this class loader? (true = yes, false = no)
	 */
	private $debug = false;

	/**
	 * Instance of this class
	 */
	private static $selfInstance = null;

	/**
	 * The *public* constructor
	 *
	 * @param		$cfgInstance		Configuration class instance
	 * @return	void
	 */
	public function __construct (FrameworkConfiguration $cfgInstance) {
		// Set suffix and prefix from configuration
		$this->suffix = $cfgInstance->readConfig('class_suffix');
		$this->prefix = $cfgInstance->readConfig('class_prefix');

		// Estimate length of prefix and suffix for substr() function (cache)
		$this->suffixLen = strlen($this->suffix);
		$this->prefixLen = strlen($this->prefix);

		// Set configuration instance
		$this->cfgInstance = $cfgInstance;

		// Set own instance
		self::$selfInstance = $this;
	}

	/**
	 * Getter for an instance of this class
	 *
	 * @return	$selfInstance		An instance of this class
	 */
	public final static function getInstance () {
		// Is the instance there?
		if (is_null(self::$selfInstance)) {
			// Get a new one
			self::$selfInstance = new ClassLoader(FrameworkConfiguration::getInstance());
		} // END - if

		// Return the instance
		return self::$selfInstance;
	}

	/**
	 * Scans recursively a local path for class files which must have a prefix and a suffix as given by $this->suffix and $this->prefix
	 *
	 * @param		$basePath		The relative base path to PATH constant for all classes
	 * @param		$ignoreList	An optional list (array or string) of directory names which shall be ignored
	 * @return	void
	 */
	public function loadClasses ($basePath, $ignoreList = array() ) {
		// Convert string to array
		if (!is_array($ignoreList)) $ignoreList = array($ignoreList);

		// Directories which our class loader ignores by default while
		// deep-scanning the directory structure. See scanLocalPath() for
		// details.
		$ignoreList[] = ".";
		$ignoreList[] = "..";
		$ignoreList[] = ".htaccess";
		$ignoreList[] = ".svn";

		// Keep it in class for later usage
		$this->ignoreList = $ignoreList;

		// Set base directory which holds all our classes, we should use an
		// absolute path here so is_dir(), is_file() and so on will always
		// find the correct files and dirs.
		$basePath2 = realpath($basePath);

		// If the basePath is false it is invalid
		if ($basePath2 === false) {
			// TODO: Do not die here.
			die("Cannot read {$basePath} !");
		} else {
			// Set base path
			$basePath = $basePath2;
		}

		// Get a new iterator
		//* DEBUG: */ echo "<strong>Base path: {$basePath}</strong><br />\n";
		$iterator = new RecursiveDirectoryIterator($basePath);
		$recursive = new RecursiveIteratorIterator($iterator);
		foreach ($recursive as $entry) {
			// Get filename from iterator
			$fileName = $entry->getFileName();

			// Is this file wanted?
			//* DEBUG: */ echo "FOUND:{$fileName}<br />\n";
			if ((!in_array($fileName, $this->ignoreList)) && (substr($fileName, 0, $this->prefixLen) == $this->prefix) && (substr($fileName, -$this->suffixLen, $this->suffixLen) == $this->suffix)) {
				// Get the FQFN and add it to our class list
				$fqfn = $entry->getRealPath();
				//* DEBUG: */ echo "ADD: {$fileName}<br />\n";
				$this->classes[$fileName] = $fqfn;
			}
		}
	}

	/**
	 * Load extra config files
	 *
	 * @return	void
	 */
	public function loadExtraConfigs () {
		// Backup old prefix
		$oldPrefix = $this->prefix;

		// Set new prefix (temporary!)
		$this->prefix = "config-";
		$this->prefixLen = strlen($this->prefix);

		// Set base directory
		$basePath = sprintf("%sinc/config/", PATH);

		// Load all classes from the config directory
		$this->loadClasses($basePath);

		// Set the prefix back
		$this->prefix = $oldPrefix;
		$this->prefixLen = strlen($this->prefix);
	}

	/**
	 * Tries to find the given class in our list. This method ignores silently
	 * missing classes or interfaces. So if you use class_exists() this method
	 * does not interrupt your program.
	 *
	 * @param	$className	The class we shall load
	 * @return	void
	 */
	public function includeClass ($className) {
		// Create a name with prefix and suffix
		$fileName = $this->prefix . $className . $this->suffix;

		// Now look it up in our index
		if (isset($this->classes[$fileName])) {
			if ($this->classes[$fileName] != "loaded") {
				// File is found so load it only once
				require($this->classes[$fileName]);

				// Mark it as loaded
				$this->classes[$fileName] = "loaded";
			} // END - if
		} // END - if
	}
}

// [EOF]
?>