<?php

// constants are slow, so we use as few as possible
if (! defined ( 'HTMLPURIFIER_PREFIX' )) {
	define ( 'HTMLPURIFIER_PREFIX', realpath ( dirname ( __FILE__ ) . '/..' ) );
}

// accomodations for versions earlier than 5.0.2
// borrowed from PHP_Compat, LGPL licensed, by Aidan Lister <aidan@php.net>
if (! defined ( 'PHP_EOL' )) {
	switch (strtoupper ( substr ( PHP_OS, 0, 3 ) )) {
		case 'WIN' :
			define ( 'PHP_EOL', "\r\n" );
			break;
		case 'DAR' :
			define ( 'PHP_EOL', "\r" );
			break;
		default :
			define ( 'PHP_EOL', "\n" );
	}
}

/**
 * Bootstrap class that contains meta-functionality for HTML Purifier such as
 * the autoload function.
 *
 * @note
 * This class may be used without any other files from HTML Purifier.
 */
class HTMLPurifier_Bootstrap {
	
	/**
	 * Autoload function for HTML Purifier
	 * 
	 * @param string $class
	 *        	Class to load
	 * @return bool
	 */
	public static function autoload($class) {
		$file = HTMLPurifier_Bootstrap::getPath ( $class );
		if (! $file) {
			return false;
		}
		// Technically speaking, it should be ok and more efficient to
		// just do 'require', but Antonio Parraga reports that with
		// Zend extensions such as Zend debugger and APC, this invariant
		// may be broken. Since we have efficient alternatives, pay
		// the cost here and avoid the bug.
		require_once HTMLPURIFIER_PREFIX . '/' . $file;
		return true;
	}
	
	/**
	 * Returns the path for a specific class.
	 * 
	 * @param string $class
	 *        	Class path to get
	 * @return string
	 */
	public static function getPath($class) {
		if (strncmp ( 'HTMLPurifier', $class, 12 ) !== 0) {
			return false;
		}
		// Custom implementations
		if (strncmp ( 'HTMLPurifier_Language_', $class, 22 ) === 0) {
			$code = str_replace ( '_', '-', substr ( $class, 22 ) );
			$file = 'HTMLPurifier/Language/classes/' . $code . '.php';
		} else {
			$file = str_replace ( '_', '/', $class ) . '.php';
		}
		if (! file_exists ( HTMLPURIFIER_PREFIX . '/' . $file )) {
			return false;
		}
		return $file;
	}
	
	/**
	 * "Pre-registers" our autoloader on the SPL stack.
	 */
	public static function registerAutoload() {
		$autoload = array (
				'HTMLPurifier_Bootstrap',
				'autoload' 
		);
		if (($funcs = spl_autoload_functions ()) === false) {
			spl_autoload_register ( $autoload );
		} elseif (function_exists ( 'spl_autoload_unregister' )) {
			if (version_compare ( PHP_VERSION, '5.3.0', '>=' )) {
				// prepend flag exists, no need for shenanigans
				spl_autoload_register ( $autoload, true, true );
			} else {
				$buggy = version_compare ( PHP_VERSION, '5.2.11', '<' );
				$compat = version_compare ( PHP_VERSION, '5.1.2', '<=' ) && version_compare ( PHP_VERSION, '5.1.0', '>=' );
				foreach ( $funcs as $func ) {
					if ($buggy && is_array ( $func )) {
						// :TRICKY: There are some compatibility issues and some
						// places where we need to error out
						$reflector = new ReflectionMethod ( $func [0], $func [1] );
						if (! $reflector->isStatic ()) {
							throw new Exception ( 'HTML Purifier autoloader registrar is not compatible
                                with non-static object methods due to PHP Bug #44144;
                                Please do not use HTMLPurifier.autoload.php (or any
                                file that includes this file); instead, place the code:
                                spl_autoload_register(array(\'HTMLPurifier_Bootstrap\', \'autoload\'))
                                after your own autoloaders.' );
						}
						// Suprisingly, spl_autoload_register supports the
						// Class::staticMethod callback format, although call_user_func doesn't
						if ($compat) {
							$func = implode ( '::', $func );
						}
					}
					spl_autoload_unregister ( $func );
				}
				spl_autoload_register ( $autoload );
				foreach ( $funcs as $func ) {
					spl_autoload_register ( $func );
				}
			}
		}
	}
}

// vim: et sw=4 sts=4