discuz 多语言翻译 lang()

function lang($file, $langvar = null, $vars = array(), $default = null) {
    echo $file.':'.$langvar.':';
	global $_G;
	$fileinput = $file;
	list($path, $file) = explode('/', $file);
	if(!$file) {
        echo('1-');
		$file = $path;
		$path = '';
	}
	if(strpos($file, ':') !== false) {
        echo('2-');
		$path = 'plugin';
		list($file) = explode(':', $file);
	}
	if($path != 'plugin') {
        echo('3-');
		$key = $path == '' ? $file : $path.'_'.$file;

		if(!isset($_G['lang'][$key])) {
            echo('31-');
			include DISCUZ_ROOT.'./source/language/'.($path == '' ? '' : $path.'/').'lang_'.$file.'.php';
            var_dump(DISCUZ_ROOT.'./source/language/'.($path == '' ? '' : $path.'/').'lang_'.$file.'.php');
			$_G['lang'][$key] = $lang;
		}
		if(defined('IN_MOBILE') && !defined('TPL_DEFAULT')) {
            echo('32-');
			include DISCUZ_ROOT.'./source/language/mobile/lang_template.php';
			$_G['lang'][$key] = array_merge($_G['lang'][$key], $lang);
		}
		if($file != 'error' && !isset($_G['cache']['pluginlanguage_system'])) {
            echo('33-');
			loadcache('pluginlanguage_system');
		}
		if(!isset($_G['hooklang'][$fileinput])) {
            echo('34-');
			if(isset($_G['cache']['pluginlanguage_system'][$fileinput]) && is_array($_G['cache']['pluginlanguage_system'][$fileinput])) {
				$_G['lang'][$key] = array_merge($_G['lang'][$key], $_G['cache']['pluginlanguage_system'][$fileinput]);
			}
			$_G['hooklang'][$fileinput] = true;
		}
		$returnvalue = &$_G['lang'];
	} else {
        echo('4-');
		if(empty($_G['config']['plugindeveloper'])) {
			loadcache('pluginlanguage_script');
		} elseif(!isset($_G['cache']['pluginlanguage_script'][$file]) && preg_match("/^[a-z]+[a-z0-9_]*$/i", $file)) {
			if(@include(DISCUZ_ROOT.'./data/plugindata/'.$file.'.lang.php')) {
				$_G['cache']['pluginlanguage_script'][$file] = $scriptlang[$file];
			} else {
				loadcache('pluginlanguage_script');
			}
		}
		$returnvalue = & $_G['cache']['pluginlanguage_script'];
		$key = &$file;
	}
	$return = $langvar !== null ? (isset($returnvalue[$key][$langvar]) ? $returnvalue[$key][$langvar] : null) : $returnvalue[$key];
	$return = $return === null ? ($default !== null ? $default : $langvar) : $return;
	$searchs = $replaces = array();
	if($vars && is_array($vars)) {
        echo('5-');
		foreach($vars as $k => $v) {
			$searchs[] = '{'.$k.'}';
			$replaces[] = $v;
		}
	}
	if(is_string($return) && strpos($return, '{_G/') !== false) {
        echo('6-');
		preg_match_all('/\{_G\/(.+?)\}/', $return, $gvar);
		foreach($gvar[0] as $k => $v) {
			$searchs[] = $v;
			$replaces[] = getglobal($gvar[1][$k]);
		}
	}
	$return = str_replace($searchs, $replaces, $return);
    echo('7</br>');
	return $return;
}