// Licensed as MIT

/** Filter and normalize (partly relative) path. The resulting path does not contain multiple slashes and will always be absolute (starting with a slash). Intermediate ../ are expanded (resolved). If a path specifies more ../ than possible an exception is thrown.
 * @param {String} path... one path or multiple path fragments (as multipe arguments)
 * @return {String} normalized and filtered, absolute path with no trailing slash
 */
function normalizePath(str){
    var path = "", i;

    if (arguments.length > 1) {
        for (i = 0; i < arguments.length; i++) {
            path += "/" + arguments[i];
        }
        return normalizePath(path);
    }

    path = "/" + str;
    path = path.replace(/\/+$/g, "");
    path = path.replace(/\/+/g, "/");
    while (path.indexOf("..") > -1 && path.indexOf("/..") != 0) {
        path = path.replace(/[^\.\/]+\/\.\.\//g, "");
    }
    if (path.indexOf("/..") === 0) {
        throw new Error("Malformed path '"+ str +"' (does not resolve to absolute path: '"+ path +"')");
    }
    path = path.replace(/\.\//g, "");
    return path;
}