/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

var fs = require('fs');

module.exports = function(dir, extension, callback) {
    fs.readdir(dir, function(err, list) {
        if (err) {
            return callback(err);
        }

        var suffix = '.' + extension;
        list = list.filter(function(file) {
            if (!extension) {
                return true;
            }
            return file.indexOf(suffix, file.length - suffix.length) !== -1;
        });

        callback(null, list);
    });
};
