/**
 * Copyright (c) 2015, biezhi 王爵 (biezhi.me@gmail.com)
 *
 * Licensed 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.
 */
package com.blade.kit;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;

/**
 * IP工具类
 *
 * @author	<a href="mailto:biezhi.me@gmail.com" target="_blank">biezhi</a>
 * @since	1.0
 */
public class IPKit {

	/**
	 * @param request
	 *            IP
	 * @return IP Address
	 */
	public static String getIpAddrByRequest(HttpServletRequest request) {
		String ip = request.getHeader("x-forwarded-for");
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("Proxy-Client-IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("WL-Proxy-Client-IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
		}
		return ip;
	}

	/**
	 * @return 本机IP
	 * @throws SocketException
	 */
	public static String getRealIp() throws SocketException {
		String localip = null;// 本地IP，如果没有配置外网IP则返回它
		String netip = null;// 外网IP

		Enumeration<NetworkInterface> netInterfaces = NetworkInterface.getNetworkInterfaces();
		InetAddress ip = null;
		boolean finded = false;// 是否找到外网IP
		while (netInterfaces.hasMoreElements() && !finded) {
			NetworkInterface ni = netInterfaces.nextElement();
			Enumeration<InetAddress> address = ni.getInetAddresses();
			while (address.hasMoreElements()) {
				ip = address.nextElement();
				if (!ip.isSiteLocalAddress() && !ip.isLoopbackAddress() && ip.getHostAddress().indexOf(":") == -1) {// 外网IP
					netip = ip.getHostAddress();
					finded = true;
					break;
				} else if (ip.isSiteLocalAddress() && !ip.isLoopbackAddress() && ip.getHostAddress().indexOf(":") == -1) {// 内网IP
					localip = ip.getHostAddress();
				}
			}
		}

		if (netip != null && !"".equals(netip)) {
			return netip;
		} else {
			return localip;
		}
	}

}