package com.nuvole.util;

import jakarta.servlet.http.HttpServletRequest;

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

public class IPUtil {

    /*
     * @Author : liu.q [916000612@qq.com]
     * @Date : 2019-05-11 17:06
     * @Description :获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if (ip.indexOf(",") != -1) {
                ip = ip.split(",")[0];
            }
        }
        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.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }


    /**
     * 获取本地IP地址（局域网）
     *
     * @Author: lc
     * @Date: 2019/11/8 11:59
     */
    public static String getLocalHostIp() {
        try {
            InetAddress candidateAddress = null;
            // 遍历所有的网络接口
            for (Enumeration ifaces = NetworkInterface.getNetworkInterfaces(); ifaces.hasMoreElements(); ) {
                NetworkInterface iface = (NetworkInterface) ifaces.nextElement();
                // 在所有的接口下再遍历IP
                for (Enumeration inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements(); ) {
                    InetAddress inetAddr = (InetAddress) inetAddrs.nextElement();
                    if (!inetAddr.isLoopbackAddress()) {// 排除loopback类型地址
                        if (inetAddr.isSiteLocalAddress()) {
                            // 如果是site-local地址
                            return inetAddr.toString().replace("/", "");
                        } else if (candidateAddress == null) {
                            //site-local类型的地址未被发现，先记录候选地址
                            candidateAddress = inetAddr;
                        }
                    }
                }
            }
            if (candidateAddress != null) {
                return candidateAddress.toString().replace("/", "");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }
}