package com.corewing.app.util;

import javax.servlet.http.HttpServletRequest;

/**
 * IP 工具类
 */
public class IpUtil {

    /**
     * 获取客户端真实IP
     *
     * @param request HttpServletRequest
     * @return 客户端IP地址
     */
    public static String getClientIp(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        // 对于通过多个代理的情况，第一个IP为客户端真实IP，多个IP按照','分割
        if (ip != null && ip.length() > 15 && ip.contains(",")) {
            ip = ip.substring(0, ip.indexOf(","));
        }

        return ip;
    }
}
