package com.walker.web.util;

import com.fasterxml.jackson.databind.node.ObjectNode;
import com.walker.infrastructure.utils.JsonUtils;
import com.walker.infrastructure.utils.StringUtils;
import com.walker.web.Constants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

/**
 * 获取IP方法
 *
 * @author Mike
 */
public class IpUtils {

    protected static final transient Logger logger = LoggerFactory.getLogger(IpUtils.class);

    public static final String UNKNOWN_TEXT = "unknown";
    public static final String LOCALHOST = "127.0.0.1";

    /**
     * 获取客户端IP
     *
     * @param request 请求对象
     * @return IP地址
     */
    public static String getIpAddr(HttpServletRequest request)
    {
        if (request == null)
        {
            return "unknown";
        }
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || UNKNOWN_TEXT.equalsIgnoreCase(ip))
        {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_TEXT.equalsIgnoreCase(ip))
        {
            ip = request.getHeader("X-Forwarded-For");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_TEXT.equalsIgnoreCase(ip))
        {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN_TEXT.equalsIgnoreCase(ip))
        {
            ip = request.getHeader("X-Real-IP");
        }

        if (ip == null || ip.length() == 0 || UNKNOWN_TEXT.equalsIgnoreCase(ip))
        {
            ip = request.getRemoteAddr();
        }

        return "0:0:0:0:0:0:0:1".equals(ip) ? LOCALHOST : getMultistageReverseProxyIp(ip);
    }

    /**
     * 检查是否为内部IP地址
     *
     * @param ip IP地址
     * @return 结果
     */
    public static boolean internalIp(String ip)
    {
        byte[] addr = textToNumericFormatV4(ip);
        return internalIp(addr) || LOCALHOST.equals(ip);
    }

    /**
     * 检查是否为内部IP地址
     *
     * @param addr byte地址
     * @return 结果
     */
    private static boolean internalIp(byte[] addr)
    {
        if (addr == null || addr.length < 2)
        {
            return true;
        }
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        // 10.x.x.x/8
        final byte SECTION_1 = 0x0A;
        // 172.16.x.x/12
        final byte SECTION_2 = (byte) 0xAC;
        final byte SECTION_3 = (byte) 0x10;
        final byte SECTION_4 = (byte) 0x1F;
        // 192.168.x.x/16
        final byte SECTION_5 = (byte) 0xC0;
        final byte SECTION_6 = (byte) 0xA8;
        switch (b0)
        {
            case SECTION_1:
                return true;
            case SECTION_2:
                if (b1 >= SECTION_3 && b1 <= SECTION_4)
                {
                    return true;
                }
            case SECTION_5:
                switch (b1)
                {
                    case SECTION_6:
                        return true;
                }
            default:
                return false;
        }
    }

    /**
     * 将IPv4地址转换成字节
     *
     * @param text IPv4地址
     * @return byte 字节
     */
    public static byte[] textToNumericFormatV4(String text)
    {
        if (text.length() == 0)
        {
            return null;
        }

        byte[] bytes = new byte[4];
        String[] elements = text.split("\\.", -1);
        try
        {
            long l;
            int i;
            switch (elements.length)
            {
                case 1:
                    l = Long.parseLong(elements[0]);
                    if ((l < 0L) || (l > 4294967295L))
                    {
                        return null;
                    }
                    bytes[0] = (byte) (int) (l >> 24 & 0xFF);
                    bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
                    bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 2:
                    l = Integer.parseInt(elements[0]);
                    if ((l < 0L) || (l > 255L))
                    {
                        return null;
                    }
                    bytes[0] = (byte) (int) (l & 0xFF);
                    l = Integer.parseInt(elements[1]);
                    if ((l < 0L) || (l > 16777215L))
                    {
                        return null;
                    }
                    bytes[1] = (byte) (int) (l >> 16 & 0xFF);
                    bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 3:
                    for (i = 0; i < 2; ++i)
                    {
                        l = Integer.parseInt(elements[i]);
                        if ((l < 0L) || (l > 255L))
                        {
                            return null;
                        }
                        bytes[i] = (byte) (int) (l & 0xFF);
                    }
                    l = Integer.parseInt(elements[2]);
                    if ((l < 0L) || (l > 65535L))
                    {
                        return null;
                    }
                    bytes[2] = (byte) (int) (l >> 8 & 0xFF);
                    bytes[3] = (byte) (int) (l & 0xFF);
                    break;
                case 4:
                    for (i = 0; i < 4; ++i)
                    {
                        l = Integer.parseInt(elements[i]);
                        if ((l < 0L) || (l > 255L))
                        {
                            return null;
                        }
                        bytes[i] = (byte) (int) (l & 0xFF);
                    }
                    break;
                default:
                    return null;
            }
        }
        catch (NumberFormatException e)
        {
            return null;
        }
        return bytes;
    }

    /**
     * 获取IP地址
     *
     * @return 本地IP地址
     */
    public static String getHostIp()
    {
        try
        {
            return InetAddress.getLocalHost().getHostAddress();
        }
        catch (UnknownHostException e)
        {
        }
        return LOCALHOST;
    }

    /**
     * 获取主机名
     *
     * @return 本地主机名
     */
    public static String getHostName()
    {
        try
        {
            return InetAddress.getLocalHost().getHostName();
        }
        catch (UnknownHostException e)
        {
        }
        return "未知";
    }

    /**
     * 从多级反向代理中获得第一个非unknown IP地址
     *
     * @param ip 获得的IP地址
     * @return 第一个非unknown IP地址
     */
    public static String getMultistageReverseProxyIp(String ip)
    {
        // 多级反向代理检测
        if (ip != null && ip.indexOf(StringUtils.DEFAULT_SPLIT_SEPARATOR) > 0)
        {
            final String[] ips = ip.trim().split(StringUtils.DEFAULT_SPLIT_SEPARATOR);
            for (String subIp : ips)
            {
                if (false == isUnknown(subIp))
                {
                    ip = subIp;
                    break;
                }
            }
        }
        return ip;
    }

    /**
     * 检测给定字符串是否为未知，多用于检测HTTP请求相关
     *
     * @param checkString 被检测的字符串
     * @return 是否未知
     */
    public static boolean isUnknown(String checkString) {
        return StringUtils.isEmpty(checkString) || UNKNOWN_TEXT.equalsIgnoreCase(checkString);
    }

    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    //~ 根据IP调用第三方服务查询地理位置名称，2023-01-05
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    // IP地址查询
    public static final String IP_URL = "http://whois.pconline.com.cn/ipJson.jsp";

    /**
     * 根据IP地址调用三方服务，查询位置信息: 省 市
     * @param ip
     * @return
     */
    public static String getLocationByIP(String ip){
        // 内网不查询
        if (IpUtils.internalIp(ip)) {
            return "内网IP";
        }
        try {
            String rspStr = HttpUtils.sendGet(IP_URL, "ip=" + ip + "&json=true", Constants.CHARSET_GBK);
            if (StringUtils.isEmpty(rspStr))
            {
                logger.error("获取地理位置异常 {}", ip);
                return UNKNOWN_TEXT;
            }
            ObjectNode objectNode = JsonUtils.jsonStringToObjectNode(rspStr);
            if(objectNode == null){
                return StringUtils.EMPTY_STRING;
            }
            String region = objectNode.get("pro").asText();
            String city = objectNode.get("city").asText();
//            JSONObject obj = JSON.parseObject(rspStr);
//            String region = obj.getString("pro");
//            String city = obj.getString("city");
            return String.format("%s %s", region, city);
        }
        catch (Exception e) {
            logger.error("获取地理位置异常 {}", ip);
            return StringUtils.EMPTY_STRING;
        }
    }

    /**
     * 获取ip地址对应的城市区域信息。
     * @param ip
     * @param restTemplate
     * @return
     * @date 2023-06-29
     */
    public static final Location getLocationAli(String ip, RestTemplate restTemplate){
        Map<String, String> map = new HashMap();
        map.put("ip", ip);
        map.put("accessKey", "alibaba-inc");

        try{
            ResponseEntity<String> entity = restTemplate.postForEntity(LOCATION_URL_TAOBAO, map, String.class);
            if(!entity.getStatusCode().is2xxSuccessful()){
                logger.error("ip远程获取locatioin错误:" + entity.getBody());
                return null;
            }
            String data = entity.getBody();
            if(StringUtils.isEmpty(data)){
                logger.error("ip获取location远程返回空数据，ip = " + ip);
                return null;
            }
            Map<String, Object> locationMap = JsonUtils.jsonStringToObject(data, Map.class);
            if ("query success".equals(locationMap.get("msg").toString())) {
                Location location = new Location();
                location.setCountry(locationMap.get("country").toString());
                location.setCity(locationMap.get("city").toString());
                location.setRegion(locationMap.get("region").toString());
                return location;
            }
            return null;

        } catch (Exception ex){
            logger.error("ip获取location错误:" + ex.getMessage(), ex);
            return null;
        }
    }

    private static final String LOCATION_URL_TAOBAO = "http://ip.taobao.com/outGetIpInfo";
}