package com.shawn.rule;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.ThreadLocalRandom;

import org.apache.commons.lang.math.RandomUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.ILoadBalancer;
import com.netflix.loadbalancer.RandomRule;
import com.netflix.loadbalancer.Server;
import java.net.*;
import java.util.*;
import lombok.extern.slf4j.Slf4j;

/**
 * 
 * @ClassName: GameCenterBalanceRule
 * @Description: 根据node对服务进行负载均衡。
 */
@Component
@Scope("prototype")
@Slf4j
public class NodeBalanceRule extends RandomRule {

    @Override
    public Server choose(Object key) {
        if (key == null) {
            return super.choose(null);
        }

        List<Server> servers = getLoadBalancer().getReachableServers();
//        log.info("server size is : {} , serverList is : {}" , servers.size() ,servers);


        Optional<Server> serverOpt = servers.stream().filter(server -> server.getId().contains(String.valueOf(key))).findFirst();
        if(serverOpt.isPresent()) {
        	log.info("choose rule..." + key);
        	return serverOpt.get();
        }

        // 根据本机ip，走本机的子服务
        // 获取本机ip
        String localIp = getLocalIP();
//        log.info("localIp:" + localIp);
        Optional<Server> opt_local = servers.stream().filter(server -> server.getId().contains(localIp)).findFirst();
        if(opt_local.isPresent()) { // 优先走本机
//            log.info("choose local server: {}" , opt_local.get());
            return opt_local.get();
        }else{ // 走同网段
            String localIp2 = localIp.substring(0,localIp.lastIndexOf("."));
            Optional<Server> opt_local2 = servers.stream().filter(server -> server.getId().contains(localIp2)).findFirst();
            if(opt_local2.isPresent()){
//                log.info("choose same segment: {}" , opt_local2.get());
                return opt_local2.get();
            }
        }

//        log.info("choose Random server");
        return super.choose(null);
    }

    /**
     * 获取本机ip
     * @return
     */
    public static String getLocalIP() {
        String localIP = "127.0.0.1";
        try {
            OK:
            for (Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces(); interfaces.hasMoreElements(); ) {
                NetworkInterface networkInterface = interfaces.nextElement();
                if (networkInterface.isLoopback() || networkInterface.isVirtual() || !networkInterface.isUp()) {
                    continue;
                }
                Enumeration<InetAddress> addresses = networkInterface.getInetAddresses();
                while (addresses.hasMoreElements()) {
                    InetAddress address = addresses.nextElement();
                    if (address instanceof Inet4Address) {
                        localIP = address.getHostAddress();
                        break OK;
                    }
                }
            }
        } catch (SocketException e) {
            e.printStackTrace();
        }
        return localIP;
    }

}