package com.artisan.customrules;
import com.alibaba.cloud.nacos.NacosDiscoveryProperties;
import com.alibaba.cloud.nacos.ribbon.NacosServer;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.BaseLoadBalancer;
import com.netflix.loadbalancer.Server;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.StringUtils;
import java.util.ArrayList;
import java.util.List;
/**
 * @author 小工匠
 * @version 1.0
 * @description: 同一个集群优先调用策略
 * @date 2022/2/3 0:47
 * @mark: show me the code , change the world
 */
@Slf4j
public class SameClusterPriorityRule extends AbstractLoadBalancerRule {
    @Autowired
    private NacosDiscoveryProperties discoveryProperties;
    @Override
    public void initWithNiwsConfig(IClientConfig iClientConfig) {
    }
    @Override
    public Server choose(Object key) {
        try {
            //第一步:获取当前服务所在的集群
            String currentClusterName = discoveryProperties.getClusterName();
            //第二步:获取一个负载均衡对象
            BaseLoadBalancer baseLoadBalancer = (BaseLoadBalancer) getLoadBalancer();
            //第三步:获取当前调用的微服务的名称
            String invokedSerivceName = baseLoadBalancer.getName();
            //第四步:获取nacos clinet的服务注册发现组件的api
            NamingService namingService = discoveryProperties.namingServiceInstance();
            //第五步:获取所有的服务实例
            List<Instance> allInstance = namingService.getAllInstances(invokedSerivceName);
            List<Instance> theSameClusterNameInstList = new ArrayList<>();
            //第六步:过滤筛选同集群下的所有实例
            for (Instance instance : allInstance) {
                if (StringUtils.endsWithIgnoreCase(instance.getClusterName(), currentClusterName)) {
                    theSameClusterNameInstList.add(instance);
                }
            }
            Instance toBeChooseInstance;
            //第七步:选择合适的一个实例调用
            if (theSameClusterNameInstList.isEmpty()) {
                toBeChooseInstance = ArtisanWeightedBalancer.chooseInstanceByRandomWeight(allInstance);
                log.info("发生跨集群调用--->当前微服务所在集群:{},被调用微服务所在集群:{},Host:{},Port:{}",
                        currentClusterName, toBeChooseInstance.getClusterName(), toBeChooseInstance.getIp(), toBeChooseInstance.getPort());
            } else {
                toBeChooseInstance = ArtisanWeightedBalancer.chooseInstanceByRandomWeight(theSameClusterNameInstList);
                log.info("同集群调用--->当前微服务所在集群:{},被调用微服务所在集群:{},Host:{},Port:{}",
                        currentClusterName, toBeChooseInstance.getClusterName(), toBeChooseInstance.getIp(), toBeChooseInstance.getPort());
            }
            return new NacosServer(toBeChooseInstance);
        } catch (NacosException e) {
            log.error("同集群优先权重负载均衡算法选择异常:{}", e);
        }
        return null;
    }
}