content: /*
   * Copyright 1999-2022 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  package com.alibaba.nacos.istio.xds;
  
  import com.alibaba.nacos.istio.api.ApiGenerator;
  import com.alibaba.nacos.istio.misc.IstioConfig;
  import com.alibaba.nacos.istio.misc.Loggers;
  import com.alibaba.nacos.istio.model.IstioService;
  import com.alibaba.nacos.istio.model.PushRequest;
  import com.google.protobuf.Any;
  import io.envoyproxy.envoy.config.cluster.v3.Cluster;
  import io.envoyproxy.envoy.config.core.v3.AggregatedConfigSource;
  import io.envoyproxy.envoy.config.core.v3.ConfigSource;
  import io.envoyproxy.envoy.config.core.v3.Http1ProtocolOptions;
  import io.envoyproxy.envoy.config.core.v3.Http2ProtocolOptions;
  import io.envoyproxy.envoy.config.core.v3.TrafficDirection;
  import io.envoyproxy.envoy.service.discovery.v3.Resource;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import static com.alibaba.nacos.istio.api.ApiConstants.CLUSTER_TYPE;
  import static com.alibaba.nacos.istio.util.IstioCrdUtil.buildClusterName;
  import static io.envoyproxy.envoy.config.core.v3.ApiVersion.V2_VALUE;
  
  /**
   * @author RocketEngine26
   * @date 2022/8/17
   */
  public final class CdsGenerator implements ApiGenerator<Any> {
      
      private static volatile CdsGenerator singleton = null;
      
      public static CdsGenerator getInstance() {
          if (singleton == null) {
              synchronized (CdsGenerator.class) {
                  if (singleton == null) {
                      singleton = new CdsGenerator();
                  }
              }
          }
          return singleton;
      }
      
      @Override
      public List<Any> generate(PushRequest pushRequest) {
          if (!pushRequest.isFull()) {
              return null;
          }
          List<Any> result = new ArrayList<>();
          IstioConfig istioConfig = pushRequest.getResourceSnapshot().getIstioConfig();
          Map<String, IstioService> istioServiceMap = pushRequest.getResourceSnapshot().getIstioResources().getIstioServiceMap();
          for (Map.Entry<String, IstioService> entry : istioServiceMap.entrySet()) {
              String name = buildClusterName(TrafficDirection.OUTBOUND, "",
                      entry.getKey() + '.' +  istioConfig.getDomainSuffix(), entry.getValue().getPort());
              
              Cluster.Builder cluster = Cluster.newBuilder().setName(name).setType(Cluster.DiscoveryType.EDS)
                      .setEdsClusterConfig(Cluster.EdsClusterConfig.newBuilder().setServiceName(name).setEdsConfig(
                              ConfigSource.newBuilder().setAds(AggregatedConfigSource.newBuilder())
                                      .setResourceApiVersionValue(V2_VALUE).build()).build());
              if ("grpc".equals(entry.getValue().getProtocol())) {
                  cluster.setHttp2ProtocolOptions(Http2ProtocolOptions.newBuilder().build());
              } else {
                  cluster.setHttpProtocolOptions(Http1ProtocolOptions.newBuilder().build());
              }
      
              result.add(Any.newBuilder().setValue(cluster.build().toByteString()).setTypeUrl(CLUSTER_TYPE).build());
          }
          
          return result;
      }
      
      @Override
      public List<Resource> deltaGenerate(PushRequest pushRequest) {
          Loggers.MAIN.info("Delta Cds Not supported");
          return null;
      }
  }