/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.hadoop.hive.llap.tezplugins.helpers;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
import org.apache.hadoop.hive.llap.protocol.LlapTaskUmbilicalProtocol;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.mapreduce.MRJobConfig;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.authorize.PolicyProvider;
import org.apache.hadoop.security.authorize.Service;
import org.apache.hadoop.security.token.Token;
import org.apache.tez.common.security.JobTokenIdentifier;
import org.apache.tez.common.security.JobTokenSecretManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LlapTaskUmbilicalServer {

  private static final Logger LOG = LoggerFactory.getLogger(LlapTaskUmbilicalServer.class);

  protected volatile Server server;
  private final InetSocketAddress address;
  private final AtomicBoolean started = new AtomicBoolean(true);

  public LlapTaskUmbilicalServer(Configuration conf, LlapTaskUmbilicalProtocol umbilical, int numHandlers, String tokenIdentifier, Token<JobTokenIdentifier> token) throws
      IOException {
    JobTokenSecretManager jobTokenSecretManager =
        new JobTokenSecretManager();
    jobTokenSecretManager.addTokenForJob(tokenIdentifier, token);

    server = new RPC.Builder(conf)
        .setProtocol(LlapTaskUmbilicalProtocol.class)
        .setBindAddress("0.0.0.0")
        .setPort(0)
        .setInstance(umbilical)
        .setNumHandlers(numHandlers)
        .setSecretManager(jobTokenSecretManager).build();

    if (conf.getBoolean(CommonConfigurationKeysPublic.HADOOP_SECURITY_AUTHORIZATION, false)) {
      server.refreshServiceAcl(conf, new LlapUmbilicalExternalPolicyProvider());
    }

    server.start();
    this.address = NetUtils.getConnectAddress(server);
    LOG.info(
        "Started TaskUmbilicalServer: " + umbilical.getClass().getName() + " at address: " + address +
            " with numHandlers=" + numHandlers);
  }

  public InetSocketAddress getAddress() {
    return this.address;
  }

  public int getNumOpenConnections() {
    return server.getNumOpenConnections();
  }

  public void shutdownServer() {
    if (started.get()) { // Primarily to avoid multiple shutdowns.
      started.set(false);
      server.stop();
    }
  }

  public static class LlapUmbilicalExternalPolicyProvider extends PolicyProvider {

    private static final Service[] services = {
      new Service(
          MRJobConfig.MR_AM_SECURITY_SERVICE_AUTHORIZATION_TASK_UMBILICAL,
          LlapTaskUmbilicalProtocol.class)
    };

    @Override
    public Service[] getServices() {
      return services.clone();
    }
  }
}