/**
* 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.tez.dag.utils;

import java.net.InetSocketAddress;
import java.util.List;
import java.util.Vector;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.yarn.api.ApplicationConstants;
import org.apache.hadoop.yarn.api.ApplicationConstants.Environment;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.tez.runtime.task.TezChild;

public class TezRuntimeChildJVM {

    // FIXME
  public static enum LogName {
    /** Log on the stdout of the task. */
    STDOUT ("stdout"),

    /** Log on the stderr of the task. */
    STDERR ("stderr"),

    /** Log on the map-reduce system logs of the task. */
    SYSLOG ("syslog"),

    /** The java profiler information. */
    PROFILE ("profile.out"),

    /** Log the debug script's stdout  */
    DEBUGOUT ("debugout");

    private String prefix;

    private LogName(String prefix) {
      this.prefix = prefix;
    }

    @Override
    public String toString() {
      return prefix;
    }
  }

  private static String getTaskLogFile(LogName filter) {
    return ApplicationConstants.LOG_DIR_EXPANSION_VAR + Path.SEPARATOR +
        filter.toString();
  }

  public static List<String> getVMCommand(
      InetSocketAddress taskAttemptListenerAddr,
      String containerIdentifier,
      String tokenIdentifier,
      int applicationAttemptNumber,
      String javaOpts) {

    Vector<String> vargs = new Vector<String>(9);

    vargs.add(Environment.JAVA_HOME.$() + "/bin/java");

    //set custom javaOpts
    vargs.add(javaOpts);

    Path childTmpDir = new Path(Environment.PWD.$(),
        YarnConfiguration.DEFAULT_CONTAINER_TEMP_DIR);
    vargs.add("-Djava.io.tmpdir=" + childTmpDir);

    // Add main class and its arguments
    vargs.add(TezChild.class.getName());  // main of Child

    // pass TaskAttemptListener's address
    vargs.add(taskAttemptListenerAddr.getAddress().getHostName());
    vargs.add(Integer.toString(taskAttemptListenerAddr.getPort()));
    vargs.add(containerIdentifier);
    vargs.add(tokenIdentifier);
    vargs.add(Integer.toString(applicationAttemptNumber));

    vargs.add("1>" + getTaskLogFile(LogName.STDOUT));
    vargs.add("2>" + getTaskLogFile(LogName.STDERR));

    // TODO Is this StringBuilder really required ? YARN already accepts a list of commands.
    // Final commmand
    StringBuilder mergedCommand = new StringBuilder();
    for (CharSequence str : vargs) {
      mergedCommand.append(str).append(" ");
    }
    Vector<String> vargsFinal = new Vector<String>(1);
    vargsFinal.add(mergedCommand.toString());
    return vargsFinal;
  }
}