/**
 * 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.shims;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.Trash;
import org.apache.hadoop.hive.shims.HadoopShimsSecure;
import org.apache.hadoop.mapred.ClusterStatus;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TaskLogServlet;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.util.Progressable;

/**
 * Implemention of shims against Hadoop 0.20 with Security.
 */
public class Hadoop20SShims extends HadoopShimsSecure {

  @Override
  public String getTaskAttemptLogUrl(JobConf conf,
    String taskTrackerHttpAddress, String taskAttemptId)
    throws MalformedURLException {
    URL taskTrackerHttpURL = new URL(taskTrackerHttpAddress);
    return TaskLogServlet.getTaskLogUrl(
      taskTrackerHttpURL.getHost(),
      Integer.toString(taskTrackerHttpURL.getPort()),
      taskAttemptId);
  }

  @Override
  public JobTrackerState getJobTrackerState(ClusterStatus clusterStatus) throws Exception {
    JobTrackerState state;
    switch (clusterStatus.getJobTrackerState()) {
    case INITIALIZING:
      return JobTrackerState.INITIALIZING;
    case RUNNING:
      return JobTrackerState.RUNNING;
    default:
      String errorMsg = "Unrecognized JobTracker state: " + clusterStatus.getJobTrackerState();
      throw new Exception(errorMsg);
    }
  }

  @Override
  public org.apache.hadoop.mapreduce.TaskAttemptContext newTaskAttemptContext(Configuration conf, final Progressable progressable) {
    return new org.apache.hadoop.mapreduce.TaskAttemptContext(conf, new TaskAttemptID()) {
      @Override
      public void progress() {
        progressable.progress();
      }
    };
  }

  @Override
  public org.apache.hadoop.mapreduce.JobContext newJobContext(Job job) {
    return new org.apache.hadoop.mapreduce.JobContext(job.getConfiguration(), job.getJobID());
  }

  @Override
  public boolean isLocalMode(Configuration conf) {
    return "local".equals(getJobLauncherRpcAddress(conf));
  }

  @Override
  public String getJobLauncherRpcAddress(Configuration conf) {
    return conf.get("mapred.job.tracker");
  }

  @Override
  public void setJobLauncherRpcAddress(Configuration conf, String val) {
    conf.set("mapred.job.tracker", val);
  }

  @Override
  public String getJobLauncherHttpAddress(Configuration conf) {
    return conf.get("mapred.job.tracker.http.address");
  }

  @Override
  public boolean moveToAppropriateTrash(FileSystem fs, Path path, Configuration conf)
          throws IOException {
    // older versions of Hadoop don't have a Trash constructor based on the
    // Path or FileSystem. So need to achieve this by creating a dummy conf.
    // this needs to be filtered out based on version

    Configuration dupConf = new Configuration(conf);
    FileSystem.setDefaultUri(dupConf, fs.getUri());
    Trash trash = new Trash(dupConf);
    return trash.moveToTrash(path);
  }
  
  @Override
  public long getDefaultBlockSize(FileSystem fs, Path path) {
    return fs.getDefaultBlockSize();
  }

  @Override
  public short getDefaultReplication(FileSystem fs, Path path) {
    return fs.getDefaultReplication();
  }  
}