/**
 * 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.mapred.jobcontrol;

import java.io.IOException;
import java.text.NumberFormat;
import java.util.Iterator;
import java.util.ArrayList;
import java.util.Random;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;

/**
 * This class performs unit test for Job/JobControl classes.
 *  
 * @author runping
 *
 */
public class TestJobControl extends junit.framework.TestCase {

  private static NumberFormat idFormat = NumberFormat.getInstance();
  static {
    idFormat.setMinimumIntegerDigits(4);
    idFormat.setGroupingUsed(false);
  }

  static private Random rand = new Random();

  private static void cleanData(FileSystem fs, Path dirPath)
    throws IOException {
    fs.delete(dirPath);
  }

  private static String generateRandomWord() {
    return idFormat.format(rand.nextLong());
  }

  private static String generateRandomLine() {
    long r = rand.nextLong() % 7;
    long n = r + 20;
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < n; i++) {
      sb.append(generateRandomWord()).append(" ");
    }
    sb.append("\n");
    return sb.toString();
  }

  private static void generateData(FileSystem fs, Path dirPath)
    throws IOException {
    FSDataOutputStream out = fs.create(new Path(dirPath, "data.txt"));
    for (int i = 0; i < 100000; i++) {
      String line = TestJobControl.generateRandomLine();
      out.write(line.getBytes("UTF-8"));
    }
    out.close();
  }

  public static class DataCopy extends MapReduceBase implements Mapper,
                                                                Reducer {
    public void map(WritableComparable key, Writable value,
                    OutputCollector output, Reporter reporter) throws IOException {
      output.collect(new Text(key.toString()), value);
    }

    public void reduce(WritableComparable key, Iterator values,
                       OutputCollector output, Reporter reporter) throws IOException {
      Text dumbKey = new Text("");
      while (values.hasNext()) {
        Text data = (Text) values.next();
        output.collect(dumbKey, data);
      }
    }
  }

  private static JobConf createCopyJob(ArrayList indirs, Path outdir)
    throws Exception {

    Configuration defaults = new Configuration();
    JobConf theJob = new JobConf(defaults, TestJobControl.class);
    theJob.setJobName("DataMoveJob");

    theJob.setInputPath((Path) indirs.get(0));
    if (indirs.size() > 1) {
      for (int i = 1; i < indirs.size(); i++) {
        theJob.addInputPath((Path) indirs.get(i));
      }
    }
    theJob.setMapperClass(DataCopy.class);
    theJob.setOutputPath(outdir);
    theJob.setOutputKeyClass(Text.class);
    theJob.setOutputValueClass(Text.class);
    theJob.setReducerClass(DataCopy.class);
    theJob.setNumMapTasks(12);
    theJob.setNumReduceTasks(4);
    return theJob;
  }

  /**
   * This is a main function for testing JobControl class.
   * It first cleans all the dirs it will use. Then it generates some random text
   * data in TestJobControlData/indir. Then it creates 4 jobs: 
   *      Job 1: copy data from indir to outdir_1
   *      Job 2: copy data from indir to outdir_2
   *      Job 3: copy data from outdir_1 and outdir_2 to outdir_3
   *      Job 4: copy data from outdir to outdir_4
   * The jobs 1 and 2 have no dependency. The job 3 depends on jobs 1 and 2.
   * The job 4 depends on job 3.
   * 
   * Then it creates a JobControl object and add the 4 jobs to the JobControl object.
   * Finally, it creates a thread to run the JobControl object and monitors/reports
   * the job states.
   * 
   * @param args
   */
  public static void doJobControlTest() throws Exception {
        
    Configuration defaults = new Configuration();
    FileSystem fs = FileSystem.get(defaults);
    Path rootDataDir = new Path(System.getProperty("test.build.data", "."), "TestJobControlData");
    Path indir = new Path(rootDataDir, "indir");
    Path outdir_1 = new Path(rootDataDir, "outdir_1");
    Path outdir_2 = new Path(rootDataDir, "outdir_2");
    Path outdir_3 = new Path(rootDataDir, "outdir_3");
    Path outdir_4 = new Path(rootDataDir, "outdir_4");

    cleanData(fs, indir);
    generateData(fs, indir);

    cleanData(fs, outdir_1);
    cleanData(fs, outdir_2);
    cleanData(fs, outdir_3);
    cleanData(fs, outdir_4);

    ArrayList<Job> dependingJobs = null;

    ArrayList<Path> inPaths_1 = new ArrayList<Path>();
    inPaths_1.add(indir);
    JobConf jobConf_1 = createCopyJob(inPaths_1, outdir_1);
    Job job_1 = new Job(jobConf_1, dependingJobs);
    ArrayList<Path> inPaths_2 = new ArrayList<Path>();
    inPaths_2.add(indir);
    JobConf jobConf_2 = createCopyJob(inPaths_2, outdir_2);
    Job job_2 = new Job(jobConf_2, dependingJobs);

    ArrayList<Path> inPaths_3 = new ArrayList<Path>();
    inPaths_3.add(outdir_1);
    inPaths_3.add(outdir_2);
    JobConf jobConf_3 = createCopyJob(inPaths_3, outdir_3);
    dependingJobs = new ArrayList<Job>();
    dependingJobs.add(job_1);
    dependingJobs.add(job_2);
    Job job_3 = new Job(jobConf_3, dependingJobs);

    ArrayList<Path> inPaths_4 = new ArrayList<Path>();
    inPaths_4.add(outdir_3);
    JobConf jobConf_4 = createCopyJob(inPaths_4, outdir_4);
    dependingJobs = new ArrayList<Job>();
    dependingJobs.add(job_3);
    Job job_4 = new Job(jobConf_4, dependingJobs);

    JobControl theControl = new JobControl("Test");
    theControl.addJob(job_1);
    theControl.addJob(job_2);
    theControl.addJob(job_3);
    theControl.addJob(job_4);

    Thread theController = new Thread(theControl);
    theController.start();
    while (!theControl.allFinished()) {

      System.out.println("Jobs in waiting state: "
                         + theControl.getWaitingJobs().size());
      System.out.println("Jobs in ready state: "
                         + theControl.getReadyJobs().size());
      System.out.println("Jobs in running state: "
                         + theControl.getRunningJobs().size());
      System.out.println("Jobs in success state: "
                         + theControl.getSuccessfulJobs().size());
      System.out.println("Jobs in failed state: "
                         + theControl.getFailedJobs().size());
      System.out.println("\n");

      try {
        Thread.sleep(5000);
      } catch (Exception e) {

      }
    }
    System.out.println("Jobs are all done???");
    System.out.println("Jobs in waiting state: "
                       + theControl.getWaitingJobs().size());
    System.out.println("Jobs in ready state: "
                       + theControl.getReadyJobs().size());
    System.out.println("Jobs in running state: "
                       + theControl.getRunningJobs().size());
    System.out.println("Jobs in success state: "
                       + theControl.getSuccessfulJobs().size());
    System.out.println("Jobs in failed state: "
                       + theControl.getFailedJobs().size());
    System.out.println("\n");
        
    if (job_1.getState() != Job.FAILED && 
        job_1.getState() != Job.DEPENDENT_FAILED && 
        job_1.getState() != Job.SUCCESS) {
           
      String states = "job_1:  " + job_1.getState() + "\n";
      throw new Exception("The state of job_1 is not in a complete state\n" + states);
    }
        
    if (job_2.getState() != Job.FAILED &&
        job_2.getState() != Job.DEPENDENT_FAILED && 
        job_2.getState() != Job.SUCCESS) {
           
      String states = "job_2:  " + job_2.getState() + "\n";
      throw new Exception("The state of job_2 is not in a complete state\n" + states);
    }
        
    if (job_3.getState() != Job.FAILED && 
        job_3.getState() != Job.DEPENDENT_FAILED && 
        job_3.getState() != Job.SUCCESS) {
           
      String states = "job_3:  " + job_3.getState() + "\n";
      throw new Exception("The state of job_3 is not in a complete state\n" + states);
    }
    if (job_4.getState() != Job.FAILED && 
        job_4.getState() != Job.DEPENDENT_FAILED && 
        job_4.getState() != Job.SUCCESS) {
           
      String states = "job_4:  " + job_4.getState() + "\n";
      throw new Exception("The state of job_4 is not in a complete state\n" + states);
    }
        
    if (job_1.getState() == Job.FAILED || 
        job_2.getState() == Job.FAILED ||
        job_1.getState() == Job.DEPENDENT_FAILED || 
        job_2.getState() == Job.DEPENDENT_FAILED) {
      if (job_3.getState() != Job.DEPENDENT_FAILED) {
        String states = "job_1:  " + job_1.getState() + "\n";
        states = "job_2:  " + job_2.getState() + "\n";
        states = "job_3:  " + job_3.getState() + "\n";
        states = "job_4:  " + job_4.getState() + "\n";
        throw new Exception("The states of jobs 1, 2, 3, 4 are not consistent\n" + states);
      }
    }
    if (job_3.getState() == Job.FAILED || 
        job_3.getState() == Job.DEPENDENT_FAILED) {
      if (job_4.getState() != Job.DEPENDENT_FAILED) {
        String states = "job_3:  " + job_3.getState() + "\n";
        states = "job_4:  " + job_4.getState() + "\n";
        throw new Exception("The states of jobs 3, 4 are not consistent\n" + states);
      }
    }
        
    theControl.stop();
  }

  public void testJobControl() throws Exception {
    doJobControlTest();
  }
    
  public static void main(String[] args) {
    TestJobControl test = new TestJobControl();
    try {
      test.testJobControl();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}
