/**
 * 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.gridmix;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.mapreduce.test.system.MRCluster;
import org.apache.hadoop.mapreduce.test.system.JTProtocol;
import org.apache.hadoop.mapreduce.test.system.JTClient;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobStatus;
import org.apache.hadoop.mapred.gridmix.RoundRobinUserResolver;
import org.apache.hadoop.mapred.gridmix.EchoUserResolver;
import org.apache.hadoop.mapred.gridmix.SubmitterUserResolver;
import org.apache.hadoop.mapred.gridmix.test.system.UtilsForGridmix;
import org.apache.hadoop.mapred.gridmix.test.system.GridMixRunMode;
import org.apache.hadoop.mapred.gridmix.test.system.GridMixConfig;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.ContentSummary;
import org.junit.BeforeClass;
import org.junit.AfterClass;
import org.junit.Test;
import org.junit.Assert;
import java.io.IOException;

/**
 * Verify the Gridmix data generation with various submission policies and 
 * user resolver modes.
 */
public class TestGridMixDataGeneration {
  private static final Log LOG = 
      LogFactory.getLog(TestGridMixDataGeneration.class);
  private static Configuration conf = new Configuration();
  private static MRCluster cluster;
  private static JTClient jtClient;
  private static JTProtocol rtClient;
  private static Path gridmixDir;
  private static int cSize;

  @BeforeClass
  public static void before() throws Exception {
    String [] excludeExpList = {"java.net.ConnectException", 
                                "java.io.IOException"};
    cluster = MRCluster.createCluster(conf);
    cluster.setExcludeExpList(excludeExpList);
    cluster.setUp();
    cSize = cluster.getTTClients().size();
    jtClient = cluster.getJTClient();
    rtClient = jtClient.getProxy();
    gridmixDir = new Path("herriot-gridmix");
    UtilsForGridmix.createDirs(gridmixDir, rtClient.getDaemonConf());
  }

  @AfterClass
  public static void after() throws Exception {
    UtilsForGridmix.cleanup(gridmixDir,conf);
    cluster.tearDown();
  }
  
  /**
   * Generate the data in a STRESS submission policy with SubmitterUserResolver 
   * mode and verify whether the generated data matches with given 
   * input size or not.
   * @throws IOException
   */
  @Test
  public void testGenerateDataWithSTRESSSubmission() throws Exception {
    conf = rtClient.getDaemonConf();
    final long inputSizeInMB = cSize * 128;
    String [] runtimeValues = {"LOADJOB",
                               SubmitterUserResolver.class.getName(),
                               "STRESS",
                               inputSizeInMB + "m",
                               "file:///dev/null"};

    String [] otherArgs = {
        "-D", GridMixConfig.GRIDMIX_DISTCACHE_ENABLE + "=false", 
        "-D", GridMixConfig.GRIDMIX_COMPRESSION_ENABLE + "=false"
    };
    int exitCode = 
        UtilsForGridmix.runGridmixJob(gridmixDir, conf, 
            GridMixRunMode.DATA_GENERATION.getValue(), 
            runtimeValues, otherArgs);
    Assert.assertEquals("Data generation has failed.", 0 , exitCode);
    checkGeneratedDataAndJobStatus(inputSizeInMB);
  }
  
  /**
   * Generate the data in a REPLAY submission policy with RoundRobinUserResolver
   * mode and verify whether the generated data matches with the given 
   * input size or not.
   * @throws Exception
   */
  @Test
  public void testGenerateDataWithREPLAYSubmission() throws Exception {
    conf = rtClient.getDaemonConf();
    final long inputSizeInMB = cSize * 300;
    String [] runtimeValues = 
               {"LOADJOB",
                RoundRobinUserResolver.class.getName(),
                "REPLAY",
                inputSizeInMB +"m",
                "file://" + UtilsForGridmix.getProxyUsersFile(conf),
                "file:///dev/null"};
    
    String [] otherArgs = {
        "-D", GridMixConfig.GRIDMIX_DISTCACHE_ENABLE + "=false", 
        "-D", GridMixConfig.GRIDMIX_COMPRESSION_ENABLE + "=false"
    };

    int exitCode = 
        UtilsForGridmix.runGridmixJob(gridmixDir, conf, 
            GridMixRunMode.DATA_GENERATION.getValue(), 
            runtimeValues, otherArgs);
    Assert.assertEquals("Data generation has failed.", 0 , exitCode);
    checkGeneratedDataAndJobStatus(inputSizeInMB); 
  }
  
  /**
   * Generate the data in a SERIAL submission policy with EchoUserResolver
   * mode and also set the no.of bytes per file in the data.Verify whether each 
   * file size matches with given per file size or not and also 
   * verify the overall size of generated data.
   * @throws Exception
   */
  @Test
  public void testGenerateDataWithSERIALSubmission() throws Exception {
    conf = rtClient.getDaemonConf();
    long perNodeSizeInMB = 500; // 500 mb per node data
    final long inputSizeInMB = cSize * perNodeSizeInMB;
    String [] runtimeValues ={"LOADJOB", 
                              EchoUserResolver.class.getName(), 
                              "SERIAL", 
                              inputSizeInMB + "m", 
                              "file:///dev/null"};
    long bytesPerFile = 200  * 1024 * 1024; // 200 mb per file of data
    String [] otherArgs = {
        "-D", GridMixConfig.GRIDMIX_BYTES_PER_FILE + "=" + bytesPerFile, 
        "-D", GridMixConfig.GRIDMIX_DISTCACHE_ENABLE + "=false", 
        "-D", GridMixConfig.GRIDMIX_COMPRESSION_ENABLE + "=false"
    };
    int exitCode = 
        UtilsForGridmix.runGridmixJob(gridmixDir, conf, 
            GridMixRunMode.DATA_GENERATION.getValue(), 
            runtimeValues, otherArgs);
    Assert.assertEquals("Data generation has failed.", 0 , exitCode);
    LOG.info("Verify the eache file size in a generate data.");
    verifyEachNodeSize(new Path(gridmixDir, "input"), perNodeSizeInMB);
    verifyNumOfFilesGeneratedInEachNode(new Path(gridmixDir, "input"), 
                                        perNodeSizeInMB, bytesPerFile);
    checkGeneratedDataAndJobStatus(inputSizeInMB);
  }
  
  private void checkGeneratedDataAndJobStatus(long inputSize) 
      throws IOException {
    LOG.info("Verify the generated data size.");
    long dataSizeInMB = getDataSizeInMB(new Path(gridmixDir,"input"));
    Assert.assertTrue("Generate data has not matched with given size",
       dataSizeInMB + 0.1 > inputSize || dataSizeInMB - 0.1 < inputSize);
 
    JobClient jobClient = jtClient.getClient();
    int len = jobClient.getAllJobs().length;
    LOG.info("Verify the job status after completion of job.");
    Assert.assertEquals("Job has not succeeded.", JobStatus.SUCCEEDED, 
                        jobClient.getAllJobs()[len-1].getRunState());
  }
  
  private void verifyEachNodeSize(Path inputDir, long dataSizePerNode) 
      throws IOException {
    FileSystem fs = inputDir.getFileSystem(conf);
    FileStatus [] fstatus = fs.listStatus(inputDir);
    for (FileStatus fstat : fstatus) {
      if ( fstat.isDirectory()) {
        long fileSize = getDataSizeInMB(fstat.getPath());
        Assert.assertTrue("The Size has not matched with given "
                         + "per node file size(" + dataSizePerNode +"MB)", 
                         fileSize + 0.1 > dataSizePerNode 
                         || fileSize - 0.1 < dataSizePerNode);
      }
    }    
  }

  private void verifyNumOfFilesGeneratedInEachNode(Path inputDir, 
      long nodeSize, long fileSize) throws IOException {
    long fileCount = nodeSize/fileSize;
    long expFileCount = Math.round(fileCount);
    expFileCount = expFileCount + ((nodeSize%fileSize != 0)? 1:0);
    FileSystem fs = inputDir.getFileSystem(conf);
    FileStatus [] fstatus = fs.listStatus(inputDir);
    for (FileStatus fstat : fstatus) {
      if ( fstat.isDirectory()) {
        FileSystem nodeFs = fstat.getPath().getFileSystem(conf);
        long actFileCount = nodeFs.getContentSummary(
            fstat.getPath()).getFileCount();
        Assert.assertEquals("File count has not matched.", expFileCount, 
                            actFileCount);
      }
    }
  }

  private static long getDataSizeInMB(Path inputDir) throws IOException {
    FileSystem fs = inputDir.getFileSystem(conf);
    ContentSummary csmry = fs.getContentSummary(inputDir);
    long dataSize = csmry.getLength();
    dataSize = dataSize/(1024 * 1024);
    return dataSize;
  }
}