/**
    *
    * 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.hbase.mapreduce;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotEquals;
  import static org.junit.Assert.assertTrue;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.NavigableMap;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.HTable;
  import org.apache.hadoop.hbase.client.Result;
  import org.apache.hadoop.hbase.client.Scan;
  import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.mapreduce.InputSplit;
  import org.apache.hadoop.mapreduce.Job;
  import org.apache.hadoop.mapreduce.Reducer;
  import org.apache.hadoop.mapreduce.TaskCounter;
  import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
  import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
  import org.junit.AfterClass;
  import org.junit.Assert;
  import org.junit.BeforeClass;
  
  
  /**
   * <p>
   * Tests various scan start and stop row scenarios. This is set in a scan and
   * tested in a MapReduce job to see if that is handed over and done properly
   * too.
   * </p>
   * <p>
   * This test is broken into two parts in order to side-step the test timeout
   * period of 900, as documented in HBASE-8326.
   * </p>
   */
  public abstract class TestTableInputFormatScanBase {
  
    private static final Log LOG = LogFactory.getLog(TestTableInputFormatScanBase.class);
    static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  
    static final byte[] TABLE_NAME = Bytes.toBytes("scantest");
    static final byte[] INPUT_FAMILY = Bytes.toBytes("contents");
    static final byte[][] INPUT_FAMILYS = {Bytes.toBytes("content1"), Bytes.toBytes("content2")};
    static final String KEY_STARTROW = "startRow";
    static final String KEY_LASTROW = "stpRow";
  
    private static HTable table = null;
  
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      // test intermittently fails under hadoop2 (2.0.2-alpha) if shortcircuit-read (scr) is on.
      // this turns it off for this test.  TODO: Figure out why scr breaks recovery. 
      System.setProperty("hbase.tests.use.shortcircuit.reads", "false");
  
      // switch TIF to log at DEBUG level
      TEST_UTIL.enableDebug(TableInputFormat.class);
      TEST_UTIL.enableDebug(TableInputFormatBase.class);
      TEST_UTIL.setJobWithoutMRCluster();
      // start mini hbase cluster
      TEST_UTIL.startMiniCluster(3);
      // create and fill table
      table = TEST_UTIL.createMultiRegionTable(TableName.valueOf(TABLE_NAME), INPUT_FAMILY);
      TEST_UTIL.loadTable(table, INPUT_FAMILY, false);
    }
  
    @AfterClass
    public static void tearDownAfterClass() throws Exception {
      TEST_UTIL.shutdownMiniCluster();
    }
 
   /**
    * Pass the key and value to reduce.
    */
   public static class ScanMapper
   extends TableMapper<ImmutableBytesWritable, ImmutableBytesWritable> {
 
     /**
      * Pass the key and value to reduce.
      *
      * @param key  The key, here "aaa", "aab" etc.
      * @param value  The value is the same as the key.
      * @param context  The task context.
      * @throws IOException When reading the rows fails.
      */
     @Override
     public void map(ImmutableBytesWritable key, Result value,
       Context context)
     throws IOException, InterruptedException {
       if (value.size() != 1) {
         throw new IOException("There should only be one input column");
       }
       Map<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>>
         cf = value.getMap();
       if(!cf.containsKey(INPUT_FAMILY)) {
         throw new IOException("Wrong input columns. Missing: '" +
           Bytes.toString(INPUT_FAMILY) + "'.");
       }
       String val = Bytes.toStringBinary(value.getValue(INPUT_FAMILY, null));
       LOG.info("map: key -> " + Bytes.toStringBinary(key.get()) +
         ", value -> " + val);
       context.write(key, key);
     }
 
   }
 
   /**
    * Checks the last and first key seen against the scanner boundaries.
    */
   public static class ScanReducer
   extends Reducer<ImmutableBytesWritable, ImmutableBytesWritable,
                   NullWritable, NullWritable> {
 
     private String first = null;
     private String last = null;
 
     protected void reduce(ImmutableBytesWritable key,
         Iterable<ImmutableBytesWritable> values, Context context)
     throws IOException ,InterruptedException {
       int count = 0;
       for (ImmutableBytesWritable value : values) {
         String val = Bytes.toStringBinary(value.get());
         LOG.info("reduce: key[" + count + "] -> " +
           Bytes.toStringBinary(key.get()) + ", value -> " + val);
         if (first == null) first = val;
         last = val;
         count++;
       }
     }
 
     protected void cleanup(Context context)
     throws IOException, InterruptedException {
       Configuration c = context.getConfiguration();
       String startRow = c.get(KEY_STARTROW);
       String lastRow = c.get(KEY_LASTROW);
       LOG.info("cleanup: first -> \"" + first + "\", start row -> \"" + startRow + "\"");
       LOG.info("cleanup: last -> \"" + last + "\", last row -> \"" + lastRow + "\"");
       if (startRow != null && startRow.length() > 0) {
         assertEquals(startRow, first);
       }
       if (lastRow != null && lastRow.length() > 0) {
         assertEquals(lastRow, last);
       }
     }
 
   }
 
   /**
    * Tests an MR Scan initialized from properties set in the Configuration.
    * 
    * @throws IOException
    * @throws ClassNotFoundException
    * @throws InterruptedException
    */
   protected void testScanFromConfiguration(String start, String stop, String last)
   throws IOException, InterruptedException, ClassNotFoundException {
     String jobName = "ScanFromConfig" + (start != null ? start.toUpperCase(Locale.ROOT) : "Empty") +
       "To" + (stop != null ? stop.toUpperCase(Locale.ROOT) : "Empty");
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     c.set(TableInputFormat.INPUT_TABLE, Bytes.toString(TABLE_NAME));
     c.set(TableInputFormat.SCAN_COLUMN_FAMILY, Bytes.toString(INPUT_FAMILY));
     c.set(KEY_STARTROW, start != null ? start : "");
     c.set(KEY_LASTROW, last != null ? last : "");
 
     if (start != null) {
       c.set(TableInputFormat.SCAN_ROW_START, start);
     }
 
     if (stop != null) {
       c.set(TableInputFormat.SCAN_ROW_STOP, stop);
     }
 
     Job job = new Job(c, jobName);
     job.setMapperClass(ScanMapper.class);
     job.setReducerClass(ScanReducer.class);
     job.setMapOutputKeyClass(ImmutableBytesWritable.class);
     job.setMapOutputValueClass(ImmutableBytesWritable.class);
     job.setInputFormatClass(TableInputFormat.class);
     job.setNumReduceTasks(1);
     FileOutputFormat.setOutputPath(job, new Path(job.getJobName()));
     TableMapReduceUtil.addDependencyJars(job);
     assertTrue(job.waitForCompletion(true));
   }
 
   /**
    * Tests a MR scan using specific start and stop rows.
    *
    * @throws IOException
    * @throws ClassNotFoundException
    * @throws InterruptedException
    */
   protected void testScan(String start, String stop, String last)
   throws IOException, InterruptedException, ClassNotFoundException {
     String jobName = "Scan" + (start != null ? start.toUpperCase(Locale.ROOT) : "Empty") +
       "To" + (stop != null ? stop.toUpperCase(Locale.ROOT) : "Empty");
     LOG.info("Before map/reduce startup - job " + jobName);
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     Scan scan = new Scan();
     scan.addFamily(INPUT_FAMILY);
     if (start != null) {
       scan.setStartRow(Bytes.toBytes(start));
     }
     c.set(KEY_STARTROW, start != null ? start : "");
     if (stop != null) {
       scan.setStopRow(Bytes.toBytes(stop));
     }
     c.set(KEY_LASTROW, last != null ? last : "");
     LOG.info("scan before: " + scan);
     Job job = new Job(c, jobName);
     TableMapReduceUtil.initTableMapperJob(
       Bytes.toString(TABLE_NAME), scan, ScanMapper.class,
       ImmutableBytesWritable.class, ImmutableBytesWritable.class, job);
     job.setReducerClass(ScanReducer.class);
     job.setNumReduceTasks(1); // one to get final "first" and "last" key
     FileOutputFormat.setOutputPath(job,
         new Path(TEST_UTIL.getDataTestDir(), job.getJobName()));
     LOG.info("Started " + job.getJobName());
     assertTrue(job.waitForCompletion(true));
     LOG.info("After map/reduce completion - job " + jobName);
   }
 
 
   /**
    * Tests Number of inputSplits for MR job when specify number of mappers for TableInputFormatXXX
    * This test does not run MR job
    *
    * @throws IOException
    * @throws ClassNotFoundException
    * @throws InterruptedException
    */
   public void testNumOfSplits(int splitsPerRegion, int expectedNumOfSplits) throws IOException,
       InterruptedException,
       ClassNotFoundException {
     String jobName = "TestJobForNumOfSplits";
     LOG.info("Before map/reduce startup - job " + jobName);
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     Scan scan = new Scan();
     scan.addFamily(INPUT_FAMILY);
     c.setInt("hbase.mapreduce.input.mappers.per.region", splitsPerRegion);
     c.set(KEY_STARTROW, "");
     c.set(KEY_LASTROW, "");
     Job job = new Job(c, jobName);
     TableMapReduceUtil.initTableMapperJob(TableName.valueOf(TABLE_NAME).getNameAsString(), scan, ScanMapper.class,
         ImmutableBytesWritable.class, ImmutableBytesWritable.class, job);
     TableInputFormat tif = new TableInputFormat();
     tif.setConf(job.getConfiguration());
     List<InputSplit> splits = tif.getSplits(job);
     for (InputSplit split : splits) {
       TableSplit tableSplit = (TableSplit) split;
       // In table input format, we do no store the scanner at the split level
       // because we use the scan object from the map-reduce job conf itself.
       Assert.assertTrue(tableSplit.getScanAsString().isEmpty());
     }
     Assert.assertEquals(expectedNumOfSplits, splits.size());
   }
 
   /**
    * Run MR job to check the number of mapper = expectedNumOfSplits
    * @throws IOException
    * @throws InterruptedException
    * @throws ClassNotFoundException
    */
   public void testNumOfSplitsMR(int splitsPerRegion, int expectedNumOfSplits) throws IOException,
       InterruptedException,
       ClassNotFoundException {
     String jobName = "TestJobForNumOfSplits-MR";
     LOG.info("Before map/reduce startup - job " + jobName);
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     Scan scan = new Scan();
     scan.addFamily(INPUT_FAMILY);
     c.setInt("hbase.mapreduce.input.mappers.per.region", splitsPerRegion);
     Job job = new Job(c, jobName);
     TableMapReduceUtil.initTableMapperJob(Bytes.toString(TABLE_NAME), scan, ScanMapper.class,
         ImmutableBytesWritable.class, ImmutableBytesWritable.class, job);
     job.setReducerClass(ScanReducer.class);
     job.setNumReduceTasks(1);
     job.setOutputFormatClass(NullOutputFormat.class);
     assertTrue("job failed!", job.waitForCompletion(true));
     // for some reason, hbase does not expose JobCounter.TOTAL_LAUNCHED_MAPS,
     // we use TaskCounter.SHUFFLED_MAPS to get total launched maps
     assertEquals("Saw the wrong count of mappers per region", expectedNumOfSplits,
         job.getCounters().findCounter(TaskCounter.SHUFFLED_MAPS).getValue());
   }
 
   /**
    * Run MR job to test autobalance for setting number of mappers for TIF
    * This does not run real MR job
    */
   public void testAutobalanceNumOfSplit() throws IOException {
     // set up splits for testing
     List<InputSplit> splits = new ArrayList<>(5);
     int[] regionLen = {100, 200, 200, 400, 600};
     for (int i = 0; i < 5; i++) {
       InputSplit split = new TableSplit(TableName.valueOf(TABLE_NAME), new Scan(),
           Bytes.toBytes(i), Bytes.toBytes(i + 1), "", "", regionLen[i] * 1048576);
       splits.add(split);
     }
     TableInputFormat tif = new TableInputFormat();
     List<InputSplit> res = tif.calculateAutoBalancedSplits(splits, 1073741824);
 
     assertEquals("Saw the wrong number of splits", 5, res.size());
     TableSplit ts1 = (TableSplit) res.get(0);
     assertEquals("The first split end key should be", 2, Bytes.toInt(ts1.getEndRow()));
     TableSplit ts2 = (TableSplit) res.get(1);
     assertEquals("The second split regionsize should be", 200 * 1048576, ts2.getLength());
     TableSplit ts3 = (TableSplit) res.get(2);
     assertEquals("The third split start key should be", 3, Bytes.toInt(ts3.getStartRow()));
     TableSplit ts4 = (TableSplit) res.get(4);
     assertNotEquals("The seventh split start key should not be", 4, Bytes.toInt(ts4.getStartRow()));
   }
 }