/**
 * Copyright The Apache Software Foundation
 *
 * 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.client;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.testclassification.LargeTests;
import org.apache.hadoop.hbase.MiniHBaseCluster;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.experimental.categories.Category;

@Category(LargeTests.class)
public class TestHTableMultiplexerFlushCache {
  final Log LOG = LogFactory.getLog(getClass());
  private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  private static byte[] FAMILY = Bytes.toBytes("testFamily");
  private static byte[] QUALIFIER1 = Bytes.toBytes("testQualifier_1");
  private static byte[] QUALIFIER2 = Bytes.toBytes("testQualifier_2");
  private static byte[] VALUE1 = Bytes.toBytes("testValue1");
  private static byte[] VALUE2 = Bytes.toBytes("testValue2");
  private static int SLAVES = 3;
  private static int PER_REGIONSERVER_QUEUE_SIZE = 100000;

  /**
   * @throws java.lang.Exception
   */
  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
    TEST_UTIL.startMiniCluster(SLAVES);
  }

  /**
   * @throws java.lang.Exception
   */
  @AfterClass
  public static void tearDownAfterClass() throws Exception {
    TEST_UTIL.shutdownMiniCluster();
  }

  private static void checkExistence(HTable htable, byte[] row, byte[] family, byte[] quality,
      byte[] value) throws Exception {
    // verify that the Get returns the correct result
    Result r;
    Get get = new Get(row);
    get.addColumn(family, quality);
    int nbTry = 0;
    do {
      assertTrue("Fail to get from " + htable.getName() + " after " + nbTry + " tries", nbTry < 50);
      nbTry++;
      Thread.sleep(100);
      r = htable.get(get);
    } while (r == null || r.getValue(family, quality) == null);
    assertEquals("value", Bytes.toStringBinary(value),
      Bytes.toStringBinary(r.getValue(family, quality)));
  }

  @Test
  public void testOnRegionChange() throws Exception {
    TableName TABLE = TableName.valueOf("testOnRegionChange");
    final int NUM_REGIONS = 10;
    HTable htable = TEST_UTIL.createTable(TABLE, new byte[][] { FAMILY }, 3,
      Bytes.toBytes("aaaaa"), Bytes.toBytes("zzzzz"), NUM_REGIONS);

    HTableMultiplexer multiplexer = new HTableMultiplexer(TEST_UTIL.getConfiguration(), 
      PER_REGIONSERVER_QUEUE_SIZE);
    
    byte[][] startRows = htable.getStartKeys();
    byte[] row = startRows[1];
    assertTrue("2nd region should not start with empty row", row != null && row.length > 0);

    Put put = new Put(row).add(FAMILY, QUALIFIER1, VALUE1);
    assertTrue("multiplexer.put returns", multiplexer.put(TABLE, put));
    
    checkExistence(htable, row, FAMILY, QUALIFIER1, VALUE1);

    // Now let's shutdown the regionserver and let regions moved to other servers.
    HRegionLocation loc = htable.getRegionLocation(row);
    MiniHBaseCluster hbaseCluster = TEST_UTIL.getHBaseCluster(); 
    hbaseCluster.stopRegionServer(loc.getServerName());
    TEST_UTIL.waitUntilAllRegionsAssigned(TABLE);

    // put with multiplexer.
    put = new Put(row).add(FAMILY, QUALIFIER2, VALUE2);
    assertTrue("multiplexer.put returns", multiplexer.put(TABLE, put));

    checkExistence(htable, row, FAMILY, QUALIFIER2, VALUE2);
  }
}