/**
    * 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.master;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.mockito.Mockito.when;
  
  import java.io.IOException;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.*;
  import org.apache.hadoop.hbase.coordination.BaseCoordinatedStateManager;
  import org.apache.hadoop.hbase.coordination.OpenRegionCoordination;
  import org.apache.hadoop.hbase.coordination.ZkCoordinatedStateManager;
  import org.apache.hadoop.hbase.coordination.ZkOpenRegionCoordination;
  import org.apache.hadoop.hbase.executor.EventType;
  import org.apache.hadoop.hbase.master.handler.OpenedRegionHandler;
  import org.apache.hadoop.hbase.regionserver.HRegion;
  import org.apache.hadoop.hbase.regionserver.HRegionServer;
  import org.apache.hadoop.hbase.regionserver.Region;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.MockServer;
  import org.apache.hadoop.hbase.zookeeper.ZKAssign;
  import org.apache.hadoop.hbase.zookeeper.ZKTableStateManager;
  import org.apache.hadoop.hbase.zookeeper.ZKUtil;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.data.Stat;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.mockito.Mockito;
  
  @Category(MediumTests.class)
  public class TestOpenedRegionHandler {
  
    private static final Log LOG = LogFactory
        .getLog(TestOpenedRegionHandler.class);
  
    private HBaseTestingUtility TEST_UTIL;
    private final int NUM_MASTERS = 1;
    private final int NUM_RS = 1;
    private Configuration conf;
    private Configuration resetConf;
    private ZooKeeperWatcher zkw;
  
    @Before
    public void setUp() throws Exception {
      conf = HBaseConfiguration.create();
      conf.setBoolean("hbase.assignment.usezk", true);
      TEST_UTIL = HBaseTestingUtility.createLocalHTU(conf);
    }
  
    @After
    public void tearDown() throws Exception {
      // Stop the cluster
      TEST_UTIL.shutdownMiniCluster();
      TEST_UTIL = new HBaseTestingUtility(resetConf);
    }
  
    @Test
    public void testOpenedRegionHandlerOnMasterRestart() throws Exception {
      // Start the cluster
      log("Starting cluster");
      conf = HBaseConfiguration.create();
      conf.setBoolean("hbase.assignment.usezk", true);
      resetConf = conf;
      TEST_UTIL = new HBaseTestingUtility(conf);
      TEST_UTIL.startMiniCluster(NUM_MASTERS, NUM_RS);
      String tableName = "testOpenedRegionHandlerOnMasterRestart";
      MiniHBaseCluster cluster = createRegions(tableName);
      abortMaster(cluster);
  
      HRegionServer regionServer = cluster.getRegionServer(0);
      Region region = getRegionBeingServed(cluster, regionServer);
 
     // forcefully move a region to OPENED state in zk
     // Create a ZKW to use in the test
     zkw = HBaseTestingUtility.createAndForceNodeToOpenedState(TEST_UTIL,
         region, regionServer.getServerName());
 
     // Start up a new master
     log("Starting up a new master");
     cluster.startMaster().getMaster();
     log("Waiting for master to be ready");
     cluster.waitForActiveAndReadyMaster();
     log("Master is ready");
 
     // Failover should be completed, now wait for no RIT
     log("Waiting for no more RIT");
     ZKAssign.blockUntilNoRIT(zkw);
   }
   @Test
   public void testShouldNotCompeleteOpenedRegionSuccessfullyIfVersionMismatches()
       throws Exception {
     HRegion region = null;
     try {
       int testIndex = 0;
       TEST_UTIL.startMiniZKCluster();
       final Server server = new MockServer(TEST_UTIL);
       HTableDescriptor htd = new HTableDescriptor(
           TableName.valueOf("testShouldNotCompeleteOpenedRegionSuccessfullyIfVersionMismatches"));
       HColumnDescriptor fam = new HColumnDescriptor("fam");
       htd.addFamily(fam);
       HRegionInfo hri = new HRegionInfo(htd.getTableName(),
           Bytes.toBytes(testIndex), Bytes.toBytes(testIndex + 1));
       region = HRegion.createHRegion(hri, TEST_UTIL.getDataTestDir(), TEST_UTIL.getConfiguration(), htd);
       assertNotNull(region);
       AssignmentManager am = Mockito.mock(AssignmentManager.class);
       RegionStates rsm = Mockito.mock(RegionStates.class);
       Mockito.doReturn(rsm).when(am).getRegionStates();
       when(rsm.isRegionInTransition(hri)).thenReturn(false);
       when(rsm.getRegionState(hri)).thenReturn(
         new RegionState(region.getRegionInfo(), RegionState.State.OPEN,
           System.currentTimeMillis(), server.getServerName()));
       // create a node with OPENED state
       zkw = HBaseTestingUtility.createAndForceNodeToOpenedState(TEST_UTIL,
           region, server.getServerName());
       when(am.getTableStateManager()).thenReturn(new ZKTableStateManager(zkw));
       Stat stat = new Stat();
       String nodeName = ZKAssign.getNodeName(zkw, region.getRegionInfo()
           .getEncodedName());
       ZKUtil.getDataAndWatch(zkw, nodeName, stat);
 
       // use the version for the OpenedRegionHandler
       BaseCoordinatedStateManager csm = new ZkCoordinatedStateManager();
       csm.initialize(server);
       csm.start();
 
       OpenRegionCoordination orc = csm.getOpenRegionCoordination();
       ZkOpenRegionCoordination.ZkOpenRegionDetails zkOrd =
         new ZkOpenRegionCoordination.ZkOpenRegionDetails();
       zkOrd.setServerName(server.getServerName());
       zkOrd.setVersion(stat.getVersion());
       OpenedRegionHandler handler = new OpenedRegionHandler(server, am, region
           .getRegionInfo(), orc, zkOrd);
       // Once again overwrite the same znode so that the version changes.
       ZKAssign.transitionNode(zkw, region.getRegionInfo(), server
           .getServerName(), EventType.RS_ZK_REGION_OPENED,
           EventType.RS_ZK_REGION_OPENED, stat.getVersion());
 
       // Should not invoke assignmentmanager.regionOnline. If it is 
       // invoked as per current mocking it will throw null pointer exception.
       boolean expectedException = false;
       try {
         handler.process();
       } catch (Exception e) {
         expectedException = true;
       }
       assertFalse("The process method should not throw any exception.",
           expectedException);
       List<String> znodes = ZKUtil.listChildrenAndWatchForNewChildren(zkw,
           zkw.assignmentZNode);
       String regionName = znodes.get(0);
       assertEquals("The region should not be opened successfully.", regionName,
           region.getRegionInfo().getEncodedName());
     } finally {
       HRegion.closeHRegion(region);
       TEST_UTIL.shutdownMiniZKCluster();
     }
   }
   private MiniHBaseCluster createRegions(String tableName)
       throws InterruptedException, ZooKeeperConnectionException, IOException,
       KeeperException {
     MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
     log("Waiting for active/ready master");
     cluster.waitForActiveAndReadyMaster();
     zkw = new ZooKeeperWatcher(conf, "testOpenedRegionHandler", null);
 
     // Create a table with regions
     byte[] table = Bytes.toBytes(tableName);
     byte[] family = Bytes.toBytes("family");
     TEST_UTIL.createTable(table, family);
 
     //wait till the regions are online
     log("Waiting for no more RIT");
     ZKAssign.blockUntilNoRIT(zkw);
 
     return cluster;
   }
   private void abortMaster(MiniHBaseCluster cluster) {
     // Stop the master
     log("Aborting master");
     cluster.abortMaster(0);
     cluster.waitOnMaster(0);
     log("Master has aborted");
   }
   private Region getRegionBeingServed(MiniHBaseCluster cluster,
       HRegionServer regionServer) {
     Collection<Region> onlineRegionsLocalContext = regionServer
         .getOnlineRegionsLocalContext();
     Iterator<Region> iterator = onlineRegionsLocalContext.iterator();
     Region region = null;
     while (iterator.hasNext()) {
       region = iterator.next();
       if (!region.getRegionInfo().isMetaTable()) {
         break;
       }
     }
     return region;
   }
   private void log(String msg) {
     LOG.debug("\n\nTRR: " + msg + "\n");
   }
 
 }