/*
    * 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.chaos.actions;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.commons.lang.math.RandomUtils;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.chaos.factories.MonkeyConstants;
  import org.apache.hadoop.hbase.client.Admin;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
  * Action that tries to move every region of a table.
  */
  public class MoveRegionsOfTableAction extends Action {
    private static final Logger LOG =
        LoggerFactory.getLogger(MoveRegionsOfTableAction.class);
    private final long sleepTime;
    private final TableName tableName;
    private final long maxTime;
  
    public MoveRegionsOfTableAction(TableName tableName) {
      this(-1, MonkeyConstants.DEFAULT_MOVE_REGIONS_MAX_TIME, tableName);
    }
  
    @Override protected Logger getLogger() {
      return LOG;
    }
  
    public MoveRegionsOfTableAction(long sleepTime, long maxSleepTime, TableName tableName) {
      this.sleepTime = sleepTime;
      this.tableName = tableName;
      this.maxTime = maxSleepTime;
    }
  
    @Override
    public void perform() throws Exception {
      if (sleepTime > 0) {
        Thread.sleep(sleepTime);
      }
  
      Admin admin = this.context.getHBaseIntegrationTestingUtility().getHBaseAdmin();
      Collection<ServerName> serversList = admin.getClusterStatus().getServers();
      ServerName[] servers = serversList.toArray(new ServerName[serversList.size()]);
  
      getLogger().info("Performing action: Move regions of table " + tableName);
      List<HRegionInfo> regions = admin.getTableRegions(tableName);
      if (regions == null || regions.isEmpty()) {
        getLogger().info("Table " + tableName + " doesn't have regions to move");
        return;
      }
  
      Collections.shuffle(regions);
  
      long start = System.currentTimeMillis();
      for (HRegionInfo regionInfo:regions) {
  
        // Don't try the move if we're stopping
        if (context.isStopping()) {
          return;
        }
  
        try {
          String destServerName =
            servers[RandomUtils.nextInt(servers.length)].getServerName();
          getLogger().debug("Moving " + regionInfo.getRegionNameAsString() + " to " + destServerName);
          admin.move(regionInfo.getEncodedNameAsBytes(), Bytes.toBytes(destServerName));
        } catch (Exception ex) {
          getLogger().warn("Move failed, might be caused by other chaos: " + ex.getMessage());
        }
        if (sleepTime > 0) {
          Thread.sleep(sleepTime);
        }
  
        // put a limit on max num regions. Otherwise, this won't finish
        // with a sleep time of 10sec, 100 regions will finish in 16min
       if (System.currentTimeMillis() - start > maxTime) {
         break;
       }
     }
   }
 }