/*
    * 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.List;
  
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
  import org.apache.hadoop.hbase.client.Admin;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
  * Action that tries to flush a random region of a table.
  */
  public class FlushRandomRegionOfTableAction extends Action {
    private static final Logger LOG =
        LoggerFactory.getLogger(FlushRandomRegionOfTableAction.class);
    private final long sleepTime;
    private final TableName tableName;
  
    public FlushRandomRegionOfTableAction(TableName tableName) {
      this (-1, tableName);
    }
  
    public FlushRandomRegionOfTableAction(int sleepTime, TableName tableName) {
      this.sleepTime = sleepTime;
      this.tableName = tableName;
    }
  
    @Override protected Logger getLogger() {
      return LOG;
    }
  
    @Override
    public void perform() throws Exception {
      HBaseTestingUtility util = context.getHBaseIntegrationTestingUtility();
      Admin admin = util.getHBaseAdmin();
  
      getLogger().info("Performing action: Flush random region of table " + tableName);
      List<HRegionInfo> regions = admin.getTableRegions(tableName);
      if (regions == null || regions.isEmpty()) {
        getLogger().info("Table " + tableName + " doesn't have regions to flush");
        return;
      }
  
      HRegionInfo region = PolicyBasedChaosMonkey.selectRandomItem(
        regions.toArray(new HRegionInfo[0]));
      getLogger().debug("Flushing region " + region.getRegionNameAsString());
      try {
        admin.flushRegion(region.getRegionName());
      } catch (Exception ex) {
        getLogger().warn("Flush failed, might be caused by other chaos: " + ex.getMessage());
      }
      if (sleepTime > 0) {
        Thread.sleep(sleepTime);
      }
    }
  }