/*
    * 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.io.IOException;
  import java.util.Random;
  
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Admin;
  import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Action that changes the encoding on a column family from a list of tables.
   */
  public class ChangeEncodingAction extends Action {
    private final TableName tableName;
  
    private Admin admin;
    private Random random;
    private static final Logger LOG = LoggerFactory.getLogger(ChangeEncodingAction.class);
  
    public ChangeEncodingAction(TableName tableName) {
      this.tableName = tableName;
      this.random = new Random();
    }
  
    @Override protected Logger getLogger() {
      return LOG;
    }
  
    @Override
    public void init(ActionContext context) throws IOException {
      super.init(context);
      this.admin = context.getHBaseIntegrationTestingUtility().getHBaseAdmin();
    }
  
    @Override
    public void perform() throws Exception {
      HTableDescriptor tableDescriptor = admin.getTableDescriptor(tableName);
      HColumnDescriptor[] columnDescriptors = tableDescriptor.getColumnFamilies();
  
      if (columnDescriptors == null || columnDescriptors.length == 0) {
        return;
      }
  
      getLogger().debug("Performing action: Changing encodings on " + tableName);
      // possible DataBlockEncoding id's
      int[] possibleIds = {0, 2, 3, 4, 6};
      for (HColumnDescriptor descriptor : columnDescriptors) {
        short id = (short) possibleIds[random.nextInt(possibleIds.length)];
        descriptor.setDataBlockEncoding(DataBlockEncoding.getEncodingById(id));
        getLogger().debug("Set encoding of column family " + descriptor.getNameAsString()
          + " to: " + descriptor.getDataBlockEncoding());
      }
  
      // Don't try the modify if we're stopping
      if (context.isStopping()) {
        return;
      }
      admin.modifyTable(tableName, tableDescriptor);
    }
  }