/*
    * 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 java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.NavigableMap;
  import java.util.UUID;
  
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.security.access.Permission;
  import org.apache.hadoop.hbase.security.visibility.CellVisibility;
  import org.apache.hadoop.hbase.util.Bytes;
  
  /**
   * Performs Append operations on a single row.
   * <p>
   * Note that this operation does not appear atomic to readers. Appends are done
   * under a single row lock, so write operations to a row are synchronized, but
   * readers do not take row locks so get and scan operations can see this
   * operation partially completed.
   * <p>
   * To append to a set of columns of a row, instantiate an Append object with the
   * row to append to. At least one column to append must be specified using the
   * {@link #add(byte[], byte[], byte[])} method.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class Append extends Mutation {
    private static final String RETURN_RESULTS = "_rr_";
    /**
     * @param returnResults
     *          True (default) if the append operation should return the results.
     *          A client that is not interested in the result can save network
     *          bandwidth setting this to false.
     */
    public Append setReturnResults(boolean returnResults) {
      setAttribute(RETURN_RESULTS, Bytes.toBytes(returnResults));
      return this;
    }
  
    /**
     * @return current setting for returnResults
     */
    public boolean isReturnResults() {
      byte[] v = getAttribute(RETURN_RESULTS);
      return v == null ? true : Bytes.toBoolean(v);
    }
  
    /**
     * Create a Append operation for the specified row.
     * <p>
     * At least one column must be appended to.
     * @param row row key; makes a local copy of passed in array.
     */
    public Append(byte[] row) {
      this(row, 0, row.length);
    }
    /**
     * Copy constructor
     * @param a
     */
    public Append(Append a) {
      this.row = a.getRow();
      this.ts = a.getTimeStamp();
      this.familyMap.putAll(a.getFamilyCellMap());
      for (Map.Entry<String, byte[]> entry : a.getAttributesMap().entrySet()) {
        this.setAttribute(entry.getKey(), entry.getValue());
      }
    }
  
    /** Create a Append operation for the specified row.
     * <p>
     * At least one column must be appended to.
     * @param rowArray Makes a copy out of this buffer.
     * @param rowOffset
     * @param rowLength
     */
    public Append(final byte [] rowArray, final int rowOffset, final int rowLength) {
     checkRow(rowArray, rowOffset, rowLength);
     this.row = Bytes.copy(rowArray, rowOffset, rowLength);
   }
 
   /**
    * Add the specified column and value to this Append operation.
    * @param family family name
    * @param qualifier column qualifier
    * @param value value to append to specified column
    * @return this
    */
   public Append add(byte [] family, byte [] qualifier, byte [] value) {
     KeyValue kv = new KeyValue(this.row, family, qualifier, this.ts, KeyValue.Type.Put, value);
     return add(kv);
   }
 
   /**
    * Add column and value to this Append operation.
    * @param cell
    * @return This instance
    */
   @SuppressWarnings("unchecked")
   public Append add(final Cell cell) {
     // Presume it is KeyValue for now.
     byte [] family = CellUtil.cloneFamily(cell);
     List<Cell> list = this.familyMap.get(family);
     if (list == null) {
       list  = new ArrayList<Cell>();
     }
     // find where the new entry should be placed in the List
     list.add(cell);
     this.familyMap.put(family, list);
     return this;
   }
 
   @Override
   public Append setAttribute(String name, byte[] value) {
     return (Append) super.setAttribute(name, value);
   }
 
   @Override
   public Append setId(String id) {
     return (Append) super.setId(id);
   }
 
   @Override
   public Append setDurability(Durability d) {
     return (Append) super.setDurability(d);
   }
 
   @Override
   public Append setFamilyCellMap(NavigableMap<byte[], List<Cell>> map) {
     return (Append) super.setFamilyCellMap(map);
   }
 
   @Override
   public Append setClusterIds(List<UUID> clusterIds) {
     return (Append) super.setClusterIds(clusterIds);
   }
 
   @Override
   public Append setCellVisibility(CellVisibility expression) {
     return (Append) super.setCellVisibility(expression);
   }
 
   @Override
   public Append setACL(String user, Permission perms) {
     return (Append) super.setACL(user, perms);
   }
 
   @Override
   public Append setACL(Map<String, Permission> perms) {
     return (Append) super.setACL(perms);
   }
 
   @Override
   public Append setTTL(long ttl) {
     return (Append) super.setTTL(ttl);
   }
 }