/**
 * 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.accumulo.pig;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map.Entry;
import java.util.SortedMap;

import org.apache.accumulo.core.client.IteratorSetting;
import org.apache.accumulo.core.client.mapreduce.AccumuloInputFormat;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Mutation;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.user.WholeRowIterator;
import org.apache.accumulo.core.security.ColumnVisibility;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.DataByteArray;
import org.apache.pig.data.DefaultDataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;

/**
 * A LoadStoreFunc for retrieving data from and storing data to Accumulo
 * 
 * A Key/Val pair will be returned as tuples: (key, colfam, colqual, colvis, timestamp, value). All fields except timestamp are DataByteArray, timestamp is a
 * long.
 * 
 * Tuples can be written in 2 forms: (key, colfam, colqual, colvis, value) OR (key, colfam, colqual, value)
 * 
 */
public class AccumuloWholeRowStorage extends AbstractAccumuloStorage {
  private static final Log LOG = LogFactory.getLog(AccumuloWholeRowStorage.class);
  
  public AccumuloWholeRowStorage() {}
  
  @Override
  protected Tuple getTuple(Key key, Value value) throws IOException {
    
    SortedMap<Key,Value> rowKVs = WholeRowIterator.decodeRow(key, value);
    List<Tuple> columns = new ArrayList<Tuple>(rowKVs.size());
    for (Entry<Key,Value> e : rowKVs.entrySet()) {
      columns.add(columnToTuple(e.getKey().getColumnFamily(), e.getKey().getColumnQualifier(), e.getKey().getColumnVisibility(), e.getKey().getTimestamp(),
          e.getValue()));
    }
    
    // and wrap it in a tuple
    Tuple tuple = TupleFactory.getInstance().newTuple(2);
    tuple.set(0, new DataByteArray(key.getRow().getBytes()));
    tuple.set(1, new DefaultDataBag(columns));
    
    return tuple;
  }
  
  private Tuple columnToTuple(Text colfam, Text colqual, Text colvis, long ts, Value val) throws IOException {
    Tuple tuple = TupleFactory.getInstance().newTuple(5);
    tuple.set(0, new DataByteArray(colfam.getBytes()));
    tuple.set(1, new DataByteArray(colqual.getBytes()));
    tuple.set(2, new DataByteArray(colvis.getBytes()));
    tuple.set(3, new Long(ts));
    tuple.set(4, new DataByteArray(val.get()));
    return tuple;
  }
  
  @Override
  protected void configureInputFormat(Job job) {
    AccumuloInputFormat.addIterator(job, new IteratorSetting(50, WholeRowIterator.class));
  }
  
  @Override
  public Collection<Mutation> getMutations(Tuple tuple) throws ExecException, IOException {
    
    Mutation mut = new Mutation(Utils.objToText(tuple.get(0)));
    DefaultDataBag columns = (DefaultDataBag) tuple.get(1);
    for (Tuple column : columns) {
      Text cf = Utils.objToText(column.get(0));
      Text cq = Utils.objToText(column.get(1));
      Text cv = Utils.objToText(column.get(2));
      Long ts = (Long) column.get(3);
      Value val = new Value(Utils.objToBytes(column.get(4)));
      
      mut.put(cf, cq, new ColumnVisibility(cv), ts, val);
    }
    
    return Collections.singleton(mut);
  }
}