/*
    * 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.chukwa.extraction.hbase;
  
  import java.nio.ByteBuffer;
  import java.nio.charset.Charset;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.util.ArrayList;
  
  import org.apache.hadoop.chukwa.Chunk;
  import org.apache.hadoop.chukwa.datacollection.writer.hbase.Reporter;
  import org.apache.hadoop.chukwa.util.HBaseUtil;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.log4j.Logger;
  
  public abstract class AbstractProcessor {
    static Logger LOG = Logger.getLogger(AbstractProcessor.class);
  
    protected int entryCount = 0;
    protected String primaryKeyHelper;
    protected String sourceHelper;
  
    protected byte[] key = null;
    byte[] CF = "t".getBytes(Charset.forName("UTF-8"));
  
    boolean chunkInErrorSaved = false;
    ArrayList<Put> output = null;
    ArrayList<Put> meta = null;
    Reporter reporter = null;
    long time = System.currentTimeMillis();
    Chunk chunk = null;
    MessageDigest md5 = null;
  
    public AbstractProcessor() throws NoSuchAlgorithmException {
      md5 = MessageDigest.getInstance("md5");
    }
  
    protected abstract void parse(byte[] recordEntry) throws Throwable;
  
    /**
     * Generic metric function to add a metric to HBase with full primary key and
     * source computed.
     * 
     * @param time is timestamp in epoch
     * @param metric is metric name
     * @param source is data source name
     * @param value is metric value in bytes
     * @param output is an array list of Put operations
     */
    public void addRecord(long time, String metric, String source, byte[] value,
        ArrayList<Put> output) {
      String primaryKey = new StringBuilder(primaryKeyHelper).append(".")
          .append(metric).toString();
      byte[] key = HBaseUtil.buildKey(time, primaryKey, source);
      Put put = new Put(key);
      byte[] timeInBytes = ByteBuffer.allocate(8).putLong(time).array();
      put.addColumn(CF, timeInBytes, time, value);
      output.add(put);
      reporter.putMetric(chunk.getDataType(), primaryKey);
      reporter.putSource(chunk.getDataType(), source);
    }
  
    public void addRecord(String primaryKey, String value) {
      addRecord(primaryKey, value.getBytes(Charset.forName("UTF-8")));
    }
  
    /**
     * Generic function to add a metric to HBase metric table, this function
     * assumes "time" and "source" have been defined and will construct primaryKey
     * only, without recompute time and source md5.
     * 
     * @param metric is metric name
     * @param value is metric value in bytes
     */
    public void addRecord(String metric, byte[] value) {
      String primaryKey = new StringBuilder(primaryKeyHelper).append(".")
          .append(metric).toString();
      byte[] key = HBaseUtil.buildKey(time, primaryKey, sourceHelper);
      Put put = new Put(key);
      byte[] timeInBytes = ByteBuffer.allocate(8).putLong(time).array();
      put.addColumn(CF, timeInBytes, time, value);
      output.add(put);
     reporter.putMetric(chunk.getDataType(), primaryKey);
   }
 
   /**
    * Process a chunk to store in HBase.
    * 
    * @param chunk is a Chukwa chunk
    * @param output is an array of Put operations
    * @param reporter is a reporter to track progress
    * @throws Throwable if there is problem parsing data
    */
   public void process(Chunk chunk, ArrayList<Put> output, Reporter reporter)
       throws Throwable {
     this.output = output;
     this.reporter = reporter;
     this.chunk = chunk;
     this.primaryKeyHelper = chunk.getDataType();
     this.sourceHelper = chunk.getSource();
     reporter.putSource(primaryKeyHelper, sourceHelper);
     parse(chunk.getData());
     addMeta();
   }
 
   protected void addMeta() {
     byte[] key = HBaseUtil.buildKey(time, chunk.getDataType(), sourceHelper);
     Put put = new Put(key);
     String family = "a";
     byte[] timeInBytes = ByteBuffer.allocate(8).putLong(time).array();
     put.addColumn(family.getBytes(Charset.forName("UTF-8")), timeInBytes, time, chunk.getTags().getBytes(Charset.forName("UTF-8")));
     output.add(put);
   }
 
 }