/*
    * 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.datacollection.writer.hbase;
  
  import java.io.IOException;
  import java.security.NoSuchAlgorithmException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Timer;
  import java.util.TimerTask;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.chukwa.Chunk;
  import org.apache.hadoop.chukwa.conf.ChukwaConfiguration;
  import org.apache.hadoop.chukwa.datacollection.writer.ChukwaWriter;
  import org.apache.hadoop.chukwa.datacollection.writer.PipelineableWriter;
  import org.apache.hadoop.chukwa.datacollection.writer.WriterException;
  import org.apache.hadoop.chukwa.extraction.hbase.AbstractProcessor;
  import org.apache.hadoop.chukwa.extraction.hbase.ProcessorFactory;
  import org.apache.hadoop.chukwa.extraction.hbase.UnknownRecordTypeException;
  import org.apache.hadoop.chukwa.util.ExceptionUtil;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Connection;
  import org.apache.hadoop.hbase.client.ConnectionFactory;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.hadoop.hbase.client.Table;
  import org.apache.log4j.Logger;
  
  public class HBaseWriter extends PipelineableWriter {
    static Logger log = Logger.getLogger(HBaseWriter.class);
    private static final String CHUKWA_TABLE = "chukwa";
    private static final String CHUKWA_META_TABLE = "chukwa_meta";
    boolean reportStats;
    volatile long dataSize = 0;
    final Timer statTimer;
    private ArrayList<Put> output;
    private Reporter reporter;
    private ChukwaConfiguration conf;
    private Configuration hconf;
    String defaultProcessor;
    private static Connection connection;
    
    private class StatReportingTask extends TimerTask {
      private long lastTs = System.currentTimeMillis();
      private long lastDataSize = 0;
  
      public void run() {
        long time = System.currentTimeMillis();
        long interval = time - lastTs;
        lastTs = time;
  
        long ds = dataSize;
        long dataRate = 1000 * (ds - lastDataSize) / interval; // bytes/sec
        // refers only to data field, not including http or chukwa headers
        lastDataSize = ds;
  
        log.info("stat=HBaseWriter|dataRate="
            + dataRate);
      }
    };
  
    public HBaseWriter() throws IOException {
      this(true);
    }
  
    public HBaseWriter(boolean reportStats) throws IOException {
      /* HBase Version >= 0.89.x */
      this(reportStats, new ChukwaConfiguration(), HBaseConfiguration.create());
    }
  
    public HBaseWriter(ChukwaConfiguration conf, Configuration hconf) throws IOException {
      this(true, conf, hconf);
    }
  
    private HBaseWriter(boolean reportStats, ChukwaConfiguration conf, Configuration hconf) throws IOException {
      this.reportStats = reportStats;
      this.conf = conf;
      this.hconf = hconf;
      this.statTimer = new Timer();
      this.defaultProcessor = conf.get(
        "chukwa.demux.mapper.default.processor",
       "org.apache.hadoop.chukwa.extraction.hbase.DefaultProcessor");
     log.info("hbase.zookeeper.quorum: " + hconf.get(HConstants.ZOOKEEPER_QUORUM) + ":" + hconf.get(HConstants.ZOOKEEPER_CLIENT_PORT));
     if (reportStats) {
       statTimer.schedule(new StatReportingTask(), 1000, 10 * 1000);
     }
     output = new ArrayList<Put>();
     try {
       reporter = new Reporter();
     } catch (NoSuchAlgorithmException e) {
       throw new IOException("Can not register hashing algorithm.");
     }
     if (connection == null || connection.isClosed()) {
       connection = ConnectionFactory.createConnection(hconf);
     }
   }
 
   public void close() {
     if (reportStats) {
       statTimer.cancel();
     }
   }
 
   public void init(Configuration conf) throws WriterException {
     if (connection == null || connection.isClosed()) {
       try {
         connection = ConnectionFactory.createConnection(hconf);
       } catch (IOException e) {
         throw new WriterException("HBase is offline, retry later...");
       }
     }
   }
 
   @Override
   public CommitStatus add(List<Chunk> chunks) throws WriterException {
     CommitStatus rv = ChukwaWriter.COMMIT_OK;
     try {
       Table hbase = connection.getTable(TableName.valueOf(CHUKWA_TABLE));
       Table meta = connection.getTable(TableName.valueOf(CHUKWA_META_TABLE));
       for(Chunk chunk : chunks) {
         synchronized (this) {
           try {
             AbstractProcessor processor = getProcessor(chunk.getDataType());
             processor.process(chunk, output, reporter);
             hbase.put(output);
             meta.put(reporter.getInfo());
           } catch (Throwable e) {
             log.warn(output);
             log.warn(ExceptionUtil.getStackTrace(e));
           }
           dataSize += chunk.getData().length;
           output.clear();
           reporter.clear();
         }
       }
       hbase.close();
       meta.close();
     } catch (Exception e) {
       log.error(ExceptionUtil.getStackTrace(e));
       throw new WriterException("Failed to store data to HBase.");
     }    
     if (next != null) {
       rv = next.add(chunks); //pass data through
     }
     return rv;
   }
 
   private AbstractProcessor getProcessor(String dataType) throws UnknownRecordTypeException {
     String processorClass = findProcessor(conf.get(dataType, defaultProcessor), defaultProcessor);
     return ProcessorFactory.getProcessor(processorClass);
   }
 
   /**
    * Look for mapper parser class in the demux configuration.
    * Demux configuration has been changed since CHUKWA-581 to
    * support mapping of both mapper and reducer, and this utility
    * class is to detect the mapper class and return the mapper
    * class only.
    *
    */
   private String findProcessor(String processors, String defaultProcessor) {
     if(processors.startsWith(",")) {
       // No mapper class defined.
       return defaultProcessor;
     } else if(processors.contains(",")) {
       // Both mapper and reducer defined.
       String[] parsers = processors.split(",");
       return parsers[0];
     }
     // No reducer defined.
     return processors;
   }
 }