/*
 * 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.nutch.indexer;

import java.io.IOException;
import java.lang.invoke.MethodHandles;
import java.text.SimpleDateFormat;
import java.util.Iterator;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.ByteWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.lib.NullOutputFormat;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.nutch.crawl.CrawlDatum;
import org.apache.nutch.crawl.CrawlDb;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.nutch.util.NutchJob;
import org.apache.nutch.util.TimingUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The class scans CrawlDB looking for entries with status DB_GONE (404) or
 * DB_DUPLICATE and sends delete requests to indexers for those documents.
 */

public class CleaningJob implements Tool {
  private static final Logger LOG = LoggerFactory
      .getLogger(MethodHandles.lookup().lookupClass());
  private Configuration conf;

  @Override
  public Configuration getConf() {
    return conf;
  }

  @Override
  public void setConf(Configuration conf) {
    this.conf = conf;
  }

  public static class DBFilter implements
      Mapper<Text, CrawlDatum, ByteWritable, Text> {
    private ByteWritable OUT = new ByteWritable(CrawlDatum.STATUS_DB_GONE);

    @Override
    public void configure(JobConf arg0) {
    }

    @Override
    public void close() throws IOException {
    }

    @Override
    public void map(Text key, CrawlDatum value,
        OutputCollector<ByteWritable, Text> output, Reporter reporter)
        throws IOException {

      if (value.getStatus() == CrawlDatum.STATUS_DB_GONE
          || value.getStatus() == CrawlDatum.STATUS_DB_DUPLICATE) {
        output.collect(OUT, key);
      }
    }
  }

  public static class DeleterReducer implements
      Reducer<ByteWritable, Text, Text, ByteWritable> {
    private static final int NUM_MAX_DELETE_REQUEST = 1000;
    private int numDeletes = 0;
    private int totalDeleted = 0;

    private boolean noCommit = false;

    IndexWriters writers = null;

    @Override
    public void configure(JobConf job) {
      writers = new IndexWriters(job);
      try {
        writers.open(job, "Deletion");
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
      noCommit = job.getBoolean("noCommit", false);
    }

    @Override
    public void close() throws IOException {
      // BUFFERING OF CALLS TO INDEXER SHOULD BE HANDLED AT INDEXER LEVEL
      // if (numDeletes > 0) {
      // LOG.info("CleaningJob: deleting " + numDeletes + " documents");
      // // TODO updateRequest.process(solr);
      // totalDeleted += numDeletes;
      // }

      writers.close();

      if (totalDeleted > 0 && !noCommit) {
        writers.commit();
      }

      LOG.info("CleaningJob: deleted a total of " + totalDeleted + " documents");
    }

    @Override
    public void reduce(ByteWritable key, Iterator<Text> values,
        OutputCollector<Text, ByteWritable> output, Reporter reporter)
        throws IOException {
      while (values.hasNext()) {
        Text document = values.next();
        writers.delete(document.toString());
        totalDeleted++;
        reporter.incrCounter("CleaningJobStatus", "Deleted documents", 1);
        // if (numDeletes >= NUM_MAX_DELETE_REQUEST) {
        // LOG.info("CleaningJob: deleting " + numDeletes
        // + " documents");
        // // TODO updateRequest.process(solr);
        // // TODO updateRequest = new UpdateRequest();
        // writers.delete(key.toString());
        // totalDeleted += numDeletes;
        // numDeletes = 0;
        // }
      }
    }
  }

  public void delete(String crawldb, boolean noCommit) throws IOException {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    long start = System.currentTimeMillis();
    LOG.info("CleaningJob: starting at " + sdf.format(start));

    JobConf job = new NutchJob(getConf());

    FileInputFormat.addInputPath(job, new Path(crawldb, CrawlDb.CURRENT_NAME));
    job.setBoolean("noCommit", noCommit);
    job.setInputFormat(SequenceFileInputFormat.class);
    job.setOutputFormat(NullOutputFormat.class);
    job.setMapOutputKeyClass(ByteWritable.class);
    job.setMapOutputValueClass(Text.class);
    job.setMapperClass(DBFilter.class);
    job.setReducerClass(DeleterReducer.class);

    job.setJobName("CleaningJob");

    // need to expicitely allow deletions
    job.setBoolean(IndexerMapReduce.INDEXER_DELETE, true);

    JobClient.runJob(job);

    long end = System.currentTimeMillis();
    LOG.info("CleaningJob: finished at " + sdf.format(end) + ", elapsed: "
        + TimingUtil.elapsedTime(start, end));
  }

  public int run(String[] args) throws IOException {
    if (args.length < 1) {
      String usage = "Usage: CleaningJob <crawldb> [-noCommit]";
      LOG.error("Missing crawldb. " + usage);
      System.err.println(usage);
      IndexWriters writers = new IndexWriters(getConf());
      System.err.println(writers.describe());
      return 1;
    }

    boolean noCommit = false;
    if (args.length == 2 && args[1].equals("-noCommit")) {
      noCommit = true;
    }

    try {
      delete(args[0], noCommit);
    } catch (final Exception e) {
      LOG.error("CleaningJob: " + StringUtils.stringifyException(e));
      System.err.println("ERROR CleaningJob: "
          + StringUtils.stringifyException(e));
      return -1;
    }
    return 0;
  }

  public static void main(String[] args) throws Exception {
    int result = ToolRunner.run(NutchConfiguration.create(), new CleaningJob(),
        args);
    System.exit(result);
  }
}

@@ -3977,32 +3977,8 @@
  %7D%0A%0A
-      writers.close();%0A%0A
     
@@ -4047,24 +4047,48 @@
 );%0A      %7D%0A%0A
+      writers.close();%0A%0A
       LOG.in

fix for NUTCH-2269 contributed by r0ann3l