// kate: space-indent on; indent-width 2; mixedindent off; indent-mode cstyle;

package org.verificatum;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

public class Verificatum {

  public static class PowMapper
       extends Mapper<Object, ArrayWritable<IntWritable>, IntWritable, IntWritable>{

    private final static IntWritable one = new IntWritable(1);
    private IntWritable result = new IntWritable(1);

    public void map(Object key, ArrayWritable<IntWritable> value, Context context
                    ) throws IOException, InterruptedException {
      StringTokenizer itr = new StringTokenizer(value.toString());
      while (itr.hasMoreTokens()) {
        IntWritable[] valueArray = value.get();
        result.set(valueArray[0] * valueArray[1]);
        context.write(result, one);
      }
    }
  }


  public static void main(String[] args) throws Exception {
    Configuration conf = new Configuration();
    String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
    if (otherArgs.length != 2) {
      System.err.println("Usage: verificatum <in> <out>");
      System.exit(2);
    }
    Job job = new Job(conf, "verificatum");
    job.setJarByClass(Verificatum.class);
    job.setMapperClass(VerificatumMapper.class);
//     job.setCombinerClass(VerificatumMapper.class);
//     job.setReducerClass(VerificatumMapper.class);
    job.setOutputKeyClass(IntWritable.class);
    job.setOutputValueClass(IntWritable.class);
    FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
    FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
    System.exit(job.waitForCompletion(true) ? 0 : 1);
  }
}