package ivory.lsh.eval;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.lib.IdentityMapper;
import org.apache.hadoop.mapred.lib.IdentityReducer;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

import tl.lin.data.pair.PairOfInts;

/**
 * Read in sequence file format and output as text format.
 * 
 * @author ferhanture
 * 
 */
public class OutputResultsAsText extends Configured implements Tool {
  public static final String[] RequiredParameters = {};
  private static final Logger sLogger = Logger.getLogger(OutputResultsAsText.class);

  static enum mapoutput {
    count
  };

  private static int printUsage() {
    System.out.println("usage: [input-path] [output-path]");
    return -1;
  }

  public OutputResultsAsText() {
    super();
  }

  public String[] getRequiredParameters() {
    return RequiredParameters;
  }

  public int run(String[] args) throws Exception {
    if (args.length != 2) {
      printUsage();
      return -1;
    }
    JobConf job = new JobConf(getConf(), OutputResultsAsText.class);

    job.setJobName("OutputAsText");
    FileSystem fs = FileSystem.get(job);

    String inputPath = args[0];
    String outputPath = args[1];

    int numMappers = 300;
    int numReducers = 1;

    if (fs.exists(new Path(outputPath))) {
      sLogger.info("Output already exists! Quitting...");
      return 0;
    }
    FileInputFormat.setInputPaths(job, new Path(inputPath));
    FileOutputFormat.setOutputPath(job, new Path(outputPath));
    FileOutputFormat.setCompressOutput(job, false);

    job.set("mapred.child.java.opts", "-Xmx2048m");
    job.setInt("mapred.map.max.attempts", 10);
    job.setInt("mapred.reduce.max.attempts", 10);
    job.setInt("mapred.task.timeout", 6000000);

    sLogger.info("Running job " + job.getJobName());
    sLogger.info("Input directory: " + inputPath);
    sLogger.info("Output directory: " + outputPath);

    job.setMapperClass(IdentityMapper.class);
    job.setReducerClass(IdentityReducer.class);

    job.setMapOutputKeyClass(PairOfInts.class);
    job.setMapOutputValueClass(IntWritable.class);
    job.setOutputKeyClass(PairOfInts.class);
    job.setOutputValueClass(IntWritable.class);
    job.setNumMapTasks(numMappers);
    job.setNumReduceTasks(numReducers);
    job.setInputFormat(SequenceFileInputFormat.class);

    JobClient.runJob(job);

    return 0;
  }

  public static void main(String[] args) throws Exception {
    ToolRunner.run(new Configuration(), new OutputResultsAsText(), args);
    return;
  }

}