package wcmr;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
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 WordCount {

	public static void main(String args[]) throws Exception{
		Configuration c=new Configuration();
		String[] files=new GenericOptionsParser(c,args).getRemainingArgs();
		Path input=new Path(files[0]);
		Path output=new Path(files[1]);
		Job j=new Job(c,"wordcount");
		j.setJarByClass(WordCount.class);
		j.setMapperClass(MapForWordCount.class);
		j.setReducerClass(ReduceForWordCount.class);
		j.setOutputKeyClass(Text.class);
		j.setOutputValueClass(IntWritable.class);
		FileInputFormat.addInputPath(j, input);
		FileOutputFormat.setOutputPath(j, output);
		System.exit(j.waitForCompletion(true)?0:1);
	}
	
	public static class MapForWordCount extends Mapper<LongWritable, Text, Text, IntWritable>{
		public void map(LongWritable key, Text value, Context con) throws IOException, InterruptedException
		{
		String line = value.toString();
		String[] words=line.split(",");
			for(String word: words )
			{
			      Text outputKey = new Text(word.toUpperCase().trim());
			      IntWritable outputValue = new IntWritable(1);
			      con.write(outputKey, outputValue);
			}
		}
	}
	public static class ReduceForWordCount extends Reducer<Text, IntWritable, Text, IntWritable>
	{
		public void reduce(Text word, Iterable<IntWritable> values, Context con) throws IOException, InterruptedException
		{
			int sum = 0;
			for(IntWritable value : values)
			{
				sum += value.get();
			}
			con.write(word, new IntWritable(sum));
		}
	}
	
}
