import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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.ArrayWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
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.input.KeyValueTextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
 
import java.io.IOException;
import java.lang.Integer;
import java.util.StringTokenizer;
import java.util.TreeSet;
 
// >>> Don't Change
public class WHV2 extends Configured implements Tool {
    public static final Log LOG = LogFactory.getLog(WHV2.class);
 
    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new WHV2(), args);
        System.exit(res);
    }
 
    public static class TextArrayWritable extends ArrayWritable {
        public TextArrayWritable() {
            super(Text.class);
        }
 
        public TextArrayWritable(String[] numbers) {
            super(Text.class);
            Text[] texts = new Text[numbers.length];
            for (int i = 0; i < numbers.length; i++) {
                texts[i] = new Text(numbers[i]);
            }
            set(texts);
        }
    }
 
    @Override
    public int run(String[] args) throws Exception {
        // TODO
        Configuration conf = this.getConf();
        FileSystem fs = FileSystem.get(conf);
        Path tmpPath = new Path("/user/lada38/mp2/tmp");
        fs.delete(tmpPath, true);
 
        Job jobA = Job.getInstance(conf, "WHV2_A");
        jobA.setOutputKeyClass(Text.class);
        jobA.setOutputValueClass(IntWritable.class);
 
        jobA.setMapperClass(LinkCountMap.class);
        jobA.setReducerClass(LinkCountReduce.class);

        jobA.setMapOutputKeyClass(Text.class);
        jobA.setMapOutputValueClass(IntWritable.class);
 
        FileInputFormat.setInputPaths(jobA, new Path(args[0]));
        FileOutputFormat.setOutputPath(jobA, tmpPath);
 
        jobA.setJarByClass(WHV2.class);
        jobA.waitForCompletion(true);
 
        Job jobB = Job.getInstance(conf, "WHV2_B");
        jobB.setOutputKeyClass(NullWritable.class);
        jobB.setOutputValueClass(TextArrayWritable.class);
 
        jobB.setMapOutputKeyClass(  NullWritable.class);
        jobB.setMapOutputValueClass(TextArrayWritable.class);
 
        jobB.setMapperClass(TopLinksMap.class);
        jobB.setReducerClass(TopLinksReduce.class);
        jobB.setNumReduceTasks(1);
 
            FileInputFormat.setInputPaths(jobB, tmpPath);
        FileOutputFormat.setOutputPath(jobB, new Path(args[1]));
 
        jobB.setInputFormatClass(KeyValueTextInputFormat.class);
        jobB.setOutputFormatClass(TextOutputFormat.class);
 
        jobB.setJarByClass(WHV2.class);
        return jobB.waitForCompletion(true) ? 0 : 1;
    }
 
    public static class LinkCountMap extends Mapper<Object, Text, Text, IntWritable> {
        @Override
        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            String[] line = value.toString().split(",");
            String keyA=line[0]+" "+line[2]+" "+line[1]+" "+line[19]+" "+line[20];
            context.write(new Text(keyA),new IntWritable(1));
        }
    }
 
    public static class LinkCountReduce extends Reducer<Text, IntWritable, Text, IntWritable> {
        // TODO
        @Override
        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            Integer sum = new Integer(0);
            for (IntWritable val: values) {
                sum += val.get();
            }
 
            context.write(key, new IntWritable(sum));
        }
    }
 
    public static class TopLinksMap extends Mapper<Text, Text, NullWritable, TextArrayWritable> {
        Integer N;
        private TreeSet<Pair<Integer, String>> coutToPageIdMap = new TreeSet<Pair<Integer, String>>();
        
        @Override
        protected void setup(Context context) throws IOException,InterruptedException {
            Configuration conf = context.getConfiguration();
            this.N = conf.getInt("N", 10);
        }
        // TODO
        
        @Override
        public void map(Text key, Text value, Context context) throws IOException, InterruptedException {
            Integer count = Integer.parseInt(value.toString());
            String word = key.toString();

            coutToPageIdMap.add(new Pair <Integer , String> (count,word));
            
            if (coutToPageIdMap.size() > N) {
                coutToPageIdMap.remove(coutToPageIdMap.first());
            }
        }
 
        @Override
        protected void cleanup(Context context) throws IOException,InterruptedException {
            for (Pair<Integer , String>item : coutToPageIdMap){
            String[] strings = {item.second , item.first.toString()};
            context.write(NullWritable.get(),new TextArrayWritable(strings));

            }
        }
    }
 
    public static class TopLinksReduce extends Reducer<NullWritable, TextArrayWritable, Text, IntWritable> {
        Integer N;
        private TreeSet<Pair<Integer, String>> coutToPageIdMap = new TreeSet<Pair<Integer, String>>();
        
        @Override
        protected void setup(Context context) throws IOException,InterruptedException {
            Configuration conf = context.getConfiguration();
            this.N = conf.getInt("N", 10);
        }
        // TODO
        @Override
        public void reduce(NullWritable key, Iterable<TextArrayWritable> values, Context context) throws IOException, InterruptedException {
            for(TextArrayWritable val: values){
                Text[] pair = (Text[]) val.toArray();
                String word =  pair[0].toString();
                Integer count = Integer.parseInt(pair[1].toString());

                coutToPageIdMap.add(new Pair<Integer , String> (count , word));

                if (coutToPageIdMap.size() > this.N){
                    coutToPageIdMap.remove(coutToPageIdMap.first());
                }
            }
            for (Pair<Integer , String> item : coutToPageIdMap){
                Text word = new Text(item.second);
                IntWritable value = new IntWritable(item.first);
                context.write(word, value);
            }
        }
    }
}
 
// >>> Don't Change
class Pair<A extends Comparable<? super A>,
        B extends Comparable<? super B>>
        implements Comparable<Pair<A, B>> {
 
    public final A first;
    public final B second;
 
    public Pair(A first, B second) {
        this.first = first;
        this.second = second;
    }
 
    public static <A extends Comparable<? super A>,
            B extends Comparable<? super B>>
    Pair<A, B> of(A first, B second) {
        return new Pair<A, B>(first, second);
    }
 
    @Override
    public int compareTo(Pair<A, B> o) {
        int cmp = o == null ? 1 : (this.first).compareTo(o.first);
        return cmp == 0 ? (this.second).compareTo(o.second) : cmp;
    }
 
    @Override
    public int hashCode() {
        return 31 * hashcode(first) + hashcode(second);
    }
 
    private static int hashcode(Object o) {
        return o == null ? 0 : o.hashCode();
    }
 
    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof Pair))
            return false;
        if (this == obj)
            return true;
        return equal(first, ((Pair<?, ?>) obj).first)
                && equal(second, ((Pair<?, ?>) obj).second);
    }
 
    private boolean equal(Object o1, Object o2) {
        return o1 == o2 || (o1 != null && o1.equals(o2));
    }
 
    @Override
    public String toString() {
        return "(" + first + ", " + second + ')';
    }
}
// <<< Don't Change