import java.io.*;
import java.util.*;

import javax.swing.JFileChooser;

public class FrequenciesSorted {
	
	private static class WordPair implements Comparable<WordPair>{
		 String word;
		 int freq;
		 public WordPair(String s, int i){
			 word = s;
			 freq = i;
		 }
		 public int compareTo(WordPair wp){
			 return word.compareTo(wp.word);
		 }
	}
	private static class WPFreq implements Comparator<WordPair>{
		public int compare(WordPair o1, WordPair o2) {
			int diff = o2.freq - o1.freq;
			if (diff != 0) return diff;
			return o1.compareTo(o2);
		}
		
	}
	
	
    private static JFileChooser ourChooser = new JFileChooser(System
            .getProperties().getProperty("user.dir"));

    public static void doFreqsA(String[] words){
        double start = System.currentTimeMillis();
        List<String> list = Arrays.asList(words);
        TreeSet<String> unique = new TreeSet<String>(list);
        WordPair[] freqs = new WordPair[unique.size()];
        int index = 0;
        for(String s : unique){
            freqs[index] = new WordPair(s,Collections.frequency(list, s));
            index++;
        }
        double end = System.currentTimeMillis();
        Arrays.sort(freqs, new WPFreq());
        index = 0;
        for(WordPair s : freqs){
            System.out.printf("%d\t%s\n", s.freq, s.word);
            index++;
            if (index >= 20) break;
        }
        System.out.printf("time to complete: %f\n\n",(end-start)/1000.0);
    }
    
    public static void doFreqsB(String[] words){
        double start = System.currentTimeMillis();
        TreeMap<String,Integer> map = new TreeMap<String,Integer>();
        for(String s : words){
            if (! map.containsKey(s)){
                map.put(s, 0);
            }
            map.put(s, map.get(s)+1);
        }
        ArrayList<WordPair> list = new ArrayList<WordPair>();
        /**
         * TODO: write code here to add every (word,count) pair
         * to the ArrayList list. Loop over set of keys in map and create
         * a new WordPair object
         */
        
        //----------- code here ----------------
        
        /**
         * TODO: sort the list as was done in doFreqsA, but here use
         * Collections.sort instead of Arrays.sort, why? Sort by 
         * frequency of occurrences, not alphabetically by word
         * 
         */
        
        // ----------- code here -------------------
        
        double end = System.currentTimeMillis();
        int count = 0;
        for(WordPair wp : list){
            System.out.printf("%d\t%s\n", wp.freq, wp.word);
            count++;
            if (count >= 20) break;
        }
        System.out.printf("time to completed %f\n",(end-start)/1000.0);
    }
    
    public static void main(String[] args) throws FileNotFoundException{
        int retval = ourChooser.showOpenDialog(null);

        if (retval == JFileChooser.APPROVE_OPTION) {
            Scanner s = new Scanner(ourChooser.getSelectedFile());
            String[] words = s.useDelimiter("\\Z").next().split("\\s+");
            System.out.printf("total # words read: %d\n", words.length);
            doFreqsA(words);
            doFreqsB(words);

        }
        System.exit(0);
    }
    
}