import java.io.*;
import java.util.*;
import javax.swing.JFileChooser;

/**
 * Simple demo of Map classes to track
 * how many times every word in a file occurs.
 * @author Owen Astrachan
 */

public class MapDemo
{
    public static double testMap(BufferedReader r, Map map)
    {

	try {
	    double start = System.currentTimeMillis();
	    String line;
	    while ((line = r.readLine()) != null) {
		StringTokenizer toks = new StringTokenizer(line);
		while (toks.hasMoreTokens()) {
		    String s = toks.nextToken().toLowerCase();
		    Counter c = (Counter) map.get(s);
		    if (c == null) {
			map.put(s,new Counter(1));
		    }
		    else {
			c.increment();
		    }
		}
	    }
	    double end = System.currentTimeMillis();
	    return (end - start)/1000;	    
	}
	catch (IOException e) {
	    System.out.println("trouble reading "+e);
	}
	return 0;
    }

    public static double testArrayList(BufferedReader r, ArrayList list)
    {

	try {
	    double start = System.currentTimeMillis();
	    String line;
	    while ((line = r.readLine()) != null) {
		StringTokenizer toks = new StringTokenizer(line);
		while (toks.hasMoreTokens()) {
		    String s = toks.nextToken().toLowerCase();
		    list.add(s);
		}
	    }
	    double end = System.currentTimeMillis();
	    return (end - start)/1000;	    
	}
	catch (IOException e) {
	    System.out.println("trouble reading "+e);
	}
	return 0;
    }

    public static double processArray(ArrayList list)
    {
	double start = System.currentTimeMillis();
	int max = 0;
	int count = 1;
	int run = 1;
	Object maxObject = null;
	Object last = list.get(0);
	for(int k=1; k < list.size(); k++) {
	    Object current = list.get(k);
	    if (! current.equals(last)) {
		count++;
		if (run > max) {
		    max = run;
		    maxObject = last;
		}
		run = 0;
		last = current;
	    }
	    else {
		run++;
	    }
	}
	double end = System.currentTimeMillis();
	System.out.println("# different objects "+count);
	System.out.println("most frequent "+maxObject);
	return (end-start)/1000;
    }

    /**
     * Returns the maximally occurring string in map
     * @returns the word that occurs more frequently than any other
     */
    
    public static String mostFrequent(Map map)
    {
	Iterator it = map.keySet().iterator();
	int max = 0;
	String smax = null;
	while (it.hasNext()) {
	    String s = (String) it.next();
	    int count = ((Counter)map.get(s)).getValue();
	    if (count > max) {
		max = count;
		smax = s;
	    }
	}
	return smax;
    }

    public static void main(String[] args)
    {
	String filename = null;

	if (args.length > 0) {
	    filename = args[0];
	}
	else {
	    JFileChooser chooser = new JFileChooser(".");
	    int retval = chooser.showOpenDialog(null);	    
	    if (retval == JFileChooser.APPROVE_OPTION) {
		filename = chooser.getSelectedFile().getPath();
		System.out.println("testing "+filename);
	    }
	    else {
		filename = "MapDemo.java";
	    }
	}
	
	try { 
	    BufferedReader reader = new BufferedReader(
		                       new FileReader(filename));
	    TreeMap tmap = new TreeMap();
	    double treeTime = testMap(reader,tmap);

	    reader = new BufferedReader(
		        new FileReader(filename));
	    
	    HashMap hmap = new HashMap();
	    double hashTime = testMap(reader,hmap);

	    String max = mostFrequent(tmap);
	    System.out.print("TreeMap size = "+tmap.size());
	    System.out.println(" in time "+treeTime);
	    System.out.println("most frequent word is: "+max);

	    max = mostFrequent(hmap);
	    System.out.print("HashMap size = "+hmap.size());
	    System.out.println(" in time "+hashTime);
	    System.out.println("most frequent word is: "+max);

	    reader = new BufferedReader(
		        new FileReader(filename));
	    ArrayList list = new ArrayList();
	    double atime = testArrayList(reader,list);
	    double start = System.currentTimeMillis();
	    Collections.sort(list);
	    double end = System.currentTimeMillis();

	    System.out.println("reading array time "+atime);
	    double sortTime = (end-start)/1000;
	    System.out.println("sorting time "+sortTime);
	    double ptime = processArray(list);
	    System.out.println("total time "+(atime+sortTime+ptime));

	    Iterator it = tmap.keySet().iterator();
	    while (it.hasNext()) {
		String s = (String) it.next();
		System.out.println(tmap.get(s) + "\t" + s);
	    }
	    
	}
	catch (IOException e) {
	    System.out.println("problem creating reader "+e);
	}
	System.exit(0);   // need this to close JFileChooser
    }
    
}