import java.io.File;
import java.io.FileFilter;
import java.io.FileNotFoundException;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;
import java.util.Vector;
import java.util.Hashtable;
import java.util.Arrays;


public class Variation {

	// Password variables
	private int[] status; // Current process status for restart support
	final int DUMP_MAX = 10000; // Max. amount of passwords in memory before clearing & dumping
	private String[] generated; // Passwords tried.

	private String vary;
	private char[] varyArray;
	StringBuilder builder;
	
	private Hashtable<Character,String[]> lookup = new Hashtable<Character,String[]>();
		
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Variation c = new Variation("emmatruitjemaria");
		c.makeVariations();
		System.exit(0);
	}

	public Variation(String pwd)
	{
		this.vary = pwd;
		this.varyArray = vary.toCharArray();
		builder = new StringBuilder(vary.length());
		this.status = new int[pwd.length()];
		this.Prepare();
	}
	
	private void Prepare()
	{
		this.lookup.put('e', new String[]{"e","E","3","#"});
		this.lookup.put('a',new String[]{"a","A","4","$",""}); // Empty for 'a'-'Caps lock' mix up.
		this.lookup.put('m',new String[]{"m","M",""}); // Faulty keyboard
		this.lookup.put('t',new String[]{"t","T"});
		this.lookup.put('r',new String[]{"r","R"});
		this.lookup.put('u',new String[]{"u","U"});
		this.lookup.put('i',new String[]{"i","I","1","!"});
		this.lookup.put('j',new String[]{"j","J"});	
		
		this.generated = new String[DUMP_MAX];
	}
	
	public void makeVariations()
	{
		long start = System.currentTimeMillis();
		String passWord= "";		
		int tmpCnt = 0;
		int current = 0;
		int batch = 0;
		
		while(!passWord.equals(this.vary))
		{
			passWord = ApplyVariation();
			generated[current++] = passWord;
			tmpCnt++;
			
			if(current>=DUMP_MAX)
			{
				// Dump generated passwords
				dumpGenerated(generated, batch++);
				current=0;
				generated = new String[DUMP_MAX];
			}
		}
		
		long tookMe = System.currentTimeMillis() - start;	
		System.out.format("Done! Made %d passwords\n", tmpCnt);
		System.out.println("It took me "+ (tookMe/1000.00) + " sec. or " + (tookMe/1000.00)/60.00 +" min. ");
	}
	
	private String ApplyVariation()
	{
		int carry = 1;
		int tmp;
		int size;
		
		for(int i=vary.length()-1; i>=0 && carry==1; i--)
		{
			size = lookup.get(varyArray[i]).length;
			tmp = status[i] + 1;
			status[i] = (tmp % size);
			carry = (tmp / size);
		}
		
		builder = new StringBuilder(vary.length());
		
		for(int i=0;i<vary.length();i++)
		{
			builder.append(lookup.get(varyArray[i])[status[i]]);
		}
		
		return builder.toString();
	}
	
	private FileWriter fw;
	private String fmtFile = "%06d.pwd"; // [batch num]_[start pwd size]-[end pwd size]
	private String fmtEntry = "%s\n";

	/**
	 * Dumps the table of tried and failed passwords.
	 * 
	 * @param tried List of tried passwords
	 * @param batch Batch number
	 */
	private void dumpGenerated(String[] tried, int batch)
	{
		try
		{
			fw = new FileWriter(String.format(fmtFile, batch));
			
			for(int i=0; i<tried.length;i++)
			{
				fw.write(String.format(fmtEntry, tried[i]));
			}
			
		}
		catch(IOException ioe)
		{
			System.err.println("Cannot store batch: " + ioe.getMessage());
		}
		finally
		{
			if(fw!=null)
			{
				try
				{
					fw.flush();
					fw.close();
				}
				catch(IOException ioe)
				{
					System.err.println("Cannot close stream: " + ioe.getMessage());
				}
			}
		}
	}
}