import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;

public class Cracker {

	// Password variables
	private int[] status; // Current password pointers
	final int DUMP_MAX = 10000; // Max. amount of passwords in memory before clearing & dumping
	// NOTE: DUMP_MAX can be changed between batches!
	
	private String[] tried = new String[DUMP_MAX]; // Passwords tried.
	private int current = 0; // Current step
	private int max = 22; // Max. password length
	
	// Teriminal command variables
	private Process p;
	private int step = 0;
	private int batch = 0;
	
	// Streams
	private BufferedReader stdInput;
	//private BufferedReader stdError;
	private FileInputStream fin;
	private FileOutputStream fout;
	private ObjectOutputStream oo;
	private ObjectInputStream oi;
	
	private final String STATUS = "status.dat";
	
	char[] canUse = {
			'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z', // 26
			'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z', // 52
			'0','1','2','3','4','5','6','7','8','9', // 62
			' ','~','`','!','@','#','$','%','^','&','*','-','=','+','_' // 77
	}; // Characters to use for making up a password
	
	private int maxStat = canUse.length;
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Cracker c = new Cracker();
		c.PrepareCharacters();
		c.Crack();
		System.exit(0);
	}

	public void Crack()
	{
		boolean result = false;
		String passWord = "";
		while(!result)
		{
			passWord = GetPassWord();
			
			if(current>=DUMP_MAX)
			{
				DumpTried(tried, batch);
				DumpStatus();
				batch++; // Batch counter
				current=0;
				tried = new String[DUMP_MAX];
				System.out.println();
			}
			tried[current++] = passWord;
			result = TryPassword(passWord);			
		}
		System.out.println();
		DumpTried(tried, batch);
		
		if(result)
		{
			System.out.println("IS> " + passWord);
		}
		else
		{
			System.out.println("Huh? options depleted and no password found. That sucks....");
		}
		
		System.out.println("Done!");
	}
	
	private String GetPassWord()
	{
		int carry = 1;
		int tmp;
		for(int i=max-1; i>=0 && carry==1; i--)
		{
			tmp = status[i] + 1;			
			status[i] = tmp % maxStat;
			carry = tmp/maxStat;
		}
		
		step++;
		
		String result = "";
		
		for(int i=0;i<max;i++)
		{
			if(status[i]!=-1)
			{
				result+= canUse[status[i]];
			}
		}
		
		return result;
	}
	
	private void PrepareCharacters()
	{	
		if(new File("status.dat").exists())
		{
			RestoreStatus();
		}
		else
		{
			System.out.println("Starting a new pwd search...");
			status = new int[max];
			
			for(int i=0;i<max;i++)
			{
				status[i] = -1;
			}
		}
	}
	
	private String check = "Everything is Ok";
	
	private boolean TryPassword(String passWord)
	{
		boolean result = false;

		// Try script:
		String s = null;

        try {
        	p = Runtime.getRuntime().exec("./try \""+passWord+"\"");
                 
        	stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

            // OK: Everything is Ok
            // WRONG : Wrong password?
            
            while (!result && (s = stdInput.readLine()) != null)
            {
            	if(s.equals(check))
            	{
            		result = true;
            	}
            }
        }
        catch (Exception e) {
            System.out.println("exception happened - here's what I know: ");
            e.printStackTrace();
        }
        finally
        {
        	if(stdInput!=null)
        	{
        		try
        		{
        			p.destroy();
        			stdInput.close();
        		}
        		catch(IOException ioe)
        		{
        			System.err.println("Cannot close stream: " + ioe.getMessage());
        		}
        	}
        }

        return result;
	}
	
	private FileWriter fw;
	private String fmtFile = "%d_%d-%d.pwd"; // [batch num]_[start pwd size]-[end pwd size]
	private String fmtEntry = "%s\n";

	private void DumpTried(String[] tried, int batch)
	{
		try
		{
			System.out.format("\n[Cache dump]\nStoring %d passwords\n", tried.length);
			fw = new FileWriter(String.format(fmtFile, batch, tried[0].length(), tried[DUMP_MAX-1].length()));
			
			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());
				}
			}
		}
	}
		
	private void DumpStatus()
	{
		try
		{
			fout = new FileOutputStream(STATUS);
			oo = new ObjectOutputStream(fout);
						
			Object[] stat = 
			{
					new Integer(max),
					new Integer(batch),
					status
			};
			
			oo.writeObject(stat);			
		}
		catch(IOException ioe)
		{
			System.err.println("Cannot store status: " + status);
		}
		finally
		{
				try
				{
					if(oo!=null)
					{
						oo.flush();
						oo.close();
					}
					
					if(fout!=null)
					{
						fout.flush();
						fout.close();
					}
				}
				catch(IOException ioe)
				{
					System.err.println("Cannot close stream: " + ioe.getMessage());
				}
		}
	}
	
	private void RestoreStatus()
	{
		try
		{
			System.out.println("[Restoring status]");
			fin = new FileInputStream(STATUS);
			oi = new ObjectInputStream(fin);
			Object[] stat = (Object[]) oi.readObject();
			
			this.max = ((Integer) stat[0]).intValue();
			this.batch = ((Integer) stat[1]).intValue();
			this.status = (int[]) stat[2];
			
			System.out.format("- Max pwd length : %d\n", max);
			System.out.format("- Batch  : %d\n", batch);
			
			// Display starting point
			String s = "";
			for(int i: this.status)
			{
				if(i>=0)
				s += canUse[i];
			}

			System.out.format("- Starting with: '%s'\n\n", s);
		}
		catch(Exception ioe)
		{
			System.err.format("Cannot restore status: %s\n%s\n", ioe.getMessage(), ioe.getStackTrace());
		}
		finally
		{
				try
				{
					if(oo!=null)
					{
						oo.flush();
						oo.close();
					}
					
					if(fout!=null)
					{
						fout.flush();
						fout.close();
					}
				}
				catch(IOException ioe)
				{
					System.err.println("Cannot close stream: " + ioe.getMessage());
				}
		}
	}
}