/*
 * Created on Mar 24, 2005
 * 
 * @author jbergin
 *
 * Edited on Mar 24, 2005
 * 
 * @author Eugene Wallingford
 *         added ability to pass args via command line
 *
 */
package com.jbergin;

import java.util.Random;
import java.io.*;
import java.util.ArrayList;
/**
 * @author jbergin
 *
 */
public class RandomText
{

	public RandomText(String filename, int length, int delta)
	{
			String original = grabFile(filename);
			int originalLength = original.length();
			Random random = new Random();
			int start = random.nextInt(originalLength-delta);
			String fragment = original.substring(start, start+delta);
			text = fragment;
		//System.out.print(fragment);
			for(int i = 0; i < length-delta; i++)
			{
				char ch = findNext(original, fragment);
				text += ch;
		//System.out.print(ch);
				fragment = fragment.substring(1, delta) + ch;
			}
	}
	
	private final char findNext(String original, String fragment)
	{
		char result=' ';
		int delta = fragment.length();
		int where = 0;
		where = original.indexOf(fragment, where);
		ArrayList results = new ArrayList();
		while(where > -1)
		{
			if(where+delta < original.length())
			{
				char item = original.charAt(where+delta);
				results.add(new Character(item));
			}
			where = original.indexOf(fragment, where+1);
		}
		Random random = new Random();
		int which = random.nextInt(results.size());
		Character ch = (Character)results.get(which);
		result = ch.charValue();
		return result;
	}
	
	private static final String grabFile(String filename)
	{	String original = null;
		try
		{	FileInputStream in = new FileInputStream(filename);
			int buflen = in.available();
			BufferedInputStream s  = new BufferedInputStream(in, buflen);
			byte[] buf = new byte[buflen];
			int n = s.read(buf);
			original = new String(buf);			
		}
		catch (IOException exc)
		{
			System.out.println("Cannot open file " + filename);
			original = "";
		}
		return original;
	}
	
	public String toString()
	{
		return text;
	}
	
	private String text;
	
    public static void main(String [] args)
    {
        String filename = "repub11.txt";
        int    length   = 1000;
        int    delta    = 5;

        if ( args.length > 0 )
        {
            filename = args[0];
            length   = Integer.parseInt( args[1] );
            delta    = Integer.parseInt( args[2] );
        }

        RandomText ran = new RandomText( filename, length, delta );
        System.out.println( ran.toString() );
    }
}