package net.jtank.protocol;

import javax.swing.JFrame;
import java.util.Random;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;


/**
 * Uses a form of One-Time Pad Encryption to digitally encrypt textual data.
 *
 * Encrypts data using a one-time cyper system.
 * Theorecically unbreakable if a totally random key is used (ie, one made up by throwing a dice etc);
 * Using the randomly generated key isn't as safe, because java uses a pseudo-random number generator
 * meaning they look random, but actually are not.
 *
 *
 *@author William Denniss
 *
 * Versions:
 *
 * 04 Jan 2002: v1.0
 * - Command Line with full functionality
 *
 * 05 Jan 2002: v1.1
 * - Basic GUI added
 *
 * 13 Mar 2002: v1.2
 * - New much improved GUI
 *
 * 05 Apr 2002: v1.3
 * - GUI improved, but separated from this file.  This class vastly improved to make it more abstract
 *
 * William Denniss has asserted his right under the Australian Copyright, Designs and Patents Act 1988 to be identified as the author of this work.
 */

public class OneTimeNOCList {
	public String file1 = "text.txt";
	public String file2 = "code1.txt";
	public String file3 = "code2.txt";
	public boolean encrypt = true;




   	public static void encrypt (BufferedReader brPlain, BufferedReader bwKey, BufferedWriter bwEnc) throws IOException{

        //int currentChar = 0;
        char [] encrypted = new char [2];
        String line = brPlain.readLine();
        String keyLine = bwKey.readLine();

        while (line != null && keyLine != null) {

              for (int i = 0; i < line.length(); i++) {

                      char currentChar = line.charAt(i);
                      char currentKey = keyLine.charAt(i);
                      if ( currentChar>= 32) {

                              encrypted = encryptChar ( (char) currentChar, currentKey);


                              bwEnc.write(encrypted[0]);
                      } else {

                              bwEnc.write( (char) currentChar);
                      }

              }
              line = brPlain.readLine();
              keyLine = bwKey.readLine();

              if (line != null) {

                      bwEnc.write( '\n');
              }

        }

        //bw1.close();
        bwEnc.close();
        bwKey.close();
        brPlain.close();

	}


	public static void decrypt (BufferedWriter bw, BufferedReader br1, BufferedReader br2) throws IOException {


        //int currentChar = 0;
        char [] encrypted = new char [2];
        String line1 = br1.readLine();
        String line2 = br2.readLine();

        while (line1 != null) {

            for (int i = 0; i < line1.length(); i++) {
                encrypted[0] = line1.charAt(i);
                encrypted[1] = line2.charAt(i);

                if ( encrypted[0] >= 32) {

                //	encrypted = encryptChar ( (char) currentChar);

                    bw.write(decryptChar(encrypted));
                    //pw2.print(encrypted[1]);
                } else {
                    bw.write(encrypted[0]);
                }

            }
            line1 = br1.readLine();
            line2 = br2.readLine();

            if (line1 != null) {
                bw.write( '\n');
            }

        }


        bw.close();


	}

    public static String generateRandomKey (String toEncode) {
        String toReturn = "";
        for (int i = 0; i < toEncode.length(); i++) {
            toReturn += (char) (randomChar() + 32);
        }
        //return (toReturn);
        return formatString(toReturn, toEncode);
    }

	public static String generateRandomKey (String toEncode, String password, int method) {

        if (method == 0) {
            long hashnumber = 0;
            for (int i = 0; i < password.length(); i++) {
                hashnumber *= 10;
                hashnumber += password.charAt(i);
            }

            //System.out.println(hashnumber);
            long bigNumber = Long.parseLong("99736599483849");
            hashnumber *= bigNumber;

            //System.out.println(hashnumber);
            hashnumber = Math.abs(hashnumber ^ (int) ((hashnumber * 10) /2));
            //System.out.println(hashnumber);

            long seednumber = (int) (hashnumber / 10000000);
            long offsetnumber = hashnumber % 10000000;
            //System.out.println(seednumber + " - " + offsetnumber);

            return generateRandomKey(toEncode, seednumber, offsetnumber);
        } else {
            return null;
        }
	}


    public static String generateRandomKey (String toEncode, long seed, long offset) {
        Random numbergenerator = new Random (seed);
        for (int i = 0; i < offset; i++) {
            numbergenerator.nextLong();
        }

        String toReturn = "";
        for (int i = 0; i < toEncode.length(); i++) {
    		char randomChar = (char) numbergenerator.nextLong();
            randomChar %= (127-32);
            randomChar += 32;
            toReturn += randomChar;
        }

        return formatString(toReturn, toEncode);
    }

    public static String formatString (String toFormat, String formatTo) {
        String toReturn = "";
        for (int i = 0; i < formatTo.length(); i++) {
            if (formatTo.charAt(i) == '\n')
                toReturn += '\n';
            else
                toReturn += toFormat.charAt(i);
        }
        return toReturn;
    }

    public static char randomChar () {
   		char randomOffset = (char) (Math.random() * 1000);
		randomOffset %= (127-32);
        return randomOffset;
    }

	public static char [] encryptChar(char toencrypt) {

		char randomOffset = randomChar();
        return encryptChar(toencrypt, (char) (randomOffset+32));
    }


	public static char [] encryptChar(char toencrypt, char key) {


        if (toencrypt == '\n')
          return new char [] {'\n','\n'};

        char [] encrypted = new char [2];

        char randomOffset = (char) ((int) key - 32);

		//Basic ASCII
		if (toencrypt < 0x7F) {
			encrypted[0] = toencrypt;
			encrypted[1] = (char) (randomOffset + 32); //store random index

			encrypted[0] -= 32; //cut first 32 ASCII characters
			encrypted[0] += randomOffset; //add the offset
			encrypted[0] %= 127-32; //mod it so it wraps around
			encrypted[0] += 32; //increase it back to where it should be

		//Extended ASCII
		} else if (toencrypt < 0xFF) {
			randomOffset ++;

			encrypted[0] = toencrypt;
			encrypted[1] = (char) (randomOffset + 32 +127);

			encrypted[0] -= 32+128;
			encrypted[0] += randomOffset;
			encrypted[0] %= 127-32;
			encrypted[0] += +32+128;

			//if (!(encrypted[0] >= 160 && encrypted[0] <= 254))
			//	System.out.println(encrypted[0]+0);
			//if (!(encrypted[1] >= 160 && encrypted[1] <= 254))
			//	System.out.println(encrypted[1]+0+"r");

		//not supported
		} else {
		}

		return encrypted;
	}


	public static char decryptChar(char todecrypt []) {
                if (todecrypt[0] == '\n')
                  return '\n';

		int decrypted = 0;
		int randomOffset;

		//Basic ASCII
		if (todecrypt[0] < 0x7F) {
			decrypted = todecrypt[0];
			randomOffset = (char) (todecrypt[1] - 32);


			decrypted -= 32;
			decrypted -= randomOffset;
			if (decrypted < 0)
				decrypted += (127-32);
			decrypted += 32;

		//Extended ASCII
		} else if (todecrypt[0] < 0xFF) {
			decrypted = todecrypt[0];
			randomOffset = (char) (todecrypt[1] - 32 -127);


			decrypted -= 32 + 127;
			decrypted -= randomOffset;
			if (decrypted < 1)
				decrypted += (127-32);
			decrypted += 32 +127;

			//if (!(decrypted >= 160 && decrypted <= 254))
			//	System.out.println(decrypted+0);


		//not supported
		} else {
		}


		return (char) decrypted;
	}

}