package otp;


import java.util.Random;
import java.util.Observable;

public class OTP extends Observable {
	LinReg enc_reg = null;
	LinReg dec_reg = null;
	Random rnd = new Random();
	int config;
	int init;
        String plain="";
        String cipher="";
	
        public int[] getKeys()
        {
            int [] keys = new int[2];
            keys[0] = config;
            keys[1] = init;
            return keys;
        }
        
        public String getPlain() {
            return this.plain;
        }
        
        public String getCipher() {
            return this.cipher;
        }        
        public void setPlain(String p)
        {
            this.plain=p;
        }
        
        public void setCypher(String c)
        {
            this.cipher=c;
        }
        
        public void encrypt()
        {
            this.cipher = this.encrypt(this.config, this.init, this.plain);
        }
        
        public void decrypt()
        {
            this.plain = this.decrypt(this.config, this.init, this.cipher);
        }
        
	public int encryptOne(int clear, int key)
	{
		int cipher_int=0;
		int keyBit=0;
		int clearBit=0;
		int cipherBit=0;
		for (int i=7;i>=0;i--)
		{
			clearBit = clear & (1<<i);
			keyBit = key & (1<<i);
			cipherBit = keyBit ^ clearBit;
			cipher_int |= cipherBit;
		}
		return cipher_int;
	}
	
	public int decryptOne(int cipher, int key)
	{
		int clear = encryptOne(cipher,key);
		return clear;
	}
	
	private int encode(char c)
	{
		int ret = (int) c;
		return ret;
	}
	
	private char decode(int i)
	{
		char ret = (char) i;
		return ret;
	}
	public String encrypt(int config, int init, String plain)
	{
		enc_reg =  new LinReg(config,init);
		String cipherStr=new String();
		int key=0;
		int plain_int=0;
		int cipher_int = 0;
		char cipher_char = ' ';
		char[] cipher_chars= new char[plain.length()];
		for (int i = 0;i < plain.length(); i++)
		{
			key=enc_reg.getNextKey();
			plain_int = encode(plain.charAt(i));
			cipher_int = encryptOne(plain_int,key);
			cipher_char = decode(cipher_int);
			cipher_chars[i]=cipher_char;
		}
		cipherStr = String.copyValueOf(cipher_chars);
		return cipherStr;
	}
	
	public String decrypt(int config, int init, String cipher)
	{
		dec_reg =  new LinReg(config,init);
		String plainStr=new String();
		int key=0;
		int plain_int=0;
		int cipher_int = 0;
		char plain_char = ' ';
		char[] plain_chars= new char[cipher.length()];
		for (int i = 0;i < cipher.length(); i++)
		{
			key=dec_reg.getNextKey();
			cipher_int=encode(cipher.charAt(i));
			plain_int=decryptOne(cipher_int,key);
			plain_char=decode(plain_int);
			plain_chars[i]=plain_char;
		}
		plainStr = String.copyValueOf(plain_chars);
		return plainStr;
	}
	
	public void initialize()
	{
		setKeys(rnd.nextInt(0xff), rnd.nextInt(0xff));
	}
	
	public void setKeys(int c, int i)
	{
		config=c;
		init=i;
                enc_reg =  new LinReg(config,init);
                dec_reg =  new LinReg(config,init);
	}
	
	public void doIt()
	{
		
		//int config=0x56;
		//int init=0xf4;
		
		this.initialize();
			
/*		String plain = "A quite long text";
		String cipher= new String();
		cipher=encrypt(config,init,plain);
		System.out.println("Plain: "+plain.toUpperCase());
		System.out.println("Cipher ASCII: "+cipher.toLowerCase());
		System.out.print("Cipher dec: ");
		for (int i=0;i<cipher.length();i++)
		{
			System.out.print((int)cipher.charAt(i)+" ");
		}
		System.out.println();
		System.out.print("Cipher hex: ");
		for (int i=0;i<cipher.length();i++)
		{
			System.out.print(Integer.toHexString((int)cipher.charAt(i))+" ");
		}
		System.out.println();
		System.out.println("Decrypted: "+decrypt(config,init,cipher).toUpperCase());*/
	}
        
}