package exemplo.infraestrutura;



import java.io.UnsupportedEncodingException;

import java.math.BigInteger;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.text.SimpleDateFormat;

import java.util.Date;



import javax.crypto.Cipher;

import javax.crypto.spec.SecretKeySpec;



import org.jboss.seam.annotations.AutoCreate;

import org.jboss.seam.annotations.Name;



import exemplo.dominio.exceptions.DescriptografiaException;



@Name("criptografiaService")

@AutoCreate

public class CriptografiaService {



	private String convertToHex(byte[] data) {

		StringBuffer buf = new StringBuffer();

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

			int halfbyte = (data[i] >>> 4) & 0x0F;

			int two_halfs = 0;

			do {

				if ((0 <= halfbyte) && (halfbyte <= 9))

					buf.append((char) ('0' + halfbyte));

				else

					buf.append((char) ('a' + (halfbyte - 10)));

				halfbyte = data[i] & 0x0F;

			} while (two_halfs++ < 1);

		}

		return buf.toString();

	}



	public String SHA1(String text) {

		try {

			MessageDigest md = MessageDigest.getInstance("SHA-1");

			byte[] sha1hash = new byte[40];

			md.update(text.getBytes("iso-8859-1"), 0, text.length());

			sha1hash = md.digest();

			return convertToHex(sha1hash);

		} catch (Exception e) {

			throw new IllegalStateException(

					"Problema ao gerar o SHA-1 do valor", e);

		}

	}



	public char[] decode(String chave, String secret)

			throws DescriptografiaException {

		byte[] kbytes = chave.getBytes();

		SecretKeySpec key = new SecretKeySpec(kbytes, "Blowfish");



		BigInteger n = new BigInteger(secret, 16);

		byte[] encoding = n.toByteArray();



		try {

			Cipher cipher = Cipher.getInstance("Blowfish");

			cipher.init(Cipher.DECRYPT_MODE, key);

			byte[] decode = cipher.doFinal(encoding);

			return new String(decode).toCharArray();

		} catch (Exception e) {

			throw new DescriptografiaException(

					"Problema ao descriptografar senha", e);

		}

	}



	public String encode(String chave, String secret) {

		byte[] kbytes = chave.getBytes();

		SecretKeySpec key = new SecretKeySpec(kbytes, "Blowfish");



		try {

			Cipher cipher = Cipher.getInstance("Blowfish");

			cipher.init(Cipher.ENCRYPT_MODE, key);

			byte[] encoding = cipher.doFinal(secret.getBytes());

			BigInteger n = new BigInteger(encoding);

			return n.toString(16);

		} catch (Exception e) {

			throw new IllegalStateException("Problema ao criptografar senha", e);

		}

	}



	public static void main(String[] args) throws DescriptografiaException,

			NoSuchAlgorithmException, UnsupportedEncodingException {

		SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHm");

		CriptografiaService c = new CriptografiaService();

		String chave = "SALrafael";

		String valorCifrado = c.encode(chave,

				"rafael|" + sdf.format(new Date()) + "|123");

		System.out.println(valorCifrado);

		char[] valorDecrifrado = c.decode(chave, valorCifrado);

		System.out.println(valorDecrifrado);

		System.out.println(c.SHA1(new String(valorDecrifrado)));

	}

}