/**
    * 
    */
   package org.treetank.io.bytepipe;
   
   import static com.google.common.base.Objects.toStringHelper;
   
   import java.io.InputStream;
   import java.io.OutputStream;
  import java.security.InvalidKeyException;
  import java.security.Key;
  import java.security.NoSuchAlgorithmException;
  
  import javax.crypto.Cipher;
  import javax.crypto.CipherInputStream;
  import javax.crypto.CipherOutputStream;
  import javax.crypto.NoSuchPaddingException;
  
  import org.treetank.exception.TTByteHandleException;
  
  import com.google.inject.Inject;
  
  /**
   * Decorator for encrypting any content.
   * 
   * @author Sebastian Graf, University of Konstanz
   * 
   */
  public class Encryptor implements IByteHandler {
  
      /** Kind of the algorithm. */
      private static final String ALGORITHM = "AES";
  
      /** Key for de-/encryption. */
      private final Key mKey;
  
      /**
       * Constructor.
       * 
       * @param pKey
       *            to be injected
       */
      @Inject
      public Encryptor(final Key pKey) {
          mKey = pKey;
      }
  
      /**
       * {@inheritDoc}
       * 
       * @throws TTByteHandleException
       */
      public OutputStream serialize(final OutputStream pToSerialize) throws TTByteHandleException {
          try {
              final Cipher cipher = Cipher.getInstance(ALGORITHM);
              cipher.init(Cipher.ENCRYPT_MODE, mKey);
              return new CipherOutputStream(pToSerialize, cipher);
          } catch (final InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException exc) {
              throw new TTByteHandleException(exc);
          }
      }
  
      /**
       * {@inheritDoc}
       */
      public InputStream deserialize(InputStream pToDeserialize) throws TTByteHandleException {
          try {
              final Cipher cipher = Cipher.getInstance(ALGORITHM);
              cipher.init(Cipher.DECRYPT_MODE, mKey);
              return new CipherInputStream(pToDeserialize, cipher);
          } catch (final InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException exc) {
              throw new TTByteHandleException(exc);
          }
  
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public Encryptor clone() {
          return new Encryptor(mKey);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String toString() {
          return toStringHelper(this).toString();
      }
  
  }