/**
   * Loads wallet data from the given protocol buffer and inserts it into the given Wallet object.
   * This is primarily useful when you wish to pre-register extension objects. Note that if loading
   * fails the provided Wallet object may be in an indeterminate state and should be thrown away.
   *
   * @throws IOException if there is a problem reading the stream.
   * @throws IllegalArgumentException if the wallet is corrupt.
   */
  public void readWallet(Protos.Wallet walletProto, Wallet wallet) throws IOException {
    // TODO: This method should throw more specific exception types than IllegalArgumentException.
    // Read the scrypt parameters that specify how encryption and decryption is performed.
    if (walletProto.hasEncryptionParameters()) {
      Protos.ScryptParameters encryptionParameters = walletProto.getEncryptionParameters();
      wallet.setKeyCrypter(new KeyCrypterScrypt(encryptionParameters));
    }

    if (walletProto.hasDescription()) {
      wallet.setDescription(walletProto.getDescription());
    }

    // Read all keys
    for (Protos.Key keyProto : walletProto.getKeyList()) {
      if (!(keyProto.getType() == Protos.Key.Type.ORIGINAL
          || keyProto.getType() == Protos.Key.Type.ENCRYPTED_SCRYPT_AES)) {
        throw new IllegalArgumentException(
            "Unknown key type in wallet, type = " + keyProto.getType());
      }

      byte[] privKey = keyProto.hasPrivateKey() ? keyProto.getPrivateKey().toByteArray() : null;
      EncryptedPrivateKey encryptedPrivateKey = null;
      if (keyProto.hasEncryptedPrivateKey()) {
        Protos.EncryptedPrivateKey encryptedPrivateKeyProto = keyProto.getEncryptedPrivateKey();
        encryptedPrivateKey =
            new EncryptedPrivateKey(
                encryptedPrivateKeyProto.getInitialisationVector().toByteArray(),
                encryptedPrivateKeyProto.getEncryptedPrivateKey().toByteArray());
      }

      byte[] pubKey = keyProto.hasPublicKey() ? keyProto.getPublicKey().toByteArray() : null;

      ECKey ecKey;
      final KeyCrypter keyCrypter = wallet.getKeyCrypter();
      if (keyCrypter != null
          && keyCrypter.getUnderstoodEncryptionType() != EncryptionType.UNENCRYPTED) {
        // If the key is encrypted construct an ECKey using the encrypted private key bytes.
        ecKey = new ECKey(encryptedPrivateKey, pubKey, keyCrypter);
      } else {
        // Construct an unencrypted private key.
        ecKey = new ECKey(privKey, pubKey);
      }
      ecKey.setCreationTimeSeconds((keyProto.getCreationTimestamp() + 500) / 1000);
      wallet.addKey(ecKey);
    }

    // Read all transactions and insert into the txMap.
    for (Protos.Transaction txProto : walletProto.getTransactionList()) {
      readTransaction(txProto, wallet.getParams());
    }

    // Update transaction outputs to point to inputs that spend them
    for (Protos.Transaction txProto : walletProto.getTransactionList()) {
      WalletTransaction wtx = connectTransactionOutputs(txProto);
      wallet.addWalletTransaction(wtx);
    }

    // Update the lastBlockSeenHash.
    if (!walletProto.hasLastSeenBlockHash()) {
      wallet.setLastBlockSeenHash(null);
    } else {
      wallet.setLastBlockSeenHash(byteStringToHash(walletProto.getLastSeenBlockHash()));
    }
    if (!walletProto.hasLastSeenBlockHeight()) {
      wallet.setLastBlockSeenHeight(-1);
    } else {
      wallet.setLastBlockSeenHeight(walletProto.getLastSeenBlockHeight());
    }

    loadExtensions(wallet, walletProto);

    if (walletProto.hasVersion()) {
      wallet.setVersion(walletProto.getVersion());
    }

    // Make sure the object can be re-used to read another wallet without corruption.
    txMap.clear();
  }