// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////////

package com.google.crypto.tink;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.security.GeneralSecurityException;

/** Functions to parse and serialize Keyset in Tink's binary format based on Protobufs. */
public final class TinkProtoKeysetFormat {

  @SuppressWarnings("UnusedException")
  public static KeysetHandle parseKeyset(byte[] serializedKeyset, SecretKeyAccess access)
      throws GeneralSecurityException {
    if (access == null) {
      throw new NullPointerException("SecretKeyAccess cannot be null");
    }
    try {
      return CleartextKeysetHandle.read(BinaryKeysetReader.withBytes(serializedKeyset));
    } catch (IOException e) {
      throw new GeneralSecurityException("Parse keyset failed");
    }
  }

  @SuppressWarnings("UnusedException")
  public static byte[] serializeKeyset(KeysetHandle keysetHandle, SecretKeyAccess access)
      throws GeneralSecurityException {
    if (access == null) {
      throw new NullPointerException("SecretKeyAccess cannot be null");
    }
    try {
      ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
      CleartextKeysetHandle.write(keysetHandle, BinaryKeysetWriter.withOutputStream(outputStream));
      return outputStream.toByteArray();
    } catch (IOException e) {
      throw new GeneralSecurityException("Serialize keyset failed");
    }
  }

  @SuppressWarnings("UnusedException")
  public static KeysetHandle parseKeysetWithoutSecret(byte[] serializedKeyset)
      throws GeneralSecurityException {
    return KeysetHandle.readNoSecret(serializedKeyset);
  }

  @SuppressWarnings("UnusedException")
  public static byte[] serializeKeysetWithoutSecret(KeysetHandle keysetHandle)
      throws GeneralSecurityException {
    try {
      ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
      keysetHandle.writeNoSecret(BinaryKeysetWriter.withOutputStream(outputStream));
      return outputStream.toByteArray();
    } catch (IOException e) {
      throw new GeneralSecurityException("Serialize keyset failed");
    }
  }

  @SuppressWarnings("UnusedException")
  public static KeysetHandle parseEncryptedKeyset(
      byte[] serializedEncryptedKeyset, Aead keysetEncryptionAead, byte[] associatedData)
      throws GeneralSecurityException {
    try {
      return KeysetHandle.readWithAssociatedData(
          BinaryKeysetReader.withBytes(serializedEncryptedKeyset),
          keysetEncryptionAead,
          associatedData);
    } catch (IOException e) {
      throw new GeneralSecurityException("Parse keyset failed");
    }
  }

  @SuppressWarnings("UnusedException")
  public static byte[] serializeEncryptedKeyset(
      KeysetHandle keysetHandle, Aead keysetEncryptionAead, byte[] associatedData)
      throws GeneralSecurityException {
    try {
      ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
      keysetHandle.writeWithAssociatedData(
          BinaryKeysetWriter.withOutputStream(outputStream), keysetEncryptionAead, associatedData);
      return outputStream.toByteArray();
    } catch (IOException e) {
      throw new GeneralSecurityException("Serialize keyset failed");
    }
  }

  private TinkProtoKeysetFormat() {}
}