// Copyright 2024 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.aead;

import com.google.crypto.tink.AccessesPartialKey;
import com.google.crypto.tink.Aead;
import com.google.crypto.tink.Parameters;
import com.google.crypto.tink.aead.internal.XAesGcm;
import com.google.crypto.tink.aead.internal.XAesGcmProtoSerialization;
import com.google.crypto.tink.internal.MutableKeyCreationRegistry;
import com.google.crypto.tink.internal.MutableParametersRegistry;
import com.google.crypto.tink.internal.MutablePrimitiveRegistry;
import com.google.crypto.tink.internal.PrimitiveConstructor;
import com.google.crypto.tink.util.SecretBytes;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.Nullable;

/** This key manager generates new {@code XAesGcmKey} keys. */
public final class XAesGcmKeyManager {

  @SuppressWarnings("InlineLambdaConstant")
  private static final MutableKeyCreationRegistry.KeyCreator<XAesGcmParameters> KEY_CREATOR =
      XAesGcmKeyManager::createXAesGcmKey;

  private static final PrimitiveConstructor<XAesGcmKey, Aead> X_AES_GCM_PRIMITVE_CONSTRUCTOR =
      PrimitiveConstructor.create(XAesGcm::create, XAesGcmKey.class, Aead.class);

  private static Map<String, Parameters> namedParameters() {
    Map<String, Parameters> result = new HashMap<>();
    result.put("XAES_256_GCM_192_BIT_NONCE", PredefinedAeadParameters.XAES_256_GCM_192_BIT_NONCE);
    result.put(
        "XAES_256_GCM_192_BIT_NONCE_NO_PREFIX",
        PredefinedAeadParameters.XAES_256_GCM_192_BIT_NONCE_NO_PREFIX);
    result.put(
        "XAES_256_GCM_160_BIT_NONCE_NO_PREFIX",
        PredefinedAeadParameters.XAES_256_GCM_160_BIT_NONCE_NO_PREFIX);
    result.put(
        "X_AES_GCM_8_BYTE_SALT_NO_PREFIX",
        PredefinedAeadParameters.X_AES_GCM_8_BYTE_SALT_NO_PREFIX);
    return Collections.unmodifiableMap(result);
  }

  @AccessesPartialKey
  private static XAesGcmKey createXAesGcmKey(
      XAesGcmParameters parameters, @Nullable Integer idRequirement)
      throws GeneralSecurityException {
    return XAesGcmKey.create(parameters, SecretBytes.randomBytes(32), idRequirement);
  }

  public static void register(boolean newKeyAllowed) throws GeneralSecurityException {
    XAesGcmProtoSerialization.register();
    MutableParametersRegistry.globalInstance().putAll(namedParameters());
    MutablePrimitiveRegistry.globalInstance()
        .registerPrimitiveConstructor(X_AES_GCM_PRIMITVE_CONSTRUCTOR);
    MutableKeyCreationRegistry.globalInstance().add(KEY_CREATOR, XAesGcmParameters.class);
  }

  private XAesGcmKeyManager() {}
}