// Copyright 2021 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.jwt;

import com.google.crypto.tink.internal.MonitoringClient;
import com.google.crypto.tink.internal.MonitoringKeysetInfo;
import com.google.crypto.tink.internal.MonitoringUtil;
import com.google.crypto.tink.internal.MutableMonitoringRegistry;
import com.google.crypto.tink.internal.MutablePrimitiveRegistry;
import com.google.crypto.tink.internal.PrimitiveSet;
import com.google.crypto.tink.internal.PrimitiveWrapper;
import com.google.errorprone.annotations.Immutable;
import java.security.GeneralSecurityException;

/**
 * The implementation of {@code PrimitiveWrapper<JwtPublicKeySign, JwtPublicKeySign>}.
 *
 * <p>The returned primitive works with a keyset (rather than a single key). To sign a message, it
 * uses the primary key in the keyset, and prepends to the signature a certain prefix associated
 * with the primary key.
 */
class JwtPublicKeySignWrapper implements PrimitiveWrapper<JwtPublicKeySign, JwtPublicKeySign> {

  private static final JwtPublicKeySignWrapper WRAPPER = new JwtPublicKeySignWrapper();

  JwtPublicKeySignWrapper() {}

  @Immutable
  private static class WrappedJwtPublicKeySign implements JwtPublicKeySign {
    private final JwtPublicKeySign primary;
    private final int primaryKeyId;

    @SuppressWarnings("Immutable")
    private final MonitoringClient.Logger logger;

    public WrappedJwtPublicKeySign(final PrimitiveSet<JwtPublicKeySign> primitives) {
      this.primary = primitives.getPrimary().getFullPrimitive();
      this.primaryKeyId = primitives.getPrimary().getKeyId();
      if (primitives.hasAnnotations()) {
        MonitoringClient client = MutableMonitoringRegistry.globalInstance().getMonitoringClient();
        MonitoringKeysetInfo keysetInfo = MonitoringUtil.getMonitoringKeysetInfo(primitives);
        this.logger = client.createLogger(keysetInfo, "jwtsign", "sign");
      } else {
        this.logger = MonitoringUtil.DO_NOTHING_LOGGER;
      }
    }

    @Override
    public String signAndEncode(RawJwt token) throws GeneralSecurityException {
      try {
        String output = primary.signAndEncode(token);
        logger.log(primaryKeyId, 1);
        return output;
      } catch (GeneralSecurityException e) {
        logger.logFailure();
        throw e;
      }
    }
  }

  @Override
  public JwtPublicKeySign wrap(final PrimitiveSet<JwtPublicKeySign> primitives)
      throws GeneralSecurityException {
    return new WrappedJwtPublicKeySign(primitives);
  }

  @Override
  public Class<JwtPublicKeySign> getPrimitiveClass() {
    return JwtPublicKeySign.class;
  }

  @Override
  public Class<JwtPublicKeySign> getInputPrimitiveClass() {
    return JwtPublicKeySign.class;
  }

  /**
   * Register the wrapper within the registry.
   *
   * <p>This is required for calls to {@link Keyset.getPrimitive} with a {@link JwtPublicKeySign}
   * argument.
   */
  public static void register() throws GeneralSecurityException {
    MutablePrimitiveRegistry.globalInstance().registerPrimitiveWrapper(WRAPPER);
  }
}