// Copyright (C) 2015 The Android Open Source Project
//
// 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.gerrit.gpg.server;

import static com.google.gerrit.server.account.externalids.ExternalId.SCHEME_GPGKEY;
import static com.google.gerrit.server.mail.EmailFactories.KEY_DELETED;

import com.google.common.collect.ImmutableList;
import com.google.common.flogger.FluentLogger;
import com.google.common.io.BaseEncoding;
import com.google.gerrit.exceptions.EmailException;
import com.google.gerrit.exceptions.StorageException;
import com.google.gerrit.extensions.common.Input;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.RestModifyView;
import com.google.gerrit.gpg.PublicKeyStore;
import com.google.gerrit.gpg.PublicKeyStoreUtil;
import com.google.gerrit.server.GerritPersonIdent;
import com.google.gerrit.server.UserInitiated;
import com.google.gerrit.server.account.AccountsUpdate;
import com.google.gerrit.server.account.externalids.ExternalId;
import com.google.gerrit.server.account.externalids.ExternalIdKeyFactory;
import com.google.gerrit.server.account.externalids.ExternalIds;
import com.google.gerrit.server.mail.EmailFactories;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.io.IOException;
import java.util.Optional;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.openpgp.PGPPublicKey;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.RefUpdate;

public class DeleteGpgKey implements RestModifyView<GpgKey, Input> {
  private static final FluentLogger logger = FluentLogger.forEnclosingClass();

  private final Provider<PersonIdent> serverIdent;
  private final PublicKeyStoreUtil publicKeyStoreUtil;
  private final Provider<AccountsUpdate> accountsUpdateProvider;
  private final ExternalIds externalIds;
  private final EmailFactories emailFactories;
  private final ExternalIdKeyFactory externalIdKeyFactory;

  @Inject
  DeleteGpgKey(
      @GerritPersonIdent Provider<PersonIdent> serverIdent,
      PublicKeyStoreUtil publicKeyStoreUtil,
      @UserInitiated Provider<AccountsUpdate> accountsUpdateProvider,
      ExternalIds externalIds,
      EmailFactories emailFactories,
      ExternalIdKeyFactory externalIdKeyFactory) {
    this.serverIdent = serverIdent;
    this.publicKeyStoreUtil = publicKeyStoreUtil;
    this.accountsUpdateProvider = accountsUpdateProvider;
    this.externalIds = externalIds;
    this.emailFactories = emailFactories;
    this.externalIdKeyFactory = externalIdKeyFactory;
  }

  @Override
  public Response<?> apply(GpgKey rsrc, Input input)
      throws RestApiException, PGPException, IOException, ConfigInvalidException {
    PGPPublicKey key = rsrc.getKeyRing().getPublicKey();
    String fingerprint = BaseEncoding.base16().encode(key.getFingerprint());
    Optional<ExternalId> extId =
        externalIds.get(externalIdKeyFactory.create(SCHEME_GPGKEY, fingerprint));
    if (!extId.isPresent()) {
      throw new ResourceNotFoundException(fingerprint);
    }

    accountsUpdateProvider
        .get()
        .update(
            "Delete GPG Key via API",
            rsrc.getUser().getAccountId(),
            u -> u.deleteExternalId(extId.get()));

    PersonIdent committer = serverIdent.get();
    PersonIdent author = rsrc.getUser().newCommitterIdent(committer);

    RefUpdate.Result saveResult = publicKeyStoreUtil.deletePgpKey(key, committer, author);
    switch (saveResult) {
      case NO_CHANGE:
      case FAST_FORWARD:
        try {
          emailFactories
              .createOutgoingEmail(
                  KEY_DELETED,
                  emailFactories.createDeleteKeyEmail(
                      rsrc.getUser(), ImmutableList.of(PublicKeyStore.keyToString(key))))
              .send();
        } catch (EmailException e) {
          logger.atSevere().withCause(e).log(
              "Cannot send GPG key deletion message to %s",
              rsrc.getUser().getAccount().preferredEmail());
        }
        break;
      case LOCK_FAILURE:
      case FORCED:
      case IO_FAILURE:
      case NEW:
      case NOT_ATTEMPTED:
      case REJECTED:
      case REJECTED_CURRENT_BRANCH:
      case RENAMED:
      case REJECTED_MISSING_OBJECT:
      case REJECTED_OTHER_REASON:
      default:
        throw new StorageException(String.format("Failed to delete public key: %s", saveResult));
    }
    return Response.none();
  }
}