content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.cassandra.sidecar.handlers.snapshots;
  
  import java.io.FileNotFoundException;
  import java.nio.file.NoSuchFileException;
  import java.util.Collections;
  import java.util.Set;
  
  import com.google.inject.Inject;
  import com.google.inject.Singleton;
  import io.netty.handler.codec.http.HttpResponseStatus;
  import io.vertx.core.http.HttpServerRequest;
  import io.vertx.core.net.SocketAddress;
  import io.vertx.ext.auth.authorization.Authorization;
  import io.vertx.ext.web.RoutingContext;
  import org.apache.cassandra.sidecar.acl.authorization.BasicPermissions;
  import org.apache.cassandra.sidecar.common.server.StorageOperations;
  import org.apache.cassandra.sidecar.concurrent.ExecutorPools;
  import org.apache.cassandra.sidecar.handlers.AbstractHandler;
  import org.apache.cassandra.sidecar.handlers.AccessProtected;
  import org.apache.cassandra.sidecar.handlers.data.SnapshotRequestParam;
  import org.apache.cassandra.sidecar.utils.CassandraInputValidator;
  import org.apache.cassandra.sidecar.utils.InstanceMetadataFetcher;
  import org.jetbrains.annotations.NotNull;
  
  import static org.apache.cassandra.sidecar.utils.HttpExceptions.wrapHttpException;
  
  /**
   * The <b>DELETE</b> verb deletes an existing snapshot for the given keyspace and table.
   */
  @Singleton
  public class ClearSnapshotHandler extends AbstractHandler<SnapshotRequestParam> implements AccessProtected
  {
      @Inject
      public ClearSnapshotHandler(InstanceMetadataFetcher metadataFetcher,
                                  CassandraInputValidator validator,
                                  ExecutorPools executorPools)
      {
          super(metadataFetcher, executorPools, validator);
      }
  
      @Override
      public Set<Authorization> requiredAuthorizations()
      {
          return Collections.singleton(BasicPermissions.DELETE_SNAPSHOT.toAuthorization());
      }
  
      /**
       * Clears a snapshot for the given keyspace and table. **Note**: Currently, Cassandra does not support
       * the table parameter. We can add support in Cassandra for the additional parameter.
       *
       * @param context       the event to handle
       * @param httpRequest   the {@link HttpServerRequest} object
       * @param host          the name of the host
       * @param remoteAddress the remote address that originated the request
       * @param requestParams parameters obtained from the request
       */
      @Override
      public void handleInternal(RoutingContext context,
                                 HttpServerRequest httpRequest,
                                 @NotNull String host,
                                 SocketAddress remoteAddress,
                                 SnapshotRequestParam requestParams)
      {
          StorageOperations storageOperations = metadataFetcher.delegate(host).storageOperations();
          executorPools.service().runBlocking(() -> {
              logger.debug("Clearing snapshot request={}, remoteAddress={}, instance={}",
                           requestParams, remoteAddress, host);
              storageOperations.clearSnapshot(requestParams.snapshotName(), requestParams.keyspace(),
                                              requestParams.tableName());
              context.response().end();
          }).onFailure(cause -> processFailure(cause, context, host, remoteAddress, requestParams));
      }
  
      @Override
      protected void processFailure(Throwable cause,
                                    RoutingContext context,
                                    String host,
                                    SocketAddress remoteAddress,
                                    SnapshotRequestParam requestParams)
      {
          logger.error("ClearSnapshotHandler failed for request={}, remoteAddress={}, instance={}, method={}",
                       requestParams, remoteAddress, host, context.request().method(), cause);
          if (cause instanceof FileNotFoundException || cause instanceof NoSuchFileException)
          {
              context.fail(wrapHttpException(HttpResponseStatus.NOT_FOUND, cause.getMessage()));
          }
          else
          {
              super.processFailure(cause, context, host, remoteAddress, requestParams);
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      protected SnapshotRequestParam extractParamsOrThrow(RoutingContext context)
      {
          SnapshotRequestParam snapshotRequestParam = SnapshotRequestParam.builder()
                                                                          .qualifiedTableName(qualifiedTableName(context))
                                                                          .snapshotName(context.pathParam("snapshot"))
                                                                          .build();
          validate(snapshotRequestParam);
          return snapshotRequestParam;
      }
  
      private void validate(SnapshotRequestParam request)
      {
          validator.validateSnapshotName(request.snapshotName());
      }
  }
  