/*
 * 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.ratis.client;

import org.apache.ratis.datastream.DataStreamObserver;
import org.apache.ratis.protocol.DataStreamReply;
import org.apache.ratis.protocol.DataStreamRequest;
import org.apache.ratis.util.JavaUtils;
import org.apache.ratis.util.ReferenceCountedObject;

import java.io.Closeable;
import java.util.concurrent.CompletableFuture;

/**
 * A client interface for sending stream requests.
 * The underlying implementation is pluggable, depending on the {@link org.apache.ratis.datastream.DataStreamType}.
 * The implementations of this interface define how the requests are transported to the server.
 */
public interface DataStreamClientRpc extends Closeable {
  /** Async call to send a request. */
  default CompletableFuture<DataStreamReply> streamAsync(DataStreamRequest request) {
    throw new UnsupportedOperationException(getClass() + " does not support "
        + JavaUtils.getCurrentStackTraceElement().getMethodName());
  }

  /**
   * Async call to send a request to receive a stream of intermediate replies and a final reply.
   *
   * @param request the request
   * @param replyHandler to handle intermediate replies
   * @return a future the final reply
   */
  default CompletableFuture<DataStreamReply> streamAsync(DataStreamRequest request,
      DataStreamObserver<ReferenceCountedObject<DataStreamReply>> replyHandler) {
    throw new UnsupportedOperationException(getClass() + " does not support "
        + JavaUtils.getCurrentStackTraceElement().getMethodName());
  }
}
