/*
 * Copyright 2017 Twitter, Inc.
 *
 * 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.
 */

#ifndef HERON_API_TOPOLOGY_ICOMPONENT_H_
#define HERON_API_TOPOLOGY_ICOMPONENT_H_

#include <string>
#include <memory>

#include "config/config.h"
#include "topology/output-fields-declarer.h"

namespace heron {
namespace api {
namespace topology {

class IComponent {
 public:
  /**
   * Declare the output schema for all the streams of this topology.
   *
   * @param declarer this is used to declare output stream ids, output fields,
   * and whether or not each output stream is a direct stream
   */
  virtual void declareOutputFields(std::shared_ptr<OutputFieldsDeclarer> declarer) = 0;

  /**
   * Declare configuration specific to this component. Only a subset of the "topology.*" configs can
   * be overridden. The component configuration can be further overridden when constructing the
   * topology using {@link TopologyBuilder}
   */
  virtual std::shared_ptr<config::Config> getComponentConfiguration() = 0;
};

}  // namespace topology
}  // namespace api
}  // namespace heron

#endif  // HERON_API_TOPOLOGY_ICOMPONENT_H_
