/*
 * Copyright 2020 Yelp 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.
 */
package com.yelp.nrtsearch.server.luceneserver;

import com.google.protobuf.GeneratedMessageV3;
import com.yelp.nrtsearch.server.grpc.ReplicationServerClient;
import io.grpc.stub.StreamObserver;

/* Interface for handlers that take in an indexState and the protoBuff request and returns the protoBuff response */
public interface Handler<T extends GeneratedMessageV3, S extends GeneratedMessageV3> {

  default boolean isValidMagicHeader(int magicHeader) {
    return magicHeader == ReplicationServerClient.BINARY_MAGIC;
  }

  default void handle(IndexState indexState, T protoRequest, StreamObserver<S> responseObserver)
      throws Exception {
    throw new UnsupportedOperationException("This method is not supported");
  }

  S handle(IndexState indexState, T protoRequest) throws HandlerException;

  class HandlerException extends Exception {
    public HandlerException(Throwable err) {
      super(err);
    }

    public HandlerException(String errorMessage) {
      super(errorMessage);
    }

    public HandlerException(String errorMessage, Throwable err) {
      super(errorMessage, err);
    }
  }
}
