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 * Copyright 2016 Google LLC
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 * modification, are permitted provided that the following conditions are
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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package com.google.api.gax.grpc;

import com.google.api.core.BetaApi;
import com.google.longrunning.CancelOperationRequest;
import com.google.longrunning.DeleteOperationRequest;
import com.google.longrunning.GetOperationRequest;
import com.google.longrunning.ListOperationsRequest;
import com.google.longrunning.ListOperationsResponse;
import com.google.longrunning.Operation;
import com.google.longrunning.OperationsGrpc.OperationsImplBase;
import com.google.protobuf.AbstractMessage;
import com.google.protobuf.Empty;
import io.grpc.stub.StreamObserver;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

/** A custom mock Operations service implementation which only mocks responses for GetOperation. */
@BetaApi
public class MockOperationsExImpl extends OperationsImplBase {
  private List<AbstractMessage> requests;
  private Queue<Object> getOperationResponses;

  public MockOperationsExImpl() {
    requests = new ArrayList<>();
    getOperationResponses = new LinkedList<>();
  }

  public List<AbstractMessage> getRequests() {
    return requests;
  }

  public void addGetOperationResponse(AbstractMessage response) {
    this.getOperationResponses.add(response);
  }

  public void addGetOperationError(Throwable error) {
    this.getOperationResponses.add(error);
  }

  public void reset() {
    requests = new ArrayList<>();
    getOperationResponses = new LinkedList<>();
  }

  @Override
  public void getOperation(
      GetOperationRequest request, StreamObserver<Operation> responseObserver) {
    requests.add(request);
    Object response = getOperationResponses.remove();
    if (response instanceof Throwable) {
      responseObserver.onError((Throwable) response);
    } else if (response instanceof AbstractMessage) {
      responseObserver.onNext((Operation) response);
      responseObserver.onCompleted();
    }
  }

  @Override
  public void listOperations(
      ListOperationsRequest request, StreamObserver<ListOperationsResponse> responseObserver) {
    requests.add(request);
    responseObserver.onError(
        new UnsupportedOperationException(
            "MockOperationsExImpl: listOperations not yet supported"));
  }

  @Override
  public void cancelOperation(
      CancelOperationRequest request, StreamObserver<Empty> responseObserver) {
    requests.add(request);
    responseObserver.onNext(Empty.getDefaultInstance());
    responseObserver.onCompleted();
  }

  @Override
  public void deleteOperation(
      DeleteOperationRequest request, StreamObserver<Empty> responseObserver) {
    requests.add(request);
    responseObserver.onError(
        new UnsupportedOperationException(
            "MockOperationsExImpl: listOperations not yet supported"));
  }
}
