/*
    * Copyright 2021 TiKV Project Authors.
    *
    * 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 org.tikv.common.streaming;
  
  import static java.util.Objects.requireNonNull;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import javax.annotation.Nonnull;
  import org.tikv.kvproto.Coprocessor;
  import org.tikv.kvproto.Errorpb;
  
  public class StreamingResponse implements Iterable {
    private final Iterator<Coprocessor.Response> resultIterator;
    private final List<Coprocessor.Response> responseList;
  
    @SuppressWarnings("unchecked")
    public StreamingResponse(Iterator resultIterator) {
      requireNonNull(resultIterator, "Streaming result cannot be null!");
      this.resultIterator = resultIterator;
      responseList = new ArrayList<>();
      fetchStreamingResult();
    }
  
    private void fetchStreamingResult() {
      while (resultIterator.hasNext()) {
        responseList.add(resultIterator.next());
      }
    }
  
    public boolean hasRegionError() {
      for (Coprocessor.Response response : responseList) {
        if (response.hasRegionError()) {
          return true;
        }
      }
  
      return false;
    }
  
    public Errorpb.Error getFirstRegionError() {
      for (Coprocessor.Response response : responseList) {
        if (response.hasRegionError()) {
          return response.getRegionError();
        }
      }
  
      return null;
    }
  
    public String getFirstOtherError() {
      for (Coprocessor.Response response : responseList) {
        if (!response.getOtherError().isEmpty()) {
          return response.getOtherError();
        }
      }
      return null;
    }
  
    @Override
    @Nonnull
    public Iterator<Coprocessor.Response> iterator() {
      return responseList.iterator();
    }
  }