/*
    * 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.giraph.block_app.migration;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.giraph.block_app.framework.api.BlockWorkerContextApi;
  import org.apache.giraph.block_app.framework.api.BlockWorkerContextSendApi;
  import org.apache.giraph.conf.DefaultImmutableClassesGiraphConfigurable;
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.io.WritableComparable;
  
  /**
   * Replacement for WorkerContext when migrating to Blocks Framework,
   * disallowing functions that are tied to execution order.
   */
  @SuppressWarnings({"rawtypes", "unchecked"})
  public class MigrationWorkerContext
      extends DefaultImmutableClassesGiraphConfigurable
      implements Writable {
    private BlockWorkerContextApi api;
    private List<Writable> receivedMessages;
  
    public void setApi(BlockWorkerContextApi api) {
      this.api = api;
      this.setConf(api.getConf());
    }
  
    public void setReceivedMessages(List<Writable> receivedMessages) {
      this.receivedMessages = receivedMessages;
    }
  
    public void preSuperstep() { }
  
    public void postSuperstep() { }
  
    @SuppressWarnings("deprecation")
    public long getTotalNumVertices() {
      return api.getTotalNumVertices();
    }
  
    @SuppressWarnings("deprecation")
    public long getTotalNumEdges() {
      return api.getTotalNumEdges();
    }
  
    @Override
    public void readFields(DataInput in) throws IOException {
    }
  
    @Override
    public void write(DataOutput out) throws IOException {
    }
  
    public final int getWorkerCount() {
      return api.getWorkerCount();
    }
  
    public final int getMyWorkerIndex() {
      return api.getMyWorkerIndex();
    }
  
    public final List<Writable> getAndClearMessagesFromOtherWorkers() {
      List<Writable> ret = receivedMessages;
      receivedMessages = null;
      return ret;
    }
  
    public final void sendMessageToWorker(Writable message, int workerIndex) {
      ((BlockWorkerContextSendApi<WritableComparable, Writable>) api)
        .sendMessageToWorker(message, workerIndex);
    }
  
    /**
     * Drop-in replacement for WorkerContext when migrating to
     * Blocks Framework.
     */
    public static class MigrationFullWorkerContext
        extends MigrationWorkerContext {
      public void preApplication()
          throws InstantiationException, IllegalAccessException {
     }
 
     public void postApplication() { }
   }
 }