/*
    * 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.framework.internal;
  
  import java.util.List;
  
  import org.apache.giraph.block_app.framework.BlockUtils;
  import org.apache.giraph.block_app.framework.api.BlockWorkerContextApi;
  import org.apache.giraph.block_app.framework.api.BlockWorkerContextReceiveApi;
  import org.apache.giraph.block_app.framework.api.BlockWorkerContextSendApi;
  import org.apache.giraph.block_app.framework.output.BlockOutputHandle;
  import org.apache.hadoop.io.Writable;
  import org.apache.log4j.Logger;
  
  /**
   * Block execution logic on WorkerContext.
   */
  @SuppressWarnings({ "rawtypes" })
  public class BlockWorkerContextLogic {
    public static final Logger LOG =
        Logger.getLogger(BlockWorkerContextLogic.class);
  
    private Object workerValue;
    private BlockWorkerPieces workerPieces;
    private BlockOutputHandle outputHandle;
  
    private transient BlockWorkerContextSendApi sendApi;
  
    public BlockWorkerContextLogic() {
    }
  
    public void preApplication(BlockWorkerContextApi api,
        BlockOutputHandle outputHandle) {
      workerValue =
          BlockUtils.BLOCK_WORKER_CONTEXT_VALUE_CLASS.newInstance(api.getConf());
      this.outputHandle = outputHandle;
    }
  
    public Object getWorkerValue() {
      return workerValue;
    }
  
    public BlockOutputHandle getOutputHandle() {
      return outputHandle;
    }
  
    @SuppressWarnings("unchecked")
    public void preSuperstep(
        BlockWorkerContextReceiveApi receiveApi,
        BlockWorkerContextSendApi sendApi,
        BlockWorkerPieces workerPieces, long superstep,
        List<Writable> messages) {
      workerPieces.getBlockApiHandle().setWorkerContextReceiveApi(receiveApi);
      workerPieces.getBlockApiHandle().setWorkerContextSendApi(sendApi);
      if (BlockUtils.LOG_EXECUTION_STATUS.get(receiveApi.getConf())) {
        LOG.info("Worker executing " + workerPieces + " in " + superstep +
            " superstep");
      }
      this.sendApi = sendApi;
      this.workerPieces = workerPieces;
      if (workerPieces.getReceiver() != null) {
        workerPieces.getReceiver().workerContextReceive(
            receiveApi, workerValue, messages);
      }
    }
  
    public void postSuperstep() {
      if (workerPieces.getSender() != null) {
        workerPieces.getSender().workerContextSend(sendApi, workerValue);
      }
      workerPieces = null;
      sendApi = null;
      outputHandle.returnAllWriters();
    }
  
    public void postApplication() {
      outputHandle.closeAllWriters();
      // TODO add support through conf for postApplication, if needed.
    }
  }