/*
    * 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;
  
  import java.util.List;
  
  import org.apache.giraph.comm.messages.MessageEncodeAndStoreType;
  import org.apache.giraph.conf.BulkConfigurator;
  import org.apache.giraph.conf.GiraphConfiguration;
  import org.apache.giraph.conf.GiraphConstants;
  import org.apache.giraph.conf.StrConfOption;
  import org.apache.giraph.edge.IdAndNullArrayEdges;
  import org.apache.giraph.edge.IdAndValueArrayEdges;
  import org.apache.giraph.edge.LongDiffNullArrayEdges;
  import org.apache.giraph.types.ops.PrimitiveIdTypeOps;
  import org.apache.giraph.types.ops.TypeOps;
  import org.apache.giraph.types.ops.TypeOpsUtils;
  import org.apache.giraph.utils.ReflectionUtils;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.io.WritableComparable;
  
  /**
   * Default block factory abstract class, providing default methods that need
   * to be/can be overridden for specifying required/most common parameters,
   * to simplify setting properties.
   *
   * @param <S> Execution stage type
   */
  public abstract class AbstractBlockFactory<S> implements BlockFactory<S> {
    /**
     * Comma separated list of BulkConfigurators, that are going to be called
     * to simplify specifying of large number of properties.
     */
    public static final StrConfOption CONFIGURATORS = new StrConfOption(
        "digraph.block_factory_configurators", null, "");
  
    @Override
    public List<String> getGcJavaOpts(Configuration conf) {
      return null;
    }
  
    @Override
    public final void initConfig(GiraphConfiguration conf) {
      initConfigurators(conf);
      GiraphConstants.VERTEX_ID_CLASS.setIfUnset(conf, getVertexIDClass(conf));
      GiraphConstants.VERTEX_VALUE_CLASS.setIfUnset(
          conf, getVertexValueClass(conf));
      GiraphConstants.EDGE_VALUE_CLASS.setIfUnset(conf, getEdgeValueClass(conf));
      GiraphConstants.RESOLVER_CREATE_VERTEX_ON_MSGS.setIfUnset(
          conf, shouldCreateVertexOnMsgs(conf));
      if (shouldSendOneMessageToAll(conf)) {
        GiraphConstants.MESSAGE_ENCODE_AND_STORE_TYPE.setIfUnset(
            conf, MessageEncodeAndStoreType.EXTRACT_BYTEARRAY_PER_PARTITION);
      }
  
      BlockUtils.BLOCK_WORKER_CONTEXT_VALUE_CLASS.setIfUnset(
          conf, getWorkerContextValueClass(conf));
  
      // optimize edge structure, if available and not set already
      if (!GiraphConstants.VERTEX_EDGES_CLASS.contains(conf)) {
        @SuppressWarnings("rawtypes")
        Class<? extends WritableComparable> vertexIDClass =
            GiraphConstants.VERTEX_ID_CLASS.get(conf);
        Class<? extends Writable> edgeValueClass =
            GiraphConstants.EDGE_VALUE_CLASS.get(conf);
  
  
        @SuppressWarnings("rawtypes")
        PrimitiveIdTypeOps<? extends WritableComparable> idTypeOps =
            TypeOpsUtils.getPrimitiveIdTypeOpsOrNull(vertexIDClass);
        if (edgeValueClass.equals(NullWritable.class)) {
          if (vertexIDClass.equals(LongWritable.class)) {
            GiraphConstants.VERTEX_EDGES_CLASS.set(
                conf, LongDiffNullArrayEdges.class);
          } else if (idTypeOps != null) {
            GiraphConstants.VERTEX_EDGES_CLASS.set(
                conf, IdAndNullArrayEdges.class);
          }
        } else {
          TypeOps<?> edgeValueTypeOps =
              TypeOpsUtils.getTypeOpsOrNull(edgeValueClass);
         if (edgeValueTypeOps != null && idTypeOps != null) {
           GiraphConstants.VERTEX_EDGES_CLASS.set(
               conf, IdAndValueArrayEdges.class);
         }
       }
     }
 
     additionalInitConfig(conf);
   }
 
   @Override
   public void registerOutputs(GiraphConfiguration conf) {
   }
 
   private void initConfigurators(GiraphConfiguration conf) {
     String configurators = CONFIGURATORS.get(conf);
     if (configurators != null) {
       String[] split = configurators.split(",");
       for (String configurator : split) {
         runConfigurator(conf, configurator);
       }
     }
   }
 
   private void runConfigurator(GiraphConfiguration conf, String configurator) {
     String[] packages = getConvenienceConfiguratorPackages();
     String[] prefixes = new String[packages.length + 1];
     prefixes[0] = "";
     for (int i = 0; i < packages.length; i++) {
       prefixes[i + 1] = packages[i] + ".";
     }
 
     for (String prefix : prefixes) {
       try {
         @SuppressWarnings({ "unchecked", "rawtypes" })
         Class<BulkConfigurator> confClass =
             (Class) Class.forName(prefix + configurator);
         BulkConfigurator c = ReflectionUtils.newInstance(confClass);
         c.configure(conf);
         return;
       // CHECKSTYLE: stop EmptyBlock
       // ignore ClassNotFoundException, and continue the loop
       } catch (ClassNotFoundException e) {
       }
       // CHECKSTYLE: resume EmptyBlock
     }
     throw new IllegalStateException(
         "Configurator " + configurator + " not found");
   }
 
   /**
    * Additional configuration initialization, other then overriding
    * class specification.
    */
   protected void additionalInitConfig(GiraphConfiguration conf) {
   }
 
   /**
    * Concrete vertex id class application will use.
    */
   @SuppressWarnings("rawtypes")
   protected abstract Class<? extends WritableComparable> getVertexIDClass(
       GiraphConfiguration conf);
 
   /**
    * Concrete vertex value class application will use.
    */
   protected abstract Class<? extends Writable> getVertexValueClass(
       GiraphConfiguration conf);
 
   /**
    * Concrete edge value class application will use.
    */
   protected abstract Class<? extends Writable> getEdgeValueClass(
       GiraphConfiguration conf);
 
   /**
    * Concrete worker context value class application will use, if overridden.
    */
   protected Class<?> getWorkerContextValueClass(GiraphConfiguration conf) {
     return Object.class;
   }
 
   /**
    * Override if vertices shouldn't be created by default, if message is sent
    * to a vertex that doesn't exist.
    */
   protected boolean shouldCreateVertexOnMsgs(GiraphConfiguration conf) {
     return true;
   }
 
   // TODO - see if it should be deprecated
   protected boolean shouldSendOneMessageToAll(GiraphConfiguration conf) {
     return false;
   }
 
   /**
    * Provide list of strings representing packages where configurators will
    * be searched for, allowing that full path is not required for
    * CONFIGURATORS option.
    */
   protected String[] getConvenienceConfiguratorPackages() {
     return new String[] { };
   }
 }