/*
    * 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.io.gora;
  
  import java.io.IOException;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.giraph.edge.Edge;
  import org.apache.giraph.edge.EdgeFactory;
  import org.apache.giraph.graph.Vertex;
  import org.apache.giraph.io.gora.generated.GVertex;
  import org.apache.hadoop.io.DoubleWritable;
  import org.apache.hadoop.io.FloatWritable;
  import org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.mapreduce.InputSplit;
  import org.apache.hadoop.mapreduce.TaskAttemptContext;
  
  /**
   * Implementation of a specific reader for a generated data bean.
   */
  public class GoraTestVertexInputFormat
    extends GoraVertexInputFormat<LongWritable, DoubleWritable,
            FloatWritable> {
  
    /**
     * DEfault constructor
     */
    public GoraTestVertexInputFormat() {
    }
  
    /**
     * Creates specific vertex reader to be used inside Hadoop.
     * @param split split to be read.
     * @param context JobContext to be used.
     * @return GoraVertexReader Vertex reader to be used by Hadoop.
     */
    @Override
    public GoraVertexReader createVertexReader(
        InputSplit split, TaskAttemptContext context) throws IOException {
      putArtificialData();
      return new GoraGVertexVertexReader();
    }
  
    /**
     * Writes data into the data store in order to test it out.
     */
    @SuppressWarnings("unchecked")
    private static void putArtificialData() {
      getDataStore().put("1", createVertex("1", null));
      getDataStore().put("10", createVertex("10", null));
      getDataStore().put("100", createVertex("100", null));
      getDataStore().flush();
    }
  
    /**
     * Creates a vertex using an id and a set of edges.
     * @param id Vertex id.
     * @param edges Set of edges.
     * @return GVertex created.
     */
    public static GVertex createVertex(String id, Map<String, String> edges) {
      GVertex newVrtx = new GVertex();
      newVrtx.setVertexId(id);
      if (edges != null) {
        for (String edgeId : edges.keySet())
          newVrtx.getEdges().put(edgeId, edges.get(edgeId));
      }
      return newVrtx;
    }
  
    /**
     * Gora vertex reader
     */
    protected class GoraGVertexVertexReader extends GoraVertexReader {
  
      /**
       * Transforms a GoraObject into a Vertex object.
       * @param goraObject Object from Gora to be translated.
       * @return Vertex Result from transforming the gora object.
       */
      @Override
      protected Vertex<LongWritable, DoubleWritable, FloatWritable>
      transformVertex(Object goraObject) {
       Vertex<LongWritable, DoubleWritable, FloatWritable> vertex;
       /* create the actual vertex */
       vertex = getConf().createVertex();
       GVertex tmpGVertex = (GVertex) goraObject;
 
       LongWritable vrtxId = new LongWritable(
           Long.parseLong(tmpGVertex.getVertexId().toString()));
       DoubleWritable vrtxValue = new DoubleWritable(tmpGVertex.getVertexValue());
       vertex.initialize(vrtxId, vrtxValue);
       if (tmpGVertex.getEdges() != null && !tmpGVertex.getEdges().isEmpty()) {
         Set<CharSequence> keyIt = tmpGVertex.getEdges().keySet();
         for (CharSequence key : keyIt) {
           String keyVal = key.toString();
           String valVal = tmpGVertex.getEdges().get(key).toString();
           Edge<LongWritable, FloatWritable> edge;
           if (!keyVal.contains("vertexId")) {
             edge = EdgeFactory.create(
                 new LongWritable(Long.parseLong(keyVal)),
                 new FloatWritable(Float.parseFloat(valVal)));
             vertex.addEdge(edge);
           }
         }
       }
       return vertex;
     }
   }
 }