/**
 * 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.apex.malhar.lib.appdata.gpo;

import java.util.Map;

import org.apache.apex.malhar.lib.appdata.schemas.FieldsDescriptor;
import org.apache.apex.malhar.lib.appdata.schemas.Type;
import org.apache.commons.lang3.mutable.MutableInt;

import com.google.common.collect.Maps;

/**
 * @since 3.1.0
 */

public class SerdeFieldsDescriptor implements Serde
{
  public static final SerdeFieldsDescriptor INSTANCE = new SerdeFieldsDescriptor();

  private GPOByteArrayList bal = new GPOByteArrayList();

  private SerdeFieldsDescriptor()
  {
  }

  @Override
  public synchronized byte[] serializeObject(Object object)
  {
    FieldsDescriptor fd = (FieldsDescriptor)object;

    for (Map.Entry<String, Type> entry : fd.getFieldToType().entrySet()) {
      bal.add(GPOUtils.serializeInt(entry.getValue().ordinal()));
      bal.add(GPOUtils.serializeString(entry.getKey()));
    }

    byte[] serializedBytes = bal.toByteArray();
    bal.clear();
    bal.add(GPOUtils.serializeInt(serializedBytes.length));
    bal.add(serializedBytes);
    serializedBytes = bal.toByteArray();
    bal.clear();
    return serializedBytes;
  }

  @Override
  public synchronized Object deserializeObject(byte[] object, MutableInt offset)
  {
    Map<String, Type> fieldToType = Maps.newHashMap();

    int length = GPOUtils.deserializeInt(object, offset);
    int startIndex = offset.intValue();

    while (startIndex + length > offset.intValue()) {
      Type type = Type.values()[GPOUtils.deserializeInt(object, offset)];
      String value = GPOUtils.deserializeString(object, offset);

      fieldToType.put(value, type);
    }

    return new FieldsDescriptor(fieldToType);
  }
}
