package org.apache.helix.util;
   
   /*
    * 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.
   */
  
  import java.lang.reflect.Constructor;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.helix.ZNRecord;
  import org.apache.log4j.Logger;
  
  
  //TODO find a proper place for these methods
  public final class ZNRecordUtil
  {
    private static final Logger logger = Logger.getLogger(ZNRecordUtil.class.getName());
  
    private ZNRecordUtil()
    {
    }
  
    public static ZNRecord find(String id, List<ZNRecord> list)
    {
      for (ZNRecord record : list)
      {
        if (record.getId() != null && record.getId().equals(id))
        {
          return record;
        }
      }
      return null;
    }
  
    public static Map<String, ZNRecord> convertListToMap(List<ZNRecord> recordList)
    {
      Map<String, ZNRecord> recordMap = new HashMap<String, ZNRecord>();
      for (ZNRecord record : recordList)
      {
        if (record.getId() != null)
        {
          recordMap.put(record.getId(), record);
        }
      }
      return recordMap;
    }
  
    public static <T extends Object> List<T> convertListToTypedList(List<ZNRecord> recordList,
                                                                    Class<T> clazz)
    {
      List<T> list = new ArrayList<T>();
      for (ZNRecord record : recordList)
      {
        if (record.getId() == null)
        {
          logger.error("Invalid record: Id missing in " + record);
          continue;
        }
        try
        {
  
          Constructor<T> constructor = clazz.getConstructor(new Class[] { ZNRecord.class });
          T instance = constructor.newInstance(record);
          list.add(instance);
        }
        catch (Exception e)
        {
          logger.error("Error creating an Object of type:" + clazz.getCanonicalName(), e);
        }
      }
      return list;
    }
  
    public static <T extends Object> Map<String, T> convertListToTypedMap(List<ZNRecord> recordList,
                                                                          Class<T> clazz)
    {
      Map<String, T> map = new HashMap<String, T>();
      for (ZNRecord record : recordList)
      {
        if (record.getId() == null)
        {
         logger.error("Invalid record: Id missing in " + record);
         continue;
       }
       try
       {
 
         Constructor<T> constructor = clazz.getConstructor(new Class[] { ZNRecord.class });
         T instance = constructor.newInstance(record);
         map.put(record.getId(), instance);
       }
       catch (Exception e)
       {
         logger.error("Error creating an Object of type:" + clazz.getCanonicalName(), e);
       }
     }
     return map;
   }
 
   public static <T extends Object> List<T> convertMapToList(Map<String, T> map)
   {
     List<T> list = new ArrayList<T>();
     for (T t : map.values())
     {
       list.add(t);
     }
     return list;
   }
 }