package org.apache.helix.healthcheck;
   
   /*
    * 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.util.StringTokenizer;
  
  import org.apache.log4j.Logger;
  
  public class AggregationTypeFactory
  {
    private static final Logger logger = Logger
        .getLogger(AggregationTypeFactory.class);
  
    public AggregationTypeFactory()
    {
    }
  
    // TODO: modify this function so that it takes a single string, but can parse
    // apart params from type
    public static AggregationType getAggregationType(String input)
    {
      if (input == null)
      {
        logger.error("AggregationType name is null");
        return null;
      }
      StringTokenizer tok = new StringTokenizer(input, AggregationType.DELIM);
      String type = tok.nextToken();
      int numParams = tok.countTokens();
      String[] params = new String[numParams];
      for (int i = 0; i < numParams; i++)
      {
        if (!tok.hasMoreTokens())
        {
          logger.error("Trying to parse non-existent params");
          return null;
        }
        params[i] = tok.nextToken();
      }
  
      if (type.equals(AccumulateAggregationType.TYPE_NAME))
      {
        return new AccumulateAggregationType();
      }
      else if (type.equals(DecayAggregationType.TYPE_NAME))
      {
        if (params.length < 1)
        {
          logger
              .error("DecayAggregationType must contain <decay weight> parameter");
          return null;
        }
        return new DecayAggregationType(Double.parseDouble(params[0]));
      }
      else if (type.equals(WindowAggregationType.TYPE_NAME))
      {
        if (params.length < 1)
        {
          logger
              .error("WindowAggregationType must contain <window size> parameter");
        }
        return new WindowAggregationType(Integer.parseInt(params[0]));
      }
      else
      {
        logger.error("Unknown AggregationType " + type);
        return null;
      }
    }
  }