/**
 *
 * Copyright
 * 2009-2015 Jayway Products AB
 * 2016-2017 Föreningen Sambruk
 *
 * Licensed under AGPL, Version 3.0 (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.gnu.org/licenses/agpl.txt
 *
 * 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 se.streamsource.streamflow.infrastructure.event.domain.source.helper;

import org.json.JSONException;
import org.json.JSONObject;
import se.streamsource.streamflow.infrastructure.event.domain.DomainEvent;

/**
 * Utility class to pick out parameters by name or index as strings from a DomainEvent
 */
public class EventParameters
{
   /**
    * Get the named parameter from an event.
    *
    * @param event event with parameters
    * @param name  name of parameter
    * @return the parameter with the given name or null
    */
   public static String getParameter( DomainEvent event, String name )
   {
      String parametersJson = event.parameters().get();
      try
      {
         JSONObject jsonObject = new JSONObject( parametersJson );
         return jsonObject.get( name ).toString();
      } catch (JSONException e)
      {
         return null;
      }
   }

   /**
    * Get parameter with given index.
    *
    * @param event event with parameters
    * @param idx   index of parameter
    * @return the parameter with the given index or null
    * @throws JSONException
    */
   public static String getParameter( DomainEvent event, int idx )
   {
      try
      {
         String parametersJson = event.parameters().get();
         JSONObject jsonObject = new JSONObject( parametersJson );
         return jsonObject.get( "param" + idx ).toString();
      } catch (JSONException e)
      {
         return null;
      }
   }
}