package org.apache.helix.webapp.resources;
   
   /*
    * 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.io.IOException;
  import java.util.Map;
  
  import org.apache.helix.HelixDataAccessor;
  import org.apache.helix.HelixException;
  import org.apache.helix.PropertyKey;
  import org.apache.helix.ZNRecord;
  import org.apache.helix.PropertyKey.Builder;
  import org.apache.helix.manager.zk.ZkClient;
  import org.apache.helix.model.IdealState;
  import org.apache.helix.tools.ClusterSetup;
  import org.apache.helix.webapp.RestAdminApplication;
  import org.apache.log4j.Logger;
  import org.codehaus.jackson.JsonGenerationException;
  import org.codehaus.jackson.map.JsonMappingException;
  import org.restlet.Context;
  import org.restlet.data.MediaType;
  import org.restlet.data.Request;
  import org.restlet.data.Response;
  import org.restlet.data.Status;
  import org.restlet.resource.Representation;
  import org.restlet.resource.Resource;
  import org.restlet.resource.StringRepresentation;
  import org.restlet.resource.Variant;
  
  
  public class IdealStateResource extends Resource
  {
    private final static Logger LOG = Logger.getLogger(IdealStateResource.class);
  
    public IdealStateResource(Context context, Request request, Response response)
    {
      super(context, request, response);
      getVariants().add(new Variant(MediaType.TEXT_PLAIN));
      getVariants().add(new Variant(MediaType.APPLICATION_JSON));
    }
  
    @Override
    public boolean allowGet()
    {
      return true;
    }
  
    @Override
    public boolean allowPost()
    {
      return true;
    }
  
    @Override
    public boolean allowPut()
    {
      return false;
    }
  
    @Override
    public boolean allowDelete()
    {
      return false;
    }
  
    @Override
    public Representation represent(Variant variant)
    {
      StringRepresentation presentation = null;
      try
      {
        String clusterName = (String) getRequest().getAttributes().get("clusterName");
        String resourceName = (String) getRequest().getAttributes().get("resourceName");
        presentation = getIdealStateRepresentation(clusterName, resourceName);
      }
  
      catch (Exception e)
      {
        String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
        presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
  
        LOG.error("", e);
     }
     return presentation;
   }
 
   StringRepresentation getIdealStateRepresentation(String clusterName, String resourceName) throws JsonGenerationException,
       JsonMappingException,
       IOException
   {
     Builder keyBuilder = new PropertyKey.Builder(clusterName);
     ZkClient zkClient =
         (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
 
     String message =
         ClusterRepresentationUtil.getClusterPropertyAsString(zkClient,
                                                              clusterName,
                                                              keyBuilder.idealStates(resourceName),
                                                              MediaType.APPLICATION_JSON);
 
     StringRepresentation representation =
         new StringRepresentation(message, MediaType.APPLICATION_JSON);
 
     return representation;
   }
 
   @Override
   public void acceptRepresentation(Representation entity)
   {
     try
     {
       String clusterName = (String) getRequest().getAttributes().get("clusterName");
       String resourceName = (String) getRequest().getAttributes().get("resourceName");
       ZkClient zkClient =
           (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
       ClusterSetup setupTool = new ClusterSetup(zkClient);
 
       JsonParameters jsonParameters = new JsonParameters(entity);
       String command = jsonParameters.getCommand();
 
       if (command.equalsIgnoreCase(ClusterSetup.addIdealState))
       {
         ZNRecord newIdealState = jsonParameters.getExtraParameter(JsonParameters.NEW_IDEAL_STATE);
         HelixDataAccessor accessor =
             ClusterRepresentationUtil.getClusterDataAccessor(zkClient, clusterName);
 
         accessor.setProperty(accessor.keyBuilder().idealStates(resourceName),
                              new IdealState(newIdealState));
 
       }
       else if (command.equalsIgnoreCase(ClusterSetup.rebalance))
       {
         int replicas = 
             Integer.parseInt(jsonParameters.getParameter(JsonParameters.REPLICAS));
         String keyPrefix = jsonParameters.getParameter(JsonParameters.RESOURCE_KEY_PREFIX);
         String groupTag = jsonParameters.getParameter(ClusterSetup.instanceGroupTag);
         
           setupTool.rebalanceCluster(clusterName,
                                             resourceName,
                                             replicas,
                                             keyPrefix,
                                             groupTag);
        
       }
       else if (command.equalsIgnoreCase(ClusterSetup.expandResource))
       {
         setupTool.expandResource(clusterName, resourceName);
       }
       else if (command.equalsIgnoreCase(ClusterSetup.addResourceProperty))
       {
         Map<String, String> parameterMap = jsonParameters.cloneParameterMap();
         parameterMap.remove(JsonParameters.MANAGEMENT_COMMAND);
         for (String key : parameterMap.keySet())
         {
           setupTool.addResourceProperty(clusterName,
                                         resourceName,
                                         key,
                                         parameterMap.get(key));
         }
       }
       else
       {
         throw new HelixException("Unsupported command: " + command
             + ". Should be one of [" + ClusterSetup.addIdealState + ", "
             + ClusterSetup.rebalance + ", " + ClusterSetup.expandResource + ", "
             + ClusterSetup.addResourceProperty + "]");
       }
 
       getResponse().setEntity(getIdealStateRepresentation(clusterName, resourceName));
       getResponse().setStatus(Status.SUCCESS_OK);
     }
     catch (Exception e)
     {
       getResponse().setEntity(ClusterRepresentationUtil.getErrorAsJsonStringFromException(e),
                               MediaType.APPLICATION_JSON);
       getResponse().setStatus(Status.SUCCESS_OK);
       LOG.error("Error in posting " + entity, e);
     }
   }
 }