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 org.apache.helix.PropertyKey;
  import org.apache.helix.PropertyKey.Builder;
  import org.apache.helix.manager.zk.ZkClient;
  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.resource.Representation;
  import org.restlet.resource.Resource;
  import org.restlet.resource.StringRepresentation;
  import org.restlet.resource.Variant;
  
  
  public class ErrorResource extends Resource
  {
    private final static Logger LOG = Logger.getLogger(ErrorResource.class);
  
    public ErrorResource(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 false;
    }
  
    @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 instanceName = (String) getRequest().getAttributes().get("instanceName");
        String resourceGroup = (String) getRequest().getAttributes().get("resourceName");
  
        presentation =
            getInstanceErrorsRepresentation(clusterName,
                                            instanceName,
                                            resourceGroup);
      }
      catch (Exception e)
      {
        String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
        presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
  
        LOG.error("", e);
      }
      return presentation;
    }
 
   StringRepresentation getInstanceErrorsRepresentation(String clusterName,
                                                        String instanceName,
                                                        String resourceGroup) throws JsonGenerationException,
       JsonMappingException,
       IOException
   {
     ZkClient zkClient = (ZkClient)getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
     String instanceSessionId =
         ClusterRepresentationUtil.getInstanceSessionId(zkClient, clusterName,
                                                        instanceName);
     Builder keyBuilder = new PropertyKey.Builder(clusterName);
     String message =
         ClusterRepresentationUtil.getInstancePropertiesAsString(zkClient, clusterName,
                                                                 keyBuilder.stateTransitionErrors(instanceName,
                                                                                                  instanceSessionId,
                                                                                                  resourceGroup),
                                                                 // instanceSessionId
                                                                 // + "__"
                                                                 // + resourceGroup,
                                                                 MediaType.APPLICATION_JSON);
     StringRepresentation representation =
         new StringRepresentation(message, MediaType.APPLICATION_JSON);
     return representation;
   }
 }