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.Arrays;
  
  import org.apache.helix.HelixException;
  import org.apache.helix.PropertyKey;
  import org.apache.helix.PropertyKey.Builder;
  import org.apache.helix.manager.zk.ZkClient;
  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 InstanceResource extends Resource
  {
    private final static Logger LOG = Logger.getLogger(InstanceResource.class);
  
    public InstanceResource(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 true;
    }
  
    @Override
    public Representation represent(Variant variant)
    {
      StringRepresentation presentation = null;
      try
      {
        presentation = getInstanceRepresentation();
      }
      catch (Exception e)
      {
        String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
        presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
  
        LOG.error("", e);
      }
      return presentation;
    }
  
    StringRepresentation getInstanceRepresentation() throws JsonGenerationException,
        JsonMappingException,
       IOException
   {
     String clusterName = (String) getRequest().getAttributes().get("clusterName");
     String instanceName = (String) getRequest().getAttributes().get("instanceName");
     Builder keyBuilder = new PropertyKey.Builder(clusterName);
     ZkClient zkClient =
         (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
 
     String message =
         ClusterRepresentationUtil.getClusterPropertyAsString(zkClient,
                                                              clusterName,
                                                              MediaType.APPLICATION_JSON,
                                                              keyBuilder.instanceConfig(instanceName));
 
     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 instanceName = (String) getRequest().getAttributes().get("instanceName");
 
       JsonParameters jsonParameters = new JsonParameters(entity);
       String command = jsonParameters.getCommand();
       if (command.equalsIgnoreCase(ClusterSetup.enableInstance))
       {
         jsonParameters.verifyCommand(ClusterSetup.enableInstance);
 
         boolean enabled =
             Boolean.parseBoolean(jsonParameters.getParameter(JsonParameters.ENABLED));
 
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         setupTool.getClusterManagementTool().enableInstance(clusterName,
                                                             instanceName,
                                                             enabled);
       }
       else if (command.equalsIgnoreCase(ClusterSetup.enablePartition))
       {
         jsonParameters.verifyCommand(ClusterSetup.enablePartition);
  
         boolean enabled =
              Boolean.parseBoolean(jsonParameters.getParameter(JsonParameters.ENABLED));
 
         String[] partitions = 
             jsonParameters.getParameter(JsonParameters.PARTITION).split(";");
         String resource = 
             jsonParameters.getParameter(JsonParameters.RESOURCE);
 
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         setupTool.getClusterManagementTool().enablePartition(enabled,
                                                              clusterName,
                                                              instanceName,
                                                              resource,
                                                              Arrays.asList(partitions));
       }
       else if (command.equalsIgnoreCase(ClusterSetup.resetPartition))
       {
         jsonParameters.verifyCommand(ClusterSetup.resetPartition);
 
         String resource = 
             jsonParameters.getParameter(JsonParameters.RESOURCE);
 
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         String[] partitionNames = 
             jsonParameters.getParameter(JsonParameters.PARTITION).split("\\s+");
         setupTool.getClusterManagementTool()
                  .resetPartition(clusterName,
                                  instanceName,
                                  resource,
                                  Arrays.asList(partitionNames));
       }
       else if (command.equalsIgnoreCase(ClusterSetup.resetInstance))
       {
         jsonParameters.verifyCommand(ClusterSetup.resetInstance);
 
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         setupTool.getClusterManagementTool().resetInstance(clusterName,
                                                            Arrays.asList(instanceName));
       }
       else if (command.equalsIgnoreCase(ClusterSetup.addInstanceTag))
       {
         jsonParameters.verifyCommand(ClusterSetup.addInstanceTag);
         String tag = 
             jsonParameters.getParameter(ClusterSetup.instanceGroupTag);
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         setupTool.getClusterManagementTool().addInstanceTag(clusterName, instanceName, tag);
       }
       else if (command.equalsIgnoreCase(ClusterSetup.removeInstanceTag))
       {
         jsonParameters.verifyCommand(ClusterSetup.removeInstanceTag);
         String tag = 
             jsonParameters.getParameter(ClusterSetup.instanceGroupTag);
         ZkClient zkClient =
             (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
         ClusterSetup setupTool = new ClusterSetup(zkClient);
         setupTool.getClusterManagementTool().removeInstanceTag(clusterName, instanceName, tag);
       }
       else
       {
         throw new HelixException("Unsupported command: " + command
             + ". Should be one of [" + ClusterSetup.enableInstance + ", "
             + ClusterSetup.enablePartition + ", " + ClusterSetup.resetInstance + "]");
       }
 
       getResponse().setEntity(getInstanceRepresentation());
       getResponse().setStatus(Status.SUCCESS_OK);
     }
     catch (Exception e)
     {
       getResponse().setEntity(ClusterRepresentationUtil.getErrorAsJsonStringFromException(e),
                               MediaType.APPLICATION_JSON);
       getResponse().setStatus(Status.SUCCESS_OK);
       LOG.error("", e);
     }
   }
 
   @Override
   public void removeRepresentations()
   {
     try
     {
       String clusterName = (String) getRequest().getAttributes().get("clusterName");
       String instanceName = (String) getRequest().getAttributes().get("instanceName");
       ZkClient zkClient =
           (ZkClient) getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
 
       ClusterSetup setupTool = new ClusterSetup(zkClient);
       setupTool.dropInstanceFromCluster(clusterName, instanceName);
       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 remove", e);
     }
   }
 }