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.net.InetAddress;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.UUID;
  
  import org.apache.helix.HelixDataAccessor;
  import org.apache.helix.HelixException;
  import org.apache.helix.InstanceType;
  import org.apache.helix.PropertyPathConfig;
  import org.apache.helix.PropertyType;
  import org.apache.helix.manager.zk.DefaultSchedulerMessageHandlerFactory;
  import org.apache.helix.manager.zk.ZkClient;
  import org.apache.helix.model.LiveInstance;
  import org.apache.helix.model.Message;
  import org.apache.helix.model.Message.MessageType;
  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.Form;
  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;
  
  
  /**
   * This resource can be used to send scheduler tasks to the controller.
   * 
   * */
  public class SchedulerTasksResource extends Resource
  {
    private final static Logger LOG = Logger.getLogger(SchedulerTasksResource.class);
  
    public static String CRITERIA = "Criteria";
    public static String MESSAGETEMPLATE = "MessageTemplate";
    public static String TASKQUEUENAME = "TaskQueueName";
    public SchedulerTasksResource(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
     {
       presentation = getSchedulerTasksRepresentation();
     }
     
     catch(Exception e)
     {
       String error = ClusterRepresentationUtil.getErrorAsJsonStringFromException(e);
       presentation = new StringRepresentation(error, MediaType.APPLICATION_JSON);
 
       LOG.error("", e);
     }  
     return presentation;
   }
   
   StringRepresentation getSchedulerTasksRepresentation() throws JsonGenerationException, JsonMappingException, IOException
   {
     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);
     List<String> instances = setupTool.getClusterManagementTool().getInstancesInCluster(clusterName);
     
     HelixDataAccessor accessor = ClusterRepresentationUtil.getClusterDataAccessor(zkClient, clusterName);
     LiveInstance liveInstance = accessor.getProperty(accessor.keyBuilder().liveInstance(instanceName));
     String sessionId = liveInstance.getSessionId();
     
     StringRepresentation representation = new StringRepresentation("");//(ClusterRepresentationUtil.ObjectToJson(instanceConfigs), MediaType.APPLICATION_JSON);
     
     return representation;
   }
   
   @Override
   public void acceptRepresentation(Representation entity)
   {
     try
     {
       String clusterName = (String)getRequest().getAttributes().get("clusterName");
       Form form = new Form(entity);
       ZkClient zkClient = (ZkClient)getContext().getAttributes().get(RestAdminApplication.ZKCLIENT);
       
       String msgTemplateString = ClusterRepresentationUtil.getFormJsonParameterString(form, MESSAGETEMPLATE);
       if(msgTemplateString == null)
       {
         throw new HelixException("SchedulerTasksResource need to have MessageTemplate specified.");
       }
       Map<String, String> messageTemplate = ClusterRepresentationUtil.getFormJsonParameters(form, MESSAGETEMPLATE);
       
       String criteriaString = ClusterRepresentationUtil.getFormJsonParameterString(form, CRITERIA);
       if(criteriaString == null)
       {
         throw new HelixException("SchedulerTasksResource need to have Criteria specified.");
       }
       HelixDataAccessor accessor = ClusterRepresentationUtil.getClusterDataAccessor(zkClient, clusterName);
       LiveInstance leader = accessor.getProperty(accessor.keyBuilder().controllerLeader());
       if(leader == null)
       {
         throw new HelixException("There is no leader for the cluster " + clusterName);
       }
       
       Message schedulerMessage = new Message(MessageType.SCHEDULER_MSG, UUID.randomUUID().toString());
       schedulerMessage.getRecord().getSimpleFields().put(CRITERIA, criteriaString);
       
       schedulerMessage.getRecord().getMapFields().put(MESSAGETEMPLATE, messageTemplate);
       
       schedulerMessage.setTgtSessionId(leader.getSessionId());
       schedulerMessage.setTgtName("CONTROLLER");
       schedulerMessage.setSrcInstanceType(InstanceType.CONTROLLER);
       String taskQueueName =  ClusterRepresentationUtil.getFormJsonParameterString(form, TASKQUEUENAME);
       if(taskQueueName != null && taskQueueName.length() > 0)
       {
         schedulerMessage.getRecord().setSimpleField(DefaultSchedulerMessageHandlerFactory.SCHEDULER_TASK_QUEUE, taskQueueName);
       }
       accessor.setProperty(accessor.keyBuilder().controllerMessage(schedulerMessage.getMsgId()), schedulerMessage);
       
       Map<String, String> resultMap = new HashMap<String, String>();
       resultMap.put("StatusUpdatePath", PropertyPathConfig.getPath(PropertyType.STATUSUPDATES_CONTROLLER, clusterName, MessageType.SCHEDULER_MSG.toString(),schedulerMessage.getMsgId()));
       resultMap.put("MessageType", Message.MessageType.SCHEDULER_MSG.toString());
       resultMap.put("MsgId", schedulerMessage.getMsgId());
       
       // Assemble the rest URL for task status update
       String ipAddress = InetAddress.getLocalHost().getCanonicalHostName();
       String url = "http://" + ipAddress+":" + getContext().getAttributes().get(RestAdminApplication.PORT)
           + "/clusters/" + clusterName+"/Controller/statusUpdates/SCHEDULER_MSG/" + schedulerMessage.getMsgId();
       resultMap.put("statusUpdateUrl", url);
       
       getResponse().setEntity(ClusterRepresentationUtil.ObjectToJson(resultMap), MediaType.APPLICATION_JSON);
       getResponse().setStatus(Status.SUCCESS_OK);
     }
     catch(Exception e)
     {
       getResponse().setEntity(ClusterRepresentationUtil.getErrorAsJsonStringFromException(e),
           MediaType.APPLICATION_JSON);
       getResponse().setStatus(Status.SUCCESS_OK);
       LOG.error("", e);
     }  
   }
 }