/*
 * Copyright 2012  Research Studios Austria Forschungsges.m.b.H.
 *
 *    Licensed 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.
 */

package won.node.camel.processor.fixed;

import org.apache.jena.rdf.model.*;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import won.node.camel.processor.AbstractFromOwnerCamelProcessor;
import won.node.camel.processor.annotation.FixedMessageProcessor;
import won.protocol.message.WonMessage;
import won.protocol.message.processor.camel.WonCamelConstants;
import won.protocol.model.Connection;
import won.protocol.util.RdfUtils;
import won.protocol.vocabulary.WON;
import won.protocol.vocabulary.WONMSG;

import java.net.URI;

/**
 * User: syim
 * Date: 02.03.2015
 */
@Component
@FixedMessageProcessor(direction = WONMSG.TYPE_FROM_OWNER_STRING,messageType = WONMSG.TYPE_HINT_FEEDBACK_STRING)
public class HintFeedbackMessageFromOwnerProcessor extends AbstractFromOwnerCamelProcessor
{

  @Transactional(propagation = Propagation.REQUIRED, isolation = Isolation.READ_COMMITTED)
  public void process(final Exchange exchange) throws Exception {
    Message message = exchange.getIn();
    WonMessage wonMessage = (WonMessage) message.getHeader(WonCamelConstants.MESSAGE_HEADER);
    Connection con = connectionRepository.findOneByConnectionURIForUpdate(wonMessage.getSenderURI());
    logger.debug("HINT_FEEDBACK received from the owner side for connection {}", wonMessage.getSenderURI());
    processFeedbackMessage(con, wonMessage);
  }




  /////// TODO: move code below to the implementation of a FEEDBACK message


  /**
   * Finds feedback in the message, processes it and removes it from the message.
   *
   * @param con
   * @param message
   * @return true if feedback was present, false otherwise
   */
  private void processFeedbackMessage(final Connection con, final WonMessage message) {
    assert con != null : "connection must not be null";
    assert message != null : "message must not be null";
    final URI messageURI = message.getMessageURI();
    RdfUtils.visit(message.getMessageContent(), new RdfUtils.ModelVisitor<Object>()
    {
      @Override
      public Model visit(final Model model) {
        Resource baseResource = model.getResource(messageURI.toString());
        if (baseResource.hasProperty(WON.HAS_FEEDBACK)){
          //add the base resource as a feedback event to the connection
          processFeedback(con, baseResource);
        }
        return null;
      }
    });
  }

  private void processFeedback(Connection connection,
                               final RDFNode feedbackNode) {

    if (!feedbackNode.isResource()) {
      logger.warn("feedback node is not a resource, cannot process feedback for {}", connection.getConnectionURI());
      return;
    }
    final Resource feedbackRes = (Resource) feedbackNode;
    if (!dataService.addFeedback(connection, feedbackRes)) {
      logger.warn("failed to add feedback to resource {}", connection.getConnectionURI());
    }

  }

}