/*
    * Copyright (C) 2013 4th Line GmbH, Switzerland
    *
    * The contents of this file are subject to the terms of either the GNU
    * Lesser General Public License Version 2 or later ("LGPL") or the
    * Common Development and Distribution License Version 1 or later
    * ("CDDL") (collectively, the "License"). You may not use this file
    * except in compliance with the License. See LICENSE.txt for more
    * information.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   */
  
  package org.fourthline.cling.transport.impl;
  
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import org.fourthline.cling.model.message.gena.IncomingEventRequestMessage;
  import org.fourthline.cling.model.meta.StateVariable;
  import org.fourthline.cling.model.state.StateVariableValue;
  import org.fourthline.cling.transport.spi.GENAEventProcessor;
  import org.fourthline.cling.model.UnsupportedDataException;
  import org.seamless.xml.XmlPullParserUtils;
  import org.xmlpull.v1.XmlPullParser;
  
  import javax.enterprise.inject.Alternative;
  
  /**
   * Implementation based on the <em>Xml Pull Parser</em> XML processing API.
   * <p>
   * This processor is more lenient with parsing, looking only for the required XML tags.
   * </p>
   * <p>
   * To use this parser you need to install an implementation of the
   * <a href="http://www.xmlpull.org/impls.shtml">XMLPull API</a>.
   * </p>
   *
   * @author Michael Pujos
   */
  @Alternative
  public class PullGENAEventProcessorImpl extends GENAEventProcessorImpl {
  
  	private static Logger log = Logger.getLogger(GENAEventProcessor.class.getName());
  
  	public void readBody(IncomingEventRequestMessage requestMessage) throws UnsupportedDataException {
          log.fine("Reading body of: " + requestMessage);
          if (log.isLoggable(Level.FINER)) {
              log.finer("===================================== GENA BODY BEGIN ============================================");
              log.finer(requestMessage.getBody() != null ? requestMessage.getBody().toString() : null);
              log.finer("-===================================== GENA BODY END ============================================");
          }
  
          String body = getMessageBody(requestMessage);
  		try {
  			XmlPullParser xpp = XmlPullParserUtils.createParser(body);
  			readProperties(xpp, requestMessage);
  		} catch (Exception ex) {
  			throw new UnsupportedDataException("Can't transform message payload: " + ex.getMessage(), ex, body);	
  		}
  	}
  
  	protected void readProperties(XmlPullParser xpp, IncomingEventRequestMessage message) throws Exception {
  		// We're inside the propertyset tag
  		StateVariable[] stateVariables = message.getService().getStateVariables();
  		int event;
  		while((event = xpp.next()) != XmlPullParser.END_DOCUMENT) {
  			if(event != XmlPullParser.START_TAG) continue;
  			if(xpp.getName().equals("property")) {
  				readProperty(xpp, message, stateVariables);
  			} 
  		}
  	}
  
  	protected void readProperty(XmlPullParser xpp, IncomingEventRequestMessage message, StateVariable[] stateVariables) throws Exception  {
  		// We're inside the property tag
  		int event ;
  		do {
  			event = xpp.next();
  			if(event == XmlPullParser.START_TAG) {
  
  				String stateVariableName = xpp.getName();
  				for (StateVariable stateVariable : stateVariables) {
  					if (stateVariable.getName().equals(stateVariableName)) {
  						log.fine("Reading state variable value: " + stateVariableName);
  						String value = xpp.nextText();
  						message.getStateVariableValues().add(new StateVariableValue(stateVariable, value));
  						break;
  					}
  				} 
  			}
  		} while(event != XmlPullParser.END_DOCUMENT && (event != XmlPullParser.END_TAG || !xpp.getName().equals("property")));
  	}
  }