/*
    * Copyright  1999-2004 The Apache Software Foundation.
    *
    *  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 org.apache.savan.eventing;
  
  import java.util.Calendar;
  import java.util.Date;
  
  import javax.xml.namespace.QName;
  
  import org.apache.axiom.om.OMAbstractFactory;
  import org.apache.axiom.om.OMAttribute;
  import org.apache.axiom.om.OMElement;
  import org.apache.axiom.om.OMNode;
  import org.apache.axiom.soap.SOAP11Constants;
  import org.apache.axiom.soap.SOAP12Constants;
  import org.apache.axiom.soap.SOAPBody;
  import org.apache.axiom.soap.SOAPEnvelope;
  import org.apache.axiom.soap.SOAPFactory;
  import org.apache.axiom.soap.SOAPHeader;
  import org.apache.axis2.AxisFault;
  import org.apache.axis2.addressing.EndpointReferenceHelper;
  import org.apache.axis2.addressing.EndpointReference;
  import org.apache.axis2.context.ConfigurationContext;
  import org.apache.axis2.databinding.types.Duration;
  import org.apache.axis2.databinding.utils.ConverterUtil;
  import org.apache.axiom.om.util.UUIDGenerator;
  import org.apache.savan.SavanConstants;
  import org.apache.savan.SavanException;
  import org.apache.savan.SavanMessageContext;
  import org.apache.savan.configuration.ConfigurationManager;
  import org.apache.savan.configuration.Protocol;
  import org.apache.savan.configuration.SubscriberBean;
  import org.apache.savan.eventing.subscribers.EventingSubscriber;
  import org.apache.savan.filters.Filter;
  import org.apache.savan.subscribers.AbstractSubscriber;
  import org.apache.savan.subscribers.Subscriber;
  import org.apache.savan.subscription.ExpirationBean;
  import org.apache.savan.subscription.SubscriptionProcessor;
  import org.apache.savan.util.CommonUtil;
  import org.apache.savan.util.UtilFactory;
  
  public class EventingSubscriptionProcessor extends SubscriptionProcessor {
  
  	public void init (SavanMessageContext smc) throws SavanException {
  		//setting the subscriber_id as a property if possible.
  		
  		String id = getSubscriberID(smc);
  		if (id!=null) {
  			smc.setProperty(EventingConstants.TransferedProperties.SUBSCRIBER_UUID,id);
  		}
  	}
  	
  	public Subscriber getSubscriberFromMessage(SavanMessageContext smc) throws SavanException {
  
  		ConfigurationManager configurationManager = (ConfigurationManager) smc.getConfigurationContext().getProperty(SavanConstants.CONFIGURATION_MANAGER);
  		if (configurationManager==null)
  			throw new SavanException ("Configuration Manager not set");
  		
  		Protocol protocol = smc.getProtocol();
  		if (protocol==null)
  			throw new SavanException ("Protocol not found");
  		
  		UtilFactory utilFactory = protocol.getUtilFactory();
  		
  		SOAPEnvelope envelope = smc.getEnvelope();
  		if (envelope==null)
  			return null;
  		
  //		AbstractSubscriber subscriber = utilFactory.createSubscriber();  //eventing only works on leaf subscriber for now.
  		
  		String subscriberName = protocol.getDefaultSubscriber();
  		SubscriberBean subscriberBean = configurationManager.getSubscriberBean(subscriberName);
  		
  		AbstractSubscriber subscriber = configurationManager.getSubscriberInstance(subscriberName);
  		
  		if (!(subscriber instanceof EventingSubscriber)) {
  			String message = "Eventing protocol only support implementations of eventing subscriber as Subscribers";
  			throw new SavanException (message);
  		}
  		
  		EventingSubscriber eventingSubscriber = (EventingSubscriber) subscriber;
  		String id = UUIDGenerator.getUUID();
  		smc.setProperty(EventingConstants.TransferedProperties.SUBSCRIBER_UUID,id);
  	
 		eventingSubscriber.setId(id);
 		
 		SOAPBody body = envelope.getBody();
 		OMElement subscribeElement = body.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Subscribe));
 		if (subscribeElement==null)
 			throw new SavanException ("'Subscribe' element is not present");
 		
 		OMElement endToElement = subscribeElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.EndTo));
 		if (endToElement!=null) {
 			EndpointReference endToEPR = null;
             
             try {
                 endToEPR = EndpointReferenceHelper.fromOM(endToElement);
             }
             catch (AxisFault af) {
                 throw new SavanException(af);
             }
             
 			eventingSubscriber.setEndToEPr(endToEPR);
 		}
 		
 		OMElement deliveryElement = subscribeElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Delivery));
 		if (deliveryElement==null)
 			throw new SavanException ("Delivery element is not present");
 		
 		OMElement notifyToElement = deliveryElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.NotifyTo));
 		if (notifyToElement==null)
 			throw new SavanException ("NotifyTo element is null");
 		
 		EndpointReference notifyToEPr = null;
         
         try {
             notifyToEPr = EndpointReferenceHelper.fromOM(notifyToElement);
         }
         catch (AxisFault af) {    
             throw new SavanException(af);
         }
         
 		OMAttribute deliveryModeAttr = deliveryElement.getAttribute(new QName (EventingConstants.ElementNames.Mode));
 		String deliveryMode = null;
 		if (deliveryModeAttr!=null) {
 			deliveryMode = deliveryModeAttr.getAttributeValue().trim();
 		} else {
 			deliveryMode = EventingConstants.DEFAULT_DELIVERY_MODE;
 		}
 		
 		if (!deliveryModesupported()) {
 			//TODO throw unsupported delivery mode fault.
 		}
 		
 		Delivery delivery = new Delivery ();
 		delivery.setDeliveryEPR(notifyToEPr);
 		delivery.setDeliveryMode(deliveryMode);
 		
 		eventingSubscriber.setDelivery(delivery);
 		
 		OMElement expiresElement = subscribeElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Expires));
 		if (expiresElement!=null) {
 			String expiresText = expiresElement.getText();
 
 			if (expiresText==null){
 				String message = "Expires Text is null";
 				throw new SavanException (message);
 			}
 			
 			expiresText = expiresText.trim();
 			
 			ExpirationBean expirationBean = getExpirationBeanFromString(expiresText);
 			Date expiration = null;
 			if (expirationBean.isDuration()) {
 				Calendar calendar = Calendar.getInstance();
 				CommonUtil.addDurationToCalendar(calendar,expirationBean.getDurationValue());
 				expiration = calendar.getTime();
 			} else
 				expiration = expirationBean.getDateValue();
 			
 			
 			if (expiration==null) {
 				String message = "Cannot understand the given date-time value for the Expiration";
 				throw new SavanException (message);
 			}
 			
 			eventingSubscriber.setSubscriptionEndingTime(expiration);
 		}
 		
 		OMElement filterElement = subscribeElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Filter));
 		if (filterElement!=null) {
 			OMNode filterNode = filterElement.getFirstOMChild();
 			OMAttribute dialectAttr = filterElement.getAttribute(new QName (EventingConstants.ElementNames.Dialect));
 			Filter filter = null;
 			
 			String filterKey = EventingConstants.DEFAULT_FILTER_IDENTIFIER;
 			if (dialectAttr!=null) {
 				filterKey = dialectAttr.getAttributeValue();
 			}
 			filter = configurationManager.getFilterInstanceFromId(filterKey);
 			if (filter==null)
 				throw new SavanException ("The Filter defined by the dialect is not available");
 			
 			filter.setUp (filterNode);
 			
 			eventingSubscriber.setFilter(filter);
 		}
 		
 		return eventingSubscriber;
 	}
 
 	public void pauseSubscription(SavanMessageContext pauseSubscriptionMessage) throws SavanException {
 		throw new UnsupportedOperationException ("Eventing specification does not support this type of messages");
 	}
 
 	public void resumeSubscription(SavanMessageContext resumeSubscriptionMessage) throws SavanException {
 		throw new UnsupportedOperationException ("Eventing specification does not support this type of messages");
 	}
 
 	public ExpirationBean getExpirationBean(SavanMessageContext renewMessage) throws SavanException {
 
 		SOAPEnvelope envelope = renewMessage.getEnvelope();
 		SOAPBody body = envelope.getBody();
 		
 		ExpirationBean expirationBean = null;
 		
 		OMElement renewElement = body.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Renew));
 		if (renewElement==null) {
 			String message = "Renew element not present in the assumed Renew Message";
 			throw new SavanException (message);
 		}
 		
 		OMElement expiresElement = renewElement.getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Expires));
 		if (expiresElement!=null) {
 			String expiresText = expiresElement.getText().trim();
 			expirationBean = getExpirationBeanFromString(expiresText);
 		}
 		
 		String subscriberID = getSubscriberID(renewMessage);
 		if (subscriberID==null) {
 			String message = "Cannot find the subscriber ID";
 			throw new SavanException (message);
 		}
 		
 		renewMessage.setProperty(EventingConstants.TransferedProperties.SUBSCRIBER_UUID,subscriberID);
 		
 		expirationBean.setSubscriberID(subscriberID);
 		return expirationBean;
 	}
 
 	public String getSubscriberID(SavanMessageContext smc) throws SavanException {
 		SOAPEnvelope envelope = smc.getEnvelope();
 		SOAPHeader header = envelope.getHeader();
 		if (header==null) {
 			return null;
 		}
 		
 		OMElement ideltifierElement = envelope.getHeader().getFirstChildWithName(new QName (EventingConstants.EVENTING_NAMESPACE,EventingConstants.ElementNames.Identifier));
 		if (ideltifierElement==null) {
 			return null;
 		}
 		
 		return ideltifierElement.getText().trim();
 	}
 	
 	private ExpirationBean getExpirationBeanFromString (String expiresStr) throws SavanException {
 
 		ExpirationBean bean = new ExpirationBean ();
 		
 		//expires can be a duration or a date time.
 		//Doing the conversion using the ConverUtil helper class.
 		
 		Date date = null;
 		boolean isDuration = CommonUtil.isDuration(expiresStr);
 		
 		if (isDuration) {
 			try {
 				bean.setDuration(true);
 				Duration duration = ConverterUtil.convertToDuration(expiresStr);
 				bean.setDurationValue(duration);
 			} catch (IllegalArgumentException e) {
 				String message = "Cannot convert the Expiration value to a valid duration";
 				throw new SavanException (message,e);
 			}
 		} else {
 			try {
 			    Calendar calendar = ConverterUtil.convertToDateTime(expiresStr);
 			    date = calendar.getTime();
 			    bean.setDateValue(date);
 			} catch (Exception e) {
 				String message = "Cannot convert the Expiration value to a valid DATE/TIME";
 				throw new SavanException (message,e);
 			}
 		}
 		
 		boolean invalidExpirationTime = false;
 		if (bean.isDuration()) {
 			if (isInvalidDiration (bean.getDurationValue()))
 				invalidExpirationTime = true;
 		} else {
 			if (isDateInThePast (bean.getDateValue())) 
 				invalidExpirationTime = true;
 		}
 		
 		if (invalidExpirationTime) {
 			//TODO throw Invalid Expiration Time fault
 		}
 		
 		return bean;
 	}
 
 	public void doProtocolSpecificEndSubscription(Subscriber subscriber, String reason, ConfigurationContext configurationContext) throws SavanException {
 		String SOAPVersion = (String) subscriber.getProperty(EventingConstants.Properties.SOAPVersion);
 		if (SOAPVersion==null) 
 			throw new SavanException ("Cant find the SOAP version of the subscriber");
 		
 		SOAPFactory factory = null;
 		if (SOAP11Constants.SOAP_ENVELOPE_NAMESPACE_URI.equals(SOAPVersion))
 			factory = OMAbstractFactory.getSOAP11Factory();
 		else if (SOAP12Constants.SOAP_ENVELOPE_NAMESPACE_URI.equals(SOAPVersion))
 			factory = OMAbstractFactory.getSOAP12Factory();
 		else
 			throw new SavanException ("The subscriber has a unknown SOAP version property set");
 		
 		SOAPEnvelope envelope = factory.getDefaultEnvelope();
 	}
 	
 	private boolean deliveryModesupported() {
 		return true;
 	}
 	
 	private boolean isInvalidDiration (Duration duration) {
 		return false;
 	}
 	
 	private boolean isDateInThePast (Date date) {
 		return false;
 	}
 	
 	private boolean filterDilalectSupported (String filterDialect){ 
 		return true;
 	}
 	
 }