<?php

//
// Open Web Analytics - An Open Source Web Analytics Framework
//
// Copyright 2006-2010 Peter Adams. All rights reserved.
//
// Licensed under GPL v2.0 http://www.gnu.org/copyleft/gpl.html
//
// 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.
//
// $Id$
//

if(!class_exists('owa_observer')) {
	require_once(OWA_BASE_DIR.'owa_observer.php');
}	

/**
 * OWA Session Event handlers
 * 
 * @author      Peter Adams <peter@openwebanalytics.com>
 * @copyright   Copyright &copy; 2006-2010 Peter Adams <peter@openwebanalytics.com>
 * @license     http://www.gnu.org/copyleft/gpl.html GPL v2.0
 * @category    owa
 * @package     owa
 * @version		$Revision$	      
 * @since		owa 1.0.0
 */

class owa_sessionHandlers extends owa_observer {
    	
    /**
     * Notify Event Handler
     *
     * @param 	unknown_type $event
     * @access 	public
     */
    function notify($event) {
		
    	if ($event->get('is_new_session')) {
    		return $this->logSession($event);
    	} else {
    		return $this->logSessionUpdate($event);
    	}
    }
    
    function logSession($event) {
    	
    	// Control logic
		
		$s = owa_coreAPI::entityFactory('base.session');
		
		$s->load( $event->get('session_id') );
		
		if ( ! $s->wasPersisted() ) {
		
			$s->setProperties($event->getProperties());
		
			// Set Primary Key
			$s->set( 'id', $event->get('session_id') );
			 
			// set initial number of page views
			$s->set('num_pageviews', 1);
			$s->set('is_bounce', true);
	
			// set prior session time properties		
			$s->set('prior_session_lastreq', $event->get('last_req'));
					
			$s->set('prior_session_id', $event->get('prior_session_id'));
			
			if ($s->get('prior_session_lastreq') > 0) {
				$s->set('time_sinse_priorsession', $s->get('timestamp') - $event->get('last_req'));
				$s->set('prior_session_year', date("Y", $event->get('last_req')));
				$s->set('prior_session_month', date("M", $event->get('last_req')));
				$s->set('prior_session_day', date("d", $event->get('last_req')));
				$s->set('prior_session_hour', date("G", $event->get('last_req')));
				$s->set('prior_session_minute', date("i", $event->get('last_req')));
				$s->set('prior_session_dayofweek', date("w", $event->get('last_req')));
			}
			
			// set last_req to be the timestamp of the event that triggered this session.
			$s->set('last_req', $event->get('timestamp'));
			$s->set('days_since_first_session', $event->get('days_since_first_session'));
			$s->set('days_since_prior_session', $event->get('days_since_prior_session'));
			$s->set('num_prior_sessions', $event->get('num_prior_sessions'));
					
			// set medium
			//$s->set('medium', $event->get('medium'));
			
			// set campaign touches
			$s->set( 'latest_attributions' , $event->get( 'attribs' ) );
		
			// Make document ids	
			$s->set('first_page_id', owa_lib::setStringGuid($event->get('page_url')));
				
			$s->set('last_page_id', $s->get('first_page_id'));
		
			// Generate Referer id
			
			if ($event->get('external_referer')) {
				$s->set('referer_id', owa_lib::setStringGuid($event->get('HTTP_REFERER')));
			}	
			
			// this should already be set by the request handler.
			$s->set( 'location_id', $event->get( 'location_id' ) );
					
			$ret = $s->create();
	
			// create event message
			$session = $s->_getProperties();
			$properties = array_merge($event->getProperties(), $session);
			$properties['request_id'] = $event->get('guid');
			$ne = owa_coreAPI::supportClassFactory('base', 'event');
			$ne->setProperties($properties);
			$ne->setEventType('base.new_session');
			
			// log the new session event to the event queue
			$eq = owa_coreAPI::getEventDispatch();
			$eq->notify($ne);
			
			if ($ret) {
				return OWA_EHS_EVENT_HANDLED;
			} else {
				return OWA_EHS_EVENT_FAILED;
			}
		} else {
			owa_coreAPI::debug('Not persisting new session. Session already exists.');
			return OWA_EHS_EVENT_HANDLED;
		}
    }
    
    function logSessionUpdate($event) {
    	
    	// Make entity
		$s = owa_coreAPI::entityFactory('base.session');
		
		// Fetch from session from database
		$s->getByPk('id', $event->get('session_id'));
		
		$id = $s->get('id');
		// fail safe for when there is no existing session in DB
		if (empty($id)) {
			
			owa_coreAPI::debug("Aborting session update as no existing session was found");
			return OWA_EHS_EVENT_FAILED;
		}

		// idempotent check needed in case updates are processed out of order.
		// dont update the database if the event timestamp is older that the last_req
		// timestamp that is already set on the session object.		
		$last_req_time = $s->get('last_req');
		$event_req_time = $event->get('timestamp');

		$ret = false;

		if ($event_req_time > $last_req_time) {
		
			// increment number of page views
			$s->set('num_pageviews', $this->summarizePageviews($id));
			$s->set('is_bounce', 'false');
			
			// update timestamp of latest request that triggered the session update
			$s->set('last_req', $event->get('timestamp'));
			
			// update last page id
			$s->set('last_page_id', owa_lib::setStringGuid($event->get('page_url')));
			
			// set medium
			$s->set('medium', $event->get('medium'));
			
			// set source
			if ($event->get('source_id')) {
				$s->set('source_id', $event->get('source_id') );		
			}
				
			// set search terms
			if ($event->get('referring_search_term_id')) {
				$s->set('referring_search_term_id',  $event->get('referring_search_term_id') );		
			}
			
			// set campaign
			if ($event->get('campaign_id')) {
				$s->set('campaign_id', $event->get('campaign_id') );		
			}
			
			// set ad
			if ($event->get('ad_id')) {
				$s->set('ad_id', $event->get('ad_id') );		
			}
			
			// set campaign touches
			$s->set( 'latest_attributions' , $event->get( 'attribs' ) );
			
			// Persist to database
			$ret = $s->update();
		}
				
		// setup event message
		$session = $s->_getProperties();
		$properties = array_merge($event->getProperties(), $session);
		$properties['request_id'] = $event->get('guid');
		$ne = owa_coreAPI::supportClassFactory('base', 'event');
		$ne->setProperties($properties);
		$ne->setEventType('base.session_update');
		// Log session update event to event queue
		$eq = owa_coreAPI::getEventDispatch();
		$ret = $eq->notify( $ne );
		
		if ( $ret ) {	
			return OWA_EHS_EVENT_HANDLED;
		} else {
			return OWA_EHS_EVENT_FAILED;
		}
    }
    
    function summarizePageviews($id) {
    	
    	$ret = owa_coreAPI::summarize(array(
    			'entity'		=> 'base.request',
    			'columns'		=> array('id' => 'count_distinct'),
    			'constraints'	=> array( 'session_id' => $id ) ) );
    	
    	return $ret['id_dcount'];
    }
}

?>