<?php
/**
 * $Id$
 *
 * Facilitates adding and removing file and folder subscriptions.
 *
 * KnowledgeTree Community Edition
 * Document Management Made Simple
 * Copyright (C) 2008, 2009 KnowledgeTree Inc.
 * 
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 3 as published by the
 * Free Software Foundation.
 * 
 * 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.  See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * You can contact KnowledgeTree Inc., PO Box 7775 #87847, San Francisco, 
 * California 94120-7775, or email info@knowledgetree.com.
 * 
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 * 
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "Powered by
 * KnowledgeTree" logo and retain the original copyright notice. If the display of the 
 * logo is not reasonably feasible for technical reasons, the Appropriate Legal Notices
 * must display the words "Powered by KnowledgeTree" and retain the original 
 * copyright notice.
 * Contributor( s): ______________________________________
 */ 

require_once(KT_LIB_DIR . "/subscriptions/Subscription.inc");
require_once(KT_LIB_DIR . "/subscriptions/subscriptions.inc.php");

class SubscriptionManager {

    /**
     * Creates a subscription.
     *
     * @param int the user to create the subscription for     
     * @param int the external id to create the subscription for
     * @param int the subscription type     
     * @return true if the subscription creation succeed, false and error message otherwise
     */
    function createSubscription($iUserID, $iExternalID, $iSubscriptionType) {
        global $lang_sub_exists;

        if (!Subscription::exists($iUserID, $iExternalID, $iSubscriptionType)) {
            $oSubscription = new Subscription($iUserID, $iExternalID, $iSubscriptionType);
            if ($oSubscription->create()) {
                return true;
            } else {
                // error message set in Subscription::create
                return false;
            }
        } else {
            // TODO: lookup username and folder name from ids for error message
            $_SESSION["errorMessage"] = $lang_sub_exists . " type=$iSubscriptionType, ID=$iExternalID, userID=$iUserID";
            return false;
        }
    }

    /**
     * Removes all subscriptions
     *
     * @param int the user to create the subscription for     
     * @param int the external id to create the subscription for
     * @param int the subscription type     
     * @return true if the subscription creation succeed, false and error message otherwise
     */
    function removeSubscriptions($iExternalID, $iSubscriptionType ) {
        global $lang_sub_not_exists;

        // first retrieve all the subscribers to this content
        $aSubscriptions = SubscriptionManager::retrieveSubscriptions($iExternalID, $iSubscriptionType);
        $bResult = true;
        for ($i = 0; $i < count($aSubscriptions); $i++) {
            // delete them
            if ($aSubscriptions[$i]->delete()) {
                $bResult = $bResult && true;
            } else {
                $bResult = $bResult && false;
            }
        }
        return $bResult;
    }
    
    /**
     * Retrieves all subscriptions for the specified content.
     *
     * @param int the external id to create the subscription for
     * @param int the subscription type
     */
    function retrieveSubscriptions($iExternalID, $iSubscriptionType) {
        global $default;

        $sql = $default->db;
        if ($sql->query(array("SELECT id FROM " . Subscription::getTableName($iSubscriptionType) .  " " ./*ok*/
                        "WHERE " . Subscription::getIdFieldName($iSubscriptionType) . " = ?", $iExternalID))) {
            $aSubscriptions = array();
            while ($sql->next_record()) {
                $aSubscriptions[] = & Subscription::get($sql->f("id"), $iSubscriptionType);
            }
        } else {
            $_SESSION["errorMessage"] = $lang_err_database;
            return false;
        }
        return $aSubscriptions;
    }        

    /**
     * Clears the alert from the selected subscription and returns the
     * path to the document.
     *
     * @param int the subscription ID to view
     * @param int the subscription type
     * @return string link to the subscription content, false if the operation failed
     */
    function viewSubscription($iSubscriptionID, $iSubscriptionType) {
        // instantiate subscription from id
        $oSubscription = Subscription::get($iSubscriptionID, $iSubscriptionType);
        if ($oSubscription) {
            // update the alerted flag
            $oSubscription->setIsAlerted(false);
            // save the update
            if ($oSubscription->update()) {
                // return the url to the content
                return $oSubscription->getContentUrl();
            } else {
                // error message set by Subscription::updates
                return false;
            }
        } else {
            // error message set by Subscription::get
            return false;
        }
    }

    /**
    * Retrieves all subscriptions for this user.
    *
    * @param integer the ID of the user to retrieve subscriptions for
    * @return array of subscription objects
    */
    function listSubscriptions($iUserID) {
        return $aSubscriptions = kt_array_merge(SubscriptionManager::retrieveUserSubscriptions($iUserID, SubscriptionEvent::subTypes('Folder')),
                                             SubscriptionManager::retrieveUserSubscriptions($iUserID, SubscriptionEvent::subTypes('Document')));
    }
    
    /**
    * Retrieves the users's subscriptions
    *
    * @param integer the ID of the user to retrieve subscriptions for
    * @return array of subscription objects, false if the database interaction fails
    */
    function retrieveUserSubscriptions($iUserID, $iSubscriptionType) {
    
        $table = Subscription::getTableName($iSubscriptionType); // EVIL!
        $aQuery = array(
            "SELECT id FROM $table WHERE user_id = ?",
            $iUserID,
        );
    
    
        $res = DBUtil::getResultArrayKey($aQuery, 'id');
        if (PEAR::isError($res)) {
            // isn't this hideous?
            $_SESSION['_ktErrorMessage'][] = $res->getMessage();
            return false;
        }

        $items = array();
        foreach ($res as $id) {
            $item = Subscription::get($id, $iSubscriptionType);
            if ($item->isValid()) {
                $items[] = $item;
            }
        }

        return $items;
    }
    
    /**
    * Retrieves all alerted subscriptions for this user.
    *
    * @param integer the ID of the user to retrieve alerted subscriptions for
    * @return array of subscription objects
    */    
    function listSubscriptionAlerts($iUserID) {
        return $aSubscriptions = kt_array_merge(SubscriptionManager::retrieveSubscriptionAlerts($iUserID, SubscriptionEvent::subTypes("Folder")),
                                             SubscriptionManager::retrieveSubscriptionAlerts($iUserID, SubscriptionEvent::subTypes("Document")));        
    }

    /**
    * Retrieves the users's subscriptions
    *
    * @param integer the ID of the user to retrieve subscriptions for
    * @return array of subscription objects, false if the database interaction fails
    */
    function retrieveSubscriptionAlerts($iUserID, $iSubscriptionType) {
        global $default;

        $sql = $default->db;
        if ($sql->query(array("SELECT id FROM " . Subscription::getTableName($iSubscriptionType) .  " " ./*ok*/
                        "WHERE user_id = ? " .
                        "AND is_alerted = ?", array($iUserID, true)))) {
            $aSubscriptions = array();
            while ($sql->next_record()) {
                $aSubscriptions[] = & Subscription::get($sql->f("id"), $iSubscriptionType);
            }
        } else {
            $_SESSION["errorMessage"] = $lang_err_database;
            return false;
        }
        return $aSubscriptions;
    }
}
?>