5 files changed, 918 insertions, 125 deletions
diff --git a/3rdparty/Sabre/CalDAV/Backend/Abstract.php b/3rdparty/Sabre/CalDAV/Backend/Abstract.php
index 7aba1d69ffe..88e5b4a1a07 100755
--- a/3rdparty/Sabre/CalDAV/Backend/Abstract.php
+++ b/3rdparty/Sabre/CalDAV/Backend/Abstract.php
@@ -1,47 +1,19 @@
 <?php
 
+use Sabre\VObject;
+
 /**
  * Abstract Calendaring backend. Extend this class to create your own backends.
  *
+ * Checkout the BackendInterface for all the methods that must be implemented.
+ *
  * @package Sabre
  * @subpackage CalDAV
  * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
- * @author Evert Pot (http://www.rooftopsolutions.nl/) 
+ * @author Evert Pot (http://www.rooftopsolutions.nl/)
  * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
  */
-abstract class Sabre_CalDAV_Backend_Abstract {
-
-    /**
-     * Returns a list of calendars for a principal.
-     *
-     * Every project is an array with the following keys:
-     *  * id, a unique id that will be used by other functions to modify the
-     *    calendar. This can be the same as the uri or a database key.
-     *  * uri, which the basename of the uri with which the calendar is
-     *    accessed.
-     *  * principaluri. The owner of the calendar. Almost always the same as
-     *    principalUri passed to this method.
-     *
-     * Furthermore it can contain webdav properties in clark notation. A very
-     * common one is '{DAV:}displayname'.
-     *
-     * @param string $principalUri
-     * @return array
-     */
-    abstract function getCalendarsForUser($principalUri);
-
-    /**
-     * Creates a new calendar for a principal.
-     *
-     * If the creation was a success, an id must be returned that can be used to reference
-     * this calendar in other methods, such as updateCalendar.
-     *
-     * @param string $principalUri
-     * @param string $calendarUri
-     * @param array $properties
-     * @return void
-     */
-    abstract function createCalendar($principalUri,$calendarUri,array $properties);
+abstract class Sabre_CalDAV_Backend_Abstract implements Sabre_CalDAV_Backend_BackendInterface {
 
     /**
      * Updates properties for a calendar.
@@ -75,7 +47,7 @@ abstract class Sabre_CalDAV_Backend_Abstract {
      * (403 Forbidden), which in turn also caused {DAV:}owner to fail
      * (424 Failed Dependency) because the request needs to be atomic.
      *
-     * @param string $calendarId
+     * @param mixed $calendarId
      * @param array $mutations
      * @return bool|array
      */
@@ -86,83 +58,97 @@ abstract class Sabre_CalDAV_Backend_Abstract {
     }
 
     /**
-     * Delete a calendar and all it's objects
+     * Performs a calendar-query on the contents of this calendar.
      *
-     * @param string $calendarId
-     * @return void
-     */
-    abstract function deleteCalendar($calendarId);
-
-    /**
-     * Returns all calendar objects within a calendar.
-     *
-     * Every item contains an array with the following keys:
-     *   * id - unique identifier which will be used for subsequent updates
-     *   * calendardata - The iCalendar-compatible calendar data
-     *   * uri - a unique key which will be used to construct the uri. This can be any arbitrary string.
-     *   * lastmodified - a timestamp of the last modification time
-     *   * etag - An arbitrary string, surrounded by double-quotes. (e.g.:
-     *   '  "abcdef"')
-     *   * calendarid - The calendarid as it was passed to this function.
-     *   * size - The size of the calendar objects, in bytes.
-     *
-     * Note that the etag is optional, but it's highly encouraged to return for
-     * speed reasons.
-     *
-     * The calendardata is also optional. If it's not returned
-     * 'getCalendarObject' will be called later, which *is* expected to return
-     * calendardata.
-     *
-     * If neither etag or size are specified, the calendardata will be
-     * used/fetched to determine these numbers. If both are specified the
-     * amount of times this is needed is reduced by a great degree.
-     *
-     * @param string $calendarId
-     * @return array
-     */
-    abstract function getCalendarObjects($calendarId);
-
-    /**
-     * Returns information from a single calendar object, based on it's object
-     * uri.
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by Sabre_CalDAV_CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
      *
-     * The returned array must have the same keys as getCalendarObjects. The
-     * 'calendardata' object is required here though, while it's not required
-     * for getCalendarObjects.
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
      *
-     * @param string $calendarId
-     * @param string $objectUri
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on either VEVENT or VTODO.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in Sabre_CalDAV_CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * @param mixed $calendarId
+     * @param array $filters
      * @return array
      */
-    abstract function getCalendarObject($calendarId,$objectUri);
+    public function calendarQuery($calendarId, array $filters) {
 
-    /**
-     * Creates a new calendar object.
-     *
-     * @param string $calendarId
-     * @param string $objectUri
-     * @param string $calendarData
-     * @return void
-     */
-    abstract function createCalendarObject($calendarId,$objectUri,$calendarData);
+        $result = array();
+        $objects = $this->getCalendarObjects($calendarId);
 
-    /**
-     * Updates an existing calendarobject, based on it's uri.
-     *
-     * @param string $calendarId
-     * @param string $objectUri
-     * @param string $calendarData
-     * @return void
-     */
-    abstract function updateCalendarObject($calendarId,$objectUri,$calendarData);
+        $validator = new Sabre_CalDAV_CalendarQueryValidator();
+
+        foreach($objects as $object) {
+
+            if ($this->validateFilterForObject($object, $filters)) {
+                $result[] = $object['uri'];
+            }
+
+        }
+
+        return $result;
+
+    }
 
     /**
-     * Deletes an existing calendar object.
+     * This method validates if a filters (as passed to calendarQuery) matches
+     * the given object.
      *
-     * @param string $calendarId
-     * @param string $objectUri
-     * @return void
+     * @param array $object
+     * @param array $filter
+     * @return bool
      */
-    abstract function deleteCalendarObject($calendarId,$objectUri);
+    protected function validateFilterForObject(array $object, array $filters) {
+
+        // Unfortunately, setting the 'calendardata' here is optional. If
+        // it was excluded, we actually need another call to get this as
+        // well.
+        if (!isset($object['calendardata'])) {
+            $object = $this->getCalendarObject($object['calendarid'], $object['uri']);
+        }
+
+        $data = is_resource($object['calendardata'])?stream_get_contents($object['calendardata']):$object['calendardata'];
+        $vObject = VObject\Reader::read($data);
+
+        $validator = new Sabre_CalDAV_CalendarQueryValidator();
+        return $validator->validate($vObject, $filters);
+
+    }
+
 
 }
diff --git a/3rdparty/Sabre/CalDAV/Backend/BackendInterface.php b/3rdparty/Sabre/CalDAV/Backend/BackendInterface.php
new file mode 100755
index 00000000000..881538ab60e
--- /dev/null
+++ b/3rdparty/Sabre/CalDAV/Backend/BackendInterface.php
@@ -0,0 +1,231 @@
+<?php
+
+/**
+ * Every CalDAV backend must at least implement this interface.
+ * 
+ * @package Sabre
+ * @subpackage CalDAV
+ * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
+ * @author Evert Pot (http://www.rooftopsolutions.nl/) 
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+interface Sabre_CalDAV_Backend_BackendInterface {
+
+    /**
+     * Returns a list of calendars for a principal.
+     *
+     * Every project is an array with the following keys:
+     *  * id, a unique id that will be used by other functions to modify the
+     *    calendar. This can be the same as the uri or a database key.
+     *  * uri, which the basename of the uri with which the calendar is
+     *    accessed.
+     *  * principaluri. The owner of the calendar. Almost always the same as
+     *    principalUri passed to this method.
+     *
+     * Furthermore it can contain webdav properties in clark notation. A very
+     * common one is '{DAV:}displayname'.
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getCalendarsForUser($principalUri);
+
+    /**
+     * Creates a new calendar for a principal.
+     *
+     * If the creation was a success, an id must be returned that can be used to reference
+     * this calendar in other methods, such as updateCalendar.
+     *
+     * @param string $principalUri
+     * @param string $calendarUri
+     * @param array $properties
+     * @return void
+     */
+    public function createCalendar($principalUri,$calendarUri,array $properties);
+
+    /**
+     * Updates properties for a calendar.
+     *
+     * The mutations array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param mixed $calendarId
+     * @param array $mutations
+     * @return bool|array
+     */
+    public function updateCalendar($calendarId, array $mutations); 
+
+    /**
+     * Delete a calendar and all it's objects
+     *
+     * @param mixed $calendarId
+     * @return void
+     */
+    public function deleteCalendar($calendarId);
+
+    /**
+     * Returns all calendar objects within a calendar.
+     *
+     * Every item contains an array with the following keys:
+     *   * id - unique identifier which will be used for subsequent updates
+     *   * calendardata - The iCalendar-compatible calendar data
+     *   * uri - a unique key which will be used to construct the uri. This can be any arbitrary string.
+     *   * lastmodified - a timestamp of the last modification time
+     *   * etag - An arbitrary string, surrounded by double-quotes. (e.g.:
+     *   '  "abcdef"')
+     *   * calendarid - The calendarid as it was passed to this function.
+     *   * size - The size of the calendar objects, in bytes.
+     *
+     * Note that the etag is optional, but it's highly encouraged to return for
+     * speed reasons.
+     *
+     * The calendardata is also optional. If it's not returned
+     * 'getCalendarObject' will be called later, which *is* expected to return
+     * calendardata.
+     *
+     * If neither etag or size are specified, the calendardata will be
+     * used/fetched to determine these numbers. If both are specified the
+     * amount of times this is needed is reduced by a great degree.
+     *
+     * @param mixed $calendarId
+     * @return array
+     */
+    public function getCalendarObjects($calendarId);
+
+    /**
+     * Returns information from a single calendar object, based on it's object
+     * uri.
+     *
+     * The returned array must have the same keys as getCalendarObjects. The
+     * 'calendardata' object is required here though, while it's not required
+     * for getCalendarObjects.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @return array
+     */
+    public function getCalendarObject($calendarId,$objectUri);
+
+    /**
+     * Creates a new calendar object.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function createCalendarObject($calendarId,$objectUri,$calendarData);
+
+    /**
+     * Updates an existing calendarobject, based on it's uri.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function updateCalendarObject($calendarId,$objectUri,$calendarData);
+
+    /**
+     * Deletes an existing calendar object.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @return void
+     */
+    public function deleteCalendarObject($calendarId,$objectUri);
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by Sabre_CalDAV_CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
+     *
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
+     *
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on either VEVENT or VTODO.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in Sabre_CalDAV_CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * @param mixed $calendarId
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery($calendarId, array $filters); 
+
+}
diff --git a/3rdparty/Sabre/CalDAV/Backend/NotificationSupport.php b/3rdparty/Sabre/CalDAV/Backend/NotificationSupport.php
new file mode 100755
index 00000000000..d5a1409d9b9
--- /dev/null
+++ b/3rdparty/Sabre/CalDAV/Backend/NotificationSupport.php
@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * Adds caldav notification support to a backend.
+ *
+ * Note: This feature is experimental, and may change in between different
+ * SabreDAV versions.
+ *
+ * Notifications are defined at:
+ * http://svn.calendarserver.org/repository/calendarserver/CalendarServer/trunk/doc/Extensions/caldav-notifications.txt
+ *
+ * These notifications are basically a list of server-generated notifications 
+ * displayed to the user. Users can dismiss notifications by deleting them.
+ *
+ * The primary usecase is to allow for calendar-sharing.
+ *
+ * @package Sabre
+ * @subpackage CalDAV
+ * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
+ * @author Evert Pot (http://www.rooftopsolutions.nl/) 
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+interface Sabre_CalDAV_Backend_NotificationSupport extends Sabre_CalDAV_Backend_BackendInterface {
+
+    /**
+     * Returns a list of notifications for a given principal url.
+     *
+     * The returned array should only consist of implementations of
+     * Sabre_CalDAV_Notifications_INotificationType. 
+     * 
+     * @param string $principalUri
+     * @return array 
+     */
+    public function getNotificationsForPrincipal($principalUri);
+
+    /**
+     * This deletes a specific notifcation.
+     *
+     * This may be called by a client once it deems a notification handled. 
+     * 
+     * @param string $principalUri 
+     * @param Sabre_CalDAV_Notifications_INotificationType $notification 
+     * @return void
+     */
+    public function deleteNotification($principalUri, Sabre_CalDAV_Notifications_INotificationType $notification); 
+
+}
diff --git a/3rdparty/Sabre/CalDAV/Backend/PDO.php b/3rdparty/Sabre/CalDAV/Backend/PDO.php
index ddacf940c74..447f5f590cf 100755
--- a/3rdparty/Sabre/CalDAV/Backend/PDO.php
+++ b/3rdparty/Sabre/CalDAV/Backend/PDO.php
@@ -1,5 +1,7 @@
 <?php
 
+use Sabre\VObject;
+
 /**
  * PDO CalDAV backend
  *
@@ -9,12 +11,22 @@
  * @package Sabre
  * @subpackage CalDAV
  * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
- * @author Evert Pot (http://www.rooftopsolutions.nl/) 
+ * @author Evert Pot (http://www.rooftopsolutions.nl/)
  * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
  */
 class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
 
     /**
+     * We need to specify a max date, because we need to stop *somewhere*
+     *
+     * On 32 bit system the maximum for a signed integer is 2147483647, so
+     * MAX_DATE cannot be higher than date('Y-m-d', 2147483647) which results
+     * in 2038-01-19 to avoid problems when the date is converted
+     * to a unix timestamp.
+     */
+    const MAX_DATE = '2038-01-01';
+
+    /**
      * pdo
      *
      * @var PDO
@@ -37,8 +49,9 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
 
     /**
      * List of CalDAV properties, and how they map to database fieldnames
+     * Add your own properties by simply adding on to this array.
      *
-     * Add your own properties by simply adding on to this array
+     * Note that only string-based properties are supported here.
      *
      * @var array
      */
@@ -90,6 +103,7 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
         $fields[] = 'ctag';
         $fields[] = 'components';
         $fields[] = 'principaluri';
+        $fields[] = 'transparent';
 
         // Making fields a comma-delimited list
         $fields = implode(', ', $fields);
@@ -110,6 +124,7 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
                 'principaluri' => $row['principaluri'],
                 '{' . Sabre_CalDAV_Plugin::NS_CALENDARSERVER . '}getctag' => $row['ctag']?$row['ctag']:'0',
                 '{' . Sabre_CalDAV_Plugin::NS_CALDAV . '}supported-calendar-component-set' => new Sabre_CalDAV_Property_SupportedCalendarComponentSet($components),
+                '{' . Sabre_CalDAV_Plugin::NS_CALDAV . '}schedule-calendar-transp' => new Sabre_CalDAV_Property_ScheduleCalendarTransp($row['transparent']?'transparent':'opaque'),
             );
 
 
@@ -142,11 +157,13 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
             'principaluri',
             'uri',
             'ctag',
+            'transparent',
         );
         $values = array(
             ':principaluri' => $principalUri,
             ':uri'          => $calendarUri,
             ':ctag'         => 1,
+            ':transparent'  => 0,
         );
 
         // Default value
@@ -160,6 +177,10 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
             }
             $values[':components'] = implode(',',$properties[$sccs]->getValue());
         }
+        $transp = '{' . Sabre_CalDAV_Plugin::NS_CALDAV . '}schedule-calendar-transp';
+        if (isset($properties[$transp])) {
+            $values[':transparent'] = $properties[$transp]->getValue()==='transparent';
+        }
 
         foreach($this->propertyMap as $xmlName=>$dbName) {
             if (isset($properties[$xmlName])) {
@@ -225,17 +246,25 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
 
         foreach($mutations as $propertyName=>$propertyValue) {
 
-            // We don't know about this property.
-            if (!isset($this->propertyMap[$propertyName])) {
-                $hasError = true;
-                $result[403][$propertyName] = null;
-                unset($mutations[$propertyName]);
-                continue;
+            switch($propertyName) {
+                case '{' . Sabre_CalDAV_Plugin::NS_CALDAV . '}schedule-calendar-transp' :
+                    $fieldName = 'transparent';
+                    $newValues[$fieldName] = $propertyValue->getValue()==='transparent';
+                    break;
+                default :
+                    // Checking the property map
+                    if (!isset($this->propertyMap[$propertyName])) {
+                        // We don't know about this property.
+                        $hasError = true;
+                        $result[403][$propertyName] = null;
+                        unset($mutations[$propertyName]);
+                        continue;
+                    }
+
+                    $fieldName = $this->propertyMap[$propertyName];
+                    $newValues[$fieldName] = $propertyValue;
             }
 
-            $fieldName = $this->propertyMap[$propertyName];
-            $newValues[$fieldName] = $propertyValue;
-
         }
 
         // If there were any errors we need to fail the request
@@ -316,9 +345,22 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
      */
     public function getCalendarObjects($calendarId) {
 
-        $stmt = $this->pdo->prepare('SELECT * FROM '.$this->calendarObjectTableName.' WHERE calendarid = ?');
+        $stmt = $this->pdo->prepare('SELECT id, uri, lastmodified, etag, calendarid, size FROM '.$this->calendarObjectTableName.' WHERE calendarid = ?');
         $stmt->execute(array($calendarId));
-        return $stmt->fetchAll();
+
+        $result = array();
+        foreach($stmt->fetchAll(\PDO::FETCH_ASSOC) as $row) {
+            $result[] = array(
+                'id'           => $row['id'],
+                'uri'          => $row['uri'],
+                'lastmodified' => $row['lastmodified'],
+                'etag'         => '"' . $row['etag'] . '"',
+                'calendarid'   => $row['calendarid'],
+                'size'         => (int)$row['size'],
+            );
+        }
+
+        return $result;
 
     }
 
@@ -336,44 +378,166 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
      */
     public function getCalendarObject($calendarId,$objectUri) {
 
-        $stmt = $this->pdo->prepare('SELECT * FROM '.$this->calendarObjectTableName.' WHERE calendarid = ? AND uri = ?');
+        $stmt = $this->pdo->prepare('SELECT id, uri, lastmodified, etag, calendarid, size, calendardata FROM '.$this->calendarObjectTableName.' WHERE calendarid = ? AND uri = ?');
         $stmt->execute(array($calendarId, $objectUri));
-        return $stmt->fetch();
+        $row = $stmt->fetch(\PDO::FETCH_ASSOC);
+
+        if(!$row) return null;
+
+        return array(
+            'id'           => $row['id'],
+            'uri'          => $row['uri'],
+            'lastmodified' => $row['lastmodified'],
+            'etag'         => '"' . $row['etag'] . '"',
+            'calendarid'   => $row['calendarid'],
+            'size'         => (int)$row['size'],
+            'calendardata' => $row['calendardata'],
+         );
 
     }
 
+
     /**
      * Creates a new calendar object.
      *
-     * @param string $calendarId
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
      * @param string $objectUri
      * @param string $calendarData
-     * @return void
+     * @return string|null
      */
     public function createCalendarObject($calendarId,$objectUri,$calendarData) {
 
-        $stmt = $this->pdo->prepare('INSERT INTO '.$this->calendarObjectTableName.' (calendarid, uri, calendardata, lastmodified) VALUES (?,?,?,?)');
-        $stmt->execute(array($calendarId,$objectUri,$calendarData,time()));
+        $extraData = $this->getDenormalizedData($calendarData);
+
+        $stmt = $this->pdo->prepare('INSERT INTO '.$this->calendarObjectTableName.' (calendarid, uri, calendardata, lastmodified, etag, size, componenttype, firstoccurence, lastoccurence) VALUES (?,?,?,?,?,?,?,?,?)');
+        $stmt->execute(array(
+            $calendarId,
+            $objectUri,
+            $calendarData,
+            time(),
+            $extraData['etag'],
+            $extraData['size'],
+            $extraData['componentType'],
+            $extraData['firstOccurence'],
+            $extraData['lastOccurence'],
+        ));
         $stmt = $this->pdo->prepare('UPDATE '.$this->calendarTableName.' SET ctag = ctag + 1 WHERE id = ?');
         $stmt->execute(array($calendarId));
 
+        return '"' . $extraData['etag'] . '"';
+
     }
 
     /**
      * Updates an existing calendarobject, based on it's uri.
      *
-     * @param string $calendarId
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
      * @param string $objectUri
      * @param string $calendarData
-     * @return void
+     * @return string|null
      */
     public function updateCalendarObject($calendarId,$objectUri,$calendarData) {
 
-        $stmt = $this->pdo->prepare('UPDATE '.$this->calendarObjectTableName.' SET calendardata = ?, lastmodified = ? WHERE calendarid = ? AND uri = ?');
-        $stmt->execute(array($calendarData,time(),$calendarId,$objectUri));
+        $extraData = $this->getDenormalizedData($calendarData);
+
+        $stmt = $this->pdo->prepare('UPDATE '.$this->calendarObjectTableName.' SET calendardata = ?, lastmodified = ?, etag = ?, size = ?, componenttype = ?, firstoccurence = ?, lastoccurence = ? WHERE calendarid = ? AND uri = ?');
+        $stmt->execute(array($calendarData,time(), $extraData['etag'], $extraData['size'], $extraData['componentType'], $extraData['firstOccurence'], $extraData['lastOccurence'] ,$calendarId,$objectUri));
         $stmt = $this->pdo->prepare('UPDATE '.$this->calendarTableName.' SET ctag = ctag + 1 WHERE id = ?');
         $stmt->execute(array($calendarId));
 
+        return '"' . $extraData['etag'] . '"';
+
+    }
+
+    /**
+     * Parses some information from calendar objects, used for optimized
+     * calendar-queries.
+     *
+     * Returns an array with the following keys:
+     *   * etag
+     *   * size
+     *   * componentType
+     *   * firstOccurence
+     *   * lastOccurence
+     *
+     * @param string $calendarData
+     * @return array
+     */
+    protected function getDenormalizedData($calendarData) {
+
+        $vObject = VObject\Reader::read($calendarData);
+        $componentType = null;
+        $component = null;
+        $firstOccurence = null;
+        $lastOccurence = null;
+        foreach($vObject->getComponents() as $component) {
+            if ($component->name!=='VTIMEZONE') {
+                $componentType = $component->name;
+                break;
+            }
+        }
+        if (!$componentType) {
+            throw new Sabre_DAV_Exception_BadRequest('Calendar objects must have a VJOURNAL, VEVENT or VTODO component');
+        }
+        if ($componentType === 'VEVENT') {
+            $firstOccurence = $component->DTSTART->getDateTime()->getTimeStamp();
+            // Finding the last occurence is a bit harder
+            if (!isset($component->RRULE)) {
+                if (isset($component->DTEND)) {
+                    $lastOccurence = $component->DTEND->getDateTime()->getTimeStamp();
+                } elseif (isset($component->DURATION)) {
+                    $endDate = clone $component->DTSTART->getDateTime();
+                    $endDate->add(VObject\DateTimeParser::parse($component->DURATION->value));
+                    $lastOccurence = $endDate->getTimeStamp();
+                } elseif ($component->DTSTART->getDateType()===VObject\Property\DateTime::DATE) {
+                    $endDate = clone $component->DTSTART->getDateTime();
+                    $endDate->modify('+1 day');
+                    $lastOccurence = $endDate->getTimeStamp();
+                } else {
+                    $lastOccurence = $firstOccurence;
+                }
+            } else {
+                $it = new VObject\RecurrenceIterator($vObject, (string)$component->UID);
+                $maxDate = new DateTime(self::MAX_DATE);
+                if ($it->isInfinite()) {
+                    $lastOccurence = $maxDate->getTimeStamp();
+                } else {
+                    $end = $it->getDtEnd();
+                    while($it->valid() && $end < $maxDate) {
+                        $end = $it->getDtEnd();
+                        $it->next();
+
+                    }
+                    $lastOccurence = $end->getTimeStamp();
+                }
+
+            }
+        }
+
+        return array(
+            'etag' => md5($calendarData),
+            'size' => strlen($calendarData),
+            'componentType' => $componentType,
+            'firstOccurence' => $firstOccurence,
+            'lastOccurence'  => $lastOccurence,
+        );
+
     }
 
     /**
@@ -392,5 +556,132 @@ class Sabre_CalDAV_Backend_PDO extends Sabre_CalDAV_Backend_Abstract {
 
     }
 
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by Sabre_CalDAV_CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
+     *
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
+     *
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on a VEVENT.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in Sabre_CalDAV_CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * This specific implementation (for the PDO) backend optimizes filters on
+     * specific components, and VEVENT time-ranges.
+     *
+     * @param string $calendarId
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery($calendarId, array $filters) {
+
+        $result = array();
+        $validator = new Sabre_CalDAV_CalendarQueryValidator();
+
+        $componentType = null;
+        $requirePostFilter = true;
+        $timeRange = null;
+
+        // if no filters were specified, we don't need to filter after a query
+        if (!$filters['prop-filters'] && !$filters['comp-filters']) {
+            $requirePostFilter = false;
+        }
+
+        // Figuring out if there's a component filter
+        if (count($filters['comp-filters']) > 0 && !$filters['comp-filters'][0]['is-not-defined']) {
+            $componentType = $filters['comp-filters'][0]['name'];
+
+            // Checking if we need post-filters
+            if (!$filters['prop-filters'] && !$filters['comp-filters'][0]['comp-filters'] && !$filters['comp-filters'][0]['time-range'] && !$filters['comp-filters'][0]['prop-filters']) {
+                $requirePostFilter = false;
+            }
+            // There was a time-range filter
+            if ($componentType == 'VEVENT' && isset($filters['comp-filters'][0]['time-range'])) {
+                $timeRange = $filters['comp-filters'][0]['time-range'];
+
+                // If start time OR the end time is not specified, we can do a
+                // 100% accurate mysql query.
+                if (!$filters['prop-filters'] && !$filters['comp-filters'][0]['comp-filters'] && !$filters['comp-filters'][0]['prop-filters'] && (!$timeRange['start'] || !$timeRange['end'])) {
+                    $requirePostFilter = false;
+                }
+            }
 
+        }
+
+        if ($requirePostFilter) {
+            $query = "SELECT uri, calendardata FROM ".$this->calendarObjectTableName." WHERE calendarid = :calendarid";
+        } else {
+            $query = "SELECT uri FROM ".$this->calendarObjectTableName." WHERE calendarid = :calendarid";
+        }
+
+        $values = array(
+            'calendarid' => $calendarId,
+        );
+
+        if ($componentType) {
+            $query.=" AND componenttype = :componenttype";
+            $values['componenttype'] = $componentType;
+        }
+
+        if ($timeRange && $timeRange['start']) {
+            $query.=" AND lastoccurence > :startdate";
+            $values['startdate'] = $timeRange['start']->getTimeStamp();
+        }
+        if ($timeRange && $timeRange['end']) {
+            $query.=" AND firstoccurence < :enddate";
+            $values['enddate'] = $timeRange['end']->getTimeStamp();
+        }
+
+        $stmt = $this->pdo->prepare($query);
+        $stmt->execute($values);
+
+        $result = array();
+        while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+            if ($requirePostFilter) {
+                if (!$this->validateFilterForObject($row, $filters)) {
+                    continue;
+                }
+            }
+            $result[] = $row['uri'];
+
+        }
+
+        return $result;
+
+    }
 }
diff --git a/3rdparty/Sabre/CalDAV/Backend/SharingSupport.php b/3rdparty/Sabre/CalDAV/Backend/SharingSupport.php
new file mode 100755
index 00000000000..f73f0ff3d8a
--- /dev/null
+++ b/3rdparty/Sabre/CalDAV/Backend/SharingSupport.php
@@ -0,0 +1,238 @@
+<?php
+
+/**
+ * Adds support for sharing features to a CalDAV server.
+ *
+ * Note: This feature is experimental, and may change in between different
+ * SabreDAV versions.
+ *
+ * Early warning: Currently SabreDAV provides no implementation for this. This
+ * is, because in it's current state there is no elegant way to do this.
+ * The problem lies in the fact that a real CalDAV server with sharing support
+ * would first need email support (with invite notifications), and really also
+ * a browser-frontend that allows people to accept or reject these shares.
+ *
+ * In addition, the CalDAV backends are currently kept as independent as
+ * possible, and should not be aware of principals, email addresses or
+ * accounts.
+ *
+ * Adding an implementation for Sharing to standard-sabredav would contradict
+ * these goals, so for this reason this is currently not implemented, although
+ * it may very well in the future; but probably not before SabreDAV 2.0.
+ *
+ * The interface works however, so if you implement all this, and do it
+ * correctly sharing _will_ work. It's not particularly easy, and I _urge you_
+ * to make yourself acquainted with the following document first:
+ *
+ * https://trac.calendarserver.org/browser/CalendarServer/trunk/doc/Extensions/caldav-sharing.txt
+ *
+ * An overview
+ * ===========
+ *
+ * Implementing this interface will allow a user to share his or her calendars
+ * to other users. Effectively, when a calendar is shared the calendar will
+ * show up in both the Sharer's and Sharee's calendar-home root.
+ * This interface adds a few methods that ensure that this happens, and there
+ * are also a number of new requirements in the base-class you must now follow.
+ *
+ *
+ * How it works
+ * ============
+ *
+ * When a user shares a calendar, the addShare() method will be called with a
+ * list of sharees that are now added, and a list of sharees that have been
+ * removed.
+ * Removal is instant, but when a sharee is added the sharee first gets a
+ * chance to accept or reject the invitation for a share.
+ *
+ * After a share is accepted, the calendar will be returned from
+ * getUserCalendars for both the sharer, and the sharee.
+ *
+ * If the sharee deletes the calendar, only their share gets deleted. When the
+ * owner deletes a calendar, it will be removed for everybody.
+ *
+ *
+ * Notifications
+ * =============
+ *
+ * During all these sharing operations, a lot of notifications are sent back
+ * and forward.
+ *
+ * Whenever the list of sharees for a calendar has been changed (they have been
+ * added, removed or modified) all sharees should get a notification for this
+ * change.
+ * This notification is always represented by:
+ *
+ * Sabre_CalDAV_Notifications_Notification_Invite
+ *
+ * In the case of an invite, the sharee may reply with an 'accept' or
+ * 'decline'. These are always represented by:
+ *
+ * Sabre_CalDAV_Notifications_Notification_Invite
+ *
+ *
+ * Calendar access by sharees
+ * ==========================
+ *
+ * As mentioned earlier, shared calendars must now also be returned for
+ * getCalendarsForUser for sharees. A few things change though.
+ *
+ * The following properties must be specified:
+ *
+ * 1. {http://calendarserver.org/ns/}shared-url
+ *
+ * This property MUST contain the url to the original calendar, that is.. the
+ * path to the calendar from the owner.
+ *
+ * 2. {http://sabredav.org/ns}owner-principal
+ *
+ * This is a url to to the principal who is sharing the calendar.
+ *
+ * 3. {http://sabredav.org/ns}read-only
+ *
+ * This should be either 0 or 1, depending on if the user has read-only or
+ * read-write access to the calendar.
+ *
+ * Only when this is done, the calendar will correctly be marked as a calendar
+ * that's shared to him, thus allowing clients to display the correct interface
+ * and ACL enforcement.
+ *
+ * If a sharee deletes their calendar, only their instance of the calendar
+ * should be deleted, the original should still exists.
+ * Pretty much any 'dead' WebDAV properties on these shared calendars should be
+ * specific to a user. This means that if the displayname is changed by a
+ * sharee, the original is not affected. This is also true for:
+ *   * The description
+ *   * The color
+ *   * The order
+ *   * And any other dead properties.
+ *
+ * Properties like a ctag should not be different for multiple instances of the
+ * calendar.
+ *
+ * Lastly, objects *within* calendars should also have user-specific data. The
+ * two things that are user-specific are:
+ *   * VALARM objects
+ *   * The TRANSP property
+ *
+ * This _also_ implies that if a VALARM is deleted by a sharee for some event,
+ * this has no effect on the original VALARM.
+ *
+ * Understandably, the this last requirement is one of the hardest.
+ * Realisticly, I can see people ignoring this part of the spec, but that could
+ * cause a different set of issues.
+ *
+ *
+ * Publishing
+ * ==========
+ *
+ * When a user publishes a url, the server should generate a 'publish url'.
+ * This is a read-only url, anybody can use to consume the calendar feed.
+ *
+ * Calendars are in one of two states:
+ *   * published
+ *   * unpublished
+ *
+ * If a calendar is published, the following property should be returned
+ * for each calendar in getCalendarsForPrincipal.
+ *
+ * {http://calendarserver.org/ns/}publish-url
+ *
+ * This element should contain a {DAV:}href element, which points to the
+ * public url that does not require authentication. Unlike every other href,
+ * this url must be absolute.
+ *
+ * Ideally, the following property is always returned
+ *
+ * {http://calendarserver.org/ns/}pre-publish-url
+ *
+ * This property should contain the url that the calendar _would_ have, if it
+ * were to be published. iCal uses this to display the url, before the user
+ * will actually publish it.
+ *
+ *
+ * Selectively disabling publish or share feature
+ * ==============================================
+ *
+ * If Sabre_CalDAV_Property_AllowedSharingModes is returned from
+ * getCalendarsByUser, this allows the server to specify wether either sharing,
+ * or publishing is supported.
+ *
+ * This allows a client to determine in advance which features are available,
+ * and update the interface appropriately. If this property is not returned by
+ * the backend, the SharingPlugin automatically injects it and assumes both
+ * features are available.
+ *
+ * @package Sabre
+ * @subpackage CalDAV
+ * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
+ * @author Evert Pot (http://www.rooftopsolutions.nl/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+interface Sabre_CalDAV_Backend_SharingSupport extends Sabre_CalDAV_Backend_NotificationSupport {
+
+    /**
+     * Updates the list of shares.
+     *
+     * The first array is a list of people that are to be added to the
+     * calendar.
+     *
+     * Every element in the add array has the following properties:
+     *   * href - A url. Usually a mailto: address
+     *   * commonName - Usually a first and last name, or false
+     *   * summary - A description of the share, can also be false
+     *   * readOnly - A boolean value
+     *
+     * Every element in the remove array is just the address string.
+     *
+     * Note that if the calendar is currently marked as 'not shared' by and
+     * this method is called, the calendar should be 'upgraded' to a shared
+     * calendar.
+     *
+     * @param mixed $calendarId
+     * @param array $add
+     * @param array $remove
+     * @return void
+     */
+    function updateShares($calendarId, array $add, array $remove);
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the Sabre_CalDAV_SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * @param mixed $calendarId
+     * @return array
+     */
+    function getShares($calendarId);
+
+    /**
+     * This method is called when a user replied to a request to share.
+     *
+     * If the user chose to accept the share, this method should return the
+     * newly created calendar url.
+     *
+     * @param string href The sharee who is replying (often a mailto: address)
+     * @param int status One of the SharingPlugin::STATUS_* constants
+     * @param string $calendarUri The url to the calendar thats being shared
+     * @param string $inReplyTo The unique id this message is a response to
+     * @param string $summary A description of the reply
+     * @return null|string
+     */
+    function shareReply($href, $status, $calendarUri, $inReplyTo, $summary = null);
+
+    /**
+     * Publishes a calendar
+     *
+     * @param mixed $calendarId
+     * @param bool $value
+     * @return void
+     */
+    function setPublishStatus($calendarId, $value);
+
+}