[sync] Support for importing recurring Outlook events [PATCH]

[Todd Pytel]

The following diff should allow importing of recurring events from the
Sync4J Outlook connector. No support for exceptions yet, but all of the
standard SIF-format RecurrenceTypes are implemented. 

While I'm looking at it, are there specific recurrence bugs involved
with http://bugs.horde.org/ticket/?id=3885 ? I didn't test absolutely
every permutation of recurrence parameters, but I tried a lot of things
and they seemed to work correctly.

--- SyncML/Device/Sync4j.php.orig	2006-08-08 15:06:58.000000000 -0500
+++ SyncML/Device/Sync4j.php	2006-08-09 01:15:57.000000000 -0500
@@ -62,6 +62,15 @@
             $contentType = 'text/x-vtodo';
             break;
         }
+        
+        // Always remove client UID. UID will be seperately passed in
+        // XML.
+        $content = preg_replace('/(\r\n|\r|\n)UID:.*?(\r\n|\r|\n)/',
'\1', $content, 1);
+
+        // Ensure valid newline termination.
+        if (substr($content, -1) != "\n" && substr($content, -1) !=
"\r") {
+            $content .= "\r\n";
+        }
 
         if (DEBUGLOG_ICALENDARDATA) {
             $fp = @fopen('/tmp/sync/log.txt', 'a');
@@ -315,9 +324,53 @@
 
         $vEvent->setAttribute('LOCATION', $a['Location']);
 
+        if ($a['IsRecurring'] == 1) {
+
+            $typearray = array('DAILY','WEEKLY','MONTHLY','MONTHLY',
+                'NOTUSED','MONTHLY','MONTHLY');
+            $recurtype = $a['RecurrenceType'];
+
+            $rule = "FREQ=" . $typearray[$recurtype] . ";";
+            $rule .= "INTERVAL=" . $a['Interval'];
+
+            if ($recurtype == 1 || $recurtype == 3 || $recurtype == 6)
{
+                $rule .= ";BYDAY=";
+                if ($recurtype == 3 || $recurtype == 6) {
+                    $rule .= $a['Instance'];
+                }
+                $rule .= $this->maskToString($a['DayOfWeekMask']); 
+            }
+
+            if ($a['NoEndDate'] == 0) {
+                $rule .= ';UNTIL=' . $a['PatternEndDate'];
+            }    
+     
+            $vEvent->setAttribute('RRULE', $rule); 
+        }     
+
         return $vEvent->exportvCalendar();
     }
 
+    // Converts a SIF DayOfWeekMask to a string of days, used above
+
+    function maskToString($mask) 
+    {
+        $days = array('SU','MO','TU','WE','TH','FR','SA');
+
+        $result = "";
+        $i = 0;
+        for ($i=0; $mask > 0; $i++) {
+            if ($mask % 2 != 0) {
+                $result .= $days[$i] . ",";
+                $mask--;
+            }
+            $mask /= 2;
+        }
+
+        $result = substr_replace($result, "", -1);
+        return $result;
+    }
+
     function sif2vtodo($sif)
     {
         $a = SyncML_Device_sync4j::sif2array($sif);