T1461: Convert windows timezones into Olson format in iTip

Summary:
iCalendar is used to parse iTip data, but it does not support windows tz.
Fixes T1461

Reviewers: #pykolab_developers, vanmeeuwen

Reviewed By: #pykolab_developers, vanmeeuwen

Subscribers: vanmeeuwen

Maniphest Tasks: T1461

Differential Revision: https://git.kolab.org/D219

2 files changed, 38 insertions, 5 deletions

diff --git a/pykolab/itip/__init__.py b/pykolab/itip/__init__.py
index eda4f04..4999fad 100644
--- a/pykolab/itip/__init__.py
+++ b/pykolab/itip/__init__.py
@@ -2,12 +2,14 @@ import icalendar
 import pykolab
 import traceback
 import kolabformat
+import re
 
 from pykolab.xml import to_dt
 from pykolab.xml import event_from_ical
 from pykolab.xml import todo_from_ical
 from pykolab.xml import participant_status_label
 from pykolab.translate import _
+from tzlocal import windows_tz
 
 log = pykolab.getLogger('pykolab.wallace')
 
@@ -18,7 +20,6 @@ def events_from_message(message, methods=None):
 def todos_from_message(message, methods=None):
     return objects_from_message(message, ["VTODO"], methods)
 
-
 def objects_from_message(message, objnames, methods=None):
     """
         Obtain the iTip payload from email.message <message>
@@ -51,6 +52,9 @@ def objects_from_message(message, objnames, methods=None):
 
             log.debug(_("Raw iTip payload (%r): %r") % (part.get_param('charset'), itip_payload), level=9)
 
+            # Convert unsupported timezones, etc.
+            itip_payload = _convert_itip_payload(itip_payload)
+
             # Python iCalendar prior to 3.0 uses "from_string".
             if hasattr(icalendar.Calendar, 'from_ical'):
                 cal = icalendar.Calendar.from_ical(itip_payload)
@@ -141,7 +145,6 @@ def objects_from_message(message, objnames, methods=None):
 
     return itip_objects
 
-
 def check_event_conflict(kolab_event, itip_event):
     """
         Determine whether the given kolab event conflicts with the given itip event
@@ -210,10 +213,35 @@ def check_event_conflict(kolab_event, itip_event):
 
     return conflict
 
-
 def _is_transparent(event):
     return event.get_transparency() or event.get_status() == kolabformat.StatusCancelled
 
+def _convert_itip_payload(itip):
+    matchlist = re.findall("^((DTSTART|DTEND|DUE|EXDATE|COMPLETED)[:;][^\n]+)$", itip, re.MULTILINE)
+
+    for match in matchlist:
+        match = match[0]
+        search = re.search(";TZID=([^:;]+)", match)
+
+        if search:
+            tzorig = tzdest = search.group(1).replace('"', '')
+
+            # timezone in Olson-database format, nothing to convert
+            if re.match("[a-zA-Z]+/[a-zA-Z0-9_+-]+", tzorig):
+                continue
+
+            # convert timezone from windows format to Olson
+            if tzorig in windows_tz.win_tz:
+                tzdest = windows_tz.win_tz[tzorig]
+
+                # @TODO: Should be prefer server time if it has the same offset?
+
+            # replace old with new timezone name
+            if tzorig != tzdest:
+                replace = match.replace(search.group(0), ";TZID=" + tzdest)
+                itip = itip.replace("\n" + match, "\n" + replace)
+
+    return itip
 
 def check_date_conflict(_es, _ee, _is, _ie):
     """
@@ -238,7 +266,7 @@ def check_date_conflict(_es, _ee, _is, _ie):
             conflict = True
         else:
             conflict = False
-    
+
     return conflict
 
 
diff --git a/tests/unit/test-011-itip.py b/tests/unit/test-011-itip.py
index 38e00b8..173a26e 100644
--- a/tests/unit/test-011-itip.py
+++ b/tests/unit/test-011-itip.py
@@ -286,7 +286,7 @@ METHOD:REQUEST
 BEGIN:VEVENT
 UID:eea25142-fb1c-4831-a02d-ac9fb4c16b70
 DTSTAMP:20140213T125414Z
-DTSTART;TZID=3DEurope/London:20140713T100000
+DTSTART;TZID=3D"W. Europe Standard Time":20140713T100000
 DTEND;TZID=3DEurope/London:20140713T140000
 SUMMARY:Testing =C3=9Cmlauts
 DESCRIPTION:Testing =C3=9Cmlauts
@@ -375,6 +375,11 @@ class TestITip(unittest.TestCase):
         self.assertEqual(xml.get_summary(), "Testing Ümlauts")
         self.assertEqual(xml.get_location(), "Rue the Genève")
 
+        # Timezone conversion
+        itips = itip.events_from_message(message_from_string(itip_unicode))
+        xml = itips[0]['xml']
+        self.assertEqual(xml.get_start().tzinfo.__str__(), "Europe/Berlin")
+
     def test_002_check_date_conflict(self):
         astart = datetime.datetime(2014, 7, 13, 10, 0, 0)
         aend = astart + datetime.timedelta(hours=2)