# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1431883914 -7200
# Node ID 9824a7a3082702e1ced8d8b70aef9332c0eae1f2
# Parent  11b5c79e5a9c0f94bc8964df2def9ee8258468d3
Fix/simplify recurrence and period comparisons.

diff -r 11b5c79e5a9c -r 9824a7a30827 imiptools/dates.py
--- a/imiptools/dates.py	Sun May 17 19:25:22 2015 +0200
+++ b/imiptools/dates.py	Sun May 17 19:31:54 2015 +0200
@@ -431,13 +431,22 @@
 
     return dtstart_attr and dtstart_attr.get("TZID") or dtend_attr and dtend_attr.get("TZID") or None
 
-def to_recurrence_start(recurrenceid, tzid):
+def get_recurrence_start(recurrenceid, tzid):
 
     """
     Return 'recurrenceid' in a form suitable for comparison with free/busy start
     datetimes, using 'tzid' to convert recurrence identifiers that are dates.
     """
 
-    return format_datetime(to_utc_datetime(get_datetime(recurrenceid), tzid))
+    return to_utc_datetime(get_datetime(recurrenceid), tzid)
+
+def to_recurrence_start(recurrenceid, tzid):
+
+    """
+    Return 'recurrenceid' in a form suitable for use as an unambiguous
+    identifier, using 'tzid' to convert recurrence identifiers that are dates.
+    """
+
+    return format_datetime(get_recurrence_start(recurrenceid, tzid))
 
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r 11b5c79e5a9c -r 9824a7a30827 imipweb/event.py
--- a/imipweb/event.py	Sun May 17 19:25:22 2015 +0200
+++ b/imipweb/event.py	Sun May 17 19:31:54 2015 +0200
@@ -22,8 +22,9 @@
 from datetime import date, timedelta
 from imiptools.client import update_attendees, update_participation
 from imiptools.data import get_uri, uri_dict, uri_values
-from imiptools.dates import format_datetime, get_datetime, get_datetime_item, \
-                            get_period_item, to_date, to_datetime, to_timezone
+from imiptools.dates import format_datetime, get_datetime_item, \
+                            get_period_item, get_recurrence_start, to_date, \
+                            to_timezone
 from imiptools.mail import Messenger
 from imiptools.period import have_conflict
 from imipweb.data import EventPeriod, \
@@ -65,16 +66,16 @@
 
     def is_replaced(self, period, recurrenceids):
         for s in recurrenceids:
-            dt = to_timezone(get_datetime(s), self.get_tzid())
-            if to_datetime(period.get_start(), self.get_tzid()) == dt:
+            dt = get_recurrence_start(s, self.get_tzid())
+            if period.get_start() == dt:
                 return s
         return None
 
     def is_affected(self, period, recurrenceid):
         if not recurrenceid:
             return None
-        dt = to_timezone(get_datetime(recurrenceid), self.get_tzid())
-        if to_datetime(period.get_start(), self.get_tzid()) == dt:
+        dt = get_recurrence_start(recurrenceid, self.get_tzid())
+        if period.get_start() == dt:
             return recurrenceid
         return None