# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1411557409 -7200
# Node ID 63937ac3d03c8f541571b4aef34378204ddf1801
# Parent  db37d281b8ff1e480d71f45aadc5372b448fc366
Added timezone awareness; fixed event replies, producing all event records.

diff -r db37d281b8ff -r 63937ac3d03c imip_agent.py
--- a/imip_agent.py	Tue Sep 23 23:32:11 2014 +0200
+++ b/imip_agent.py	Wed Sep 24 13:16:49 2014 +0200
@@ -1,12 +1,15 @@
 #!/usr/bin/env python
 
 from bisect import bisect_left, insort_left
+from datetime import date, datetime
 from email import message_from_file
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
+from pytz import timezone, UnknownTimeZoneError
 from smtplib import SMTP
 from vCalendar import parse, ParseError, SECTION_TYPES
 import imip_store
+import re
 import sys
 
 try:
@@ -47,6 +50,18 @@
     "text/x-vcalendar", "application/ics",  # other possibilities
     ]
 
+# iCalendar date and datetime parsing (from DateSupport in MoinSupport).
+
+date_icalendar_regexp_str = ur'(?P<year>[0-9]{4})(?P<month>[0-9]{2})(?P<day>[0-9]{2})'
+datetime_icalendar_regexp_str = date_icalendar_regexp_str + \
+    ur'(?:' \
+    ur'T(?P<hour>[0-2][0-9])(?P<minute>[0-5][0-9])(?P<second>[0-6][0-9])' \
+    ur'(?P<utc>Z)?' \
+    ur')?'
+
+match_date_icalendar = re.compile(date_icalendar_regexp_str, re.UNICODE).match
+match_datetime_icalendar = re.compile(datetime_icalendar_regexp_str, re.UNICODE).match
+
 # Content interpretation.
 
 def get_itip_structure(elements):
@@ -104,12 +119,49 @@
 def get_value(d, name):
     return get_values(d, name, False)
 
+def get_utc_datetime(d, name):
+    value, attr = get_item(d, name)
+    dt = get_datetime(value, attr)
+    if isinstance(dt, datetime):
+        return dt.astimezone(timezone("UTC")).strftime("%Y%m%dT%H%M%SZ")
+    else:
+        return dt.strftime("%Y%m%d")
+
 def get_address(value):
     return value.startswith("mailto:") and value[7:] or value
 
 def get_uri(value):
     return value.startswith("mailto:") and value or "mailto:%s" % value
 
+def get_datetime(value, attr):
+    try:
+        tz = attr.has_key("TZID") and timezone(attr["TZID"]) or None
+    except UnknownTimeZoneError:
+        tz = None
+
+    m = match_datetime_icalendar(value)
+    if m:
+        dt = datetime(
+            int(m.group("year")), int(m.group("month")), int(m.group("day")),
+            int(m.group("hour")), int(m.group("minute")), int(m.group("second"))
+            )
+
+        # Impose the indicated timezone.
+        # NOTE: This needs an ambiguity policy for DST changes.
+
+        tz = m.group("utc") and timezone("UTC") or tz or None
+        if tz is not None:
+            return tz.localize(dt)
+        else:
+            return dt
+
+    m = match_date_icalendar(value)
+    if m:
+        return date(
+            int(m.group("year")), int(m.group("month")), int(m.group("day"))
+            )
+    return None
+
 # Time management.
 
 def insert_period(freebusy, period):
@@ -302,6 +354,9 @@
     def get_value(self, name):
         return get_value(self.details, name)
 
+    def get_utc_datetime(self, name):
+        return get_utc_datetime(self.details, name)
+
     def filter_by_recipients(self, values):
         return self.recipients.intersection(map(get_address, values))
 
@@ -374,6 +429,8 @@
 
         # Process each attendee separately.
 
+        calendar = []
+
         for attendee, attendee_attr in attendees.items():
 
             # Check for event using UID.
@@ -402,8 +459,8 @@
             # If newer than any old version, discard old details from the
             # free/busy record and check for suitability.
 
-            dtstart = self.get_value("DTSTART")
-            dtend = self.get_value("DTEND")
+            dtstart = self.get_utc_datetime("DTSTART")
+            dtend = self.get_utc_datetime("DTEND")
 
             conflict = False
             freebusy = self.store.get_freebusy(attendee)
@@ -432,7 +489,9 @@
                 attendee_attr["PARTSTAT"] = "DECLINED"
 
             self.details["ATTENDEE"] = [(attendee, attendee_attr)]
-            return [("VEVENT", {}, get_structure_items(self.details))]
+            calendar.append(("VEVENT", {}, get_structure_items(self.details)))
+
+        return calendar
 
 class Freebusy(Handler):