# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1427064198 -3600
# Node ID 321f8e56f3d3f2f88597722a9a6bf827956f13d7
# Parent  188404c542da8efef59f35bea5b93c1fc31e2d11
Expose period origins upon request for events.

diff -r 188404c542da -r 321f8e56f3d3 imiptools/data.py
--- a/imiptools/data.py	Sun Mar 22 22:08:20 2015 +0100
+++ b/imiptools/data.py	Sun Mar 22 23:43:18 2015 +0100
@@ -19,6 +19,7 @@
 this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
+from bisect import bisect_left
 from datetime import datetime, timedelta
 from email.mime.text import MIMEText
 from imiptools.dates import format_datetime, get_datetime, get_duration, \
@@ -100,14 +101,14 @@
     # Computed results.
 
     def has_recurrence(self, tzid, recurrence):
-        recurrences = [start for start, end in get_periods(self, tzid, recurrence, True)]
+        recurrences = [start for start, end in get_periods(self, tzid, recurrence, inclusive=True)]
         return recurrence in recurrences
 
-    def get_periods(self, tzid, end):
-        return get_periods(self, tzid, end)
+    def get_periods(self, tzid, end, origin=False):
+        return get_periods(self, tzid, end, origin=origin)
 
-    def get_periods_for_freebusy(self, tzid, end):
-        periods = self.get_periods(tzid, end)
+    def get_periods_for_freebusy(self, tzid, end, origin=False):
+        periods = self.get_periods(tzid, end, origin)
         return get_periods_for_freebusy(self, periods, tzid)
 
     def get_tzid(self):
@@ -367,12 +368,16 @@
 def get_tzid(dtstart_attr, dtend_attr):
     return dtstart_attr.get("TZID") or dtend_attr.get("TZID")
 
-def get_periods(obj, tzid, window_end, inclusive=False):
+def get_periods(obj, tzid, window_end, inclusive=False, origin=False):
 
     """
     Return periods for the given object 'obj', confining materialised periods
     to before the given 'window_end' datetime. If 'inclusive' is set to a true
     value, any period occurring at the 'window_end' will be included.
+
+    If 'origin' is set to a true value, the property type providing each period
+    will be included in the results, with each result taking the form
+    (start, end, property type).
     """
 
     rrule = obj.get_value("RRULE")
@@ -394,7 +399,8 @@
     tzid = get_tzid(dtstart_attr, dtend_attr) or tzid
 
     if not rrule:
-        periods = [(dtstart, dtend)]
+        origin_value = origin and ("DTSTART",) or ()
+        periods = [(dtstart, dtend) + origin_value]
     else:
         # Recurrence rules create multiple instances to be checked.
         # Conflicts may only be assessed within a period defined by policy
@@ -403,12 +409,13 @@
 
         selector = get_rule(dtstart, rrule)
         parameters = get_parameters(rrule)
+        origin_value = origin and ("RRULE",) or ()
         periods = []
 
         for start in selector.materialise(dtstart, window_end, parameters.get("COUNT"), parameters.get("BYSETPOS"), inclusive):
             start = to_timezone(datetime(*start), tzid)
             end = start + duration
-            periods.append((start, end))
+            periods.append((start, end) + origin_value)
 
     # Add recurrence dates.
 
@@ -416,11 +423,17 @@
     rdates = obj.get_date_values("RDATE", tzid)
 
     if rdates:
+        origin_value = origin and ("RDATE",) or ()
         for rdate in rdates:
             if isinstance(rdate, tuple):
-                periods.add(rdate)
+                periods.add(rdate + origin_value)
             else:
-                periods.add((rdate, rdate + duration))
+                periods.add((rdate, rdate + duration) + origin_value)
+
+    # Return a sorted list of the periods.
+
+    periods = list(periods)
+    periods.sort()
 
     # Exclude exception dates.
 
@@ -432,13 +445,10 @@
                 period = exdate
             else:
                 period = (exdate, exdate + duration)
-            if period in periods:
-                periods.remove(period)
+            i = bisect_left(periods, period)
+            while i < len(periods) and periods[i][:2] == period:
+                del periods[i]
 
-    # Return a sorted list of the periods.
-
-    periods = list(periods)
-    periods.sort()
     return periods
 
 def get_periods_for_freebusy(obj, periods, tzid):
@@ -461,10 +471,11 @@
 
     l = []
 
-    for start, end in periods:
+    for t in periods:
+        start, end = t[:2]
         start, end = get_freebusy_period(start, end, tzid)
         start, end = [to_timezone(x, "UTC") for x in start, end]
-        l.append((format_datetime(start), format_datetime(end)))
+        l.append((format_datetime(start), format_datetime(end)) + t[2:])
 
     return l