# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1446131804 -3600
# Node ID ecd915425718b07ec930a059abd804095a23096a
# Parent  0bf0e235f9e22414f57f8cd6f69e916460f42a98
Check corrected periods against the free/busy schedules of all attendees.
Used the coalescing of busy periods from attendees followed by the inversion of
the result to get the available free periods.

diff -r 0bf0e235f9e2 -r ecd915425718 imiptools/handlers/scheduling.py
--- a/imiptools/handlers/scheduling.py	Wed Oct 28 18:08:40 2015 +0100
+++ b/imiptools/handlers/scheduling.py	Thu Oct 29 16:16:44 2015 +0100
@@ -21,16 +21,20 @@
 
 from imiptools.data import uri_values
 from imiptools.dates import ValidityError, to_timezone
-from imiptools.period import get_common_periods, invert_freebusy, \
+from imiptools.period import coalesce_freebusy, invert_freebusy, \
                              periods_from, remove_event_periods, \
                              remove_periods
 
-def schedule_in_freebusy(handler):
+def schedule_in_freebusy(handler, freebusy=None):
 
     """
     Attempt to schedule the current object of the given 'handler' in the
     free/busy schedule of a resource, returning an indication of the kind of
     response to be returned.
+
+    If 'freebusy' is specified, the given collection of busy periods will be
+    used to determine whether any conflicts occur. Otherwise, the current user's
+    free/busy records will be used.
     """
 
     # If newer than any old version, discard old details from the
@@ -38,7 +42,7 @@
 
     periods = handler.get_periods(handler.obj)
 
-    freebusy = handler.store.get_freebusy(handler.user)
+    freebusy = freebusy or handler.store.get_freebusy(handler.user)
     offers = handler.store.get_freebusy_offers(handler.user)
 
     # Check the periods against any scheduled events and against
@@ -102,7 +106,7 @@
     # There should already be free/busy information for the user.
 
     user_freebusy = handler.store.get_freebusy(handler.user)
-    all_freebusy = [user_freebusy]
+    busy = user_freebusy
 
     # Subtract any periods from this event from the free/busy collections.
 
@@ -115,12 +119,16 @@
             freebusy = handler.store.get_freebusy_for_other(handler.user, attendee)
             if freebusy:
                 remove_periods(freebusy, event_periods)
-                all_freebusy.append(freebusy)
+                busy += freebusy
+
+    # Obtain the combined busy periods.
+
+    busy.sort()
+    busy = coalesce_freebusy(busy)
 
     # Obtain free periods.
 
-    all_free = [invert_freebusy(fb) for fb in all_freebusy]
-    free = get_common_periods(all_free)
+    free = invert_freebusy(busy)
     permitted_values = handler.get_permitted_values()
     periods = []
 
@@ -194,7 +202,7 @@
 
     # Check one last time, reverting the change if not scheduled.
 
-    scheduled = schedule_in_freebusy(handler)
+    scheduled = schedule_in_freebusy(handler, busy)
 
     if scheduled == "DECLINED":
         handler.set_object(obj)
diff -r 0bf0e235f9e2 -r ecd915425718 imiptools/period.py
--- a/imiptools/period.py	Wed Oct 28 18:08:40 2015 +0100
+++ b/imiptools/period.py	Thu Oct 29 16:16:44 2015 +0100
@@ -716,33 +716,6 @@
 
     return free
 
-def get_common_periods(all_freebusy):
-
-    "Return common periods to all collections in the 'all_freebusy' list."
-
-    if not all_freebusy:
-        return None
-
-    common = all_freebusy[0]
-
-    # Intersect periods with the current common set.
-
-    for freebusy in all_freebusy[1:]:
-        new_common = []
-
-        # Find the overlapping periods and then obtain the regions that
-        # are common to both sets.
-
-        for period in freebusy:
-            for overlapping in get_overlapping(common, period):
-                p = period.common(overlapping)
-                if p:
-                    new_common.append(p)
-
-        common = new_common
-
-    return common
-
 # Period layout.
 
 def get_scale(periods, tzid, view_period=None):