# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1423585813 -3600
# Node ID 9f4fbe205b683c164137359a2866a7e31a0180fc
# Parent  82f4dfc693c0cf4034327e2af9dfc3d8653d2b41
Added support for sending CANCEL messages to uninvited attendees.

diff -r 82f4dfc693c0 -r 9f4fbe205b68 imip_manager.py
--- a/imip_manager.py	Tue Feb 10 17:26:23 2015 +0100
+++ b/imip_manager.py	Tue Feb 10 17:30:13 2015 +0100
@@ -248,17 +248,37 @@
         if self.messenger and self.messenger.sender != get_address(organiser):
             organiser_attr["SENT-BY"] = get_uri(self.messenger.sender)
 
+        to_cancel = []
+
         if removed:
-            attendee_map = uri_dict(self.obj.get_value_map("ATTENDEE"))
-            self.obj["ATTENDEE"] = [(attendee, attendee_attr)
-                for (attendee, attendee_attr) in attendee_map.items()
-                if attendee not in removed]
+            attendees = uri_items(self.obj.get_items("ATTENDEE"))
+            remaining = []
+
+            for attendee, attendee_attr in attendees:
+                if attendee in removed:
+                    to_cancel.append((attendee, attendee_attr))
+                else:
+                    remaining.append((attendee, attendee_attr))
+
+            self.obj["ATTENDEE"] = remaining
 
         self.update_dtstamp()
         self.set_sequence(update)
 
         self.send_message(method, get_address(organiser), for_organiser=True)
 
+        # When cancelling, replace the attendees with those for whom the event
+        # is now cancelled.
+
+        if to_cancel:
+            self.obj["ATTENDEE"] = to_cancel
+            self.send_message("CANCEL", get_address(organiser), for_organiser=True)
+
+            # Just in case more work is done with this event, the attendees are
+            # now restored.
+
+            self.obj["ATTENDEE"] = remaining
+
         return True
 
 class Manager(Common):