# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1463091776 -7200
# Node ID d674245140c305c5f8f62e8b97b84a22e56f3a29
# Parent  6bc9f39224a9c51c94f60a7ba04a95052184c811
Added some support for recognising multiple delegators and delegates.

diff -r 6bc9f39224a9 -r d674245140c3 imiptools/data.py
--- a/imiptools/data.py	Thu May 12 23:15:18 2016 +0200
+++ b/imiptools/data.py	Fri May 13 00:22:56 2016 +0200
@@ -973,22 +973,35 @@
     """
     Using the 'attendee_map', check the attributes for the given 'attendee'
     provided as 'attendee_attr', following the delegation chain back to the
-    delegator and forward again to yield the delegate identity. Return
-    whether this identity is the given 'attendee', providing the delegator
-    identity; otherwise return None.
+    delegators and forward again to yield the delegate identities in each
+    case. Pictorially...
+
+    attendee -> DELEGATED-FROM -> delegator
+           ? <-  DELEGATED-TO  <---
+
+    Return whether 'attendee' was identified as a delegate by providing the
+    identity of any delegators referencing the attendee.
     """
 
+    delegators = []
+
     # The recipient should have a reference to the delegator.
 
     delegated_from = attendee_attr and attendee_attr.get("DELEGATED-FROM")
-    delegated_from = delegated_from and delegated_from[0]
-    delegator = delegated_from and attendee_map.get(delegated_from)
+    if delegated_from:
+
+        # Examine all delegators.
+
+        for delegator in delegated_from:
+            delegator_attr = attendee_map.get(delegator)
 
-    # The delegator should have a reference to the recipient.
+            # The delegator should have a reference to the recipient.
 
-    delegated_to = delegator and delegator.get("DELEGATED-TO")
-    delegated_to = delegated_to and delegated_to[0]
-    return delegated_to == attendee and delegated_from or None
+            delegated_to = delegator_attr and delegator_attr.get("DELEGATED-TO")
+            if delegated_to and attendee in delegated_to:
+                delegators.append(delegator)
+
+    return delegators
 
 def get_periods(obj, tzid, end=None, inclusive=False):
 
diff -r 6bc9f39224a9 -r d674245140c3 imiptools/handlers/resource.py
--- a/imiptools/handlers/resource.py	Thu May 12 23:15:18 2016 +0200
+++ b/imiptools/handlers/resource.py	Fri May 13 00:22:56 2016 +0200
@@ -90,7 +90,7 @@
         "Attempt to schedule the current object for the current user."
 
         attendee_attr = uri_dict(self.obj.get_value_map("ATTENDEE"))[self.user]
-        delegate = None
+        delegates = None
 
         # Attempt to schedule the event.
 
@@ -124,7 +124,7 @@
                 if scheduled == "ACCEPTED":
                     self.confirm_scheduling()
 
-            # For delegated proposals, prepare a request to the delegate in
+            # For delegated proposals, prepare a request to the delegates in
             # addition to the usual response.
 
             elif scheduled == "DELEGATED":
@@ -134,8 +134,7 @@
                 # The recipient will have indicated the delegate whose details
                 # will have been added to the object.
 
-                delegated_to = attendee_attr["DELEGATED-TO"]
-                delegate = delegated_to and delegated_to[0]
+                delegates = attendee_attr["DELEGATED-TO"]
 
             # For countered proposals, record the offer in the resource's
             # free/busy collection.
@@ -169,21 +168,23 @@
         self.update_sender(attendee_attr)
         attendees = [(self.user, attendee_attr)]
 
-        # Add the delegate if delegating (RFC 5546 being inconsistent here since
+        # Add delegates if delegating (RFC 5546 being inconsistent here since
         # it provides an example reply to the organiser without the delegate).
 
-        if delegate:
-            delegate_attr = uri_dict(self.obj.get_value_map("ATTENDEE"))[delegate]
-            attendees.append((delegate, delegate_attr))
+        if delegates:
+            for delegate in delegates:
+                delegate_attr = uri_dict(self.obj.get_value_map("ATTENDEE"))[delegate]
+                attendees.append((delegate, delegate_attr))
 
         # Reply to the delegator in addition to the organiser if replying to a
         # delegation request.
 
-        delegator = self.is_delegation()
-        if delegator:
-            delegator_attr = uri_dict(self.obj.get_value_map("ATTENDEE"))[delegator]
-            attendees.append((delegator, delegator_attr))
-            recipients.append(get_address(delegator))
+        delegators = self.is_delegation()
+        if delegators:
+            for delegator in delegators:
+                delegator_attr = uri_dict(self.obj.get_value_map("ATTENDEE"))[delegator]
+                attendees.append((delegator, delegator_attr))
+                recipients.append(get_address(delegator))
 
         # Prepare the response for the organiser plus any delegator.
 
@@ -191,11 +192,11 @@
         self.update_dtstamp()
         self.add_result(method, recipients, self.object_to_part(method, self.obj))
 
-        # If delegating, send a request to the delegate.
+        # If delegating, send a request to the delegates.
 
-        if delegate:
+        if delegates:
             method = "REQUEST"
-            self.add_result(method, [get_address(delegate)], self.object_to_part(method, self.obj))
+            self.add_result(method, map(get_address, delegates), self.object_to_part(method, self.obj))
 
     def _cancel_for_attendee(self):