# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1441664805 -7200
# Node ID ebed7907e1bab3e70b5d80a5f22edb4640253abe
# Parent  a679617f46fa74cdb143dadb384d147c93e03995
Added initial support for free/busy "offers" so that counter-proposals may be
able to temporarily reserve periods and thus prevent the allocation of such
periods to other events before an organiser is able to respond.

diff -r a679617f46fa -r ebed7907e1ba imip_store.py
--- a/imip_store.py	Tue Sep 08 00:23:49 2015 +0200
+++ b/imip_store.py	Tue Sep 08 00:26:45 2015 +0200
@@ -629,6 +629,56 @@
 
     release_freebusy = release_lock
 
+    # Tentative free/busy periods related to countering.
+
+    def get_freebusy_offers(self, user):
+
+        "Get free/busy offers for the given 'user'."
+
+        offers = []
+        expired = []
+        now = datetime.now()
+
+        # Expire old offers and save the collection if modified.
+
+        l = self.get_freebusy_for_update(user, "freebusy-offers")
+        try:
+            for fb in l:
+                if fb.expires and get_datetime(fb.expires) <= now:
+                    expired.append(fb)
+                else:
+                    offers.append(fb)
+
+            if expired:
+                self.set_freebusy_offers_in_update(user, offers)
+
+        finally:
+            self.release_freebusy(user)
+
+        return offers
+
+    def get_freebusy_offers_for_update(self, user):
+
+        """
+        Get free/busy offers for the given 'user', locking the table. Dependent
+        code must release this lock regardless of it completing successfully.
+        """
+
+        self.acquire_lock(user)
+        return self.get_freebusy_offers(user)
+
+    def set_freebusy_offers(self, user, freebusy):
+
+        "For the given 'user', set 'freebusy' offers."
+
+        return self.set_freebusy(user, freebusy, "freebusy-offers")
+
+    def set_freebusy_offers_in_update(self, user, freebusy):
+
+        "For the given 'user', set 'freebusy' offers during a compound update."
+
+        return self.set_freebusy_in_update(user, freebusy, "freebusy-offers")
+
     # Object status details access.
 
     def _get_requests(self, user, queue):
diff -r a679617f46fa -r ebed7907e1ba imiptools/handlers/common.py
--- a/imiptools/handlers/common.py	Tue Sep 08 00:23:49 2015 +0200
+++ b/imiptools/handlers/common.py	Tue Sep 08 00:26:45 2015 +0200
@@ -125,4 +125,40 @@
         finally:
             self.store.release_freebusy(self.user)
 
+    def update_event_in_freebusy_offers(self):
+
+        "Update free/busy offers when handling an object."
+
+        freebusy = self.store.get_freebusy_offers_for_update(self.user)
+        try:
+            # Obtain the attendance attributes for this user, if available.
+
+            self.update_freebusy_for_participant(freebusy, self.user)
+
+            # Remove original recurrence details replaced by additional
+            # recurrences, as well as obsolete additional recurrences.
+
+            self.remove_freebusy_for_recurrences(freebusy, self.store.get_recurrences(self.user, self.uid))
+            self.store.set_freebusy_offers_in_update(self.user, freebusy)
+
+        finally:
+            self.store.release_freebusy(self.user)
+
+        return True
+
+    def remove_event_from_freebusy_offers(self):
+
+        "Remove free/busy offers when handling an object."
+
+        freebusy = self.store.get_freebusy_offers_for_update(self.user)
+        try:
+            self.remove_from_freebusy(freebusy)
+            self.remove_freebusy_for_recurrences(freebusy)
+            self.store.set_freebusy_offers_in_update(self.user, freebusy)
+
+        finally:
+            self.store.release_freebusy(self.user)
+
+        return True
+
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r a679617f46fa -r ebed7907e1ba imiptools/handlers/resource.py
--- a/imiptools/handlers/resource.py	Tue Sep 08 00:23:49 2015 +0200
+++ b/imiptools/handlers/resource.py	Tue Sep 08 00:26:45 2015 +0200
@@ -79,6 +79,7 @@
         "Attempt to schedule the current object for the current user."
 
         method = "REPLY"
+        attendee_attr = self.obj.get_value_map("ATTENDEE")[self.user]
 
         # Check any constraints on the request.
 
@@ -88,7 +89,7 @@
         # Refuse to schedule obviously invalid requests.
 
         except ValidityError:
-            scheduled = False
+            attendee_attr = self.update_participation(self.obj, "DECLINED")
 
         # With a valid request, determine whether the event can be scheduled.
 
@@ -101,53 +102,69 @@
             # free/busy record and check for suitability.
 
             periods = self.obj.get_periods(tzid, self.get_window_end())
-            freebusy = self.store.get_freebusy(self.user)
-            scheduled = self.can_schedule(freebusy, periods)
+
+            freebusy = self.store.get_freebusy_for_update(self.user)
+            try:
+                offers = self.store.get_freebusy_offers(self.user)
 
-            # Where the corrected object can be scheduled, issue a counter
-            # request.
+                # Check the periods against any scheduled events and against
+                # any outstanding offers.
 
-            if scheduled and corrected:
-                method = "COUNTER"
+                scheduled = self.can_schedule(freebusy, periods)
+                scheduled = scheduled and self.can_schedule(offers, periods)
 
-            # Find the next available slot if the event cannot be scheduled.
+                # Where the corrected object can be scheduled, issue a counter
+                # request.
 
-            #elif not scheduled and len(periods) == 1:
+                if scheduled and corrected:
+                    method = "COUNTER"
 
-            #    # Find a free period, update the object with the details.
+                # Find the next available slot if the event cannot be scheduled.
+
+                #elif not scheduled and len(periods) == 1:
 
-            #    duration = periods[0].get_duration()
-            #    free = invert_freebusy(freebusy)
+                #    # Find a free period, update the object with the details.
+
+                #    duration = periods[0].get_duration()
+                #    free = invert_freebusy(freebusy)
 
-            #    for found in periods_from(free, periods[0]):
-            #        # NOTE: Correct the found period first.
-            #        if found.get_duration() >= duration
-            #            scheduled = True
-            #            method = "COUNTER"
-            #            # NOTE: Set the period using the original duration.
-            #            break
+                #    for found in periods_from(free, periods[0]):
+                #        # NOTE: Correct the found period first.
+                #        if found.get_duration() >= duration
+                #            scheduled = True
+                #            method = "COUNTER"
+                #            # NOTE: Set the period using the original duration.
+                #            break
 
-        # Update the participation of the resource in the object.
+                # Update the participation of the resource in the object.
+
+                attendee_attr = self.update_participation(self.obj,
+                    scheduled and "ACCEPTED" or "DECLINED")
 
-        if method == "REPLY":
-            attendee_attr = self.update_participation(self.obj,
-                scheduled and "ACCEPTED" or "DECLINED")
+                # Update free/busy information.
+
+                if method == "REPLY":
+                    self.update_event_in_freebusy(for_organiser=False)
+                    self.remove_event_from_freebusy_offers()
 
-            # Set the complete event or an additional occurrence.
+                # For countered proposals, record the offer in the resource's
+                # free/busy collection.
 
-            event = self.obj.to_node()
-            self.store.set_event(self.user, self.uid, self.recurrenceid, event)
+                elif method == "COUNTER":
+                    self.update_event_in_freebusy_offers()
 
-            # Remove additional recurrences if handling a complete event.
+            finally:
+                self.store.release_freebusy(self.user)
 
-            if not self.recurrenceid:
-                self.store.remove_recurrences(self.user, self.uid)
+        # Set the complete event or an additional occurrence.
+
+        event = self.obj.to_node()
+        self.store.set_event(self.user, self.uid, self.recurrenceid, event)
 
-            # Update free/busy information.
+        # Remove additional recurrences if handling a complete event.
 
-            self.update_event_in_freebusy(for_organiser=False)
-        else:
-            attendee_attr = self.obj.get_value_map("ATTENDEE")[self.user]
+        if not self.recurrenceid:
+            self.store.remove_recurrences(self.user, self.uid)
 
         # Make a version of the object with just this attendee, update the
         # DTSTAMP in the response, and return the object for sending.
@@ -172,6 +189,12 @@
         self.store.set_event(self.user, self.uid, self.recurrenceid, self.obj.to_node())
         self.store.cancel_event(self.user, self.uid, self.recurrenceid)
 
+    def _revoke_for_attendee(self):
+
+        "Revoke any counter-proposal recorded as a free/busy offer."
+
+        self.remove_event_from_freebusy_offers()
+
 class Event(ResourceHandler):
 
     "An event handler."
@@ -196,12 +219,9 @@
 
     def declinecounter(self):
 
-        """
-        Since this handler does not send counter proposals, it will not handle
-        replies to such proposals.
-        """
+        "Revoke any counter-proposal."
 
-        pass
+        self._record_and_respond(self._revoke_for_attendee)
 
     def publish(self):
 
diff -r a679617f46fa -r ebed7907e1ba imiptools/period.py
--- a/imiptools/period.py	Tue Sep 08 00:23:49 2015 +0200
+++ b/imiptools/period.py	Tue Sep 08 00:26:45 2015 +0200
@@ -156,12 +156,16 @@
 
     "A free/busy record abstraction."
 
-    def __init__(self, start, end, uid=None, transp=None, recurrenceid=None, summary=None, organiser=None):
+    def __init__(self, start, end, uid=None, transp=None, recurrenceid=None, summary=None, organiser=None, expires=None):
 
         """
         Initialise a free/busy period with the given 'start' and 'end' points,
         plus any 'uid', 'transp', 'recurrenceid', 'summary' and 'organiser'
         details.
+
+        An additional 'expires' parameter can be used to indicate an expiry
+        datetime in conjunction with free/busy offers made when countering
+        event proposals.
         """
 
         self.start = isinstance(start, datetime) and start or get_datetime(start)
@@ -171,6 +175,7 @@
         self.recurrenceid = recurrenceid
         self.summary = summary
         self.organiser = organiser
+        self.expires = expires
 
     def as_tuple(self, strings_only=False):
 
@@ -187,7 +192,8 @@
             self.transp or strings_only and "OPAQUE" or None,
             self.recurrenceid or null(self.recurrenceid),
             self.summary or null(self.summary),
-            self.organiser or null(self.organiser)
+            self.organiser or null(self.organiser),
+            self.expires or null(self.expires)
             )
 
     def __cmp__(self, other):
diff -r a679617f46fa -r ebed7907e1ba tests/test_resource_invitation_constraints.sh
--- a/tests/test_resource_invitation_constraints.sh	Tue Sep 08 00:23:49 2015 +0200
+++ b/tests/test_resource_invitation_constraints.sh	Tue Sep 08 00:26:45 2015 +0200
@@ -10,6 +10,10 @@
 PREFS=/tmp/prefs
 ARGS="-S $STORE -P $STATIC -p $PREFS -d"
 USER="mailto:resource-room-sauna@example.com"
+FBFILE="$STORE/$USER/freebusy"
+FBOFFERFILE="$STORE/$USER/freebusy-offers"
+TAB=`printf '\t'`
+
 ERROR=err.tmp
 
 rm -r $STORE
@@ -41,6 +45,15 @@
 && echo "Success" \
 || echo "Failed"
 
+   ! [ -e "$FBFILE" ] \
+|| ! grep -q "^20141126T151500Z${TAB}20141126T170000Z" "$FBFILE" \
+&& echo "Success" \
+|| echo "Failed"
+
+   grep -q "^20141126T151500Z${TAB}20141126T170000Z" "$FBOFFERFILE" \
+&& echo "Success" \
+|| echo "Failed"
+
   "$RESOURCE_SCRIPT" $ARGS < "$TEMPLATES/fb-request-sauna-all.txt" 2>> $ERROR \
 | "$SHOWMAIL" \
 > out3.tmp
@@ -60,6 +73,15 @@
 && echo "Success" \
 || echo "Failed"
 
+   grep -q "^20141126T150000Z${TAB}20141126T151500Z" "$FBFILE" \
+&& echo "Success" \
+|| echo "Failed"
+
+   ! grep -q "^20141126T150000Z${TAB}20141126T151500Z" "$FBOFFERFILE" \
+&& ! grep -q "^20141126T151500Z${TAB}20141126T170000Z" "$FBOFFERFILE" \
+&& echo "Success" \
+|| echo "Failed"
+
   "$RESOURCE_SCRIPT" $ARGS < "$TEMPLATES/fb-request-sauna-all.txt" 2>> $ERROR \
 | "$SHOWMAIL" \
 > out6.tmp