1 files changed, 23 insertions, 0 deletions
diff --git a/pim/lib/cal/backend.go b/pim/lib/cal/backend.go
index 6dcacc2..6ed488c 100644
--- a/pim/lib/cal/backend.go
+++ b/pim/lib/cal/backend.go
@@ -39,3 +39,26 @@ type Backend interface {
 type Describer interface {
 	Describe() string
 }
+
+// Identity is implemented by a backend that knows whose calendar this
+// is. In iTIP your identity is the mailto: in your own ATTENDEE line --
+// there is no separate field for it -- so without this nothing can tell
+// which of an event's attendees is you. Aliases are listed because you
+// may be invited at one address and reply from another.
+type Identity interface {
+	Me() []string
+}
+
+// RSVPer is implemented by a backend that can answer an invitation.
+//
+// Accepting is two writes: update your own copy, and tell the organiser.
+// A CalDAV server advertising calendar-auto-schedule does both from one
+// PUT. A backend that cannot do both should not implement this at all,
+// so that writing to partstat fails honestly rather than doing half of
+// it and looking like it worked.
+//
+// recurID is the zero time to answer a whole series, or the start of
+// one occurrence to answer only that.
+type RSVPer interface {
+	RSVP(uid string, recurID time.Time, partstat string) error
+}