From dc63df90588da0c0aecb0e446a9fbdb94afbd41c Mon Sep 17 00:00:00 2001
From: Conrad Hoffmann <ch@bitfehler.net>
Date: Wed, 31 Aug 2022 12:09:00 +0200
Subject: [PATCH] carddav: evaluate recurrence in match helper

The match helper will now properly return recurring events if any of
their recurrences fall into the queried time range. A test for this was
added as well.
---
 caldav/match.go      | 14 ++++++++++++--
 caldav/match_test.go | 18 ++++++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/caldav/match.go b/caldav/match.go
index b881183..948b33c 100644
--- a/caldav/match.go
+++ b/caldav/match.go
@@ -127,9 +127,19 @@ func matchPropFilter(filter PropFilter, comp *ical.Component) (bool, error) {
 func matchCompTimeRange(start, end time.Time, comp *ical.Component) (bool, error) {
 	// See https://datatracker.ietf.org/doc/html/rfc4791#section-9.9
 
-	// TODO handle "infinity" values in query
-	// TODO handle recurring events
+	// evaluate recurring components
+	rset, err := comp.RecurrenceSet(start.Location())
+	if err != nil {
+		return false, err
+	}
+	if rset != nil {
+		// TODO we can only set inclusive to true or false, but really the
+		// start time is inclusive while the end time is not :/
+		return len(rset.Between(start, end, true)) > 0, nil
+	}
 
+	// TODO handle "infinity" values in query
+	// TODO handle more than just events
 	if comp.Name != ical.CompEvent {
 		return false, nil
 	}
diff --git a/caldav/match_test.go b/caldav/match_test.go
index e911846..73114bb 100644
--- a/caldav/match_test.go
+++ b/caldav/match_test.go
@@ -253,6 +253,24 @@ END:VCALENDAR`)
 			addrs: []CalendarObject{event1, event2, event3, todo1},
 			want:  []CalendarObject{event1},
 		},
+		{
+			// Query a time range that only returns a result if recurrence is properly evaluated.
+			name: "recurring events in time range",
+			query: &CalendarQuery{
+				CompFilter: CompFilter{
+					Name: "VCALENDAR",
+					Comps: []CompFilter{
+						CompFilter{
+							Name:  "VEVENT",
+							Start: toDate(t, "20060103T000000Z"),
+							End:   toDate(t, "20060104T000000Z"),
+						},
+					},
+				},
+			},
+			addrs: []CalendarObject{event1, event2, event3, todo1},
+			want:  []CalendarObject{event2},
+		},
 		// TODO add more examples
 	} {
 		t.Run(tc.name, func(t *testing.T) {