fix calculation for future tournaments

Author: Luke Gehorsam

CHANGELOG.md

@@ -5,6 +5,10 @@ The format is based on [keep a changelog](http://keepachangelog.com) and this pr
 
 ## [Unreleased]
 
+### Fixed
+- Fixes calculation of leaderboard and tournament times for rare types of CRON expressions that don't execute at a fixed interval.
+- Improved how start and end times are calculated for tournaments occuring in the future.
+
 ### [3.17.1] - 2023-08-23
 ### Added
 - Add Satori `recompute` optional input parameter to relevant operations.

server/core_tournament.go

@@ -731,23 +731,26 @@ func TournamentRecordsHaystack(ctx context.Context, logger *zap.Logger, db *sql.
 func calculateTournamentDeadlines(startTime, endTime, duration int64, resetSchedule *cronexpr.Expression, t time.Time) (int64, int64, int64) {
 	tUnix := t.UTC().Unix()
 	if resetSchedule != nil {
-		if tUnix < startTime {
-			// if startTime is in the future, always use startTime
-			t = time.Unix(startTime, 0).UTC()
-			tUnix = t.UTC().Unix()
-		}
-
 		var startActiveUnix int64
-		// check if we are landing squarely on the reset schedule
-		if resetSchedule.Next(t.Add(-1*time.Second)) == t {
-			startActiveUnix = tUnix
+
+		if tUnix < startTime {
+			//  the supplied time is behind the start time
+			startActiveUnix = resetSchedule.Next(time.Unix(startTime, 0).UTC()).UTC().Unix()
 		} else {
-			// otherwise assume the supplied time is ahead of the reset schedule.
-			startActiveUnix = resetSchedule.Last(t).UTC().Unix()
+			// check if we are landing squarely on the reset schedule
+			landsOnSched := resetSchedule.Next(t.Add(-1*time.Second)) == t
+			if landsOnSched {
+				startActiveUnix = tUnix
+			} else {
+				startActiveUnix = resetSchedule.Last(t).UTC().Unix()
+			}
 		}
 
+		// endActiveUnix is when the current iteration ends.
 		endActiveUnix := startActiveUnix + duration
-		expiryUnix := resetSchedule.Next(t).UTC().Unix()
+		// expiryUnix represent the start of the next schedule, i.e., when the next iteration begins. It's when the current records "expire".
+		expiryUnix := resetSchedule.Next(time.Unix(startActiveUnix, 0).UTC()).UTC().Unix()
+
 		if endActiveUnix > expiryUnix {
 			// Cap the end active to the same time as the expiry.
 			endActiveUnix = expiryUnix

server/core_tournament_test.go

@@ -97,15 +97,16 @@ func TestTournamentNowIsBeforeStart(t *testing.T) {
 		t.Fatal("Invalid cron schedule", err)
 		return
 	}
+
 	var now int64 = 1692003600       // 14 August 2023, 9:00:00
 	var startTime int64 = 1693558800 // 1 September 2023, 9:00:00
-	var duration int64 = 604800 * 1  // 1 week
+	var duration int64 = 604800 * 4  // 4 Weeks
+
 	nowUnix := time.Unix(now, 0).UTC()
-	startActiveUnix, endActiveUnix, expiryTime := calculateTournamentDeadlines(startTime, 0, duration, sched, nowUnix)
-	// September 14, 2023, 9:00:00
+	startActiveUnix, endActiveUnix, _ := calculateTournamentDeadlines(startTime, 0, duration, sched, nowUnix)
+
+	// 14 September 2023, 9:00:00
 	require.Equal(t, int64(1694682000), startActiveUnix, "Start active times should be equal.")
-	// September 21, 2023, 9:00:00
-	require.Equal(t, int64(1695286800), endActiveUnix, "End active times should be equal.")
-	// October 14, 2023 9:00:00
-	require.Equal(t, int64(1697274000), expiryTime, "Next reset times should be equal.")
+	// 12 October 2023, 9:00:00
+	require.Equal(t, int64(1697101200), endActiveUnix, "End active times should be equal.")
 }