Preserve fleet match timing across empty telemetry

src/lib/server/fleet/status-updates.ts

@@ -20,15 +20,13 @@ export function successfulStatusFields(
     };
 }
 
-/** Occupancy timers and match clearing follow the same source as the UI. */
+/** Occupancy follows the UI's source; only gameplay evidence changes match timing. */
 export function activityFields(current: ServerRow, status: ServerObservation): Partial<ServerRow> {
     if (status.health !== 'online' || status.last_players === null) return {};
     return status.last_players > 0
         ? { active_since: current.active_since ?? status.last_seen_at, inactive_since: null }
         : {
               active_since: null,
-              inactive_since: current.inactive_since ?? status.last_seen_at,
-              game_started_at: null,
-              game_ended_at: null
+              inactive_since: current.inactive_since ?? status.last_seen_at
           };
 }

src/lib/server/fleet/telemetry.ts

@@ -25,46 +25,55 @@ export function saveTelemetry(report: GameTelemetry): GameTelemetry {
             ? JSON.parse(row.payload)
             : undefined;
         recordLeaderboardTelemetry(handle, report);
-        // Record each occupancy transition at receipt, before a heartbeat can
-        // replace game_start or an empty report between status polls.
-        const after = latestGameSubmission(report.server);
-        if (!after || Date.parse(report.receivedAt) > Date.parse(after)) {
-            if (report.players.length > 0) {
-                handle
-                    .prepare(
-                        'UPDATE servers SET active_since = COALESCE(active_since, ?), inactive_since = NULL WHERE name = ?'
-                    )
-                    .run(report.receivedAt, report.server);
-                if (report.event === 'game_start') {
-                    handle
-                        .prepare(
-                            'UPDATE servers SET game_started_at = ?, game_ended_at = NULL WHERE name = ?'
-                        )
-                        .run(report.receivedAt, report.server);
-                } else if (report.event === 'game_end') {
-                    handle
-                        .prepare('UPDATE servers SET game_ended_at = ? WHERE name = ?')
-                        .run(report.receivedAt, report.server);
-                }
-            } else {
-                handle
-                    .prepare(
-                        `UPDATE servers SET active_since = NULL, inactive_since = COALESCE(inactive_since, ?),
-                    game_started_at = NULL, game_ended_at = NULL WHERE name = ?`
-                    )
-                    .run(report.receivedAt, report.server);
-            }
-        }
+        const match = handle
+            .prepare(
+                'SELECT id, started_at, start_observed FROM leaderboard_matches WHERE server = ? ORDER BY id DESC LIMIT 1'
+            )
+            .get(report.server) as { id: number; started_at: string; start_observed: number };
+        const sameMatch = previous?.timing?.matchId === match.id;
         const serverTiming = handle
             .prepare(
                 `SELECT active_since AS activeSince, inactive_since AS inactiveSince,
             game_started_at AS gameStartedAt, game_ended_at AS gameEndedAt FROM servers WHERE name = ?`
             )
             .get(report.server) as ServerTiming;
-        const match = handle
-            .prepare('SELECT id FROM leaderboard_matches WHERE server = ? ORDER BY id DESC LIMIT 1')
-            .get(report.server) as { id: number };
-        const sameMatch = previous?.timing?.matchId === match.id;
+        // Record each occupancy transition at receipt, before a heartbeat can
+        // replace game_start or an empty report between status polls.
+        const after = latestGameSubmission(report.server);
+        if (!after || Date.parse(report.receivedAt) > Date.parse(after)) {
+            const occupied = report.players.length > 0;
+            serverTiming.activeSince = occupied
+                ? (serverTiming.activeSince ?? report.receivedAt)
+                : null;
+            serverTiming.inactiveSince = occupied
+                ? null
+                : (serverTiming.inactiveSince ?? report.receivedAt);
+            // Match boundaries follow history, independently of roster occupancy.
+            // Recover starts discarded by older receivers only when a start was
+            // actually observed; an inferred match has no known start time.
+            const startedAt =
+                report.event === 'game_start'
+                    ? report.receivedAt
+                    : ((sameMatch ? serverTiming.gameStartedAt : null) ??
+                      (match.start_observed ? match.started_at : null));
+            serverTiming.gameStartedAt =
+                startedAt && (!after || Date.parse(startedAt) > Date.parse(after))
+                    ? startedAt
+                    : null;
+            serverTiming.gameEndedAt = report.event === 'game_end' ? report.receivedAt : null;
+            handle
+                .prepare(
+                    `UPDATE servers SET active_since = ?, inactive_since = ?,
+                game_started_at = ?, game_ended_at = ? WHERE name = ?`
+                )
+                .run(
+                    serverTiming.activeSince,
+                    serverTiming.inactiveSince,
+                    serverTiming.gameStartedAt,
+                    serverTiming.gameEndedAt,
+                    report.server
+                );
+        }
         // A gap beyond the normal heartbeat window cannot establish continuity.
         const continuous =
             previous && Date.parse(report.receivedAt) - Date.parse(previous.receivedAt) <= 120_000;