update: use findSnapshotBefore instead of findClosetSnapshot in regular snapshot scheduling

lib/db/snapshotSchedule.ts

@@ -114,6 +114,31 @@ export async function findClosestSnapshot(
 	};
 }
 
+export async function findSnapshotBefore(
+	client: Client,
+	aid: number,
+	targetTime: Date,
+): Promise<Snapshot | null> {
+	const query = `
+        SELECT created_at, views
+        FROM video_snapshot
+        WHERE aid = $1
+		AND created_at <= $2::timestamptz
+        ORDER BY created_at DESC
+        LIMIT 1
+	`;
+	const result = await client.queryObject<{ created_at: string; views: number }>(
+		query,
+		[aid, targetTime.toISOString()],
+	);
+	if (result.rows.length === 0) return null;
+	const row = result.rows[0];
+	return {
+		created_at: new Date(row.created_at).getTime(),
+		views: row.views,
+	};
+}
+
 export async function hasAtLeast2Snapshots(client: Client, aid: number) {
 	const res = await client.queryObject<{ count: number }>(
 		`SELECT COUNT(*) FROM video_snapshot WHERE aid = $1`,

lib/mq/exec/snapshotTick.ts

@@ -3,6 +3,7 @@ import { db } from "lib/db/init.ts";
 import { getLatestVideoSnapshot, getVideosNearMilestone } from "lib/db/snapshot.ts";
 import {
 	findClosestSnapshot,
+	findSnapshotBefore,
 	getLatestSnapshot,
 	getSnapshotsInNextSecond,
 	getVideosWithoutActiveSnapshotSchedule,
@@ -139,7 +140,7 @@ export const collectMilestoneSnapshotsWorker = async (_job: Job) => {
 const getRegularSnapshotInterval = async (client: Client, aid: number) => {
 	const now = Date.now();
 	const date = new Date(now - 24 * HOUR);
-	const oldSnapshot = await findClosestSnapshot(client, aid, date);
+	const oldSnapshot = await findSnapshotBefore(client, aid, date);
 	const latestSnapshot = await getLatestSnapshot(client, aid);
 	if (!oldSnapshot || !latestSnapshot) return 0;
 	if (oldSnapshot.created_at === latestSnapshot.created_at) return 0;