hot inventions

apps/api/src/inventions-db.ts

@@ -14,10 +14,11 @@
  * shaped after a real `GET /api/inventions/v1?inventionId=…` response.
  *
  * Who OWNS an invention is a separate table (`inventory_invention`, written by the
- * `econ` worker at purchase time); this module only reads it, to fold bought inventions
- * into the caller's own list. See @repo/domain's inventory-invention-db.ts.
+ * `econ` worker at purchase time); this module only reads it — to fold bought inventions
+ * into the caller's own list, and to rank the "top today" feed by what players actually
+ * picked up today. See @repo/domain's inventory-invention-db.ts.
  */
-import { getOwnedInventionIds } from '@repo/domain'
+import { getInventionAcquisitionCounts, getOwnedInventionIds } from '@repo/domain'
 
 /**
  * Schema DDL (mirror of migrations/0002_invention.sql + 0003_invention_featured.sql +
@@ -351,31 +352,43 @@ async function publicInventions(db: D1Database, featuredOnly = false): Promise<S
 	return results.map((r) => JSON.parse(r.data) as SavedInvention)
 }
 
-/** Engagement score used to rank the top feed (downloads weigh most, then cheers). */
-function topScore(invention: SavedInvention): number {
-	const n = (v: unknown): number => (typeof v === 'number' ? v : 0)
-	return (
-		n(invention.NumDownloads) * 3 +
-		n(invention.CheerCount) * 2 +
-		n(invention.NumPlayersHaveUsedInRoom)
-	)
+/** Midnight UTC today, as the ISO timestamp `acquired_at` is compared against. */
+function startOfUtcDay(): string {
+	return `${new Date().toISOString().slice(0, 10)}T00:00:00.000Z`
 }
 
 /**
- * The "top today" feed — published inventions ranked by engagement. The real feed
- * ranks by *today's* activity; we don't track per-day counters, so this ranks by
- * lifetime engagement instead. Ties fall back to invention id so paging is stable.
- * Paginated via skip/take; returns a bare array, like the other invention feeds.
+ * The "top today" feed — the inventions other players picked up TODAY, most first.
+ *
+ * Ranked from the acquisitions the `econ` worker records in `inventory_invention` at
+ * purchase time, grouped by invention, rather than from the lifetime counters on the
+ * invention itself: those never reset, so "top today" used to mean "top ever" and the
+ * shelf only changed when something overtook a total built up over months.
+ *
+ * "Today" is the UTC day, matching the timestamps econ writes. The day therefore rolls
+ * over at 00:00 UTC wherever the player is, and the feed IS EMPTY until the first
+ * acquisition of that day — nothing stands in for it, the same way the featured feed
+ * serves nothing while nothing is curated.
+ *
+ * An acquired invention that has since been unpublished or hidden drops out: this is a
+ * public feed, so it is filtered like every other one. Paginated via skip/take AFTER
+ * that filtering, so a hidden invention doesn't leave a hole in a page.
  */
 export async function getTopInventions(
 	db: D1Database,
 	skip: number,
 	take: number
 ): Promise<SavedInvention[]> {
-	const inventions = await publicInventions(db)
-	return inventions
-		.sort((a, b) => topScore(b) - topScore(a) || b.InventionId - a.InventionId)
-		.slice(skip, skip + take)
+	const counts = await getInventionAcquisitionCounts(db, startOfUtcDay())
+	if (counts.length === 0) return []
+
+	// getInventionsByIds answers in the order it is asked, so the ranking survives the
+	// load; ids with no invention row left (deleted) simply drop out.
+	const ranked = await getInventionsByIds(
+		db,
+		counts.map((c) => c.inventionId)
+	)
+	return ranked.filter((i) => i.IsPublished && !i.HideFromPlayer).slice(skip, skip + take)
 }
 
 /**

apps/api/src/routes/avatar.ts

@@ -622,17 +622,20 @@ export const avatarRoutes = new Hono<App>({ strict: false })
 		}
 	)
 
-	// The "top today" invention feed — published inventions ranked by engagement
-	// (lifetime, not per-day: we keep no daily counters). Paginated via skip/take
-	// (take defaults to 50, as the client asks for). Bare array.
+	// The "top today" invention feed — the inventions most acquired since 00:00 UTC,
+	// counted from the purchase rows the `econ` worker writes. A real day window, so an
+	// empty list is a quiet day rather than a bug. Paginated via skip/take (take defaults
+	// to 50, as the client asks for). Bare array.
 	.get(
 		'/api/inventions/v1/toptoday',
 		describeRoute({
 			tags: ['Inventions'],
 			summary: 'The “top today” feed',
 			description:
-				'Published inventions ranked by engagement — lifetime, not per-day: we keep no ' +
-				'daily counters, so “today” is a label, not a window.',
+				'Published inventions ranked by how many players acquired them TODAY (since ' +
+				'00:00 UTC), counted from the purchase records — free grants included, one per ' +
+				'player per invention. Genuinely a day window: empty until the day’s first ' +
+				'acquisition, and it resets at midnight UTC.',
 			parameters: pageParams(50),
 			responses: { 200: json(InventionDto.array(), 'The top inventions') },
 		}),

apps/api/src/test/integration/api.test.ts

@@ -1138,14 +1138,15 @@ describe('public endpoints', () => {
 		const ids = async (res: Response): Promise<number[]> =>
 			((await res.json()) as SavedInvention[]).map((i) => i.InventionId)
 
-		// Nothing is flagged IsFeatured yet, so featured is EMPTY — it does not stand in the
-		// top feed, which by now has published inventions in it.
-		const beforeTop = await ids(await exports.default.fetch(`${ORIGIN}/api/inventions/v1/toptoday`))
-		expect(beforeTop.length).toBeGreaterThan(0)
-		const beforeFeatured = await ids(
-			await exports.default.fetch(`${ORIGIN}/api/inventions/v1/featured`)
+		// Both feeds start EMPTY, for different reasons: nothing is flagged IsFeatured, and
+		// the only inventions acquired so far in this file are an unpublished one and an id
+		// with no invention row — neither of which a public feed may show.
+		expect(await ids(await exports.default.fetch(`${ORIGIN}/api/inventions/v1/toptoday`))).toEqual(
+			[]
+		)
+		expect(await ids(await exports.default.fetch(`${ORIGIN}/api/inventions/v1/featured`))).toEqual(
+			[]
 		)
-		expect(beforeFeatured).toEqual([])
 
 		const feedInvention = (
 			id: number,
@@ -1183,11 +1184,24 @@ describe('public endpoints', () => {
 				.run()
 		}
 
-		// Top: engagement-ranked, so the biggest download counts lead.
+		// Today's acquisitions, which is what "top today" now counts: 201 picked up by three
+		// players, 203 by one. 204/205 are acquired too — an unpublished and a hidden
+		// invention can still be owned — and must not surface in a public feed.
+		for (const accountId of [7001, 7002, 7003]) await grantInvention(env.DB, accountId, 201)
+		await grantInvention(env.DB, 7001, 203)
+		await grantInvention(env.DB, 7001, 204)
+		await grantInvention(env.DB, 7002, 205)
+		// 202 was acquired, but not today — the window is the current UTC day, so it is out.
+		await env.DB.prepare(
+			'INSERT INTO inventory_invention (account_id, invention_id, acquired_at) VALUES (?1, ?2, ?3)'
+		)
+			.bind(7004, 202, '2020-01-01T00:00:00.000Z')
+			.run()
+
+		// Top: most acquisitions today first. Download counts no longer rank anything — 202
+		// has the biggest of them and is absent entirely.
 		const top = await ids(await exports.default.fetch(`${ORIGIN}/api/inventions/v1/toptoday`))
-		expect(top.slice(0, 3)).toEqual([202, 203, 201])
-		expect(top).not.toContain(204)
-		expect(top).not.toContain(205)
+		expect(top).toEqual([201, 203])
 
 		// Featured: only the flagged, visible inventions — newest first. 201 is published but
 		// unflagged, so it stays out however popular it is.
@@ -1197,6 +1211,10 @@ describe('public endpoints', () => {
 		// skip/take paginate both feeds.
 		const page = await exports.default.fetch(`${ORIGIN}/api/inventions/v1/toptoday?skip=1&take=1`)
 		expect(await ids(page)).toEqual([203])
+		// Pagination happens after the visibility filter, so the hidden/unpublished
+		// acquisitions don't leave holes in a page.
+		const firstPage = await exports.default.fetch(`${ORIGIN}/api/inventions/v1/toptoday?take=1`)
+		expect(await ids(firstPage)).toEqual([201])
 		const featuredPage = await exports.default.fetch(
 			`${ORIGIN}/api/inventions/v1/featured?skip=1&take=1`
 		)

packages/domain/src/inventory-invention-db.ts

@@ -62,6 +62,36 @@ export async function ownsInvention(
 	return row !== null
 }
 
+/**
+ * How many times each invention was acquired at or after `since`, most-acquired first
+ * (ties broken by newest invention, so paging is stable). Backs the `api` worker's "top
+ * today" feed, which passes the start of the current UTC day.
+ *
+ * `acquired_at` holds `toISOString()` output, which is fixed-width UTC, so a lexical
+ * `>=` on the string is a chronological comparison — no date parsing in SQL.
+ *
+ * This counts ACQUISITIONS, not spend: a free invention's grant is a row here just like
+ * a paid one, and one player can only ever contribute a single row per invention (the
+ * table's primary key), so a popular invention can't be inflated by one buyer. Creators
+ * are absent by design — they own theirs through `CreatorPlayerId` and never buy it —
+ * which is what makes this a measure of what other people picked up.
+ */
+export async function getInventionAcquisitionCounts(
+	db: D1Database,
+	since: string
+): Promise<Array<{ inventionId: number; count: number }>> {
+	const { results } = await db
+		.prepare(
+			`SELECT invention_id, COUNT(*) AS count FROM inventory_invention
+			 WHERE acquired_at >= ?1
+			 GROUP BY invention_id
+			 ORDER BY count DESC, invention_id DESC`
+		)
+		.bind(since)
+		.all<{ invention_id: number; count: number }>()
+	return results.map((r) => ({ inventionId: r.invention_id, count: r.count }))
+}
+
 /** The ids of every invention a player has bought, oldest purchase first. */
 export async function getOwnedInventionIds(db: D1Database, accountId: number): Promise<number[]> {
 	const { results } = await db