[www] add single person notify for fun

apps/notify/src/notifications-hub.ts

@@ -448,6 +448,28 @@ export class NotificationsHub extends DurableObject<Env> {
 		return { sent: this.broadcastToConnected(payload) }
 	}
 
+	/**
+	 * The targeted form of {@link coachMessageAll}: the same `MessageReceived` frame from
+	 * the Coach account (player 1), addressed to one player with a `ToPlayerId` — the shape
+	 * `api`'s player-to-player send uses.
+	 *
+	 * Unlike the broadcast this one QUEUES when the recipient is offline (see
+	 * {@link notifyPlayer}). The broadcast is online-only because it has no recipient to
+	 * hold anything for; a message written to a named player is worth keeping until they
+	 * next connect.
+	 */
+	async coachMessage(
+		playerId: number,
+		content: string
+	): Promise<{ delivered: number; queued: boolean }> {
+		return this.notifyPlayer(playerId, NotificationType.MessageReceived, {
+			FromPlayerId: COACH_PLAYER_ID,
+			ToPlayerId: playerId,
+			Type: COACH_MESSAGE_TYPE,
+			Data: content,
+		})
+	}
+
 	/** Broadcast a notification to every connected (handshaken) client. */
 	async broadcast(
 		notificationType: string | number,

apps/notify/src/notify.app.ts

@@ -176,6 +176,25 @@ const app = new Hono<App>()
 		return c.json({ success: true, ...result })
 	})
 
+	// The targeted form of the broadcast above: one coach message to ONE player. Queued
+	// by the hub when they're offline (unlike coach-message-all, which reaches only
+	// whoever is connected), so this arrives either way.
+	.post('/internal/coach-message', async (c) => {
+		const body = await c.req
+			.json<{ playerId?: number; messageContent?: string }>()
+			.catch(() => null)
+		const content = typeof body?.messageContent === 'string' ? body.messageContent.trim() : ''
+		if (typeof body?.playerId !== 'number' || !Number.isInteger(body.playerId)) {
+			return c.json({ error: 'playerId is required' }, 400)
+		}
+		if (content === '') return c.json({ error: 'messageContent is required' }, 400)
+		const result = await c.env.RECFLARE_NOTIFICATIONS_HUB.getByName(HUB_INSTANCE).coachMessage(
+			body.playerId,
+			content
+		)
+		return c.json({ success: true, ...result })
+	})
+
 	// Read-only view of the hub's routing state, for working out why a notification
 	// didn't arrive: which connections are live, which players each one receives for,
 	// and what's queued for a player who wasn't reachable.

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

@@ -65,7 +65,12 @@ interface HubRecord {
 async function connect(
 	id: string,
 	opts: { headers?: Record<string, string>; query?: string } = {}
-): Promise<{ ws: WebSocket; waitFor: (pred: (r: HubRecord) => boolean) => Promise<HubRecord> }> {
+): Promise<{
+	ws: WebSocket
+	waitFor: (pred: (r: HubRecord) => boolean) => Promise<HubRecord>
+	/** Everything this socket has received so far — for asserting something did NOT arrive. */
+	records: HubRecord[]
+}> {
 	// The hub only accepts identified connections, so default to a token; pass explicit
 	// `headers` (`{}` for none) where the test is about who is connecting.
 	const auth = opts.headers ?? (await bearer(String(DEFAULT_CONNECT_PLAYER), ['gameClient']))
@@ -113,7 +118,7 @@ async function connect(
 	ws.send(`{"protocol":"json","version":1}${RS}`)
 	await waitFor((r) => r.type === 1 && r.target === 'OnConnect')
 
-	return { ws, waitFor }
+	return { ws, waitFor, records }
 }
 
 const send = (ws: WebSocket, msg: HubRecord) => ws.send(JSON.stringify(msg) + RS)
@@ -337,6 +342,72 @@ describe('notification delivery', () => {
 		b.ws.close()
 	})
 
+	test('coach-message reaches only the named player, addressed to them', async () => {
+		const playerId = 9010
+		const target = await connect('coach-one', {
+			headers: await bearer(String(playerId), ['gameClient']),
+		})
+		const bystander = await connect('coach-one-bystander')
+		send(target.ws, {
+			type: 1,
+			invocationId: 's',
+			target: 'SubscribeToPlayers',
+			arguments: [{ playerIds: [playerId] }],
+		})
+		await target.waitFor((r) => r.type === 3 && r.invocationId === 's')
+
+		const res = await post('/internal/coach-message', { playerId, messageContent: 'just you' })
+		expect(res.status).toBe(200)
+		expect(await res.json()).toMatchObject({ delivered: 1, queued: false })
+
+		const note = await target.waitFor((r) => r.type === 1 && r.target === 'Notification')
+		const payload = JSON.parse((note.arguments as string[])[0]) as {
+			Id: string
+			Msg: Record<string, unknown>
+		}
+		expect(payload.Id).toBe('2') // MessageReceived
+		// Same Coach frame as the broadcast, plus the recipient the broadcast can't name.
+		expect(payload.Msg).toMatchObject({
+			FromPlayerId: 1,
+			ToPlayerId: playerId,
+			Type: 100,
+			Data: 'just you',
+		})
+
+		// The point of the targeted send: nobody else's socket sees it. The bystander is
+		// subscribed to nothing, and a broadcast would have reached it regardless.
+		expect(bystander.records.some((r) => r.target === 'Notification')).toBe(false)
+
+		target.ws.close()
+		bystander.ws.close()
+	})
+
+	test('coach-message queues for a player who is offline', async () => {
+		const playerId = 9011
+		const res = await post('/internal/coach-message', {
+			playerId,
+			messageContent: 'catch you later',
+		})
+		expect(await res.json()).toMatchObject({ delivered: 0, queued: true })
+
+		// Unlike the broadcast, it survives until they connect.
+		const { ws, waitFor } = await connect('coach-one-late')
+		send(ws, { type: 1, target: 'SubscribeToPlayers', arguments: [{ playerIds: [playerId] }] })
+		const note = await waitFor((r) => r.type === 1 && r.target === 'Notification')
+		expect(
+			(JSON.parse((note.arguments as string[])[0]) as { Msg: Record<string, unknown> }).Msg
+		).toMatchObject({ FromPlayerId: 1, ToPlayerId: playerId, Data: 'catch you later' })
+		ws.close()
+	})
+
+	test('coach-message 400s without a player or a message', async () => {
+		expect((await post('/internal/coach-message', { messageContent: 'nobody' })).status).toBe(400)
+		expect((await post('/internal/coach-message', { playerId: 9012 })).status).toBe(400)
+		expect(
+			(await post('/internal/coach-message', { playerId: 9012, messageContent: '   ' })).status
+		).toBe(400)
+	})
+
 	test('coach-message-all 400s on an empty message', async () => {
 		const res = await post('/internal/coach-message-all', { messageContent: '   ' })
 		expect(res.status).toBe(400)

apps/www/src/client/App.tsx

@@ -572,6 +572,42 @@ const coachMessageAll = (messageContent: string): Promise<{ sent?: number }> =>
 		authed: true,
 	})
 
+/**
+ * The same coach message to ONE player. `notify` queues it when they're offline, so
+ * `queued` (rather than a 0 delivery) is what "they weren't online" looks like here —
+ * it still arrives on their next connect, unlike the broadcast.
+ */
+const coachMessage = (
+	playerId: number,
+	messageContent: string
+): Promise<{ delivered?: number; queued?: boolean }> =>
+	call<{ delivered?: number; queued?: boolean }>(`${where().notify}/internal/coach-message`, {
+		json: { playerId, messageContent },
+		authed: true,
+	})
+
+/**
+ * Resolve an `@username` to the account id the workers address a player by.
+ *
+ * `accounts` serves no exact-name lookup, so this goes through the PREFIX search and
+ * keeps only an exact (case-insensitive) hit: a prefix match is a different player, and
+ * sending a message to whoever happened to sort first would be worse than refusing. The
+ * exact name always sorts first among its own prefixes, so it's inside the search limit
+ * whenever it exists.
+ */
+async function accountIdForUsername(input: string): Promise<number> {
+	const name = input.trim().replace(/^@/, '')
+	if (name === '') throw new Error('Enter a username to send to.')
+	const matches = await call<Array<{ accountId?: number; username?: string }>>(
+		`${where().accounts}/account/search?name=${encodeURIComponent(name)}`
+	)
+	const found = Array.isArray(matches)
+		? matches.find((m) => m.username?.toLowerCase() === name.toLowerCase())
+		: undefined
+	if (typeof found?.accountId !== 'number') throw new Error(`There's no player called @${name}.`)
+	return found.accountId
+}
+
 /** Minimal history-based router: current pathname + a navigate() that pushes state. */
 function useRouter() {
 	const [path, setPath] = useState(() => window.location.pathname)
@@ -2092,7 +2128,7 @@ function Dashboard({
 		...(isAdmin()
 			? [
 					{ id: 'maintenance', label: 'Server maintenance', render: () => <MaintenanceForm /> },
-					{ id: 'coach', label: 'Broadcast message', render: () => <CoachMessageForm /> },
+					{ id: 'coach', label: 'Coach message', render: () => <CoachMessageForm /> },
 				]
 			: []),
 	]
@@ -2227,28 +2263,61 @@ function RoomCard({
 	)
 }
 
-/** Admin-only: send a coach/system message to every online player. */
+/**
+ * Admin-only: send a coach/system message, either to one player by `@username` or to
+ * everyone online.
+ *
+ * The two go to different endpoints because they behave differently, not just in reach:
+ * the broadcast is online-only (nothing holds a message with no addressee), while a named
+ * recipient's message is queued by the hub and delivered whenever they next connect. The
+ * recipient box therefore says which of those the operator is about to do.
+ */
 function CoachMessageForm() {
+	const [recipient, setRecipient] = useState('')
 	const [message, setMessage] = useState('')
 	const { pending, error, done, run } = useAction()
+	// The `@` is how the name is written, not part of it — accepted either way, shown back
+	// with it, and sent without it.
+	const handle = recipient.trim().replace(/^@/, '')
+	const toOne = handle !== ''
 
 	return (
 		<section className="card">
-			<h2>Broadcast message</h2>
+			<h2>Coach message</h2>
 			<p className="muted">
-				Send a message from the Coach to every connected player. Players who aren&apos;t online
-				won&apos;t receive it.
+				Send a message from the Coach to one player, or leave the recipient blank to send it to
+				every connected player. A broadcast reaches only who is online right now; a message to one
+				player waits for them if they aren&apos;t.
 			</p>
 			<form
 				onSubmit={(e) => {
 					e.preventDefault()
 					void run(async () => {
-						const { sent } = await coachMessageAll(message.trim())
+						const content = message.trim()
+						if (!toOne) {
+							const { sent } = await coachMessageAll(content)
+							setMessage('')
+							return `Sent to ${sent ?? 0} online player${sent === 1 ? '' : 's'}.`
+						}
+						// Resolved before sending: the workers address players by id, and a name that
+						// matches nobody should be a refusal rather than a message into the void.
+						const { queued } = await coachMessage(await accountIdForUsername(handle), content)
 						setMessage('')
-						return `Sent to ${sent ?? 0} online player${sent === 1 ? '' : 's'}.`
+						return queued === true
+							? `@${handle} is offline — it will arrive when they next connect.`
+							: `Sent to @${handle}.`
 					})
 				}}
 			>
+				<label>
+					Send to
+					<input
+						value={recipient}
+						placeholder="@username — blank sends to everyone online"
+						autoComplete="off"
+						onChange={(e) => setRecipient(e.target.value)}
+					/>
+				</label>
 				<label>
 					Message
 					<textarea
@@ -2261,7 +2330,7 @@ function CoachMessageForm() {
 				{error && <p className="error">{error}</p>}
 				{done && <p className="ok">{done}</p>}
 				<button type="submit" disabled={pending}>
-					{pending ? 'Sending…' : 'Send to all online'}
+					{pending ? 'Sending…' : toOne ? `Send to @${handle}` : 'Send to all online'}
 				</button>
 			</form>
 		</section>