feat: DJ can be contributor, volume, theme switch, clock sync, 90s blindtest

Playtest feedback round 2:
- blindtest DJ can now be anyone incl. the track's contributor (pickDj only
  excludes bots) — no more "immunity" for whoever isn't picked
- blindtest rounds last 90s (longer listen + typing)
- per-player volume slider (persisted), YT player setVolume + origin/enablejsapi
- theme switcher (light/dark/system) on home + room header
- clock sync: clients estimate the server-clock offset (time:sync) so the
  countdown is identical across devices (was off by each device's clock skew);
  also used for blindtest media sync

Note on duplicates: anti-repeat is per room code (quiz_played) — it works when
you replay in the SAME room, but a new room starts fresh. Verified e2e: two
chained games in one room share 0 questions.

Verified: typecheck 4/4, lint 4/4, 24 server tests, web build; e2e dedup (0
overlap) and clock/DJ behavior.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/game/modes/blindtest/blindtest-round.test.ts

@@ -44,7 +44,7 @@ describe("match", () => {
 })
 
 describe("BlindtestRound", () => {
-  test("start : le DJ est neutre (jamais le contributeur)", () => {
+  test("start : le DJ est un humain connecté (le contributeur peut tomber DJ)", () => {
     const rooms = new RoomManager()
     const { room, player: a } = rooms.create("Alice", "sa")
     const { player: b } = rooms.join(room.code, "Bob", "sb")
@@ -53,10 +53,24 @@ describe("BlindtestRound", () => {
 
     const round = new BlindtestRound()
     const start = round.start(room)
-    expect(start.djId).toBe(b.id) // Bob (pas Alice, la contributrice)
+    // N'importe quel humain (Alice incluse), jamais un bot ni null.
+    expect([a.id, b.id]).toContain(start.djId!)
     expect(start.payload).toEqual({ trackId: "t1", youtubeId: "abc12345678" })
   })
 
+  test("start : un bot n'est jamais DJ", () => {
+    const rooms = new RoomManager()
+    const { room, player: a } = rooms.create("Alice", "sa")
+    rooms.addBot(room)
+    rooms.addBot(room)
+    room.blindtestTracks = [track(a.id)]
+    prepareBlindtestForRoom(room)
+
+    const round = new BlindtestRound()
+    // Alice est la seule humaine → DJ forcément Alice (les bots sont exclus).
+    expect(round.start(room).djId).toBe(a.id)
+  })
+
   test("who_added : le contributeur gagne par tromperie (mauvaises devinettes)", () => {
     const rooms = new RoomManager()
     const { room, player: a } = rooms.create("Alice", "sa")

apps/server/src/game/modes/blindtest/blindtest-round.ts

@@ -32,10 +32,14 @@ interface BlindtestRoundData {
   track: BlindtestTrack
 }
 
-/** Tire un DJ neutre : un humain connecté qui n'a pas soumis ce titre. */
-function pickDj(room: ServerRoom, submittedBy: string): string | null {
+// Le blindtest dure plus longtemps (écoute + saisie).
+const BLINDTEST_DURATION_SEC = 90
+
+/** Tire un DJ : n'importe quel humain connecté (y compris le contributeur, pour
+ *  ne pas donner d'« immunité » à celui qui n'est jamais tiré). */
+function pickDj(room: ServerRoom): string | null {
   const eligible = [...room.players.values()].filter(
-    (p) => p.connected && !p.isBot && p.id !== submittedBy
+    (p) => p.connected && !p.isBot
   )
   if (eligible.length === 0) {
     return null
@@ -77,13 +81,14 @@ export class BlindtestRound implements GameRound {
 
   start(room: ServerRoom): RoundStart {
     const track = takeTrack(room)
-    // DJ neutre (jamais le contributeur) : il pilote la lecture et vote à l'aveugle.
-    const djId = track ? pickDj(room, track.submittedBy) : null
+    // DJ = n'importe quel humain (le contributeur peut tomber DJ).
+    const djId = track ? pickDj(room) : null
     const payload: BlindtestRoundPayload | null = track
       ? { trackId: track.id, youtubeId: track.youtubeId }
       : null
     return {
       djId,
+      durationSec: BLINDTEST_DURATION_SEC,
       payload,
       secretPlayerId: track?.submittedBy,
       data: track ? { track } : null,

apps/server/src/handlers.ts

@@ -61,6 +61,9 @@ export function registerRoomHandlers(
     })
   }
 
+  // Synchro d'horloge : le client mesure l'offset avec l'horloge serveur.
+  socket.on("time:sync", (ack) => ack(Date.now()))
+
   socket.on("room:create", (payload, ack) => {
     // Le pseudo est choisi dans la room (player:setName) : on crée sans nom.
     const name = cleanName(payload?.playerName) ?? ""

apps/web/src/components/blindtest-view.tsx

@@ -15,6 +15,7 @@ import { useYoutube, type YoutubeApi } from "@/lib/youtube"
 import { Countdown } from "@/components/countdown"
 import { Avatar } from "@/components/avatar"
 import { useI18n } from "@/i18n/context"
+import { serverNow } from "@/lib/clock"
 
 const inputClass =
   "border-input bg-background h-10 w-full rounded-md border px-3 py-2 text-sm focus-visible:ring-ring focus-visible:ring-2 focus-visible:outline-none disabled:opacity-50"
@@ -46,12 +47,31 @@ export function BlindtestView({ snapshot }: { snapshot: RoomSnapshot }) {
   // doit "armer" le son une fois (le DJ a déjà cliqué Play, donc dispensé).
   const [audioArmed, setAudioArmed] = useState(false)
 
+  // Volume local (par joueur), mémorisé entre les manches/parties.
+  const [volume, setVolume] = useState(() => {
+    const v = Number(localStorage.getItem("nerdware-volume"))
+    return Number.isFinite(v) && v >= 0 && v <= 100 ? v : 100
+  })
+  useEffect(() => {
+    if (ready) {
+      api.setVolume(volume)
+    }
+  }, [ready, volume, api])
+  function changeVolume(v: number) {
+    setVolume(v)
+    try {
+      localStorage.setItem("nerdware-volume", String(v))
+    } catch {
+      // ignore
+    }
+  }
+
   // Non-DJ : on suit le DJ via media:sync (avec compensation de latence).
   useEffect(() => {
     if (isDj || !ready || !mediaSync) {
       return
     }
-    const elapsed = (Date.now() - mediaSync.atServerTs) / 1000
+    const elapsed = (serverNow() - mediaSync.atServerTs) / 1000
     if (mediaSync.action === "play") {
       api.seek(mediaSync.positionSec + Math.max(0, elapsed))
       if (audioArmed) {
@@ -68,7 +88,7 @@ export function BlindtestView({ snapshot }: { snapshot: RoomSnapshot }) {
   function armAudio() {
     setAudioArmed(true)
     if (mediaSync && mediaSync.action !== "pause") {
-      const elapsed = (Date.now() - mediaSync.atServerTs) / 1000
+      const elapsed = (serverNow() - mediaSync.atServerTs) / 1000
       api.seek(mediaSync.positionSec + Math.max(0, elapsed))
     }
     api.play()
@@ -125,6 +145,24 @@ export function BlindtestView({ snapshot }: { snapshot: RoomSnapshot }) {
         )}
       </div>
 
+      {!showReveal && (
+        <div className="flex items-center gap-2">
+          <Volume2 className="text-muted-foreground size-4 shrink-0" />
+          <input
+            type="range"
+            min={0}
+            max={100}
+            value={volume}
+            onChange={(e) => changeVolume(Number(e.target.value))}
+            className="accent-primary flex-1"
+            aria-label={t.blindtest.volume}
+          />
+          <span className="text-muted-foreground w-8 text-right text-xs tabular-nums">
+            {volume}
+          </span>
+        </div>
+      )}
+
       {isDj && !showReveal && (
         <DjControls ready={ready} api={api} mediaControl={mediaControl} />
       )}

apps/web/src/components/countdown.tsx

@@ -1,15 +1,17 @@
 import { useEffect, useRef, useState } from "react"
 import { motion } from "framer-motion"
 import { useRoomStore } from "@/store/room"
+import { serverNow } from "@/lib/clock"
 
 const DANGER_FROM = 10 // secondes : seuil d'entrée en mode "bombe"
 
 /**
- * Secondes restantes. Avant `startsAt` (phase de préparation / transition),
- * on affiche la durée pleine sans décompter.
+ * Secondes restantes, basées sur l'horloge serveur (serverNow) pour que tous les
+ * clients affichent le même décompte. Avant `startsAt` (préparation), on affiche
+ * la durée pleine sans décompter.
  */
 function secondsLeft(startsAt: number, endsAt: number): number {
-  const now = Date.now()
+  const now = serverNow()
   if (now < startsAt) {
     return Math.ceil((endsAt - startsAt) / 1000)
   }

apps/web/src/components/theme-toggle.tsx

@@ -0,0 +1,31 @@
+import { Monitor, Moon, Sun } from "lucide-react"
+import { useTheme } from "@/components/theme-provider"
+
+const OPTIONS = [
+  { value: "light", Icon: Sun },
+  { value: "dark", Icon: Moon },
+  { value: "system", Icon: Monitor },
+] as const
+
+/** Sélecteur de thème : clair / sombre / système. */
+export function ThemeToggle({ className = "" }: { className?: string }) {
+  const { theme, setTheme } = useTheme()
+  return (
+    <div className={`flex gap-1 ${className}`}>
+      {OPTIONS.map(({ value, Icon }) => (
+        <button
+          key={value}
+          onClick={() => setTheme(value)}
+          title={value}
+          className={`rounded-md p-1.5 transition-colors ${
+            theme === value
+              ? "bg-primary/10 text-foreground"
+              : "text-muted-foreground hover:text-foreground"
+          }`}
+        >
+          <Icon className="size-4" />
+        </button>
+      ))}
+    </div>
+  )
+}

apps/web/src/i18n/en.ts

@@ -110,6 +110,7 @@ export const en: Dict = {
   },
   blindtest: {
     enableSound: "Enable sound",
+    volume: "Volume",
     djHint: "You're the DJ 🎧 — control playback (and vote like everyone)",
     play: "Play",
     pause: "Pause",

apps/web/src/i18n/fr.ts

@@ -108,6 +108,7 @@ export const fr = {
   },
   blindtest: {
     enableSound: "Activer le son",
+    volume: "Volume",
     djHint: "Tu es le DJ 🎧 — pilote la lecture (et vote comme les autres)",
     play: "Play",
     pause: "Pause",

apps/web/src/lib/clock.ts

@@ -0,0 +1,45 @@
+// Synchro d'horloge avec le serveur : on estime l'offset (horloge serveur −
+// horloge locale) pour que tous les clients affichent le même décompte, quel que
+// soit le décalage d'horloge de chaque machine.
+
+import { socket } from "./socket"
+
+let offset = 0
+
+/** Instant courant aligné sur l'horloge serveur. */
+export function serverNow(): number {
+  return Date.now() + offset
+}
+
+/** Une mesure : renvoie [rtt, offset estimé]. */
+async function syncOnce(): Promise<[number, number]> {
+  const t0 = Date.now()
+  const serverTime = await new Promise<number>((resolve) =>
+    socket.emit("time:sync", resolve)
+  )
+  const t1 = Date.now()
+  const rtt = t1 - t0
+  // Au moment de la réponse (t1), l'horloge serveur valait ~ serverTime + rtt/2.
+  return [rtt, serverTime + rtt / 2 - t1]
+}
+
+/** Plusieurs mesures : on garde celle de plus faible latence (plus fiable). */
+async function sync(): Promise<void> {
+  let bestRtt = Infinity
+  for (let i = 0; i < 3; i++) {
+    try {
+      const [rtt, est] = await syncOnce()
+      if (rtt < bestRtt) {
+        bestRtt = rtt
+        offset = est
+      }
+    } catch {
+      return
+    }
+  }
+}
+
+socket.on("connect", () => void sync())
+if (socket.connected) {
+  void sync()
+}

apps/web/src/lib/youtube.ts

@@ -29,6 +29,8 @@ export interface YoutubeApi {
   seek: (seconds: number) => void
   time: () => number
   duration: () => number
+  /** Volume 0–100. */
+  setVolume: (v: number) => void
 }
 
 /**
@@ -95,6 +97,7 @@ export function useYoutube(youtubeId: string) {
       seek: (seconds) => playerRef.current?.seekTo(seconds, true),
       time: () => playerRef.current?.getCurrentTime() ?? 0,
       duration: () => playerRef.current?.getDuration() ?? 0,
+      setVolume: (v) => playerRef.current?.setVolume(v),
     }),
     []
   )

apps/web/src/pages/home.tsx

@@ -7,6 +7,7 @@ import { useRoomStore } from "@/store/room"
 import { useI18n } from "@/i18n/context"
 import { errorMessage } from "@/i18n/error"
 import { LanguageToggle } from "@/i18n/language-toggle"
+import { ThemeToggle } from "@/components/theme-toggle"
 
 const inputClass =
   "border-input bg-background ring-offset-background focus-visible:ring-ring h-10 w-full rounded-md border px-3 py-2 text-sm focus-visible:ring-2 focus-visible:outline-none disabled:opacity-50"
@@ -60,7 +61,10 @@ export function HomePage() {
 
   return (
     <div className="relative flex min-h-svh items-center justify-center overflow-hidden p-6">
-      <LanguageToggle className="absolute top-4 right-4 z-10" />
+      <div className="absolute top-4 right-4 z-10 flex items-center gap-2">
+        <ThemeToggle />
+        <LanguageToggle />
+      </div>
       {/* Halo animé */}
       <motion.div
         aria-hidden

apps/web/src/pages/room.tsx

@@ -19,6 +19,7 @@ import { RoundTransition } from "@/components/round-transition"
 import { PseudoScreen } from "@/components/pseudo-screen"
 import { useI18n } from "@/i18n/context"
 import { LanguageToggle } from "@/i18n/language-toggle"
+import { ThemeToggle } from "@/components/theme-toggle"
 
 export function RoomPage({ code }: { code: string }) {
   const [, navigate] = useLocation()
@@ -100,6 +101,7 @@ export function RoomPage({ code }: { code: string }) {
                 {connected ? t.room.connected : t.room.disconnected}
               </TooltipContent>
             </Tooltip>
+            <ThemeToggle />
             <LanguageToggle />
             <Button
               size="sm"

apps/web/src/store/room.ts

@@ -18,6 +18,7 @@ import {
   type VoteAckPayload,
 } from "@nerdware/shared"
 import { socket } from "@/lib/socket"
+import "@/lib/clock" // démarre la synchro d'horloge avec le serveur
 import {
   clearSession,
   getSession,

apps/web/src/types/youtube.d.ts

@@ -24,6 +24,7 @@ declare global {
       getCurrentTime(): number
       getDuration(): number
       getPlayerState(): number
+      setVolume(volume: number): void
       loadVideoById(id: string): void
       destroy(): void
     }

packages/shared/src/events.ts

@@ -158,6 +158,7 @@ export type Ack<T> = (result: { ok: true; data: T } | { ok: false; error: ErrorP
 
 /** CLIENT → SERVER */
 export interface ClientToServerEvents {
+  "time:sync": (ack: (serverNow: number) => void) => void
   "room:create": (payload: RoomCreatePayload, ack: Ack<RoomCreatedPayload>) => void
   "room:join": (payload: RoomJoinPayload, ack: Ack<RoomCreatedPayload>) => void
   "room:rejoin": (payload: RejoinPayload, ack: Ack<RoomCreatedPayload>) => void