From 8eac8d012315debf797e5581fda4e949e2232490 Mon Sep 17 00:00:00 2001
From: AyoubBenziza <ayoub.cbenziza@gmail.com>
Date: Thu, 11 Jun 2026 17:48:33 +0200
Subject: [PATCH] =?UTF-8?q?feat:=20bots=20=E2=80=94=20virtual=20players=20?=
 =?UTF-8?q?to=20fill=20a=20game?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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- server-side bot players (isBot): host adds/removes them in the lobby
  (lobby:addBot / lobby:removeBot), capped at 8 players
- bots auto-vote each round: GameRound.botAnswer generates a plausible answer
  (quiz ~50% right, blindtest guesses a random player / title); engine schedules
  the votes within the answer window and triggers early end when all have voted
- bots are never DJ (pickDj excludes them) and are excluded from the blindtest
  track-submission gate (they don't submit)
- snapshot players carry `bot`; lobby shows a 🤖 marker + add/remove controls

Verified e2e: 2 bots added, they vote, game ends with all 3 players scored
and rounds end early.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 apps/server/src/game/engine.test.ts           |  1 +
 apps/server/src/game/engine.ts                | 40 ++++++++++++++++
 .../game/modes/blindtest/blindtest-round.ts   | 25 +++++++++-
 apps/server/src/game/modes/quiz/quiz-round.ts | 16 +++++++
 apps/server/src/game/round.ts                 |  3 ++
 apps/server/src/handlers.ts                   | 22 +++++++++
 apps/server/src/rooms.ts                      | 47 +++++++++++++++++++
 apps/web/src/components/lobby-view.tsx        | 40 ++++++++++++++--
 apps/web/src/store/room.ts                    |  5 ++
 packages/shared/src/domain.ts                 |  2 +
 packages/shared/src/events.ts                 |  2 +
 11 files changed, 196 insertions(+), 7 deletions(-)

diff --git a/apps/server/src/game/engine.test.ts b/apps/server/src/game/engine.test.ts
index 991b29d..dfebac3 100644
--- a/apps/server/src/game/engine.test.ts
+++ b/apps/server/src/game/engine.test.ts
@@ -47,6 +47,7 @@ const dummyRound: GameRound = {
     return deltas
   },
   recap: () => ({ label: "2+2 ?", answer: "4", answers: [] }),
+  botAnswer: () => ({ choiceIndex: 0 }),
 }
 
 function setup(roundDurationSec: number): {
diff --git a/apps/server/src/game/engine.ts b/apps/server/src/game/engine.ts
index 66137f8..3e6aaf2 100644
--- a/apps/server/src/game/engine.ts
+++ b/apps/server/src/game/engine.ts
@@ -195,6 +195,8 @@ export class GameEngine implements RoomGameController {
       this.io.to(this.room.code).emit("round:start", base)
     }
 
+    this.scheduleBotVotes()
+
     // Attend la première condition de fin : timer écoulé OU tous votés.
     await new Promise<void>((resolve) => {
       this.resolveRoundEnd = resolve
@@ -222,6 +224,44 @@ export class GameEngine implements RoomGameController {
     this.runtime = null
   }
 
+  /** Programme le vote automatique des bots (jamais DJ ni contributeur). */
+  private scheduleBotVotes(): void {
+    if (!this.runtime) {
+      return
+    }
+    const { djId, secretPlayerId, endsAt, startedAt } = this.runtime
+    const window = Math.max(0, endsAt - startedAt)
+    const bots = [...this.room.players.values()].filter(
+      (p) => p.isBot && p.id !== djId && p.id !== secretPlayerId
+    )
+    for (const bot of bots) {
+      // Vote après l'ouverture des réponses, réparti dans la première moitié.
+      const delay = this.leadMs + 700 + Math.random() * Math.min(window * 0.5, 3500)
+      setTimeout(() => this.botVote(bot.id), delay)
+    }
+  }
+
+  /** Exécute le vote d'un bot (no-op si la manche est finie ou s'il a déjà voté). */
+  private botVote(botId: string): void {
+    if (!this.runtime || this.room.status !== "in_round") {
+      return
+    }
+    if (this.runtime.votes.has(botId)) {
+      return
+    }
+    const ctx = this.context(this.runtime)
+    this.runtime.round.submitAnswer(ctx, botId, this.runtime.round.botAnswer(ctx, botId))
+    const total = this.eligibleVoters().length
+    this.io.to(this.room.code).emit("round:voteAck", {
+      count: this.runtime.votes.size,
+      total,
+      voted: [...this.runtime.votes.keys()],
+    })
+    if (total > 0 && this.runtime.votes.size >= total) {
+      this.endRound()
+    }
+  }
+
   /** Termine la manche en cours (idempotent : timer et "tous votés" peuvent se croiser). */
   private endRound(): void {
     if (this.timer) {
diff --git a/apps/server/src/game/modes/blindtest/blindtest-round.ts b/apps/server/src/game/modes/blindtest/blindtest-round.ts
index c78ae68..db3541e 100644
--- a/apps/server/src/game/modes/blindtest/blindtest-round.ts
+++ b/apps/server/src/game/modes/blindtest/blindtest-round.ts
@@ -31,10 +31,10 @@ interface BlindtestRoundData {
   track: BlindtestTrack
 }
 
-/** Tire un DJ neutre : un joueur connecté qui n'a pas soumis ce titre. */
+/** Tire un DJ neutre : un humain connecté qui n'a pas soumis ce titre. */
 function pickDj(room: ServerRoom, submittedBy: string): string | null {
   const eligible = [...room.players.values()].filter(
-    (p) => p.connected && p.id !== submittedBy
+    (p) => p.connected && !p.isBot && p.id !== submittedBy
   )
   if (eligible.length === 0) {
     return null
@@ -98,6 +98,27 @@ export class BlindtestRound implements GameRound {
     ctx.votes.set(playerId, answer)
   }
 
+  botAnswer(ctx: RoundContext, playerId: string): Answer {
+    const { track } = ctx.data as BlindtestRoundData
+    const mode = ctx.room.settings.blindtestMode
+    // Devine un joueur au hasard (parfois le bon contributeur).
+    const others = [...ctx.room.players.values()]
+      .filter((p) => p.id !== playerId)
+      .map((p) => p.id)
+    const guessedPlayerId =
+      others[Math.floor(Math.random() * others.length)] ?? playerId
+    if (mode === "who_added") {
+      return { guessedPlayerId }
+    }
+    const right = Math.random() < 0.4
+    const title = right ? track.title : "?"
+    const artist = right ? track.artist : "?"
+    if (mode === "title_artist") {
+      return { title, artist }
+    }
+    return { title, artist, guessedPlayerId }
+  }
+
   /** Résultat par joueur (votants + bonus de tromperie du contributeur). */
   private buildResults(ctx: RoundContext): BlindtestPerPlayerResult {
     const { track } = ctx.data as BlindtestRoundData
diff --git a/apps/server/src/game/modes/quiz/quiz-round.ts b/apps/server/src/game/modes/quiz/quiz-round.ts
index 54250a1..73d3825 100644
--- a/apps/server/src/game/modes/quiz/quiz-round.ts
+++ b/apps/server/src/game/modes/quiz/quiz-round.ts
@@ -147,6 +147,22 @@ export class QuizRound implements GameRound {
     return deltas
   }
 
+  botAnswer(ctx: RoundContext): Answer {
+    const { question } = ctx.data as QuizRoundData
+    // ~50% du temps le bot répond juste, sinon une réponse plausible mais fausse.
+    const rightish = Math.random() < 0.5
+    if (isTextFormat(question)) {
+      return {
+        text: rightish ? (question.acceptedAnswers?.[0] ?? "?") : "euh…",
+      }
+    }
+    const count = question.choices?.length ?? 1
+    if (rightish && typeof question.correctIndex === "number") {
+      return { choiceIndex: question.correctIndex }
+    }
+    return { choiceIndex: Math.floor(Math.random() * count) }
+  }
+
   recap(ctx: RoundContext): RoundRecapInfo {
     const { question } = ctx.data as QuizRoundData
     const answer = isTextFormat(question)
diff --git a/apps/server/src/game/round.ts b/apps/server/src/game/round.ts
index e9a59a6..ce5e04f 100644
--- a/apps/server/src/game/round.ts
+++ b/apps/server/src/game/round.ts
@@ -63,6 +63,9 @@ export interface GameRound {
   /** Renvoie les variations de score à appliquer (le moteur les applique). */
   score(ctx: RoundContext): ScoreDelta[]
 
+  /** Réponse automatique d'un bot (vote plausible, parfois juste). */
+  botAnswer(ctx: RoundContext, playerId: string): Answer
+
   /** Résumé de la manche pour le récap de fin de partie (intitulé + réponse + média). */
   recap(ctx: RoundContext): RoundRecapInfo
 }
diff --git a/apps/server/src/handlers.ts b/apps/server/src/handlers.ts
index 8ab1faf..0292d8d 100644
--- a/apps/server/src/handlers.ts
+++ b/apps/server/src/handlers.ts
@@ -149,6 +149,27 @@ export function registerRoomHandlers(
     broadcastState(room)
   })
 
+  socket.on("lobby:addBot", () => {
+    const code = socket.data.roomCode
+    const room = code ? rooms.get(code) : undefined
+    if (!room || room.hostId !== socket.data.playerId || room.status !== "lobby") {
+      return
+    }
+    if (rooms.addBot(room)) {
+      broadcastState(room)
+    }
+  })
+
+  socket.on("lobby:removeBot", () => {
+    const code = socket.data.roomCode
+    const room = code ? rooms.get(code) : undefined
+    if (!room || room.hostId !== socket.data.playerId) {
+      return
+    }
+    rooms.removeBot(room)
+    broadcastState(room)
+  })
+
   socket.on("game:start", (ack) => {
     const code = socket.data.roomCode
     const room = code ? rooms.get(code) : undefined
@@ -192,6 +213,7 @@ export function registerRoomHandlers(
         (p) =>
           p.connected &&
           p.name !== "" &&
+          !p.isBot &&
           room.blindtestTracks.filter((t) => t.submittedBy === p.id).length < tpp
       )
       if (pending) {
diff --git a/apps/server/src/rooms.ts b/apps/server/src/rooms.ts
index d32dd67..2c8984a 100644
--- a/apps/server/src/rooms.ts
+++ b/apps/server/src/rooms.ts
@@ -18,8 +18,22 @@ export interface ServerPlayer {
   socketId: string | null
   /** Secret de reconnexion (refresh/coupure). */
   reconnectToken: string
+  /** Joueur virtuel (vote automatiquement, jamais DJ). */
+  isBot: boolean
 }
 
+const BOT_NAMES = [
+  "Bot BMO",
+  "Bot R2-D2",
+  "Bot GLaDOS",
+  "Bot Clank",
+  "Bot Wall-E",
+  "Bot K-2SO",
+  "Bot HAL",
+  "Bot Bender",
+]
+const MAX_PLAYERS = 8
+
 /** Titre soumis pour le blindtest. `submittedBy` reste secret jusqu'au reveal. */
 export interface BlindtestTrack {
   id: string
@@ -94,6 +108,37 @@ export class RoomManager {
     return this.rooms.get(code)
   }
 
+  /** Ajoute un bot (joueur virtuel) à la room. Renvoie false si plein. */
+  addBot(room: ServerRoom): boolean {
+    if (room.players.size >= MAX_PLAYERS) {
+      return false
+    }
+    const used = new Set([...room.players.values()].map((p) => p.name))
+    const name =
+      BOT_NAMES.find((n) => !used.has(n)) ?? `Bot ${room.players.size + 1}`
+    const bot: ServerPlayer = {
+      id: randomUUID(),
+      name,
+      connected: true,
+      socketId: null,
+      reconnectToken: "",
+      isBot: true,
+    }
+    room.players.set(bot.id, bot)
+    room.scores.set(bot.id, 0)
+    return true
+  }
+
+  /** Retire un bot (le dernier ajouté). */
+  removeBot(room: ServerRoom): void {
+    const bots = [...room.players.values()].filter((p) => p.isBot)
+    const last = bots[bots.length - 1]
+    if (last) {
+      room.players.delete(last.id)
+      room.scores.delete(last.id)
+    }
+  }
+
   /**
    * Retire un joueur d'une room (départ volontaire). Réassigne l'hôte si besoin,
    * supprime la room si plus personne. Renvoie la room (ou null si supprimée).
@@ -146,6 +191,7 @@ export class RoomManager {
         id: p.id,
         name: p.name,
         connected: p.connected,
+        bot: p.isBot,
       })),
       settings: room.settings,
       scores: named.map((p) => ({
@@ -168,6 +214,7 @@ export class RoomManager {
       connected: true,
       socketId,
       reconnectToken: randomUUID(),
+      isBot: false,
     }
   }
 
diff --git a/apps/web/src/components/lobby-view.tsx b/apps/web/src/components/lobby-view.tsx
index ac9fd09..c236db7 100644
--- a/apps/web/src/components/lobby-view.tsx
+++ b/apps/web/src/components/lobby-view.tsx
@@ -136,7 +136,10 @@ export function LobbyView({ snapshot }: { snapshot: RoomSnapshot }) {
   const playerId = useRoomStore((s) => s.playerId)
   const updateSettings = useRoomStore((s) => s.updateSettings)
   const startGame = useRoomStore((s) => s.startGame)
+  const addBot = useRoomStore((s) => s.addBot)
+  const removeBot = useRoomStore((s) => s.removeBot)
   const isHost = snapshot.hostId === playerId
+  const botCount = snapshot.players.filter((p) => p.bot).length
   const { gameType, mixedModes, blindtestMode, tracksPerPlayer, categories } =
     snapshot.settings
   const allCategories =
@@ -180,11 +183,13 @@ export function LobbyView({ snapshot }: { snapshot: RoomSnapshot }) {
     tracks: showBlindtest ? totalTracks : 0,
     shuffleOrder: isMixed,
   })
-  // Blindtest : tout le monde doit avoir soumis son quota de titres.
+  // Blindtest : tous les HUMAINS doivent avoir soumis leur quota (les bots non).
+  const botIds = new Set(snapshot.players.filter((p) => p.bot).map((p) => p.id))
+  const humanSubs = snapshot.submissions.filter((s) => !botIds.has(s.playerId))
   const allSubmitted =
     !showBlindtest ||
-    (snapshot.submissions.length > 0 &&
-      snapshot.submissions.every((s) => s.count >= tracksPerPlayer))
+    (humanSubs.length > 0 &&
+      humanSubs.every((s) => s.count >= tracksPerPlayer))
   const canStart = rounds.length > 0 && allSubmitted
 
   function toggleMix(mode: MixMode) {
@@ -241,12 +246,37 @@ export function LobbyView({ snapshot }: { snapshot: RoomSnapshot }) {
                 )}
               </span>
               <span className="text-muted-foreground text-xs">
-                {p.id === snapshot.hostId ? "Hôte" : ""}
-                {!p.connected && " · hors ligne"}
+                {p.bot ? "🤖 Bot" : p.id === snapshot.hostId ? "Hôte" : ""}
+                {!p.bot && !p.connected && " · hors ligne"}
               </span>
             </li>
           ))}
         </ul>
+        {isHost && (
+          <div className="flex items-center justify-between gap-2 pt-1">
+            <span className="text-muted-foreground text-xs">
+              Bots : {botCount}
+            </span>
+            <div className="flex gap-2">
+              <Button
+                size="sm"
+                variant="secondary"
+                disabled={botCount === 0}
+                onClick={removeBot}
+              >
+                <Minus /> Bot
+              </Button>
+              <Button
+                size="sm"
+                variant="secondary"
+                disabled={snapshot.players.length >= 8}
+                onClick={addBot}
+              >
+                <Plus /> Bot
+              </Button>
+            </div>
+          </div>
+        )}
       </section>
 
       <div className="flex flex-col gap-6">
diff --git a/apps/web/src/store/room.ts b/apps/web/src/store/room.ts
index 5b72134..b4b1b8a 100644
--- a/apps/web/src/store/room.ts
+++ b/apps/web/src/store/room.ts
@@ -78,6 +78,8 @@ interface RoomState {
   removeTrack: (trackId: string) => Promise<boolean>
   returnToLobby: () => void
   leaveRoom: () => void
+  addBot: () => void
+  removeBot: () => void
   vote: (choiceIndex: number) => void
   voteText: (text: string) => void
   voteBlindtest: (answer: BlindtestAnswer) => void
@@ -198,6 +200,9 @@ export const useRoomStore = create<RoomState>((set, get) => ({
     get().reset()
   },
 
+  addBot: () => socket.emit("lobby:addBot"),
+  removeBot: () => socket.emit("lobby:removeBot"),
+
   vote: (choiceIndex) => {
     if (get().hasVoted) {
       return
diff --git a/packages/shared/src/domain.ts b/packages/shared/src/domain.ts
index 8c98ea2..98508d9 100644
--- a/packages/shared/src/domain.ts
+++ b/packages/shared/src/domain.ts
@@ -24,6 +24,8 @@ export interface Player {
   id: string
   name: string
   connected: boolean
+  /** Joueur virtuel (bot) géré par le serveur. */
+  bot?: boolean
 }
 
 /** Configuration d'une épreuve planifiée dans la séquence de la partie. */
diff --git a/packages/shared/src/events.ts b/packages/shared/src/events.ts
index f0dfe38..8f71883 100644
--- a/packages/shared/src/events.ts
+++ b/packages/shared/src/events.ts
@@ -150,6 +150,8 @@ export interface ClientToServerEvents {
   "room:rejoin": (payload: RejoinPayload, ack: Ack<RoomCreatedPayload>) => void
   "player:setName": (payload: SetNamePayload) => void
   "room:leave": () => void
+  "lobby:addBot": () => void
+  "lobby:removeBot": () => void
   "lobby:updateSettings": (payload: UpdateSettingsPayload) => void
   "lobby:return": () => void
   "game:start": (ack: Ack<null>) => void