feat(bots): add named bot profiles with ELO-based difficulty

- 5 bot profiles (Holzpferd Heinz to Meister Magnus, ELO 200-1400) in
  server/bots.ts and client/bots.ts with emoji + descriptions
- Bot users auto-created in DB on server startup (role='bot')
- AI page replaced difficulty buttons with bot profile cards
- Tournament host can add bots via dropdown (POST /:code/add-bot)
- Bot auto-moves triggered on joinLobby and after each human move
- Fixed clock start order so bot-as-white games initialize correctly

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/src/app/ai/page.tsx

@@ -5,20 +5,13 @@ import { Chessboard } from "react-chessboard";
 import { Chess } from "chess.js";
 import { API_URL } from "@/config";
 import { useSession } from "@/context/session";
+import { BOTS } from "@/bots";
 import type { CSSProperties } from "react";
 
-const AI_LEVELS = [
-  { level: 1, name: "Anfänger" },
-  { level: 2, name: "Leicht" },
-  { level: 3, name: "Mittel" },
-  { level: 4, name: "Fortgeschritten" },
-  { level: 5, name: "Experte" },
-  { level: 6, name: "Meister" },
-];
-
 export default function AiGamePage() {
   const { user } = useSession();
-  const [selectedLevel, setSelectedLevel] = useState(3);
+  const [selectedBot, setSelectedBot] = useState(BOTS[2]);
+  const selectedLevel = selectedBot.level;
   const [gameStarted, setGameStarted] = useState(false);
   const [game, setGame] = useState(new Chess());
   const [playerColor, setPlayerColor] = useState<"white" | "black">("white");
@@ -152,15 +145,20 @@ export default function AiGamePage() {
 
         <div className="card bg-base-200 shadow p-6 w-full flex flex-col gap-5">
           <div>
-            <h2 className="text-lg font-semibold mb-3">Schwierigkeitsgrad</h2>
+            <h2 className="text-lg font-semibold mb-3">Gegner wählen</h2>
-            <div className="flex flex-wrap gap-2">
+            <div className="grid grid-cols-1 gap-2">
-              {AI_LEVELS.map((l) => (
+              {BOTS.map((b) => (
                 <button
-                  key={l.level}
+                  key={b.name}
-                  className={`btn ${selectedLevel === l.level ? "btn-primary" : "btn-outline"}`}
+                  className={`flex items-center gap-3 p-3 rounded-lg border-2 text-left transition-colors ${selectedBot.name === b.name ? "border-primary bg-primary/10" : "border-base-300 hover:border-primary/50"}`}
-                  onClick={() => setSelectedLevel(l.level)}
+                  onClick={() => setSelectedBot(b)}
                 >
-                  {l.level}. {l.name}
+                  <span className="text-2xl">{b.emoji}</span>
+                  <div className="flex-1">
+                    <div className="font-semibold">{b.name}</div>
+                    <div className="text-xs opacity-60">{b.description}</div>
+                  </div>
+                  <span className="badge badge-ghost badge-sm font-mono">{b.elo}</span>
                 </button>
               ))}
             </div>
@@ -196,7 +194,7 @@ export default function AiGamePage() {
 
       <div className="flex flex-col gap-4 min-w-[200px]">
         <div className="card bg-base-200 shadow p-4">
-          <p className="font-semibold text-sm opacity-70">Niveau: {AI_LEVELS.find(l => l.level === selectedLevel)?.name}</p>
+          <p className="font-semibold text-sm opacity-70">Gegner: {selectedBot.emoji} {selectedBot.name}</p>
           <p className="font-semibold text-sm opacity-70">Du spielst: {playerColor === "white" ? "Weiß ♔" : "Schwarz ♚"}</p>
         </div>
 

client/src/app/tournament/[code]/page.tsx

@@ -2,7 +2,8 @@
 
 import InviteFriendsModal from "@/components/InviteFriendsModal";
 import { useSession } from "@/context/session";
-import { fetchTournament, joinTournament, startTournament } from "@/lib/tournament";
+import { fetchTournament, joinTournament, startTournament, addBotToTournament } from "@/lib/tournament";
+import { BOTS } from "@/bots";
 import type { Tournament, TournamentRound } from "@michess/types";
 import Link from "next/link";
 import { useParams } from "next/navigation";
@@ -16,6 +17,7 @@ export default function TournamentDetailPage() {
   const [tournament, setTournament] = useState<Tournament | null>(null);
   const [loading, setLoading] = useState(true);
   const [actionLoading, setActionLoading] = useState(false);
+  const [selectedBot, setSelectedBot] = useState(BOTS[0].name);
   const intervalRef = useRef<ReturnType<typeof setInterval> | null>(null);
 
   async function load() {
@@ -47,6 +49,13 @@ export default function TournamentDetailPage() {
     setActionLoading(false);
   }
 
+  async function handleAddBot() {
+    setActionLoading(true);
+    const updated = await addBotToTournament(code, selectedBot);
+    if (updated) setTournament(updated);
+    setActionLoading(false);
+  }
+
   async function handleStart() {
     if (!user?.id) return;
     setActionLoading(true);
@@ -123,6 +132,27 @@ export default function TournamentDetailPage() {
           {tournament.status === "waiting" && isJoined && (
             <InviteFriendsModal gameCode={`tournament/${code}`} label="Freunde einladen" />
           )}
+          {isHost && tournament.status === "waiting" && (
+            <div className="flex gap-2 items-center">
+              <select
+                className="select select-sm select-bordered"
+                value={selectedBot}
+                onChange={(e) => setSelectedBot(e.target.value)}
+                disabled={actionLoading}
+              >
+                {BOTS.map((b) => (
+                  <option key={b.name} value={b.name}>{b.emoji} {b.name} ({b.elo})</option>
+                ))}
+              </select>
+              <button
+                className={"btn btn-outline btn-sm" + (actionLoading ? " loading" : "")}
+                onClick={handleAddBot}
+                disabled={actionLoading}
+              >
+                Bot hinzufügen
+              </button>
+            </div>
+          )}
           {canStart && (
             <button
               className={"btn btn-primary btn-sm" + (actionLoading ? " loading" : "")}

client/src/bots.ts

@@ -0,0 +1,8 @@
+export const BOTS = [
+    { name: "Holzpferd Heinz",     elo: 200,  level: 1, emoji: "🐴", description: "Perfekt für Einsteiger" },
+    { name: "Bauernschubser Bert", elo: 500,  level: 2, emoji: "♟",  description: "Lernt die Grundzüge" },
+    { name: "Taktiker Theo",       elo: 800,  level: 3, emoji: "🧩", description: "Kennt taktische Muster" },
+    { name: "Kombinationskarl",    elo: 1100, level: 4, emoji: "⚡",  description: "Gefährlicher Angreifer" },
+    { name: "Meister Magnus",      elo: 1400, level: 5, emoji: "👑",  description: "Fast unschlagbar" },
+];
+export type Bot = typeof BOTS[0];

client/src/lib/tournament.ts

@@ -34,3 +34,13 @@ export const startTournament = async (code: string): Promise<Tournament | null>
     if (!res.ok) return null;
     return res.json();
 };
+
+export const addBotToTournament = async (code: string, botName: string): Promise<Tournament | null> => {
+    const res = await fetch(`${API_URL}/v1/tournaments/${code}/add-bot`, {
+        method: "POST", credentials: "include",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ botName })
+    });
+    if (!res.ok) return null;
+    return res.json();
+};

server/src/bots.ts

@@ -0,0 +1,8 @@
+export const BOTS = [
+    { name: "Holzpferd Heinz",     elo: 200,  level: 1 },
+    { name: "Bauernschubser Bert", elo: 500,  level: 2 },
+    { name: "Taktiker Theo",       elo: 800,  level: 3 },
+    { name: "Kombinationskarl",    elo: 1100, level: 4 },
+    { name: "Meister Magnus",      elo: 1400, level: 5 },
+] as const;
+export const BOT_NAMES = new Set<string>(BOTS.map(b => b.name));

server/src/controllers/tournament.controller.ts

@@ -1,6 +1,7 @@
 import type { Request, Response } from "express";
 import TournamentModel from "../db/models/tournament.model.js";
 import { activeGames } from "../db/models/game.model.js";
+import { db } from "../db/index.js";
 import { nanoid } from "nanoid";
 import type { Game } from "@michess/types";
 
@@ -80,3 +81,22 @@ export const startTournament = async (req: Request, res: Response) => {
         res.status(200).json(updated);
     } catch (e) { console.error(e); res.status(500).end(); }
 };
+
+export const addBot = async (req: Request, res: Response) => {
+    if (!req.session.user?.id || typeof req.session.user.id === "string") { res.status(401).end(); return; }
+    const { botName } = req.body;
+    if (!botName) { res.status(400).json({ message: "Bot name erforderlich." }); return; }
+    try {
+        const tournament = await TournamentModel.findByCode(req.params.code);
+        if (!tournament) { res.status(404).end(); return; }
+        if (tournament.hostId !== req.session.user.id) { res.status(403).end(); return; }
+        if (tournament.status !== "waiting") { res.status(400).json({ message: "Turnier bereits gestartet." }); return; }
+        const botRes = await db.query(`SELECT id, name FROM "user" WHERE name=$1 AND role='bot'`, [botName]);
+        if (!botRes.rows[0]) { res.status(404).json({ message: "Bot nicht gefunden." }); return; }
+        const bot = botRes.rows[0];
+        const result = await TournamentModel.joinTournament(req.params.code, bot.id, bot.name);
+        if (!result) { res.status(400).json({ message: "Bot konnte nicht hinzugefügt werden." }); return; }
+        const updated = await TournamentModel.findByCode(req.params.code);
+        res.status(200).json(updated);
+    } catch (e) { console.error(e); res.status(500).end(); }
+};

server/src/routes/tournament.route.ts

@@ -1,5 +1,5 @@
 import express from "express";
-import { createTournament, getTournaments, getTournament, joinTournament, startTournament } from "../controllers/tournament.controller.js";
+import { createTournament, getTournaments, getTournament, joinTournament, startTournament, addBot } from "../controllers/tournament.controller.js";
 
 const router = express.Router();
 router.post("/", createTournament);
@@ -7,4 +7,5 @@ router.get("/", getTournaments);
 router.get("/:code", getTournament);
 router.post("/:code/join", joinTournament);
 router.post("/:code/start", startTournament);
+router.post("/:code/add-bot", addBot);
 export default router;

server/src/server.ts

@@ -9,6 +9,7 @@ import { INIT_TABLES, db } from "./db/index.js";
 import session from "./middleware/session.js";
 import routes from "./routes/index.js";
 import { init as initSocket } from "./socket/index.js";
+import { BOTS } from "./bots.js";
 
 const corsConfig = {
     origin: process.env.CORS_ORIGIN || "http://localhost:3000",
@@ -39,6 +40,14 @@ db.query(INIT_TABLES, async (err) => {
                 console.error("Failed to set admin role:", e);
             }
         }
+
+        // Create bot users if not exist
+        for (const bot of BOTS) {
+            await db.query(
+                `INSERT INTO "user" (name, role) VALUES ($1, 'bot') ON CONFLICT (name) DO NOTHING`,
+                [bot.name]
+            );
+        }
     }
 });
 

server/src/socket/game.socket.ts

@@ -5,9 +5,74 @@ import type { DisconnectReason, Socket } from "socket.io";
 import GameModel, { activeGames } from "../db/models/game.model.js";
 import TournamentModel from "../db/models/tournament.model.js";
 import { io } from "../server.js";
+import { BOTS, BOT_NAMES } from "../bots.js";
+import { AI_LEVELS, getEngine } from "../controllers/stockfish.controller.js";
 
 // TODO: clean up
 
+async function triggerBotMove(game: Game, chess: Chess) {
+    const turn = chess.turn();
+    const botPlayer = turn === "w" ? game.white : game.black;
+    const bot = BOTS.find(b => b.name === botPlayer?.name);
+    if (!bot || !game.code) return;
+
+    const sfLevel = AI_LEVELS.find(l => l.level === bot.level) ?? AI_LEVELS[2];
+    const engine = getEngine();
+    const bestMove = await engine.getBestMove(chess.fen(), sfLevel);
+    if (!bestMove) return;
+
+    // Check game still active
+    if (!activeGames.find(g => g.code === game.code)) return;
+
+    const from = bestMove.slice(0, 2);
+    const to = bestMove.slice(2, 4);
+    const promotion = bestMove[4] ?? "q";
+
+    // Time deduction for bot
+    if (game.timeControl && game.lastMoveAt !== undefined && game.whiteTimeMs !== undefined && game.blackTimeMs !== undefined) {
+        const elapsed = Date.now() - game.lastMoveAt;
+        if (turn === "w") game.whiteTimeMs = Math.max(0, game.whiteTimeMs - elapsed);
+        else game.blackTimeMs = Math.max(0, game.blackTimeMs - elapsed);
+        game.lastMoveAt = Date.now();
+    }
+
+    const result = chess.move({ from, to, promotion });
+    if (!result) return;
+
+    game.pgn = chess.pgn();
+    io.to(game.code).emit("receivedMove", { from, to, promotion });
+
+    if (game.timeControl) {
+        io.to(game.code).emit("clockUpdate", {
+            whiteTimeMs: game.whiteTimeMs,
+            blackTimeMs: game.blackTimeMs,
+            lastMoveAt: game.lastMoveAt
+        });
+    }
+
+    if (chess.isGameOver()) {
+        const prevTurn = turn; // the bot was this turn
+        let reason: Game["endReason"];
+        if (chess.isCheckmate()) reason = "checkmate";
+        else if (chess.isStalemate()) reason = "stalemate";
+        else if (chess.isThreefoldRepetition()) reason = "repetition";
+        else if (chess.isInsufficientMaterial()) reason = "insufficient";
+        else reason = "draw";
+
+        const winnerSide = reason === "checkmate" ? (prevTurn === "w" ? "white" : "black") : undefined;
+        const winnerName = winnerSide === "white" ? game.white?.name : game.black?.name;
+        game.winner = reason === "checkmate" ? winnerSide : "draw";
+        game.endReason = reason;
+
+        const saved = (await GameModel.save(game)) as Game;
+        game.id = saved?.id;
+        await TournamentModel.updateRoundResult(game.code, game.winner as "white" | "black" | "draw");
+        io.to(game.code).emit("gameOver", { reason, winnerName, winnerSide, id: game.id });
+        if (game.timeout) clearTimeout(game.timeout);
+        activeGames.splice(activeGames.indexOf(game), 1);
+    }
+}
+
 export async function joinLobby(this: Socket, gameCode: string) {
     const game = activeGames.find((g) => g.code === gameCode);
     if (!game) return;
@@ -51,6 +116,12 @@ export async function joinLobby(this: Socket, gameCode: string) {
     await this.join(gameCode);
     io.to(game.code as string).emit("receivedLatestGame", game);
 
+    // Mark bots as connected so clock start and bot trigger logic see both players ready
+    const chess = new Chess();
+    if (game.pgn) chess.loadPgn(game.pgn);
+    if (BOT_NAMES.has(game.white?.name ?? "")) game.white!.connected = true;
+    if (BOT_NAMES.has(game.black?.name ?? "")) game.black!.connected = true;
+
     // Start clock if both players are connected and game has timeControl but hasn't started timing yet
     if (game.timeControl && game.white?.connected && game.black?.connected && !game.lastMoveAt && !game.pgn) {
         game.lastMoveAt = Date.now();
@@ -60,6 +131,15 @@ export async function joinLobby(this: Socket, gameCode: string) {
             lastMoveAt: game.lastMoveAt
         });
     }
+
+    if (game.white?.connected && game.black?.connected && !chess.isGameOver()) {
+        const nextTurn = chess.turn();
+        const nextPlayer = nextTurn === "w" ? game.white : game.black;
+        if (BOT_NAMES.has(nextPlayer?.name ?? "")) {
+            // Slight delay so client receives the current game state first
+            setTimeout(() => triggerBotMove(game, chess), 500);
+        }
+    }
 }
 
 export async function leaveLobby(this: Socket, reason?: DisconnectReason, code?: string) {
@@ -233,6 +313,13 @@ export async function sendMove(this: Socket, m: { from: string; to: string; prom
                 });
             }
 
+            // Trigger bot move if next player is a bot
+            if (!chess.isGameOver() && BOT_NAMES.has((chess.turn() === "w" ? game.white : game.black)?.name ?? "")) {
+                const chessCopy = new Chess();
+                chessCopy.loadPgn(chess.pgn());
+                setTimeout(() => triggerBotMove(game, chessCopy), 300);
+            }
+
             if (chess.isGameOver()) {
                 let reason: Game["endReason"];
                 if (chess.isCheckmate()) reason = "checkmate";