Update so that either player can go first

Author: chrisreddington

mcp-server/src/handlers/elicitation-handlers.ts

@@ -30,7 +30,8 @@ export async function elicitGameCreationPreferences(
           type: "string",
           enum: ["X", "O"],
           title: "Your Symbol",
-          description: "Do you want to be X (goes first) or O (goes second)?"
+          description: "Do you want to be X (goes first) or O (goes second)?",
+          default: "X"
         },
         playerName: {
           type: "string",

mcp-server/src/handlers/game-operations.ts

@@ -318,7 +318,8 @@ export async function createGame(
   gameType: string, 
   playerName: string = 'Player', 
   gameId?: string, 
-  aiDifficulty: string = 'medium'
+  aiDifficulty: string = 'medium',
+  gameSpecificOptions?: Record<string, any>
 ) {
   // Check if game already exists (for games that support custom IDs)
   if (gameId && gameType === 'tic-tac-toe') {
@@ -341,7 +342,7 @@ export async function createGame(
   }
 
   // Create new game via API
-  const gameSession = await createGameViaAPI(gameType, playerName, gameId, aiDifficulty)
+  const gameSession = await createGameViaAPI(gameType, playerName, gameId, aiDifficulty, gameSpecificOptions)
 
   const response: any = {
     gameId: gameSession.gameState.id,

mcp-server/src/handlers/tool-handlers.ts

@@ -103,6 +103,12 @@ export const TOOL_DEFINITIONS = [
           description: 'AI difficulty level',
           default: 'medium',
         },
+        playerSymbol: {
+          type: 'string',
+          enum: ['X', 'O'],
+          description: 'Your symbol: X (goes first) or O (goes second)',
+          default: 'X',
+        },
       },
       required: [],
     },
@@ -202,9 +208,12 @@ export async function handleToolCall(name: string, args: any, server?: any) {
         const { 
           playerName: ticTacToePlayerName = 'Player', 
           gameId: ticTacToeNewGameId, 
-          aiDifficulty: ticTacToeAiDifficulty = 'medium' 
+          aiDifficulty: ticTacToeAiDifficulty = 'medium',
+          playerSymbol: ticTacToePlayerSymbol = 'X'
         } = args
-        return await createGame('tic-tac-toe', ticTacToePlayerName, ticTacToeNewGameId, ticTacToeAiDifficulty)
+        
+        const ticTacToeGameOptions = ticTacToePlayerSymbol ? { playerSymbol: ticTacToePlayerSymbol } : undefined
+        return await createGame('tic-tac-toe', ticTacToePlayerName, ticTacToeNewGameId, ticTacToeAiDifficulty, ticTacToeGameOptions)
 
       case 'create_rock_paper_scissors_game':
         const { 
@@ -262,8 +271,17 @@ async function createGameInteractive(gameType: string, gameId?: string, server?:
       const finalPlayerName = playerName || 'Player'
       const finalDifficulty = difficulty || 'medium'
 
+      // Prepare game-specific options
+      const gameSpecificOptions: Record<string, any> = {}
+      if (gameType === 'tic-tac-toe' && playerSymbol) {
+        gameSpecificOptions.playerSymbol = playerSymbol
+      }
+      if (gameType === 'rock-paper-scissors' && maxRounds) {
+        gameSpecificOptions.maxRounds = maxRounds
+      }
+      
       // Create the game with elicited preferences
-      const gameResult = await createGame(gameType, finalPlayerName, gameId, finalDifficulty)
+      const gameResult = await createGame(gameType, finalPlayerName, gameId, finalDifficulty, gameSpecificOptions)
 
       // Add elicitation information to the response
       gameResult.elicitation = {
@@ -274,6 +292,11 @@ async function createGameInteractive(gameType: string, gameId?: string, server?:
       // Add game-specific messages
       if (gameType === 'tic-tac-toe' && playerSymbol) {
         gameResult.message += ` You are playing as ${playerSymbol}.`
+        if (playerSymbol === 'X') {
+          gameResult.message += ' You go first!'
+        } else {
+          gameResult.message += ' AI goes first!'
+        }
       }
       if (gameType === 'rock-paper-scissors' && maxRounds) {
         gameResult.message += ` Playing ${maxRounds} rounds.`

mcp-server/src/server.ts

@@ -26,7 +26,7 @@ const server = new Server(
       tools: {},
       resources: {},
       prompts: {},
-      sampling: {},
+      elicitation: {},
     },
   }
 )

shared/src/games/rock-paper-scissors.ts

@@ -221,7 +221,7 @@ export class RockPaperScissorsGame implements Game<RPSGameState, RPSMove> {
    * - Game status set to 'playing'
    * - Current round set to 0
    */
-  getInitialState(players: Player[]): RPSGameState {
+  getInitialState(players: Player[], options?: any): RPSGameState {
     const maxRounds = 3; // Best of 3
     const rounds = Array.from({ length: maxRounds }, () => ({}));
 

shared/src/games/tic-tac-toe.ts

@@ -189,32 +189,53 @@ export class TicTacToeGame implements Game<TicTacToeGameState, TicTacToeMove> {
   /**
    * Creates the initial game state for a new tic-tac-toe game
    * 
-   * @param players - Array of exactly 2 players (first player gets X, second gets O)
-   * @returns Initial TicTacToeGameState with empty board and first player's turn
+   * @param players - Array of exactly 2 players
+   * @param options - Optional game configuration
+   * @returns Initial TicTacToeGameState with empty board
    * 
    * @description
    * Sets up a new game with:
    * - Empty 3x3 board (all cells null)
-   * - Player 1 assigned 'X' symbol and goes first
-   * - Player 2 assigned 'O' symbol
+   * - Player symbol assignment (X always goes first, O goes second)
+   * - Configurable turn order (who gets X and goes first)
    * - Game status set to 'playing'
    * - Timestamps initialized to current time
    */
-  getInitialState(players: Player[]): TicTacToeGameState {
+  getInitialState(players: Player[], options?: { firstPlayerId?: string }): TicTacToeGameState {
     const board: Board = [
       [null, null, null],
       [null, null, null],
       [null, null, null]
     ];
 
+    // Determine who gets X (goes first) and who gets O (goes second)
+    let firstPlayer: Player;
+    let secondPlayer: Player;
+    
+    if (options?.firstPlayerId) {
+      const firstPlayerIndex = players.findIndex(p => p.id === options.firstPlayerId);
+      if (firstPlayerIndex !== -1) {
+        firstPlayer = players[firstPlayerIndex];
+        secondPlayer = players[1 - firstPlayerIndex];
+      } else {
+        // Fallback to default order if specified player not found
+        firstPlayer = players[0];
+        secondPlayer = players[1];
+      }
+    } else {
+      // Default: first player in array goes first
+      firstPlayer = players[0];
+      secondPlayer = players[1];
+    }
+
     const playerSymbols: Record<string, 'X' | 'O'> = {};
-    playerSymbols[players[0].id] = 'X';
-    playerSymbols[players[1].id] = 'O';
+    playerSymbols[firstPlayer.id] = 'X';
+    playerSymbols[secondPlayer.id] = 'O';
 
     return {
       id: crypto.randomUUID(),
       players,
-      currentPlayerId: players[0].id,
+      currentPlayerId: firstPlayer.id,
       status: 'playing',
       createdAt: new Date(),
       updatedAt: new Date(),

shared/src/types/game.ts

@@ -36,7 +36,7 @@ export interface Game<TGameState extends BaseGameState, TMove> {
   applyMove(gameState: TGameState, move: TMove, playerId: PlayerId): TGameState;
   checkGameEnd(gameState: TGameState): GameResult | null;
   getValidMoves(gameState: TGameState, playerId: PlayerId): TMove[];
-  getInitialState(players: Player[]): TGameState;
+  getInitialState(players: Player[], options?: any): TGameState;
 }
 
 export type GameType = 'tic-tac-toe' | 'rock-paper-scissors';

web/src/app/api/games/tic-tac-toe/route.ts

@@ -8,14 +8,25 @@ const ticTacToeGame = new TicTacToeGame()
 
 export async function POST(request: NextRequest) {
   try {
-    const { playerName, gameId, aiDifficulty } = await request.json()
+    const { playerName, gameId, aiDifficulty, playerSymbol } = await request.json()
 
     const players: Player[] = [
       { id: 'player1', name: playerName || 'Player', isAI: false },
       { id: 'ai', name: 'AI', isAI: true }
     ]
 
-    const gameState = ticTacToeGame.getInitialState(players)
+    // Determine who goes first based on symbol choice
+    // X always goes first, O goes second
+    let options: { firstPlayerId?: string } | undefined;
+    if (playerSymbol === 'O') {
+      // Player chose O, so AI (who gets X) goes first
+      options = { firstPlayerId: 'ai' };
+    } else {
+      // Player chose X (default) or no preference, so player goes first
+      options = { firstPlayerId: 'player1' };
+    }
+    
+    const gameState = ticTacToeGame.getInitialState(players, options)
 
     // Use custom gameId if provided
     if (gameId) {

web/src/app/games/tic-tac-toe/page.tsx

@@ -17,6 +17,7 @@ export default function TicTacToePage() {
   const [showCreateForm, setShowCreateForm] = useState(false)
   const [showJoinForm, setShowJoinForm] = useState(false)
   const [aiDifficulty, setAiDifficulty] = useState<'easy' | 'medium' | 'hard'>('medium')
+  const [playerSymbol, setPlayerSymbol] = useState<'X' | 'O'>('X')
   const [gamesToShow, setGamesToShow] = useState(5)
   const [showDeleteModal, setShowDeleteModal] = useState(false)
   const [gameToDelete, setGameToDelete] = useState<string | null>(null)
@@ -79,9 +80,10 @@ export default function TicTacToePage() {
     setError(null)
 
     try {
-      const body: { playerName: string; gameId?: string; aiDifficulty: string } = { 
+      const body: { playerName: string; gameId?: string; aiDifficulty: string; playerSymbol: string } = { 
         playerName: 'Player',
-        aiDifficulty 
+        aiDifficulty,
+        playerSymbol
       }
       if (customGameId) {
         body.gameId = customGameId
@@ -433,6 +435,19 @@ export default function TicTacToePage() {
                   <option value="hard">🔴 Hard - Optimal play (never loses)</option>
                 </select>
               </div>
+              <div>
+                <label className="block text-sm font-semibold text-slate-700 dark:text-slate-300 mb-2">
+                  Your Symbol
+                </label>
+                <select
+                  value={playerSymbol}
+                  onChange={(e) => setPlayerSymbol(e.target.value as 'X' | 'O')}
+                  className="w-full px-4 py-3 bg-white/60 dark:bg-slate-700/60 border border-slate-200 dark:border-slate-600 rounded-xl focus:outline-none focus:ring-2 focus:ring-green-500 focus:border-transparent transition-all duration-200"
+                >
+                  <option value="X">❌ X - You go first</option>
+                  <option value="O">⭕ O - AI goes first</option>
+                </select>
+              </div>
               <div>
                 <label className="block text-sm font-semibold text-slate-700 dark:text-slate-300 mb-2">
                   Custom Game ID (optional)