M9: 체스 컴퓨터 상대를 새 체스 수 생성기(체스960)에 맞춤

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/games/src/chess/bot.test.ts

@@ -39,8 +39,8 @@ describe('chess bot', () => {
       const a = decide(make(fen), seed) as Extract<ChessAction, { type: 'move' }>;
       expect(a.from).toBe('d5');
       const c = load(fen);
-      c.move({ from: a.from, to: a.to });
+      c.make(c.findMove(a.from, a.to)!);
-      expect(c.isAttacked(a.to as 'a1', 'b')).toBe(false);
+      expect(c.isAttacked(a.to, 'b')).toBe(false);
     }
   });
 

packages/games/src/chess/bot.ts

@@ -3,23 +3,24 @@
  * checks > development / centre / pawn pushes. Promotions are scored by the new piece, so it queens
  * (and under-promotes only when queening would stalemate).
  */
-import type { PieceSymbol, Square } from 'chess.js';
 import type { BotStrategy } from '../bots/types';
 import { answerRequests, best, pick, playable, typeOf } from '../bots/policy';
 import type { ChessView } from './index';
+import { moveInfo, type PieceType } from './movegen';
 import { PIECE_VALUE, insufficientMaterial, load, pieces } from './rules';
 
-type Move = { type: 'move'; from: Square; to: Square; promotion?: 'q' | 'r' | 'b' | 'n' };
+type Move = { type: 'move'; from: string; to: string; promotion?: 'q' | 'r' | 'b' | 'n' };
 const CENTER = new Set(['d4', 'e4', 'd5', 'e5']);
 const NEAR_CENTER = new Set(['c3', 'd3', 'e3', 'f3', 'c4', 'f4', 'c5', 'f5', 'c6', 'd6', 'e6', 'f6']);
-const SAN_PIECE: Record<string, PieceSymbol> = { N: 'n', B: 'b', R: 'r', Q: 'q', K: 'k' };
+/** Piece type of a raw generator move field (1..6). */
+const TYPE = (n: number) => ' pnbrqk'[n] as PieceType;
 
 export const chessBot: BotStrategy<ChessView> = ({ view, legal, random }) => {
   const req = answerRequests(legal);
   if (req) return req;
   const moves = legal.filter((a) => typeOf(a) === 'move') as Move[];
   if (!moves.length) return pick(playable(legal), random);
-  const c = load(view.fen);
+  const c = load(view.fen, view.chess960Index !== null);
   const us = c.turn();
   const them = us === 'w' ? 'b' : 'w';
   let balance = 0;
@@ -30,14 +31,17 @@ export const chessBot: BotStrategy<ChessView> = ({ view, legal, random }) => {
   /** Worst material loss the opponent can inflict right away (mate counts as everything). */
   const threat = (): number => {
     let worst = 0;
-    for (const san of c.moves()) {
+    for (const r of c.moves()) {
-      if (san.endsWith('#')) return 1000;
+      c.make(r);
-      if (!san.includes('x')) continue;
+      const mate = c.isCheckmate();
-      const to = san.match(/[a-h][1-8]/g)!.at(-1)! as Square;
+      c.unmake();
-      const victim = c.get(to)?.type ?? 'p'; // empty target = en passant
+      if (mate) return 1000;
-      const attacker = SAN_PIECE[san[0]!] ?? 'p';
+      if (!r.captured) continue;
+      const to = moveInfo.to(r);
+      const victim = TYPE(r.captured);
+      const attacker = TYPE(r.piece);
       // A defended victim only costs the difference (they lose the attacker to our recapture).
-      const defended = c.attackers(to, us).length > 0;
+      const defended = c.isAttacked(to, us);
       const loss = defended ? Math.max(0, PIECE_VALUE[victim] - PIECE_VALUE[attacker]) : PIECE_VALUE[victim];
       worst = Math.max(worst, loss);
     }
@@ -46,17 +50,18 @@ export const chessBot: BotStrategy<ChessView> = ({ view, legal, random }) => {
 
   const score = (m: Move): number => {
     const piece = c.get(m.from)!;
-    const done = c.move({ from: m.from, to: m.to, promotion: m.promotion });
+    const done = c.findMove(m.from, m.to, m.promotion)!;
+    c.make(done);
     try {
       if (c.isCheckmate()) return 1e6;
-      const gain = (done.captured ? PIECE_VALUE[done.captured] : 0) + (done.promotion ? PIECE_VALUE[done.promotion] - 1 : 0);
+      const gain = (done.captured ? PIECE_VALUE[TYPE(done.captured)] : 0) + (done.promo ? PIECE_VALUE[TYPE(done.promo)] - 1 : 0);
       // A draw is bad when ahead, welcome when clearly behind.
       if (c.isStalemate() || insufficientMaterial(c)) return (balance + gain > 0 ? -5000 : balance + gain < -2 ? 5000 : 0) + random();
       let s = (gain - threat()) * 100;
       if (c.inCheck()) s += 25;
       // Squeeze a lone king (helps finish won endgames): fewer replies is better.
       if (theirPieces === 0) s -= c.moves().length * 3;
-      if (done.isKingsideCastle() || done.isQueensideCastle()) s += 40;
+      if (moveInfo.isCastle(done)) s += 40;
       else if (piece.type === 'k' && opening) s -= 30;
       if (CENTER.has(m.to)) s += piece.type === 'p' ? 12 : 6;
       else if (NEAR_CENTER.has(m.to)) s += 4;
@@ -67,7 +72,7 @@ export const chessBot: BotStrategy<ChessView> = ({ view, legal, random }) => {
       if (piece.type === 'p' && !opening) s += (us === 'w' ? Number(m.to[1]) : 9 - Number(m.to[1])) * 2;
       return s + random() * 5;
     } finally {
-      c.undo();
+      c.unmake();
     }
   };
   return best(moves, score, random);