feat: implement and deploy blind_chess MVP

- pnpm workspace: shared/server/client packages - Server: Fastify+ws, chess.js, FSM (touch-move + hierarchy), per-player view filter, zod validation, rate limiting, grace-window disconnect handling - Client: Svelte 5 + Vite, click-to-move board, moderator panel, promotion/draw dialogs - Shared: protocol types, ModeratorText enum, geometricMoves helper (provably zero opponent-info leak) - 43 tests pass (21 shared, 22 server incl. 4 real-WS integration) - Deploy: CT 690 on node-241 (192.168.0.245), systemd-managed, Caddy block for chess.sethpc.xyz - Live at https://chess.sethpc.xyz Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 11:20:18 -04:00
parent 9a5ad55f30
commit a6de43edc1
53 changed files with 11970 additions and 5 deletions
@@ -0,0 +1,102 @@
+import type { Piece, Square } from './types.js';
+import { fileIndex, rankIndex, squareAt } from './types.js';
+
+type Dir = readonly [number, number];
+
+const ROOK_DIRS: readonly Dir[] = [
+  [1, 0], [-1, 0], [0, 1], [0, -1],
+];
+
+const BISHOP_DIRS: readonly Dir[] = [
+  [1, 1], [1, -1], [-1, 1], [-1, -1],
+];
+
+const QUEEN_DIRS: readonly Dir[] = [...ROOK_DIRS, ...BISHOP_DIRS];
+
+const KNIGHT_OFFSETS: readonly Dir[] = [
+  [1, 2], [2, 1], [2, -1], [1, -2],
+  [-1, -2], [-2, -1], [-2, 1], [-1, 2],
+];
+
+const KING_OFFSETS: readonly Dir[] = [
+  [1, 0], [-1, 0], [0, 1], [0, -1],
+  [1, 1], [1, -1], [-1, 1], [-1, -1],
+];
+
+function rays(from: Square, dirs: readonly Dir[], own: Set<Square>): Square[] {
+  const out: Square[] = [];
+  const f0 = fileIndex(from);
+  const r0 = rankIndex(from);
+  for (const [df, dr] of dirs) {
+    let f = f0 + df;
+    let r = r0 + dr;
+    while (true) {
+      const sq = squareAt(f, r);
+      if (!sq) break;
+      if (own.has(sq)) break;
+      out.push(sq);
+      f += df;
+      r += dr;
+    }
+  }
+  return out;
+}
+
+function jumps(from: Square, offsets: readonly Dir[], own: Set<Square>): Square[] {
+  const out: Square[] = [];
+  const f0 = fileIndex(from);
+  const r0 = rankIndex(from);
+  for (const [df, dr] of offsets) {
+    const sq = squareAt(f0 + df, r0 + dr);
+    if (sq && !own.has(sq)) out.push(sq);
+  }
+  return out;
+}
+
+function pawnGeometry(from: Square, color: 'w' | 'b', own: Set<Square>): Square[] {
+  const out: Square[] = [];
+  const f0 = fileIndex(from);
+  const r0 = rankIndex(from);
+  const dir = color === 'w' ? 1 : -1;
+  const startRank = color === 'w' ? 1 : 6;
+
+  const f1 = squareAt(f0, r0 + dir);
+  if (f1 && !own.has(f1)) out.push(f1);
+
+  if (r0 === startRank) {
+    const f2 = squareAt(f0, r0 + 2 * dir);
+    if (f1 && f2 && !own.has(f1) && !own.has(f2)) out.push(f2);
+  }
+
+  for (const df of [-1, 1]) {
+    const cap = squareAt(f0 + df, r0 + dir);
+    if (cap && !own.has(cap)) out.push(cap);
+  }
+
+  return out;
+}
+
+/**
+ * Geometric (pseudo-legal-ish) moves for a piece.
+ *
+ * Reads ONLY: piece type/color, from-square, own-piece set.
+ * Reads NOT: opponent piece positions, board history, anything else.
+ *
+ * The signature is the proof of zero opponent info leak. Castling is
+ * intentionally excluded — castling legality depends on opponent state
+ * (path through check, opponent pieces between king and rook).
+ */
+export function geometricMoves(
+  piece: Piece,
+  from: Square,
+  ownSquares: Set<Square>,
+): Square[] {
+  switch (piece.type) {
+    case 'n': return jumps(from, KNIGHT_OFFSETS, ownSquares);
+    case 'k': return jumps(from, KING_OFFSETS, ownSquares);
+    case 'b': return rays(from, BISHOP_DIRS, ownSquares);
+    case 'r': return rays(from, ROOK_DIRS, ownSquares);
+    case 'q': return rays(from, QUEEN_DIRS, ownSquares);
+    case 'p': return pawnGeometry(from, piece.color, ownSquares);
+  }
+}