+import { ChessRules } from "@/base_rules";
+
+export class Knightmate2Rules extends ChessRules {
+
+ static get HasFlags() {
+ return false;
+ }
+
+ static get COMMONER() {
+ return "c";
+ }
+
+ static get PIECES() {
+ return ChessRules.PIECES.concat([V.COMMONER]);
+ }
+
+ getPpath(b) {
+ return ([V.KING, V.COMMONER].includes(b[1]) ? "Knightmate/" : "") + b;
+ }
+
+ static IsGoodPosition(position) {
+ if (position.length == 0) return false;
+ const rows = position.split("/");
+ if (rows.length != V.size.x) return false;
+ let kings = { "k": 0, "K": 0 };
+ for (let row of rows) {
+ let sumElts = 0;
+ for (let i = 0; i < row.length; i++) {
+ if (['K','k'].includes(row[i])) kings[row[i]]++;
+ if (V.PIECES.includes(row[i].toLowerCase())) sumElts++;
+ else {
+ const num = parseInt(row[i], 10);
+ if (isNaN(num) || num <= 0) return false;
+ sumElts += num;
+ }
+ }
+ if (sumElts != V.size.y) return false;
+ }
+ // 1 or 2 kings should be on board.
+ if (Object.values(kings).some(k => ![1, 2].includes(k))) return false;
+ return true;
+ }
+
+ scanKings() {}
+
+ static GenRandInitFen(randomness) {
+ return (
+ ChessRules.GenRandInitFen(randomness)
+ .replace(/k/g, 'c').replace(/K/g, 'C')
+ .replace(/n/g, 'k').replace(/N/g, 'K')
+ );
+ }
+
+ getPotentialMovesFrom([x, y]) {
+ switch (this.getPiece(x, y)) {
+ case V.COMMONER:
+ return this.getPotentialCommonerMoves([x, y]);
+ default:
+ return super.getPotentialMovesFrom([x, y]);
+ }
+ }
+
+ getPotentialCommonerMoves(sq) {
+ return this.getSlideNJumpMoves(
+ sq,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
+ }
+
+ getPotentialKingMoves(sq) {
+ return super.getPotentialKnightMoves(sq);
+ }
+
+ isAttacked(sq, color) {
+ return (
+ this.isAttackedByCommoner(sq, color) ||
+ this.isAttackedByPawn(sq, color) ||
+ this.isAttackedByRook(sq, color) ||
+ this.isAttackedByBishop(sq, color) ||
+ this.isAttackedByQueen(sq, color) ||
+ this.isAttackedByKing(sq, color)
+ );
+ }
+
+ isAttackedByKing(sq, color) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ color,
+ V.KING,
+ V.steps[V.KNIGHT],
+ "oneStep"
+ );
+ }
+
+ isAttackedByCommoner(sq, color) {
+ return this.isAttackedBySlideNJump(
+ sq,
+ color,
+ V.COMMONER,
+ V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
+ "oneStep"
+ );
+ }
+
+ postPlay() {}
+ postUndo() {}
+
+ // NOTE: 4 next functions (almost) copy-paste from Spartan Chess
+ getKingsPos(color) {
+ let kings = [];
+ for (let i=0; i<8; i++) {
+ for (let j=0; j<8; j++) {
+ if (
+ this.board[i][j] != V.EMPTY &&
+ this.getColor(i, j) == color &&
+ this.getPiece(i, j) == V.KING
+ ) {
+ kings.push({ x: i, y: j });
+ }
+ }
+ }
+ return kings;
+ }
+
+ getCheckSquares() {
+ const color = this.turn;
+ const oppCol = V.GetOppCol(color);
+ const kings = this.getKingsPos(color);
+ let res = [];
+ for (let i of [0, 1]) {
+ if (
+ kings.length >= i+1 &&
+ super.isAttacked([kings[i].x, kings[i].y], oppCol)
+ ) {
+ res.push([kings[i].x, kings[i].y]);
+ }
+ }
+ return res;
+ }
+
+ filterValid(moves) {
+ if (moves.length == 0) return [];
+ const color = moves[0].vanish[0].c;
+ const oppCol = V.GetOppCol(color);
+ // Check if both kings under attack.
+ // If yes, moves must remove at least one attack.
+ const kings = this.getKingsPos(color);
+ return moves.filter(m => {
+ this.play(m);
+ let attacks = 0;
+ for (let k of kings) {
+ const curKingPos =
+ this.board[k.x][k.y] == V.EMPTY
+ ? [m.appear[0].x, m.appear[0].y] //king moved
+ : [k.x, k.y]
+ if (super.isAttacked(curKingPos, oppCol)) attacks++;
+ else break; //no need to check further
+ }
+ this.undo(m);
+ return (
+ (kings.length == 2 && attacks <= 1) ||
+ (kings.length == 1 && attacks == 0)
+ );
+ });
+ }
+
+ getCurrentScore() {
+ if (super.atLeastOneMove()) return "*";
+ // Count kings on board
+ const color = this.turn;
+ const oppCol = V.GetOppCol(color);
+ const kings = this.getKingsPos(color);
+ if (
+ super.isAttacked([kings[0].x, kings[0].y], oppCol) ||
+ (kings.length == 2 && super.isAttacked([kings[1].x, kings[1].y], oppCol))
+ ) {
+ return (color == 'w' ? "0-1" : "1-0");
+ }
+ return "1/2"; //stalemate
+ }
+
+ static get VALUES() {
+ return {
+ p: 1,
+ r: 5,
+ c: 5, //the commoner is valuable
+ b: 3,
+ q: 9,
+ k: 1000
+ };
+ }
+
+};