| 1 | import { ChessRules } from "@/base_rules"; |
| 2 | import { randInt } from "@/utils/alea"; |
| 3 | |
| 4 | export class MonsterRules extends ChessRules { |
| 5 | static IsGoodFlags(flags) { |
| 6 | // Only black can castle |
| 7 | return !!flags.match(/^[a-z]{2,2}$/); |
| 8 | } |
| 9 | |
| 10 | static GenRandInitFen(randomness) { |
| 11 | if (randomness == 2) randomness--; |
| 12 | const fen = ChessRules.GenRandInitFen(randomness); |
| 13 | return ( |
| 14 | // 26 first chars are 6 rows + 6 slashes |
| 15 | fen.substr(0, 26) |
| 16 | // En passant available, and "half-castle" |
| 17 | .concat("1PPPPPP1/4K3 w 0 ") |
| 18 | .concat(fen.substr(-6, 2)) |
| 19 | .concat(" -") |
| 20 | ); |
| 21 | } |
| 22 | |
| 23 | getFlagsFen() { |
| 24 | return this.castleFlags['b'].map(V.CoordToColumn).join(""); |
| 25 | } |
| 26 | |
| 27 | setFlags(fenflags) { |
| 28 | this.castleFlags = { 'b': [-1, -1] }; |
| 29 | for (let i = 0; i < 2; i++) |
| 30 | this.castleFlags['b'][i] = V.ColumnToCoord(fenflags.charAt(i)); |
| 31 | } |
| 32 | |
| 33 | setOtherVariables(fen) { |
| 34 | super.setOtherVariables(fen); |
| 35 | this.subTurn = 1; |
| 36 | } |
| 37 | |
| 38 | getPotentialKingMoves([x, y]) { |
| 39 | if (this.getColor(x, y) == 'b') return super.getPotentialKingMoves([x, y]); |
| 40 | // White doesn't castle: |
| 41 | return this.getSlideNJumpMoves( |
| 42 | [x, y], |
| 43 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), |
| 44 | "oneStep" |
| 45 | ); |
| 46 | } |
| 47 | |
| 48 | isAttacked(sq, color, castling) { |
| 49 | const singleMoveAttack = super.isAttacked(sq, color); |
| 50 | if (singleMoveAttack) return true; |
| 51 | if (color == 'b' || !!castling) return singleMoveAttack; |
| 52 | // Attacks by white: double-move allowed |
| 53 | const curTurn = this.turn; |
| 54 | this.turn = 'w'; |
| 55 | const w1Moves = super.getAllPotentialMoves(); |
| 56 | this.turn = curTurn; |
| 57 | for (let move of w1Moves) { |
| 58 | this.play(move); |
| 59 | const res = super.isAttacked(sq, 'w'); |
| 60 | this.undo(move); |
| 61 | if (res) return res; |
| 62 | } |
| 63 | return false; |
| 64 | } |
| 65 | |
| 66 | play(move) { |
| 67 | move.flags = JSON.stringify(this.aggregateFlags()); |
| 68 | if (this.turn == 'b' || this.subTurn == 2) |
| 69 | this.epSquares.push(this.getEpSquare(move)); |
| 70 | else this.epSquares.push(null); |
| 71 | V.PlayOnBoard(this.board, move); |
| 72 | if (this.turn == 'w') { |
| 73 | if (this.subTurn == 1) this.movesCount++; |
| 74 | else this.turn = 'b'; |
| 75 | this.subTurn = 3 - this.subTurn; |
| 76 | } else { |
| 77 | this.turn = 'w'; |
| 78 | this.movesCount++; |
| 79 | } |
| 80 | this.postPlay(move); |
| 81 | } |
| 82 | |
| 83 | updateCastleFlags(move, piece) { |
| 84 | // Only black can castle: |
| 85 | const firstRank = 0; |
| 86 | if (piece == V.KING && move.appear[0].c == 'b') |
| 87 | this.castleFlags['b'] = [8, 8]; |
| 88 | else if ( |
| 89 | move.start.x == firstRank && |
| 90 | this.castleFlags['b'].includes(move.start.y) |
| 91 | ) { |
| 92 | const flagIdx = (move.start.y == this.castleFlags['b'][0] ? 0 : 1); |
| 93 | this.castleFlags['b'][flagIdx] = 8; |
| 94 | } |
| 95 | else if ( |
| 96 | move.end.x == firstRank && |
| 97 | this.castleFlags['b'].includes(move.end.y) |
| 98 | ) { |
| 99 | const flagIdx = (move.end.y == this.castleFlags['b'][0] ? 0 : 1); |
| 100 | this.castleFlags['b'][flagIdx] = 8; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | postPlay(move) { |
| 105 | // Definition of 'c' in base class doesn't work: |
| 106 | const c = move.vanish[0].c; |
| 107 | const piece = move.vanish[0].p; |
| 108 | if (piece == V.KING) { |
| 109 | this.kingPos[c][0] = move.appear[0].x; |
| 110 | this.kingPos[c][1] = move.appear[0].y; |
| 111 | } |
| 112 | this.updateCastleFlags(move, piece); |
| 113 | } |
| 114 | |
| 115 | undo(move) { |
| 116 | this.epSquares.pop(); |
| 117 | this.disaggregateFlags(JSON.parse(move.flags)); |
| 118 | V.UndoOnBoard(this.board, move); |
| 119 | if (this.turn == 'w') { |
| 120 | if (this.subTurn == 2) this.subTurn = 1; |
| 121 | else this.turn = 'b'; |
| 122 | this.movesCount--; |
| 123 | } else { |
| 124 | this.turn = 'w'; |
| 125 | this.subTurn = 2; |
| 126 | } |
| 127 | this.postUndo(move); |
| 128 | } |
| 129 | |
| 130 | filterValid(moves) { |
| 131 | if (this.turn == 'w' && this.subTurn == 1) { |
| 132 | return moves.filter(m1 => { |
| 133 | this.play(m1); |
| 134 | // NOTE: no recursion because next call will see subTurn == 2 |
| 135 | const res = super.atLeastOneMove(); |
| 136 | this.undo(m1); |
| 137 | return res; |
| 138 | }); |
| 139 | } |
| 140 | return super.filterValid(moves); |
| 141 | } |
| 142 | |
| 143 | static get SEARCH_DEPTH() { |
| 144 | return 1; |
| 145 | } |
| 146 | |
| 147 | getComputerMove() { |
| 148 | const color = this.turn; |
| 149 | if (color == 'w') { |
| 150 | // Generate all sequences of 2-moves |
| 151 | const moves1 = this.getAllValidMoves(); |
| 152 | moves1.forEach(m1 => { |
| 153 | m1.eval = -V.INFINITY; |
| 154 | m1.move2 = null; |
| 155 | this.play(m1); |
| 156 | const moves2 = this.getAllValidMoves(); |
| 157 | moves2.forEach(m2 => { |
| 158 | this.play(m2); |
| 159 | const eval2 = this.evalPosition(); |
| 160 | this.undo(m2); |
| 161 | if (eval2 > m1.eval) { |
| 162 | m1.eval = eval2; |
| 163 | m1.move2 = m2; |
| 164 | } |
| 165 | }); |
| 166 | this.undo(m1); |
| 167 | }); |
| 168 | moves1.sort((a, b) => b.eval - a.eval); |
| 169 | let candidates = [0]; |
| 170 | for ( |
| 171 | let i = 1; |
| 172 | i < moves1.length && moves1[i].eval == moves1[0].eval; |
| 173 | i++ |
| 174 | ) { |
| 175 | candidates.push(i); |
| 176 | } |
| 177 | const idx = candidates[randInt(candidates.length)]; |
| 178 | const move2 = moves1[idx].move2; |
| 179 | delete moves1[idx]["move2"]; |
| 180 | return [moves1[idx], move2]; |
| 181 | } |
| 182 | // For black at depth 1, super method is fine: |
| 183 | return super.getComputerMove(); |
| 184 | } |
| 185 | }; |