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f0c8ada | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 | import { Chess } from '../../libs/chess.js';
export class GamePhase {
constructor() {}
static getPhases(moves) {
if (!moves || moves.length === 0) {
return [];
}
const phases = [];
const chess = new Chess();
// Track phase changes
let currentPhase = 'opening';
for (let i = 0; i < moves.length; i++) {
// Make the move
chess.move(moves[i]);
// Determine phase at this position
const phaseInfo = this._analyzePosition(chess, i + 1);
const detectedPhase = phaseInfo.phase;
// Check for phase transition
if (detectedPhase !== currentPhase) {
phases.push({
phase: detectedPhase,
startMove: i + 1,
moveNumber: Math.ceil((i + 1) / 2),
ply: i + 1,
reason: phaseInfo.reason,
criteria: phaseInfo.criteria
});
currentPhase = detectedPhase;
}
}
// If no phases were detected, the entire game is in opening
if (phases.length === 0) {
phases.push({
phase: 'opening',
startMove: 1,
moveNumber: 1,
ply: 1,
reason: 'Game start',
criteria: { moveCount: 1 }
});
}
return phases;
}
static _analyzePosition(chess, moveCount) {
const board = chess.board();
const fen = chess.fen();
const moveNumber = chess.moveNumber();
// Calculate various position metrics
const metrics = this._calculateMetrics(board, chess, moveCount);
// Determine phase based on multiple criteria
if (this._isEndgame(metrics)) {
return {
phase: 'endgame',
reason: this._getEndgameReason(metrics),
criteria: metrics
};
} else if (this._isMiddlegame(metrics)) {
return {
phase: 'middlegame',
reason: this._getMiddlegameReason(metrics),
criteria: metrics
};
} else {
return {
phase: 'opening',
reason: this._getOpeningReason(metrics),
criteria: metrics
};
}
}
static _calculateMetrics(board, chess, moveCount) {
const metrics = {
moveCount: moveCount,
moveNumber: chess.moveNumber(),
totalPieces: 0,
developedPieces: { white: 0, black: 0 },
materialValue: { white: 0, black: 0 },
hasQueens: { white: false, black: false },
hasCastled: { white: false, black: false },
minorPiecesLeft: { white: 0, black: 0 },
majorPiecesLeft: { white: 0, black: 0 }
};
// Piece values for material calculation
const pieceValues = { p: 1, n: 3, b: 3, r: 5, q: 9, k: 0 };
// Starting positions for development tracking
const startingPositions = {
white: {
knights: ['b1', 'g1'],
bishops: ['c1', 'f1'],
rooks: ['a1', 'h1'],
queen: 'd1',
king: 'e1'
},
black: {
knights: ['b8', 'g8'],
bishops: ['c8', 'f8'],
rooks: ['a8', 'h8'],
queen: 'd8',
king: 'e8'
}
};
// Analyze each square on the board
for (let rank = 0; rank < 8; rank++) {
for (let file = 0; file < 8; file++) {
const piece = board[rank][file];
if (piece) {
metrics.totalPieces++;
const color = piece.color === 'w' ? 'white' : 'black';
const pieceType = piece.type.toLowerCase();
const square = String.fromCharCode(97 + file) + (8 - rank);
// Add to material count
metrics.materialValue[color] += pieceValues[pieceType] || 0;
// Count piece types
if (pieceType === 'q') {
metrics.hasQueens[color] = true;
metrics.majorPiecesLeft[color]++;
} else if (pieceType === 'r') {
metrics.majorPiecesLeft[color]++;
} else if (pieceType === 'n' || pieceType === 'b') {
metrics.minorPiecesLeft[color]++;
}
// Check development
const startingPos = startingPositions[color];
if (startingPos) {
let isDeveloped = false;
if (pieceType === 'n' && !startingPos.knights.includes(square)) {
isDeveloped = true;
} else if (pieceType === 'b' && !startingPos.bishops.includes(square)) {
isDeveloped = true;
} else if (pieceType === 'q' && square !== startingPos.queen) {
isDeveloped = true;
}
if (isDeveloped) {
metrics.developedPieces[color]++;
}
}
}
}
}
// Check castling status
const castlingRights = chess.getCastlingRights('w');
const blackCastlingRights = chess.getCastlingRights('b');
// If no castling rights remain, assume they've castled
// (This is a simplification - could be improved by tracking king/rook moves)
metrics.hasCastled.white = castlingRights.k === false && castlingRights.q === false;
metrics.hasCastled.black = blackCastlingRights.k === false && blackCastlingRights.q === false;
return metrics;
}
static _isEndgame(metrics) {
// Endgame criteria (any of these conditions)
const conditions = [
// No queens on board
!metrics.hasQueens.white && !metrics.hasQueens.black,
// Very few pieces left (less than 16 total)
metrics.totalPieces <= 12,
// Low material count for both sides
(metrics.materialValue.white + metrics.materialValue.black) <= 20,
// Queens traded and few minor pieces
!metrics.hasQueens.white && !metrics.hasQueens.black &&
(metrics.minorPiecesLeft.white + metrics.minorPiecesLeft.black) <= 4,
// Late in the game with limited material
metrics.moveNumber >= 40 && metrics.totalPieces <= 16
];
return conditions.some(condition => condition);
}
static _isMiddlegame(metrics) {
// Middlegame criteria
const conditions = [
// Sufficient development and move count
metrics.moveCount >= 10 &&
(metrics.developedPieces.white >= 2 || metrics.developedPieces.black >= 2),
// Castling has occurred for at least one side
metrics.hasCastled.white || metrics.hasCastled.black,
// Queens still on board but some development
(metrics.hasQueens.white || metrics.hasQueens.black) && metrics.moveCount >= 8,
// Sufficient pieces and material for middlegame complexity
metrics.totalPieces >= 20 && metrics.moveCount >= 12
];
return conditions.some(condition => condition) && !this._isEndgame(metrics);
}
static _getEndgameReason(metrics) {
if (!metrics.hasQueens.white && !metrics.hasQueens.black) {
return 'Queens traded off';
} else if (metrics.totalPieces <= 12) {
return `Few pieces remaining (${metrics.totalPieces})`;
} else if ((metrics.materialValue.white + metrics.materialValue.black) <= 20) {
return 'Low material count';
} else {
return 'Endgame characteristics detected';
}
}
static _getMiddlegameReason(metrics) {
if (metrics.hasCastled.white || metrics.hasCastled.black) {
return 'Castling completed, pieces developed';
} else if (metrics.developedPieces.white >= 2 || metrics.developedPieces.black >= 2) {
return 'Sufficient piece development';
} else if (metrics.moveCount >= 10) {
return 'Opening phase complete';
} else {
return 'Middlegame characteristics detected';
}
}
static _getOpeningReason(metrics) {
if (metrics.moveCount <= 8) {
return 'Early game development';
} else if (metrics.developedPieces.white < 2 && metrics.developedPieces.black < 2) {
return 'Limited piece development';
} else {
return 'Opening principles still apply';
}
}
// Utility method to get current phase for a position
static getCurrentPhase(chess) {
const moveCount = chess.history().length;
if (moveCount === 0) {
return {
phase: 'opening',
reason: 'Game start',
criteria: { moveCount: 0 }
};
}
return this._analyzePosition(chess, moveCount);
}
// Get phase summary for the entire game
static getGameSummary(moves) {
const phases = this.getPhases(moves);
const summary = {
totalMoves: moves.length,
totalPlies: moves.length,
phases: phases,
phaseDurations: {}
};
// Calculate phase durations
for (let i = 0; i < phases.length; i++) {
const phase = phases[i];
const nextPhase = phases[i + 1];
const endMove = nextPhase ? nextPhase.startMove - 1 : moves.length;
const duration = endMove - phase.startMove + 1;
if (!summary.phaseDurations[phase.phase]) {
summary.phaseDurations[phase.phase] = 0;
}
summary.phaseDurations[phase.phase] += duration;
}
return summary;
}
} |