xchess/lib/transitional-state.js

Chess Engine

export {Transitional}

import {
	ResignationState,
	ForfeitState,
	WinOnTimeState,
	ThreefoldRepetitionState,
	FiftyMovesState,
	DrawByResignationState,
	DrawOnTimeState,
	DrawByAgreementState,
} from './end-state.js'

function Transitional(State){

	return class TransitionalState extends State {

		forfeit(color){
			this.push(new ForfeitState(this, this, color));
			return true;
		}

		resign(color){
			if(this.isCheckmateChance(color))
				this.push(new ResignationState(this, this, color));
			else
				this.push(new DrawByResignationState(this, this, color));
			return true;
		}

		draw(color){
			if(this.halfmoveClock >= 50){
				this.push(new FiftyMovesState(this, this, color));
				return true;
			}
			if(this.repetition >= 3){
				this.push(new ThreefoldRepetitionState(this, this, color));
				return true;
			}
			return this.drawOffer.draw(color);
		}

		toDraw(color){
			this.push(new DrawByAgreementState(this, this, color));
		}

		flagFall(){
			if(this.isCheckmateChance(this.color))
				this.push(new WinOnTimeState(this, this, this.color));
			else
				this.push(new DrawOnTimeState(this, this));
			return true;
		}
	}
}