package parser.visitor;

import parser.ast.AccumulationSymbol;
import parser.ast.ExpressionAccumulation;
import parser.ast.ExpressionLabel;
import parser.ast.ExpressionTemporal;
import parser.ast.ExpressionUnaryOp;
import parser.ast.TemporalOperatorBound;
import parser.ast.TemporalOperatorBounds;
import prism.IntegerBound;
import prism.PrismLangException;


public class ReplaceAccumulationExpression extends ASTTraverseModify {

	private ExpressionAccumulation accexp;
	private String replacementLabel;
	private int replacementPosition;
	
	
	
	public ReplaceAccumulationExpression(ExpressionAccumulation accexp, String replacementLabel) {
		super();
		this.accexp = accexp;
		this.replacementLabel = replacementLabel;
		this.replacementPosition = 0;
	}

	public ReplaceAccumulationExpression(ExpressionAccumulation accexp, String replacementLabel, int replacementPosition)
	{
		this(accexp, replacementLabel);
		this.replacementPosition = replacementPosition;
	}
	
	public Object visit(ExpressionAccumulation expr) throws PrismLangException
	{
		ExpressionLabel label = new ExpressionLabel(replacementLabel);
		//System.out.println("Replacing "+expr.toString()+" with "+label.toString());
		if (expr == accexp) {
			AccumulationSymbol sym = expr.getSymbol();
			
			if (sym.isPlus()) {
				// We are looking into a bright future, wrap it in F=position
				ExpressionTemporal fLabel = new ExpressionTemporal(ExpressionTemporal.P_F, null, label);
				TemporalOperatorBounds fBounds = new TemporalOperatorBounds();
				TemporalOperatorBound fBound = IntegerBound.fromEqualBounds(replacementPosition).toTemporalOperatorBound();
				fBounds.setDefaultBound(fBound);
				fLabel.setBounds(fBounds);
				// If its a BOX, negate it
				if (sym.isBox()) {
					return new ExpressionUnaryOp(ExpressionUnaryOp.NOT, fLabel);
				} else {
					return fLabel;
				}
			} else {
				// This is a MINUS, just check for negation
				if (sym.isBox()) {
					return new ExpressionUnaryOp(ExpressionUnaryOp.NOT, label);
				} else {
					return label;
				}
			}
		} else {
			return expr;
		}
	}
}