//==============================================================================
//	
//	Copyright (c) 2002-
//	Authors:
//	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
//	
//------------------------------------------------------------------------------
//	
//	This file is part of PRISM.
//	
//	PRISM is free software; you can redistribute it and/or modify
//	it under the terms of the GNU General Public License as published by
//	the Free Software Foundation; either version 2 of the License, or
//	(at your option) any later version.
//	
//	PRISM is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU General Public License for more details.
//	
//	You should have received a copy of the GNU General Public License
//	along with PRISM; if not, write to the Free Software Foundation,
//	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//	
//==============================================================================

package parser.ast;

import param.BigRational;
import parser.EvaluateContext;
import parser.type.TypePathBool;
import parser.visitor.ASTVisitor;
import prism.PrismLangException;

public class ExpressionAccumulation extends Expression
{
	AccumulationSymbol symbol;
	AccumulationConstraint constraint;
	ExpressionRegular regexp;
	TemporalOperatorBound bound;
	
	public ExpressionAccumulation(AccumulationSymbol symbol) {
		this.symbol = symbol;
		this.setType(TypePathBool.getInstance());
	}
	
	public boolean hasRegularExpression() {
		return regexp != null;
	}
	
	public boolean hasBoundExpression() {
		return bound != null;
	}
	
	public AccumulationSymbol getSymbol() {
		return symbol;
	}
	public void setSymbol(AccumulationSymbol symbol) {
		this.symbol = symbol;
	}
	public AccumulationConstraint getConstraint() {
		return constraint;
	}
	public void setConstraint(AccumulationConstraint constraint) {
		this.constraint = constraint;
	}
	public ExpressionRegular getRegularExpression() {
		if ( hasRegularExpression() ) { return regexp; }
		else throw new RuntimeException("getRegularExpression called without RegularExpression");
	}
	public void setRegularExpression(ExpressionRegular regexp) {
		this.bound  = null;
		this.regexp = regexp;
	}
	
	public TemporalOperatorBound getBoundExpression() {
		if ( hasBoundExpression() ) { return bound; }
		else throw new RuntimeException("getBoundExpression called without BoundExpression");
	}
	
	public void setBoundExpression(TemporalOperatorBound bound) {
		if ( bound.isDefaultBound() && bound.hasUpperBound() ) {
			this.regexp= null;
			this.bound = bound;
		} else {
			throw new RuntimeException("Bounds need to be upper and default.");
		}
	}
	
	// Add a toString
	public String toString() {
		String ret = "";
		ret += symbol.toString();
		if ( hasRegularExpression() ) { ret += "( Reg:" + regexp.toString() + ")"; }
		else if ( hasBoundExpression() ) { ret += "(" + bound.toString() + ")"; } 
		else throw new RuntimeException("Cannot stringify AccumulationExpression without fragment bounds.");
		ret += "(" + constraint.toString() + ")";
		return ret;
	}

	@Override
	public boolean isConstant() {
		return false;
	}

	@Override
	public boolean isProposition() {
		return false;
	}

	@Override
	public Object evaluate(EvaluateContext ec) throws PrismLangException {
		return null;
	}
	
	@Override
	public BigRational evaluateExact(EvaluateContext ec) throws PrismLangException {
		return null;
	}

	@Override
	public boolean returnsSingleValue() {
		return false;
	}

	@Override
	public Expression deepCopy() {
		ExpressionAccumulation ret = new ExpressionAccumulation(this.getSymbol());
		
		ret.setConstraint(this.getConstraint().deepCopy());
		if ( this.hasBoundExpression() ) {
			ret.setBoundExpression(this.getBoundExpression().deepCopy());
		}
		if ( this.hasRegularExpression() ) {
			ret.setRegularExpression((ExpressionRegular) this.getRegularExpression().deepCopy());
		}
		
		return ret;
	}

	@Override
	public Object accept(ASTVisitor v) throws PrismLangException {
		return v.visit(this);
	}

}

//------------------------------------------------------------------------------