/*******************************************************************************
 * Copyright (c) 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Zend Technologies
 *******************************************************************************/
package org.eclipse.php.internal.core.typeinference.evaluators;

import org.eclipse.dltk.ast.expressions.Expression;
import org.eclipse.dltk.ast.references.TypeReference;
import org.eclipse.dltk.evaluation.types.UnknownType;
import org.eclipse.dltk.ti.GoalState;
import org.eclipse.dltk.ti.goals.ExpressionTypeGoal;
import org.eclipse.dltk.ti.goals.GoalEvaluator;
import org.eclipse.dltk.ti.goals.IGoal;
import org.eclipse.dltk.ti.types.IEvaluatedType;
import org.eclipse.php.core.compiler.ast.nodes.StaticConstantAccess;
import org.eclipse.php.internal.core.typeinference.PHPSimpleTypes;
import org.eclipse.php.internal.core.typeinference.goals.ConstantDeclarationGoal;

public class StaticConstantAccessEvaluator extends GoalEvaluator {

	private IEvaluatedType evaluatedType;

	public StaticConstantAccessEvaluator(IGoal goal) {
		super(goal);
	}

	public IGoal[] init() {
		ExpressionTypeGoal typedGoal = (ExpressionTypeGoal) goal;
		StaticConstantAccess expr = (StaticConstantAccess) typedGoal.getExpression();

		Expression dispatcher = expr.getDispatcher();
		if (dispatcher instanceof TypeReference) {
			TypeReference typeReference = (TypeReference) dispatcher;
			return new IGoal[] { new ConstantDeclarationGoal(goal.getContext(), expr.getConstant().getName(),
					typeReference.getName()) };
		}
		return IGoal.NO_GOALS;
	}

	public Object produceResult() {
		return evaluatedType;
	}

	public IGoal[] subGoalDone(IGoal subgoal, Object result, GoalState state) {
		if (state == GoalState.PRUNED || result == null || result == UnknownType.INSTANCE) {
			evaluatedType = PHPSimpleTypes.STRING;
		} else {
			evaluatedType = (IEvaluatedType) result;
		}
		return IGoal.NO_GOALS;
	}

}