/*******************************************************************************
 * 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 java.util.List;

import org.eclipse.dltk.evaluation.types.AmbiguousType;
import org.eclipse.dltk.evaluation.types.MultiTypeType;
import org.eclipse.dltk.ti.GoalState;
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.internal.core.typeinference.goals.ForeachStatementGoal;
import org.eclipse.php.internal.core.typeinference.goals.IteratorTypeGoal;

/**
 * This evaluator determines types that array expression in foreach statement
 * holds
 */
public class ForeachStatementEvaluator extends GoalEvaluator {

	private IEvaluatedType result;

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

	public IGoal[] init() {
		ForeachStatementGoal typedGoal = (ForeachStatementGoal) goal;
		return new IGoal[] { new IteratorTypeGoal(goal.getContext(), typedGoal.getExpression()) };
	}

	public IGoal[] subGoalDone(IGoal subgoal, Object result, GoalState state) {
		if (result instanceof MultiTypeType) {
			List<IEvaluatedType> types = ((MultiTypeType) result).getTypes();
			this.result = new AmbiguousType(types.toArray(new IEvaluatedType[types.size()]));
		} else if (result instanceof AmbiguousType) {
			this.result = (AmbiguousType) result;
		}
		return IGoal.NO_GOALS;
	}

	public Object produceResult() {
		return result;
	}
}