//   Copyright 2012 Georg-August-Universität Göttingen, Germany
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

package de.ugoe.cs.autoquest.tasktrees.taskequality;

import de.ugoe.cs.autoquest.tasktrees.treeifc.ITask;
import de.ugoe.cs.autoquest.tasktrees.treeifc.ITaskInstance;

/**
 * <p>
 * This comparison rule returns <code>TaskEquality.IDENTICAL</code> if the comparison of the two
 * tasks using the <code>==</code> operator returns true. Else it returns null to denote, that
 * it can not compare the tasks.
 * </p>
 * 
 * @version $Revision: $ $Date: 19.02.2012$
 * @author 2012, last modified by $Author: patrick$
 */
public class TaskIdentityRule implements TaskComparisonRule {

    /* (non-Javadoc)
     * @see TaskComparisonRule#isApplicable(ITask, ITask)
     */
    @Override
    public boolean isApplicable(ITask task1, ITask task2) {
        return (task1 == task2);
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areLexicallyEqual(ITask, ITask)
     */
    @Override
    public boolean areLexicallyEqual(ITask task1, ITask task2) {
        return (task1 == task2);
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areSyntacticallyEqual(ITask, ITask)
     */
    @Override
    public boolean areSyntacticallyEqual(ITask task1, ITask task2) {
        return (task1 == task2);
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areSemanticallyEqual(ITask, ITask)
     */
    @Override
    public boolean areSemanticallyEqual(ITask task1, ITask task2) {
        return (task1 == task2);
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#compare(ITask, ITask)
     */
    @Override
    public TaskEquality compare(ITask task1, ITask task2) {
        if (isApplicable(task1, task2)) {
            return TaskEquality.IDENTICAL;
        }
        else {
            return null;
        }
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#isApplicable(ITaskInstance, ITaskInstance)
     */
    @Override
    public boolean isApplicable(ITaskInstance instance1, ITaskInstance instance2) {
        return (instance1.getTask() == instance2.getTask());
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areLexicallyEqual(ITaskInstance, ITaskInstance)
     */
    @Override
    public boolean areLexicallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
        return (instance1.getTask() == instance2.getTask());
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areSyntacticallyEqual(ITaskInstance, ITaskInstance)
     */
    @Override
    public boolean areSyntacticallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
        return (instance1.getTask() == instance2.getTask());
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#areSemanticallyEqual(ITaskInstance, ITaskInstance)
     */
    @Override
    public boolean areSemanticallyEqual(ITaskInstance instance1, ITaskInstance instance2) {
        return (instance1.getTask() == instance2.getTask());
    }

    /* (non-Javadoc)
     * @see TaskComparisonRule#compare(ITaskInstance, ITaskInstance)
     */
    @Override
    public TaskEquality compare(ITaskInstance instance1, ITaskInstance instance2) {
        if (isApplicable(instance1, instance2)) {
            return TaskEquality.IDENTICAL;
        }
        else {
            return null;
        }
    }

}
