/*
 * Copyright (c) 2011, grossmann
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the jo-widgets.org nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.jowidgets.tools.validation;

import org.jowidgets.util.Assert;
import org.jowidgets.util.collection.IObserverSet;
import org.jowidgets.util.collection.IObserverSetFactory.Strategy;
import org.jowidgets.util.collection.ObserverSetFactory;
import org.jowidgets.validation.IValidateable;
import org.jowidgets.validation.IValidationConditionListener;
import org.jowidgets.validation.IValidationResult;

public class ValidationCache implements IValidateable {

    private final IValidationResultCreator validationResultCreator;
    private final IObserverSet<IValidationConditionListener> validationConditionListener;

    private boolean chacheDirty;
    private IValidationResult validationResult;

    public ValidationCache(final IValidationResultCreator validationResultCreator) {
        Assert.paramNotNull(validationResultCreator, "validationResultCreator");
        this.validationConditionListener = ObserverSetFactory.create(Strategy.LOW_MEMORY);
        this.validationResultCreator = validationResultCreator;
        this.chacheDirty = true;
    }

    /**
     * Marks the cache to be dirty. The currently cached value will be rejected.
     */
    public final void setDirty() {
        this.chacheDirty = true;
        for (final IValidationConditionListener listener : validationConditionListener) {
            listener.validationConditionsChanged();
        }
    }

    @Override
    public final IValidationResult validate() {
        if (chacheDirty) {
            this.validationResult = validationResultCreator.createValidationResult();
            this.chacheDirty = false;
        }
        return validationResult;
    }

    @Override
    public final void addValidationConditionListener(final IValidationConditionListener listener) {
        Assert.paramNotNull(listener, "listener");
        validationConditionListener.add(listener);
    }

    @Override
    public final void removeValidationConditionListener(final IValidationConditionListener listener) {
        Assert.paramNotNull(listener, "listener");
        validationConditionListener.remove(listener);
    }

    public final void dispose() {
        validationConditionListener.clear();
    }

    public interface IValidationResultCreator {
        IValidationResult createValidationResult();
    }

}