/*
 * Copyright (c) 2012, 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.util.priority;

import org.jowidgets.util.Assert;
import org.jowidgets.util.NullCompatibleComparison;

public final class PrioritizedResultCreator<VALUE_TYPE, PRIORITY_TYPE extends Comparable<PRIORITY_TYPE>> implements
        IPriorityValue<VALUE_TYPE, PRIORITY_TYPE> {

    private final PRIORITY_TYPE maxPriority;

    private IPriorityValue<VALUE_TYPE, PRIORITY_TYPE> currentResult;

    /**
     * Creates a new instance.
     * 
     * @param maxPriority The maximal priority of the priority type
     */
    public PrioritizedResultCreator(final PRIORITY_TYPE maxPriority) {
        Assert.paramNotNull(maxPriority, "maxPriority");
        this.maxPriority = maxPriority;
    }

    /**
     * Adds a new (partial) result.
     * 
     * @param result The result to add, may be null (null will be ignored)
     * @return true is result creator has max prio, false otherwise
     */
    public boolean addResult(final IPriorityValue<VALUE_TYPE, PRIORITY_TYPE> result) {
        if (result != null) {
            final PRIORITY_TYPE currentPrio = currentResult != null ? currentResult.getPriority() : null;
            if (NullCompatibleComparison.compareTo(result.getPriority(), currentPrio) >= 0) {
                currentResult = result;
            }
        }
        return hasMaxPrio();
    }

    /**
     * @return True, if the max priority is reached
     */
    public boolean hasMaxPrio() {
        if (currentResult != null) {
            return NullCompatibleComparison.compareTo(currentResult.getPriority(), maxPriority) >= 0;
        }
        else {
            return false;
        }
    }

    /**
     * @return The current result, may be null if no results was added
     */
    public IPriorityValue<VALUE_TYPE, PRIORITY_TYPE> getResult() {
        return currentResult;
    }

    @Override
    public VALUE_TYPE getValue() {
        if (currentResult != null) {
            return currentResult.getValue();
        }
        else {
            return null;
        }
    }

    @Override
    public PRIORITY_TYPE getPriority() {
        if (currentResult != null) {
            return currentResult.getPriority();
        }
        else {
            return null;
        }
    }

}