/*
 * Copyright (C) 2010 ZXing authors
 *
 * 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.
 */

/*
 * These authors would like to acknowledge the Spanish Ministry of Industry,
 * Tourism and Trade, for the support in the project TSI020301-2008-2
 * "PIRAmIDE: Personalizable Interactions with Resources on AmI-enabled
 * Mobile Dynamic Environments", led by Treelogic
 * ( http://www.treelogic.com/ ):
 *
 *   http://www.piramidepse.com/
 */

package com.google.zxing.oned.rss.expanded;

import com.google.zxing.oned.rss.DataCharacter;
import com.google.zxing.oned.rss.FinderPattern;

/**
 * @author Pablo Orduña, University of Deusto (pablo.orduna@deusto.es)
 */
final class ExpandedPair {

	private final boolean mayBeLast;
	private final DataCharacter leftChar;
	private final DataCharacter rightChar;
	private final FinderPattern finderPattern;

	ExpandedPair(DataCharacter leftChar, DataCharacter rightChar, FinderPattern finderPattern, boolean mayBeLast) {
		this.leftChar = leftChar;
		this.rightChar = rightChar;
		this.finderPattern = finderPattern;
		this.mayBeLast = mayBeLast;
	}

	boolean mayBeLast() {
		return this.mayBeLast;
	}

	DataCharacter getLeftChar() {
		return this.leftChar;
	}

	DataCharacter getRightChar() {
		return this.rightChar;
	}

	FinderPattern getFinderPattern() {
		return this.finderPattern;
	}

	public boolean mustBeLast() {
		return this.rightChar == null;
	}

	@Override
	public String toString() {
		return "[ " + leftChar + " , " + rightChar + " : " + (finderPattern == null ? "null" : finderPattern.getValue()) + " ]";
	}

	@Override
	public boolean equals(Object o) {
		if (!(o instanceof ExpandedPair)) {
			return false;
		}
		ExpandedPair that = (ExpandedPair) o;
		return equalsOrNull(leftChar, that.leftChar) && equalsOrNull(rightChar, that.rightChar) && equalsOrNull(finderPattern, that.finderPattern);
	}

	private static boolean equalsOrNull(Object o1, Object o2) {
		return o1 == null ? o2 == null : o1.equals(o2);
	}

	@Override
	public int hashCode() {
		return hashNotNull(leftChar) ^ hashNotNull(rightChar) ^ hashNotNull(finderPattern);
	}

	private static int hashNotNull(Object o) {
		return o == null ? 0 : o.hashCode();
	}

}
