/*
 * Copyright (C) 2012-2016 The Android Money Manager Ex Project Team
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.money.manager.ex.home;

import java.util.Comparator;

/**
 * Comparator for DatabaseMetadata objects that compares their properties.
 */
public class RecentDatabaseEntryComparator
    implements Comparator<DatabaseMetadata> {

    /**
     * Compares the two specified objects to determine their relative ordering. The ordering
     * implied by the return value of this method for all possible pairs of
     * {@code (lhs, rhs)} should form an <i>equivalence relation</i>.
     * This means that
     * <ul>
     * <li>{@code compare(a,a)} returns zero for all {@code a}</li>
     * <li>the sign of {@code compare(a,b)} must be the opposite of the sign of {@code
     * compare(b,a)} for all pairs of (a,b)</li>
     * <li>From {@code compare(a,b) > 0} and {@code compare(b,c) > 0} it must
     * follow {@code compare(a,c) > 0} for all possible combinations of {@code
     * (a,b,c)}</li>
     * </ul>
     *
     * @param lhs an {@code Object}.
     * @param rhs a second {@code Object} to compare with {@code lhs}.
     * @return an integer < 0 if {@code lhs} is less than {@code rhs}, 0 if they are
     * equal, and > 0 if {@code lhs} is greater than {@code rhs}.
     * @throws ClassCastException if objects are not of the correct type.
     */
    @Override
    public int compare(DatabaseMetadata lhs, DatabaseMetadata rhs) {
        if (lhs.isSynchronised() != rhs.isSynchronised()) return 1;
        if (!lhs.localPath.equals(rhs.localPath)) return 1;

        if (lhs.remotePath == null) lhs.remotePath = "";
        if (rhs.remotePath == null) rhs.remotePath = "";
        if (!lhs.remotePath.equals(rhs.remotePath)) return 1;

        if (lhs.isLocalFileChanged != rhs.isLocalFileChanged) return 1;

        return 0;
    }
}