/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j 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 org.neo4j.kernel.impl.store;

import static java.lang.System.arraycopy;

import java.util.Arrays;

public class LabelIdArray {
    private LabelIdArray() {}

    static long[] concatAndSort(long[] existing, long additional) {
        assertNotContains(existing, additional);

        long[] result = new long[existing.length + 1];
        arraycopy(existing, 0, result, 0, existing.length);
        result[existing.length] = additional;
        Arrays.sort(result);
        return result;
    }

    private static void assertNotContains(long[] existingLabels, long labelId) {
        if (Arrays.binarySearch(existingLabels, labelId) >= 0) {
            throw new IllegalStateException("Label " + labelId + " already exists.");
        }
    }

    static long[] filter(long[] ids, long excludeId) {
        boolean found = false;
        for (long id : ids) {
            if (id == excludeId) {
                found = true;
                break;
            }
        }
        if (!found) {
            throw new IllegalStateException("Label " + excludeId + " not found.");
        }

        long[] result = new long[ids.length - 1];
        int writerIndex = 0;
        for (long id : ids) {
            if (id != excludeId) {
                result[writerIndex++] = id;
            }
        }
        return result;
    }

    public static long[] prependNodeId(long nodeId, long[] labelIds) {
        long[] result = new long[labelIds.length + 1];
        arraycopy(labelIds, 0, result, 1, labelIds.length);
        result[0] = nodeId;
        return result;
    }

    public static long[] stripNodeId(long[] storedLongs) {
        return Arrays.copyOfRange(storedLongs, 1, storedLongs.length);
    }
}
