/*
 * 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.index.schema;

import static org.assertj.core.api.Assertions.assertThat;

import java.nio.charset.StandardCharsets;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.neo4j.test.RandomSupport;
import org.neo4j.test.extension.Inject;
import org.neo4j.test.extension.RandomExtension;
import org.neo4j.values.storable.Values;

@ExtendWith(RandomExtension.class)
class CompositeRangeKeyTest {
    @Inject
    RandomSupport random;

    /**
     * This test verify that the documented formula for calculating size limit for string array
     * actually calculate correctly.
     */
    @Test
    void testDocumentedStringArrayKeySizeFormulaIsCorrect() {
        CompositeRangeKey key = new CompositeRangeKey(1);
        int maxArrayLength = random.nextInt(500);
        int maxStringLength = random.nextInt(100);
        for (int i = 0; i < 100; i++) {
            String[] strings = random.randomValues().nextStringArrayRaw(0, maxArrayLength, 0, maxStringLength);
            key.initialize(i);
            key.writeValue(0, Values.of(strings), NativeIndexKey.Inclusion.NEUTRAL);
            assertThat(includingEntityId(calculateKeySize(strings))).isEqualTo(key.size());
        }
    }

    private static int includingEntityId(int keySize) {
        return Long.BYTES + keySize;
    }

    private static int calculateKeySize(String[] strings) {
        int arrayLength = strings.length;
        int totalStringLength = 0;
        for (String string : strings) {
            totalStringLength += string.getBytes(StandardCharsets.UTF_8).length;
        }
        return 1 + 2 + 2 * arrayLength + totalStringLength;
    }
}
