/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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
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 * under the License.
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/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.index.seqno;

import org.opensearch.test.OpenSearchTestCase;
import org.opensearch.test.EqualsHashCodeTestUtils;

import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasToString;

public class SequenceNumbersTests extends OpenSearchTestCase {

    public void testMin() {
        final long seqNo = randomNonNegativeLong();
        assertThat(SequenceNumbers.min(SequenceNumbers.NO_OPS_PERFORMED, seqNo), equalTo(seqNo));
        assertThat(
            SequenceNumbers.min(SequenceNumbers.NO_OPS_PERFORMED, SequenceNumbers.UNASSIGNED_SEQ_NO),
            equalTo(SequenceNumbers.UNASSIGNED_SEQ_NO)
        );
        assertThat(SequenceNumbers.min(SequenceNumbers.UNASSIGNED_SEQ_NO, seqNo), equalTo(seqNo));
        final long minSeqNo = randomNonNegativeLong();
        assertThat(SequenceNumbers.min(minSeqNo, seqNo), equalTo(Math.min(minSeqNo, seqNo)));

        final IllegalArgumentException e = expectThrows(
            IllegalArgumentException.class,
            () -> SequenceNumbers.min(minSeqNo, SequenceNumbers.UNASSIGNED_SEQ_NO)
        );
        assertThat(e, hasToString(containsString("sequence number must be assigned")));
    }

    public void testMax() {
        final long seqNo = randomNonNegativeLong();
        assertThat(SequenceNumbers.max(SequenceNumbers.NO_OPS_PERFORMED, seqNo), equalTo(seqNo));
        assertThat(
            SequenceNumbers.max(SequenceNumbers.NO_OPS_PERFORMED, SequenceNumbers.UNASSIGNED_SEQ_NO),
            equalTo(SequenceNumbers.UNASSIGNED_SEQ_NO)
        );
        assertThat(SequenceNumbers.max(SequenceNumbers.UNASSIGNED_SEQ_NO, seqNo), equalTo(seqNo));
        final long maxSeqNo = randomNonNegativeLong();
        assertThat(SequenceNumbers.min(maxSeqNo, seqNo), equalTo(Math.min(maxSeqNo, seqNo)));

        final IllegalArgumentException e = expectThrows(
            IllegalArgumentException.class,
            () -> SequenceNumbers.min(maxSeqNo, SequenceNumbers.UNASSIGNED_SEQ_NO)
        );
        assertThat(e, hasToString(containsString("sequence number must be assigned")));
    }

    public void testSeqNoStatsEqualsAndHashCode() {
        final long maxSeqNo = randomLongBetween(SequenceNumbers.UNASSIGNED_SEQ_NO, Long.MAX_VALUE);
        final long localCheckpoint = randomLongBetween(SequenceNumbers.UNASSIGNED_SEQ_NO, maxSeqNo);
        final long globalCheckpoint = randomLongBetween(SequenceNumbers.UNASSIGNED_SEQ_NO, localCheckpoint);
        EqualsHashCodeTestUtils.checkEqualsAndHashCode(
            new SeqNoStats(maxSeqNo, localCheckpoint, globalCheckpoint),
            stats -> new SeqNoStats(stats.getMaxSeqNo(), stats.getLocalCheckpoint(), stats.getGlobalCheckpoint())
        );
    }
}