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 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
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 * 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
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package org.elasticsearch.search.aggregations.metrics.percentiles.tdigest;

import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.metrics.percentiles.InternalPercentilesTestCase;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;

import java.util.Arrays;
import java.util.List;
import java.util.Map;

public class InternalTDigestPercentilesTests extends InternalPercentilesTestCase<InternalTDigestPercentiles> {

    @Override
    protected InternalTDigestPercentiles createTestInstance(String name,
                                                            List<PipelineAggregator> pipelineAggregators,
                                                            Map<String, Object> metaData,
                                                            boolean keyed, DocValueFormat format, double[] percents, double[] values) {
        final TDigestState state = new TDigestState(100);
        Arrays.stream(values).forEach(state::add);

        assertEquals(state.centroidCount(), values.length);
        return new InternalTDigestPercentiles(name, percents, state, keyed, format, pipelineAggregators, metaData);
    }

    @Override
    protected void assertReduced(InternalTDigestPercentiles reduced, List<InternalTDigestPercentiles> inputs) {
        final TDigestState expectedState = new TDigestState(reduced.state.compression());

        long totalCount = 0;
        for (InternalTDigestPercentiles input : inputs) {
            assertArrayEquals(reduced.keys, input.keys, 0d);
            expectedState.add(input.state);
            totalCount += input.state.size();
        }

        assertEquals(totalCount, reduced.state.size());
        if (totalCount > 0) {
            assertEquals(expectedState.quantile(0), reduced.state.quantile(0), 0d);
            assertEquals(expectedState.quantile(1), reduced.state.quantile(1), 0d);
        }
    }

    @Override
    protected Writeable.Reader<InternalTDigestPercentiles> instanceReader() {
        return InternalTDigestPercentiles::new;
    }
}
