/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.search.aggregations.metrics;

import org.elasticsearch.common.util.LongArray;
import org.elasticsearch.search.aggregations.Aggregator;
import org.elasticsearch.search.aggregations.AggregatorBase;
import org.elasticsearch.search.aggregations.AggregatorFactories;
import org.elasticsearch.search.aggregations.CardinalityUpperBound;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.support.AggregationContext;

import java.io.IOException;
import java.util.Map;

public abstract class MetricsAggregator extends AggregatorBase {
    protected MetricsAggregator(String name, AggregationContext context, Aggregator parent, Map<String, Object> metadata)
        throws IOException {
        super(name, AggregatorFactories.EMPTY, context, parent, CardinalityUpperBound.NONE, metadata);
        /*
         * MetricsAggregators may not have sub aggregators so it is safe for
         * us to pass NONE for the super ctor's subAggregatorCardinality.
         */
    }

    /**
     * Build an aggregation for data that has been collected into
     * {@code owningBucketOrd}.
     */
    public abstract InternalAggregation buildAggregation(long owningBucketOrd) throws IOException;

    @Override
    public final InternalAggregation[] buildAggregations(LongArray owningBucketOrds) throws IOException {
        return buildAggregations(Math.toIntExact(owningBucketOrds.size()), ordIdx -> buildAggregation(owningBucketOrds.get(ordIdx)));
    }
}