/*
 * 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 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 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.search.aggregations.bucket.range;

import org.elasticsearch.TransportVersion;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.AggregationBuilder;
import org.elasticsearch.search.aggregations.AggregatorFactories;
import org.elasticsearch.search.aggregations.AggregatorFactory;
import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator.Range;
import org.elasticsearch.search.aggregations.support.AggregationContext;
import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
import org.elasticsearch.search.aggregations.support.TimeSeriesValuesSourceType;
import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
import org.elasticsearch.search.aggregations.support.ValuesSourceRegistry;
import org.elasticsearch.xcontent.ObjectParser;

import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.function.DoubleUnaryOperator;

public class RangeAggregationBuilder extends AbstractRangeBuilder<RangeAggregationBuilder, Range> {
    public static final String NAME = "range";
    public static final ValuesSourceRegistry.RegistryKey<RangeAggregatorSupplier> REGISTRY_KEY = new ValuesSourceRegistry.RegistryKey<>(
        NAME,
        RangeAggregatorSupplier.class
    );

    public static final ObjectParser<RangeAggregationBuilder, String> PARSER = ObjectParser.fromBuilder(NAME, RangeAggregationBuilder::new);
    static {
        ValuesSourceAggregationBuilder.declareFields(PARSER, true, true, false);
        PARSER.declareBoolean(RangeAggregationBuilder::keyed, RangeAggregator.KEYED_FIELD);

        PARSER.declareObjectArray((agg, ranges) -> {
            for (Range range : ranges) {
                agg.addRange(range);
            }
        }, (p, c) -> RangeAggregator.Range.PARSER.parse(p, null), RangeAggregator.RANGES_FIELD);
    }

    public static void registerAggregators(ValuesSourceRegistry.Builder builder) {
        builder.register(
            REGISTRY_KEY,
            List.of(
                CoreValuesSourceType.NUMERIC,
                CoreValuesSourceType.DATE,
                CoreValuesSourceType.BOOLEAN,
                TimeSeriesValuesSourceType.COUNTER
            ),
            RangeAggregator::build,
            true
        );
    }

    public RangeAggregationBuilder(String name) {
        super(name, InternalRange.FACTORY);
    }

    /**
     * Read from a stream.
     */
    public RangeAggregationBuilder(StreamInput in) throws IOException {
        super(in, InternalRange.FACTORY, Range::new);
    }

    protected RangeAggregationBuilder(
        RangeAggregationBuilder clone,
        AggregatorFactories.Builder factoriesBuilder,
        Map<String, Object> metadata
    ) {
        super(clone, factoriesBuilder, metadata);
    }

    @Override
    protected AggregationBuilder shallowCopy(AggregatorFactories.Builder factoriesBuilder, Map<String, Object> metadata) {
        return new RangeAggregationBuilder(this, factoriesBuilder, metadata);
    }

    /**
     * Add a new range to this aggregation.
     *
     * @param key
     *            the key to use for this range in the response
     * @param from
     *            the lower bound on the distances, inclusive
     * @param to
     *            the upper bound on the distances, exclusive
     */
    public RangeAggregationBuilder addRange(String key, double from, double to) {
        addRange(new Range(key, from, to));
        return this;
    }

    /**
     * Same as {@link #addRange(String, double, double)} but the key will be
     * automatically generated based on <code>from</code> and
     * <code>to</code>.
     */
    public RangeAggregationBuilder addRange(double from, double to) {
        return addRange(null, from, to);
    }

    /**
     * Add a new range with no lower bound.
     *
     * @param key
     *            the key to use for this range in the response
     * @param to
     *            the upper bound on the distances, exclusive
     */
    public RangeAggregationBuilder addUnboundedTo(String key, double to) {
        addRange(new Range(key, null, to));
        return this;
    }

    /**
     * Same as {@link #addUnboundedTo(String, double)} but the key will be
     * computed automatically.
     */
    public RangeAggregationBuilder addUnboundedTo(double to) {
        return addUnboundedTo(null, to);
    }

    /**
     * Add a new range with no upper bound.
     *
     * @param key
     *            the key to use for this range in the response
     * @param from
     *            the lower bound on the distances, inclusive
     */
    public RangeAggregationBuilder addUnboundedFrom(String key, double from) {
        addRange(new Range(key, from, null));
        return this;
    }

    /**
     * Same as {@link #addUnboundedFrom(String, double)} but the key will be
     * computed automatically.
     */
    public RangeAggregationBuilder addUnboundedFrom(double from) {
        return addUnboundedFrom(null, from);
    }

    @Override
    protected RangeAggregatorFactory innerBuild(
        AggregationContext context,
        ValuesSourceConfig config,
        AggregatorFactory parent,
        AggregatorFactories.Builder subFactoriesBuilder
    ) throws IOException {
        RangeAggregatorSupplier aggregatorSupplier = context.getValuesSourceRegistry().getAggregator(REGISTRY_KEY, config);

        /*
         This will downgrade the precision of the range bounds to match the field's precision.  Fixes float/double issues, but not
         long/double issues.  See https://github.com/elastic/elasticsearch/issues/77033
         */
        DoubleUnaryOperator fixPrecision = config.reduceToStoredPrecisionFunction();

        // We need to call processRanges here so they are parsed before we make the decision of whether to cache the request
        Range[] ranges = processRanges(range -> {
            DocValueFormat parser = config.format();
            assert parser != null;
            double from = range.fromAsStr != null ? parser.parseDouble(range.fromAsStr, false, context::nowInMillis) : range.from;
            double to = range.toAsStr != null ? parser.parseDouble(range.toAsStr, false, context::nowInMillis) : range.to;
            return new Range(range.key, from, range.fromAsStr, to, range.toAsStr, fixPrecision);
        });
        if (ranges.length == 0) {
            throw new IllegalArgumentException("No [ranges] specified for the [" + this.getName() + "] aggregation");
        }

        return new RangeAggregatorFactory(
            name,
            config,
            ranges,
            keyed,
            rangeFactory,
            context,
            parent,
            subFactoriesBuilder,
            metadata,
            aggregatorSupplier
        );
    }

    @Override
    public String getType() {
        return NAME;
    }

    @Override
    protected ValuesSourceRegistry.RegistryKey<?> getRegistryKey() {
        return REGISTRY_KEY;
    }

    private static String generateKey(double from, double to, DocValueFormat format) {
        StringBuilder builder = new StringBuilder().append(Double.isInfinite(from) ? "*" : format.format(from))
            .append("-")
            .append(Double.isInfinite(to) ? "*" : format.format(to));
        return builder.toString();
    }

    @Override
    public TransportVersion getMinimalSupportedVersion() {
        return TransportVersion.ZERO;
    }
}
