/*
 * 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.index.fielddata.plain;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.OrdinalMap;
import org.apache.lucene.index.SortedSetDocValues;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.SortedSetSelector;
import org.apache.lucene.search.SortedSetSortField;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.util.BigArrays;
import org.elasticsearch.index.fielddata.IndexFieldData;
import org.elasticsearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
import org.elasticsearch.index.fielddata.IndexFieldDataCache;
import org.elasticsearch.index.fielddata.LeafOrdinalsFieldData;
import org.elasticsearch.index.fielddata.ScriptDocValues;
import org.elasticsearch.index.fielddata.fieldcomparator.BytesRefFieldComparatorSource;
import org.elasticsearch.indices.breaker.CircuitBreakerService;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.MultiValueMode;
import org.elasticsearch.search.aggregations.support.ValuesSourceType;
import org.elasticsearch.search.sort.BucketedSort;
import org.elasticsearch.search.sort.SortOrder;

import java.util.function.Function;

public class SortedSetOrdinalsIndexFieldData extends AbstractIndexOrdinalsFieldData {

    public static class Builder implements IndexFieldData.Builder {
        private final String name;
        private final Function<SortedSetDocValues, ScriptDocValues<?>> scriptFunction;
        private final ValuesSourceType valuesSourceType;

        public Builder(String name, ValuesSourceType valuesSourceType) {
            this(name, AbstractLeafOrdinalsFieldData.DEFAULT_SCRIPT_FUNCTION, valuesSourceType);
        }

        public Builder(String name, Function<SortedSetDocValues, ScriptDocValues<?>> scriptFunction, ValuesSourceType valuesSourceType) {
            this.name = name;
            this.scriptFunction = scriptFunction;
            this.valuesSourceType = valuesSourceType;
        }

        @Override
        public SortedSetOrdinalsIndexFieldData build(
            IndexFieldDataCache cache,
            CircuitBreakerService breakerService
        ) {
            return new SortedSetOrdinalsIndexFieldData(cache, name, valuesSourceType, breakerService, scriptFunction);
        }
    }

    public SortedSetOrdinalsIndexFieldData(
        IndexFieldDataCache cache,
        String fieldName,
        ValuesSourceType valuesSourceType,
        CircuitBreakerService breakerService,
        Function<SortedSetDocValues, ScriptDocValues<?>> scriptFunction
    ) {
        super(fieldName, valuesSourceType, cache, breakerService, scriptFunction);
    }

    @Override
    public SortField sortField(@Nullable Object missingValue, MultiValueMode sortMode, Nested nested, boolean reverse) {
        XFieldComparatorSource source = new BytesRefFieldComparatorSource(this, missingValue, sortMode, nested);
        /**
         * Check if we can use a simple {@link SortedSetSortField} compatible with index sorting and
         * returns a custom sort field otherwise.
         */
        if (nested != null ||
                (sortMode != MultiValueMode.MAX && sortMode != MultiValueMode.MIN) ||
                (source.sortMissingLast(missingValue) == false && source.sortMissingFirst(missingValue) == false)) {
            return new SortField(getFieldName(), source, reverse);
        }
        SortField sortField = new SortedSetSortField(getFieldName(), reverse,
            sortMode == MultiValueMode.MAX ? SortedSetSelector.Type.MAX : SortedSetSelector.Type.MIN);
        sortField.setMissingValue(source.sortMissingLast(missingValue) ^ reverse ?
            SortedSetSortField.STRING_LAST : SortedSetSortField.STRING_FIRST);
        return sortField;
    }

    @Override
    public BucketedSort newBucketedSort(BigArrays bigArrays, Object missingValue, MultiValueMode sortMode, Nested nested,
            SortOrder sortOrder, DocValueFormat format, int bucketSize, BucketedSort.ExtraData extra) {
        throw new IllegalArgumentException("only supported on numeric fields");
    }

    @Override
    public LeafOrdinalsFieldData load(LeafReaderContext context) {
        return new SortedSetBytesLeafFieldData(context.reader(), getFieldName(), scriptFunction);
    }

    @Override
    public LeafOrdinalsFieldData loadDirect(LeafReaderContext context) {
        return load(context);
    }

    @Override
    public OrdinalMap getOrdinalMap() {
        return null;
    }

    @Override
    public boolean supportsGlobalOrdinalsMapping() {
        return true;
    }
}
