/*
 * 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
 * specific language governing permissions and limitations
 * under the License.
 */

package org.elasticsearch.index.fielddata.plain;

import org.apache.lucene.spatial.geopoint.document.GeoPointField;
import org.apache.lucene.spatial.util.GeoEncodingUtils;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefIterator;
import org.apache.lucene.util.CharsRefBuilder;
import org.apache.lucene.util.NumericUtils;
import org.elasticsearch.Version;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.fielddata.*;
import org.elasticsearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
import org.elasticsearch.index.mapper.MappedFieldType.Names;
import org.elasticsearch.search.MultiValueMode;

import java.io.IOException;

abstract class AbstractIndexGeoPointFieldData extends AbstractIndexFieldData<AtomicGeoPointFieldData> implements IndexGeoPointFieldData {
    protected abstract static class BaseGeoPointTermsEnum {
        protected final BytesRefIterator termsEnum;

        protected BaseGeoPointTermsEnum(BytesRefIterator termsEnum) {
            this.termsEnum = termsEnum;
        }
    }

    protected static class GeoPointTermsEnum extends BaseGeoPointTermsEnum {
        private final GeoPointField.TermEncoding termEncoding;
        protected GeoPointTermsEnum(BytesRefIterator termsEnum, GeoPointField.TermEncoding termEncoding) {
            super(termsEnum);
            this.termEncoding = termEncoding;
        }

        public Long next() throws IOException {
            final BytesRef term = termsEnum.next();
            if (term == null) {
                return null;
            }
            if (termEncoding == GeoPointField.TermEncoding.PREFIX) {
                return GeoEncodingUtils.prefixCodedToGeoCoded(term);
            } else if (termEncoding == GeoPointField.TermEncoding.NUMERIC) {
                return NumericUtils.prefixCodedToLong(term);
            }
            throw new IllegalArgumentException("GeoPoint.TermEncoding should be one of: " + GeoPointField.TermEncoding.PREFIX
                + " or " + GeoPointField.TermEncoding.NUMERIC + " found: " + termEncoding);
        }
    }

    protected static class GeoPointTermsEnumLegacy extends BaseGeoPointTermsEnum {
        private final GeoPoint next;
        private final CharsRefBuilder spare;

        protected GeoPointTermsEnumLegacy(BytesRefIterator termsEnum) {
            super(termsEnum);
            next = new GeoPoint();
            spare = new CharsRefBuilder();
        }

        public GeoPoint next() throws IOException {
            final BytesRef term = termsEnum.next();
            if (term == null) {
                return null;
            }
            spare.copyUTF8Bytes(term);
            int commaIndex = -1;
            for (int i = 0; i < spare.length(); i++) {
                if (spare.charAt(i) == ',') { // saves a string creation
                    commaIndex = i;
                    break;
                }
            }
            if (commaIndex == -1) {
                assert false;
                return next.reset(0, 0);
            }
            final double lat = Double.parseDouble(new String(spare.chars(), 0, commaIndex));
            final double lon = Double.parseDouble(new String(spare.chars(), commaIndex + 1, spare.length() - (commaIndex + 1)));
            return next.reset(lat, lon);
        }
    }

    public AbstractIndexGeoPointFieldData(Index index, Settings indexSettings, Names fieldNames, FieldDataType fieldDataType, IndexFieldDataCache cache) {
        super(index, indexSettings, fieldNames, fieldDataType, cache);
    }

    @Override
    public final XFieldComparatorSource comparatorSource(@Nullable Object missingValue, MultiValueMode sortMode, Nested nested) {
        throw new IllegalArgumentException("can't sort on geo_point field without using specific sorting feature, like geo_distance");
    }

    @Override
    protected AtomicGeoPointFieldData empty(int maxDoc) {
        return AbstractAtomicGeoPointFieldData.empty(maxDoc);
    }
}