GeoPolygonFilterParser.java

/*
 * Licensed to ElasticSearch and Shay Banon 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.query;

import com.google.common.collect.Lists;
import org.apache.lucene.search.Filter;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.cache.filter.support.CacheKeyFilter;
import org.elasticsearch.index.mapper.FieldMapper;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.mapper.geo.GeoPointFieldDataType;
import org.elasticsearch.index.mapper.geo.GeoPointFieldMapper;
import org.elasticsearch.index.search.geo.GeoHashUtils;
import org.elasticsearch.index.search.geo.GeoPolygonFilter;
import org.elasticsearch.index.search.geo.GeoUtils;
import org.elasticsearch.index.search.geo.Point;

import java.io.IOException;
import java.util.List;

import static org.elasticsearch.index.query.support.QueryParsers.wrapSmartNameFilter;

/**
 * <pre>
 * {
 *     "pin.location" : {
 *         "points" : [
 *              { "lat" : 12, "lon" : 40},
 *              {}
 *         ]
 *     }
 * }
 * </pre>
 */
public class GeoPolygonFilterParser implements FilterParser {

    public static final String NAME = "geo_polygon";

    @Inject
    public GeoPolygonFilterParser() {
    }

    @Override
    public String[] names() {
        return new String[]{NAME, "geoPolygon"};
    }

    @Override
    public Filter parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
        XContentParser parser = parseContext.parser();

        boolean cache = false;
        CacheKeyFilter.Key cacheKey = null;
        String fieldName = null;
        List<Point> points = Lists.newArrayList();

        boolean normalizeLon = true;
        boolean normalizeLat = true;

        String filterName = null;
        String currentFieldName = null;
        XContentParser.Token token;

        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
            if (token == XContentParser.Token.FIELD_NAME) {
                currentFieldName = parser.currentName();
            } else if (token == XContentParser.Token.START_OBJECT) {
                fieldName = currentFieldName;

                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                    if (token == XContentParser.Token.FIELD_NAME) {
                        currentFieldName = parser.currentName();
                    } else if (token == XContentParser.Token.START_ARRAY) {
                        if ("points".equals(currentFieldName)) {
                            while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                                if (token == XContentParser.Token.FIELD_NAME) {
                                    currentFieldName = parser.currentName();
                                } else if (token == XContentParser.Token.START_ARRAY) {
                                    Point point = new Point();
                                    token = parser.nextToken();
                                    point.lon = parser.doubleValue();
                                    token = parser.nextToken();
                                    point.lat = parser.doubleValue();
                                    while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {

                                    }
                                    points.add(point);
                                } else if (token == XContentParser.Token.START_OBJECT) {
                                    Point point = new Point();
                                    while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                                        if (token == XContentParser.Token.FIELD_NAME) {
                                            currentFieldName = parser.currentName();
                                        } else if (token.isValue()) {
                                            if (currentFieldName.equals(GeoPointFieldMapper.Names.LAT)) {
                                                point.lat = parser.doubleValue();
                                            } else if (currentFieldName.equals(GeoPointFieldMapper.Names.LON)) {
                                                point.lon = parser.doubleValue();
                                            } else if (currentFieldName.equals(GeoPointFieldMapper.Names.GEOHASH)) {
                                                double[] values = GeoHashUtils.decode(parser.text());
                                                point.lat = values[0];
                                                point.lon = values[1];
                                            }
                                        }
                                    }
                                    points.add(point);
                                } else if (token.isValue()) {
                                    Point point = new Point();
                                    String value = parser.text();
                                    int comma = value.indexOf(',');
                                    if (comma != -1) {
                                        point.lat = Double.parseDouble(value.substring(0, comma).trim());
                                        point.lon = Double.parseDouble(value.substring(comma + 1).trim());
                                    } else {
                                        double[] values = GeoHashUtils.decode(value);
                                        point.lat = values[0];
                                        point.lon = values[1];
                                    }
                                    points.add(point);
                                }
                            }
                        } else {
                            throw new QueryParsingException(parseContext.index(), "[geo_polygon] filter does not support [" + currentFieldName + "]");
                        }
                    }
                }
            } else if (token.isValue()) {
                if ("_name".equals(currentFieldName)) {
                    filterName = parser.text();
                } else if ("_cache".equals(currentFieldName)) {
                    cache = parser.booleanValue();
                } else if ("_cache_key".equals(currentFieldName) || "_cacheKey".equals(currentFieldName)) {
                    cacheKey = new CacheKeyFilter.Key(parser.text());
                } else if ("normalize".equals(currentFieldName)) {
                    normalizeLat = parser.booleanValue();
                    normalizeLon = parser.booleanValue();
                } else {
                    throw new QueryParsingException(parseContext.index(), "[geo_polygon] filter does not support [" + currentFieldName + "]");
                }
            }
        }

        if (points.isEmpty()) {
            throw new QueryParsingException(parseContext.index(), "no points defined for geo_polygon filter");
        }

        if (normalizeLat || normalizeLon) {
            for (Point point : points) {
                GeoUtils.normalizePoint(point, normalizeLat, normalizeLon);
            }
        }

        MapperService.SmartNameFieldMappers smartMappers = parseContext.smartFieldMappers(fieldName);
        if (smartMappers == null || !smartMappers.hasMapper()) {
            throw new QueryParsingException(parseContext.index(), "failed to find geo_point field [" + fieldName + "]");
        }
        FieldMapper mapper = smartMappers.mapper();
        if (mapper.fieldDataType() != GeoPointFieldDataType.TYPE) {
            throw new QueryParsingException(parseContext.index(), "field [" + fieldName + "] is not a geo_point field");
        }
        fieldName = mapper.names().indexName();

        Filter filter = new GeoPolygonFilter(points.toArray(new Point[points.size()]), fieldName, parseContext.indexCache().fieldData());
        if (cache) {
            filter = parseContext.cacheFilter(filter, cacheKey);
        }
        filter = wrapSmartNameFilter(filter, smartMappers, parseContext);
        if (filterName != null) {
            parseContext.addNamedFilter(filterName, filter);
        }
        return filter;
    }
}