private Analyzer getAnalyzerAtField(
     String field, @Nullable Map<String, String> perFieldAnalyzer) {
   MapperService mapperService = indexShard.mapperService();
   Analyzer analyzer;
   if (perFieldAnalyzer != null && perFieldAnalyzer.containsKey(field)) {
     analyzer = mapperService.analysisService().analyzer(perFieldAnalyzer.get(field).toString());
   } else {
     analyzer = mapperService.smartNameFieldMapper(field).indexAnalyzer();
   }
   if (analyzer == null) {
     analyzer = mapperService.analysisService().defaultIndexAnalyzer();
   }
   return analyzer;
 }
  @Override
  public Filter parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
    XContentParser parser = parseContext.parser();

    XContentParser.Token token;

    boolean cache = false;
    CacheKeyFilter.Key cacheKey = null;
    String filterName = null;
    String currentFieldName = null;
    double lat = 0;
    double lon = 0;
    String fieldName = null;
    Object vFrom = null;
    Object vTo = null;
    boolean includeLower = true;
    boolean includeUpper = true;
    DistanceUnit unit = DistanceUnit.KILOMETERS; // default unit
    GeoDistance geoDistance = GeoDistance.ARC;
    while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
      if (token == XContentParser.Token.FIELD_NAME) {
        currentFieldName = parser.currentName();
      } else if (token == XContentParser.Token.START_ARRAY) {
        token = parser.nextToken();
        lon = parser.doubleValue();
        token = parser.nextToken();
        lat = parser.doubleValue();
        while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {}

        fieldName = currentFieldName;
      } else if (token == XContentParser.Token.START_OBJECT) {
        // the json in the format of -> field : { lat : 30, lon : 12 }
        String currentName = parser.currentName();
        fieldName = currentFieldName;
        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
          if (token == XContentParser.Token.FIELD_NAME) {
            currentName = parser.currentName();
          } else if (token.isValue()) {
            if (currentName.equals(GeoPointFieldMapper.Names.LAT)) {
              lat = parser.doubleValue();
            } else if (currentName.equals(GeoPointFieldMapper.Names.LON)) {
              lon = parser.doubleValue();
            } else if (currentName.equals(GeoPointFieldMapper.Names.GEOHASH)) {
              double[] values = GeoHashUtils.decode(parser.text());
              lat = values[0];
              lon = values[1];
            }
          }
        }
      } else if (token.isValue()) {
        if (currentFieldName.equals("from")) {
          if (token == XContentParser.Token.VALUE_NULL) {
          } else if (token == XContentParser.Token.VALUE_STRING) {
            vFrom = parser.text(); // a String
          } else {
            vFrom = parser.numberValue(); // a Number
          }
        } else if (currentFieldName.equals("to")) {
          if (token == XContentParser.Token.VALUE_NULL) {}
          if (token == XContentParser.Token.VALUE_STRING) {
            vTo = parser.text(); // a String
          } else {
            vTo = parser.numberValue(); // a Number
          }
        } else if ("include_lower".equals(currentFieldName)
            || "includeLower".equals(currentFieldName)) {
          includeLower = parser.booleanValue();
        } else if ("include_upper".equals(currentFieldName)
            || "includeUpper".equals(currentFieldName)) {
          includeUpper = parser.booleanValue();
        } else if ("gt".equals(currentFieldName)) {
          if (token == XContentParser.Token.VALUE_NULL) {
          } else if (token == XContentParser.Token.VALUE_STRING) {
            vFrom = parser.text(); // a String
          } else {
            vFrom = parser.numberValue(); // a Number
          }
          includeLower = false;
        } else if ("gte".equals(currentFieldName) || "ge".equals(currentFieldName)) {
          if (token == XContentParser.Token.VALUE_NULL) {
          } else if (token == XContentParser.Token.VALUE_STRING) {
            vFrom = parser.text(); // a String
          } else {
            vFrom = parser.numberValue(); // a Number
          }
          includeLower = true;
        } else if ("lt".equals(currentFieldName)) {
          if (token == XContentParser.Token.VALUE_NULL) {}
          if (token == XContentParser.Token.VALUE_STRING) {
            vTo = parser.text(); // a String
          } else {
            vTo = parser.numberValue(); // a Number
          }
          includeUpper = false;
        } else if ("lte".equals(currentFieldName) || "le".equals(currentFieldName)) {
          if (token == XContentParser.Token.VALUE_NULL) {}
          if (token == XContentParser.Token.VALUE_STRING) {
            vTo = parser.text(); // a String
          } else {
            vTo = parser.numberValue(); // a Number
          }
          includeUpper = true;
        } else if (currentFieldName.equals("unit")) {
          unit = DistanceUnit.fromString(parser.text());
        } else if (currentFieldName.equals("distance_type")
            || currentFieldName.equals("distanceType")) {
          geoDistance = GeoDistance.fromString(parser.text());
        } else if (currentFieldName.endsWith(GeoPointFieldMapper.Names.LAT_SUFFIX)) {
          lat = parser.doubleValue();
          fieldName =
              currentFieldName.substring(
                  0, currentFieldName.length() - GeoPointFieldMapper.Names.LAT_SUFFIX.length());
        } else if (currentFieldName.endsWith(GeoPointFieldMapper.Names.LON_SUFFIX)) {
          lon = parser.doubleValue();
          fieldName =
              currentFieldName.substring(
                  0, currentFieldName.length() - GeoPointFieldMapper.Names.LON_SUFFIX.length());
        } else if (currentFieldName.endsWith(GeoPointFieldMapper.Names.GEOHASH_SUFFIX)) {
          double[] values = GeoHashUtils.decode(parser.text());
          lat = values[0];
          lon = values[1];
          fieldName =
              currentFieldName.substring(
                  0, currentFieldName.length() - GeoPointFieldMapper.Names.GEOHASH_SUFFIX.length());
        } else 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 {
          // assume the value is the actual value
          String value = parser.text();
          int comma = value.indexOf(',');
          if (comma != -1) {
            lat = Double.parseDouble(value.substring(0, comma).trim());
            lon = Double.parseDouble(value.substring(comma + 1).trim());
          } else {
            double[] values = GeoHashUtils.decode(value);
            lat = values[0];
            lon = values[1];
          }
          fieldName = currentFieldName;
        }
      }
    }

    double from;
    double to;
    if (vFrom instanceof Number) {
      from = unit.toMiles(((Number) vFrom).doubleValue());
    } else {
      from = DistanceUnit.parse((String) vFrom, unit, DistanceUnit.MILES);
    }
    if (vTo instanceof Number) {
      to = unit.toMiles(((Number) vTo).doubleValue());
    } else {
      to = DistanceUnit.parse((String) vTo, unit, DistanceUnit.MILES);
    }

    MapperService mapperService = parseContext.mapperService();
    FieldMapper mapper = mapperService.smartNameFieldMapper(fieldName);
    if (mapper == null) {
      throw new QueryParsingException(
          parseContext.index(), "failed to find geo_point field [" + fieldName + "]");
    }
    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 GeoDistanceRangeFilter(
            lat,
            lon,
            from,
            to,
            includeLower,
            includeUpper,
            geoDistance,
            fieldName,
            parseContext.indexCache().fieldData());
    if (cache) {
      filter = parseContext.cacheFilter(filter, cacheKey);
    }
    filter = wrapSmartNameFilter(filter, parseContext.smartFieldMappers(fieldName), parseContext);
    if (filterName != null) {
      parseContext.addNamedFilter(filterName, filter);
    }
    return filter;
  }