/*
    * Copyright 2022 the original author or authors.
    *
    * Licensed 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.bremersee.geojson.converter.deserialization;
  
  import static java.util.Objects.isNull;
  import static org.bremersee.geojson.GeoJsonConstants.COORDINATES;
  import static org.bremersee.geojson.GeoJsonConstants.POLYGON;
  import static org.bremersee.geojson.GeoJsonConstants.TYPE;
  
  import java.io.Serial;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import org.locationtech.jts.geom.CoordinateSequence;
  import org.locationtech.jts.geom.GeometryFactory;
  import org.locationtech.jts.geom.LinearRing;
  import org.locationtech.jts.geom.Polygon;
  
  /**
   * The json to polygon converter.
   *
   * @author Christian Bremer
   */
  class JsonToPolygonConverter extends AbstractJsonToGeometryConverter {
  
    @Serial
    private static final long serialVersionUID = 1L;
  
    private final ObjectToCoordinateSequenceConverter coordinateSequenceConverter;
  
    /**
     * Instantiates a new json to polygon converter.
     *
     * @param geometryFactory the geometry factory
     * @param coordinateSequenceConverter the coordinate sequence converter
     */
    JsonToPolygonConverter(
        GeometryFactory geometryFactory,
        ObjectToCoordinateSequenceConverter coordinateSequenceConverter) {
  
      super(geometryFactory);
      if (isNull(coordinateSequenceConverter)) {
        throw new IllegalArgumentException("Coordinate sequence converter must be present.");
      }
      this.coordinateSequenceConverter = coordinateSequenceConverter;
    }
  
    /**
     * Convert polygon.
     *
     * @param source the source
     * @return the polygon
     */
    Polygon convert(Map<String, Object> source) {
      if (isNull(source)) {
        return null;
      }
      if (!POLYGON.equals(source.get(TYPE))) {
        throw new IllegalArgumentException(String
            .format("Source is not a %s: %s", POLYGON, source));
      }
      return convertCoordinates(source.get(COORDINATES));
    }
  
    /**
     * Convert coordinates polygon.
     *
     * @param source the source
     * @return the polygon
     */
    Polygon convertCoordinates(Object source) {
      Polygon polygon;
      if (isNull(source)) {
        polygon = getGeometryFactory().createPolygon();
      } else {
        List<CoordinateSequence> list = new ArrayList<>();
        //noinspection unchecked
        for (Object coordinates : (List<Object>) source) {
          list.add(coordinateSequenceConverter.convert(coordinates));
        }
        if (list.isEmpty()) {
          polygon = getGeometryFactory().createPolygon();
        } else if (list.size() == 1) {
          polygon = getGeometryFactory().createPolygon(list.get(0));
        } else {
         GeometryFactory gf = getGeometryFactory();
         LinearRing[] holes = new LinearRing[list.size() - 1];
         for (int i = 1; i < list.size(); i++) {
           holes[i - 1] = gf.createLinearRing(list.get(i));
         }
         polygon = gf.createPolygon(gf.createLinearRing(list.get(0)), holes);
       }
     }
     return polygon;
   }
 
 }