import { Feature, Geojson } from "../types.js";
import proj4 from "proj4";

/**
 * Devuelve el mismo geojson con las coordenadas cambiadas a la proyección pasada como parametro
 * @param {Object} geojson Objeto con las coordenadas de las parcelas
 * @param {String} projection Proyección final a la que se van a transformar las coordenadas
 * @returns {Geojson} Objeto con las coordenadas de las parcelas cambiadas
 */
export const transformCoords = (
  geojson: Geojson,
  projection: string
): Geojson => {
  const firstProjection =
    'PROJCS["WGS 84 / Pseudo-Mercator",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Mercator_1SP"],PARAMETER["central_meridian",0],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["X",EAST],AXIS["Y",NORTH],EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext  +no_defs"],AUTHORITY["EPSG","3857"]]';

  const result = {
    ...geojson,
    features: geojson.features.map((feature: Feature) => {
      return {
        ...feature,
        geometry: {
          ...feature.geometry,
          coordinates: feature.geometry.coordinates.map((subpolygon) =>
            subpolygon.map((pair) => {
              return proj4(
                firstProjection,
                projection,
                pair as [number, number]
              );
            })
          ),
        },
      };
    }),
  };
  return result;
};