department-of-veterans-affairs/vets-website

import mbxGeo from '@mapbox/mapbox-sdk/services/geocoding';
import mapboxClient from '../components/mapbox/MapboxClient';

import { BOUNDING_RADIUS } from '../constants';

const mbxClient = mbxGeo(mapboxClient);

/** ****************************************************
 * Helper functions specifically requiring the
 * MapboxClient API.
 *
 * Note: Be careful when unit testing these, causes a
 * node issue when going through the import chain.
 * Likely best to try the mock API from Mapbox.
 ***************************************************** */

/**
 * Calculates the center point of a given geographic area
 * as defined by a bounding box of an upper-left and a
 * lower-right corner.
 *
 * @param {Array<Number>} bounds An array containing the corners
 * of a coordinate bounding box
 *
 * ex: [-77.955898, 38.380263, -76.955898, 39.380263]
 *     [ lonLL    , latLL    , lonUR     , latUR    ]
 *
 * @returns Object of shape { lon, lat } on valid input,
 * empty {} object otherwise
 */
export const getBoxCenter = bounds => {
  if (bounds && bounds.length === 4) {
    const lonDiff = (bounds[2] - bounds[0]) / 2;
    const latDiff = (bounds[3] - bounds[1]) / 2;

    return { lon: bounds[0] + latDiff, lat: bounds[1] + lonDiff };
  }

  return {};
};

/**
 * Performs a reverse lookup of a geographic coordinate to
 * determine what address exists at the given location.
 *
 * @param {Number} lon Longitude coordinate
 * @param {Number} lat Latitude coordinate
 *   https://www.mapbox.com/api-documentation/?language=JavaScript#retrieve-places-near-a-location
 *   default => `[address,postcode]`
 *
 * @returns {String} The best approximation of the address for the coordinates
 */
export const reverseGeocode = async (lon, lat, types) => {
  const response = await mbxClient
    .reverseGeocode({ query: [lon, lat], types })
    .send()
    .catch();

  if (
    response.body &&
    response.body.features &&
    response.body.features.length > 0
  ) {
    const {
      features: {
        0: { place_name: placeName },
      },
    } = response.body;

    return placeName;
  }

  return null;
};

/**
 * Performs a reverse lookup of a geographic coordinate to
 * determine what address exists at the given location.
 * In the case of a bounding box will perform a lookup of the
 * center point of the box.
 *
 * @param {Array<Number>} bounds A geographic bounding box definition
 * @param @param {String} types A valid type-of-address string as defined by the Mapbox API:
 *   https://www.mapbox.com/api-documentation/?language=JavaScript#retrieve-places-near-a-location
 *   default => `[address,postcode]`
 *
 * @returns {String} The best approximation of the address for the coordinates
 */
export const reverseGeocodeBox = (bounds, types = 'address,postcode') => {
  const { lon, lat } = getBoxCenter(bounds);
  return reverseGeocode(lon, lat, types.split(','));
};

export const staticMapURL = (lat, long, mapboxToken) =>
  `https://api.mapbox.com/styles/v1/mapbox/streets-v11/static/pin-l+d83933(${long},${lat})/${long},${lat},16/500x300?access_token=${mapboxToken}`;

/**
 * Generates search criteria from lat/long geocoordinates.
 */
export const searchCriteraFromCoords = async (longitude, latitude) => {
  const response = await mbxClient
    .reverseGeocode({
      query: [longitude, latitude],
      types: ['address'],
    })
    .send();
  // TODO: display error message if geolocation fails?
  // .catch(error => error);

  const { features } = response.body;
  const placeName = features[0].place_name;
  const coordinates = features[0].center;

  return {
    bounds: features[0].bbox || [
      coordinates[0] - BOUNDING_RADIUS,
      coordinates[1] - BOUNDING_RADIUS,
      coordinates[0] + BOUNDING_RADIUS,
      coordinates[1] + BOUNDING_RADIUS,
    ],
    locationInputString: placeName,
    context: {
      location: placeName,
    },
    locationQueryString: placeName,
    position: { longitude, latitude },
  };
};