basemaps.config.js

import STAC from './src/models/stac';
import Utils from './src/utils';

const USGS_ATTRIBUTION = 'USGS Astrogeology';
const WMS = 'TileWMS';
const XYZ = 'XYZ';

// All options (except for 'is') follow the OpenLayers options for the respective source class.
const BASEMAPS = {
  earth: {
    url: 'https://tile.openstreetmap.org/{z}/{x}/{y}.png',
    title: 'OpenStreetMap',
    is: XYZ,
    attributions: '&copy; <a href="https://www.openstreetmap.org/copyright" target="_blank">OpenStreetMap</a> contributors.'
  },
  europa: {
    url: 'https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/jupiter/europa_simp_cyl.map',
    is: WMS,
    title: 'USGS Europa',
    attributions: USGS_ATTRIBUTION,
    projection: "EPSG:4326",
    params: {
      FORMAT: 'image/png',
      LAYERS: 'GALILEO_VOYAGER'
    }
  },
  mars: {
    url: 'https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/mars/mars_simp_cyl.map',
    is: WMS,
    title: 'USGS Mars',
    attributions: USGS_ATTRIBUTION,
    projection: "EPSG:4326",
    params: {
      FORMAT: 'image/png',
      LAYERS: 'MDIM21'
    }
  },
  moon: {
    url: 'https://planetarymaps.usgs.gov/cgi-bin/mapserv?map=/maps/earth/moon_simp_cyl.map',
    is: WMS,
    title: 'USGS Moon',
    attributions: USGS_ATTRIBUTION,
    projection: "EPSG:4326",
    params: {
      FORMAT: 'image/png',
      LAYERS: 'LROC_WAC'
    }
  }
};

/**
 * 
 * @param {Object} stac The STAC object
 * @param {Object} map The OL map object
 * @param {Object} i18n Vue I18N object
 * @returns {Array.<BasemapOptions>}
 */
export default function configureBasemap(stac, map, i18n) {
  let targets = ['earth'];
  if (stac instanceof STAC) {
    if (stac.isCollection() && Utils.isObject(stac.summaries) && Array.isArray(stac.summaries['ssys:targets'])) {
      targets = stac.summaries['ssys:targets'];
    }
    else if (stac.isCollection() && Array.isArray(stac['ssys:targets'])) {
      targets = stac['ssys:targets'];
    }
    else if (stac.isItem() && Array.isArray(stac.properties['ssys:targets'])) {
      targets = stac.properties['ssys:targets'];
    }
  }

  return targets.map(target => BASEMAPS[target.toLowerCase()]);
};