import Map from '../src/ol/Map.js';
import TileLayer from '../src/ol/layer/Tile.js';
import View from '../src/ol/View.js';
import WMTS from '../src/ol/source/WMTS.js';
import WMTSTileGrid from '../src/ol/tilegrid/WMTS.js';
import {fromLonLat, get as getProjection} from '../src/ol/proj.js';
import {getWidth} from '../src/ol/extent.js';

const map = new Map({
  target: 'map',
  view: new View({
    zoom: 5,
    center: fromLonLat([5, 45]),
  }),
});

const resolutions = [];
const matrixIds = [];
const proj3857 = getProjection('EPSG:3857');
const maxResolution = getWidth(proj3857.getExtent()) / 256;

for (let i = 0; i < 20; i++) {
  matrixIds[i] = i.toString();
  resolutions[i] = maxResolution / Math.pow(2, i);
}

const tileGrid = new WMTSTileGrid({
  origin: [-20037508, 20037508],
  resolutions: resolutions,
  matrixIds: matrixIds,
});

// For more information about the IGN API key see
// https://geoservices.ign.fr/blog/2021/01/29/Maj_Cles_Geoservices.html

const ign_source = new WMTS({
  url: 'https://wxs.ign.fr/choisirgeoportail/geoportail/wmts',
  layer: 'GEOGRAPHICALGRIDSYSTEMS.PLANIGNV2',
  matrixSet: 'PM',
  format: 'image/png',
  projection: 'EPSG:3857',
  tileGrid: tileGrid,
  style: 'normal',
  attributions:
    '<a href="https://www.ign.fr/" target="_blank">' +
    '<img src="https://wxs.ign.fr/static/logos/IGN/IGN.gif" title="Institut national de l\'' +
    'information géographique et forestière" alt="IGN"></a>',
});

const ign = new TileLayer({
  source: ign_source,
});

map.addLayer(ign);