import Map from '../src/ol/Map.js';
import OSM from '../src/ol/source/OSM.js';
import TileLayer from '../src/ol/layer/WebGLTile.js';
import View from '../src/ol/View.js';
import XYZ from '../src/ol/source/XYZ.js';
import {getRenderPixel} from '../src/ol/render.js';

const osm = new TileLayer({
  source: new OSM({wrapX: true}),
});

const key = 'get_your_own_D6rA4zTHduk6KOKTXzGB';

const imagery = new TileLayer({
  source: new XYZ({
    url: 'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
    attributions:
      '<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' +
      '<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>',
    maxZoom: 20,
  }),
});

const map = new Map({
  layers: [osm, imagery],
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2,
  }),
});

const swipe = document.getElementById('swipe');

imagery.on('prerender', function (event) {
  const gl = event.context;
  gl.enable(gl.SCISSOR_TEST);

  const mapSize = map.getSize(); // [width, height] in CSS pixels

  // get render coordinates and dimensions given CSS coordinates
  const bottomLeft = getRenderPixel(event, [0, mapSize[1]]);
  const topRight = getRenderPixel(event, [mapSize[0], 0]);

  const width = Math.round((topRight[0] - bottomLeft[0]) * (swipe.value / 100));
  const height = topRight[1] - bottomLeft[1];

  gl.scissor(bottomLeft[0], bottomLeft[1], width, height);
});

imagery.on('postrender', function (event) {
  const gl = event.context;
  gl.disable(gl.SCISSOR_TEST);
});

const listener = function () {
  map.render();
};
swipe.addEventListener('input', listener);
swipe.addEventListener('change', listener);