如何在Openlayers中获取绘制的多边形坐标？

var map = new ol.Map({
  target: 'map',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  view: new ol.View({
    center: ol.proj.fromLonLat([0, 0]),
    zoom: 2
  })
});

var draw = new ol.interaction.Draw({
  source: new ol.source.Vector(),
  type: 'Polygon'
});
map.addInteraction(draw);

draw.on('drawend', function(event) {
  var feature = event.feature;
  var geometry = feature.getGeometry();
  var coordinates = geometry.getCoordinates();
  console.log(coordinates);
});