goog.require('ol.Map');
goog.require('ol.View');
goog.require('ol.geom.Polygon');
goog.require('ol.interaction.Draw');
goog.require('ol.layer.Tile');
goog.require('ol.layer.Vector');
goog.require('ol.source.OSM');
goog.require('ol.source.Vector');
goog.require('ol.style.Circle');
goog.require('ol.style.Fill');
goog.require('ol.style.Stroke');
goog.require('ol.style.Style');

var raster = new ol.layer.Tile({
  source: new ol.source.OSM()
});

var source = new ol.source.Vector({wrapX: false});

var vector = new ol.layer.Vector({
  source: source,
  style: new ol.style.Style({
    fill: new ol.style.Fill({
      color: 'rgba(255, 255, 255, 0.2)'
    }),
    stroke: new ol.style.Stroke({
      color: '#ffcc33',
      width: 2
    }),
    image: new ol.style.Circle({
      radius: 7,
      fill: new ol.style.Fill({
        color: '#ffcc33'
      })
    })
  })
});

var map = new ol.Map({
  layers: [raster, vector],
  target: 'map',
  view: new ol.View({
    center: [-11000000, 4600000],
    zoom: 4
  })
});

var typeSelect = document.getElementById('type');

var draw; // global so we can remove it later
function addInteraction() {
  var value = typeSelect.value;
  if (value !== 'None') {
    var geometryFunction, maxPoints;
    if (value === 'Square') {
      value = 'Circle';
      geometryFunction = ol.interaction.Draw.createRegularPolygon(4);
    } else if (value === 'Box') {
      value = 'LineString';
      maxPoints = 2;
      geometryFunction = function(coordinates, geometry) {
        if (!geometry) {
          geometry = new ol.geom.Polygon(null);
        }
        var start = coordinates[0];
        var end = coordinates[1];
        geometry.setCoordinates([
          [start, [start[0], end[1]], end, [end[0], start[1]], start]
        ]);
        return geometry;
      };
    }
    draw = new ol.interaction.Draw({
      source: source,
      type: /** @type {ol.geom.GeometryType} */ (value),
      geometryFunction: geometryFunction,
      maxPoints: maxPoints
    });
    map.addInteraction(draw);
  }
}


/**
 * Handle change event.
 */
typeSelect.onchange = function() {
  map.removeInteraction(draw);
  addInteraction();
};

addInteraction();