text: import {} from './Leaflet.Renderer.SVG.Tile.js';
  import { PointSymbolizer } from './Symbolizer.Point.js';
  import { LineSymbolizer } from './Symbolizer.Line.js';
  import { FillSymbolizer } from './Symbolizer.Fill.js';
  
  /* 🍂class VectorGrid
   * 🍂inherits GridLayer
   *
   * A `VectorGrid` is a generic, abstract class for displaying tiled vector data.
   * it provides facilities for symbolizing and rendering the data in the vector
   * tiles, but lacks the functionality to fetch the vector tiles from wherever
   * they are.
   *
   * Extends Leaflet's `L.GridLayer`.
   */
  
  L.VectorGrid = L.GridLayer.extend({
  
  	options: {
  		// 🍂option rendererFactory = L.svg.tile
  		// A factory method which will be used to instantiate the per-tile renderers.
  		rendererFactory: L.svg.tile,
  
  		// 🍂option vectorTileLayerStyles: Object = {}
  		// A data structure holding initial symbolizer definitions for the vector features.
  		vectorTileLayerStyles: {},
  
  		// 🍂option interactive: Boolean = false
  		// Whether this `VectorGrid` fires `Interactive Layer` events.
  		interactive: false,
  
  		// 🍂option getFeatureId: Function = undefined
  		// A function that, given a vector feature, returns an unique identifier for it, e.g.
  		// `function(feat) { return feat.properties.uniqueIdField; }`.
  		// Must be defined for `setFeatureStyle` to work.
  	},
  
  	initialize: function(options) {
  		L.setOptions(this, options);
  		L.GridLayer.prototype.initialize.apply(this, arguments);
  		if (this.options.getFeatureId) {
  			this._vectorTiles = {};
  			this._overriddenStyles = {};
  			this.on('tileunload', function(e) {
  				var key = this._tileCoordsToKey(e.coords),
  				    tile = this._vectorTiles[key];
  
  				if (tile && this._map) {
  					tile.removeFrom(this._map);
  				}
  				delete this._vectorTiles[key];
  			}, this);
  		}
  		this._dataLayerNames = {};
  	},
  
  	createTile: function(coords, done) {
  
  		var storeFeatures = this.options.getFeatureId;
  
  		var tileSize = this.getTileSize();
  		var renderer = this.options.rendererFactory(coords, tileSize, this.options);
  
  		var tileBounds = this._tileCoordsToBounds(coords);	
  
  		var vectorTilePromise = this._getVectorTilePromise(coords, tileBounds);
  
  		if (storeFeatures) {
  			this._vectorTiles[this._tileCoordsToKey(coords)] = renderer;
  			renderer._features = {};
  		}
  
  		vectorTilePromise.then( function renderTile(vectorTile) {
  
  			if (vectorTile.layers && vectorTile.layers.length !== 0) {
  
  				for (var layerName in vectorTile.layers) {
  					this._dataLayerNames[layerName] = true;
  					var layer = vectorTile.layers[layerName];
  	
  					var pxPerExtent = this.getTileSize().divideBy(layer.extent);
  	
  					var layerStyle = this.options.vectorTileLayerStyles[ layerName ] ||
  					L.Path.prototype.options;
  	
  					for (var i = 0; i < layer.features.length; i++) {
  						var feat = layer.features[i];
  						var id;
  	
  						var styleOptions = layerStyle;
  						if (storeFeatures) {
  							id = this.options.getFeatureId(feat);
  							var styleOverride = this._overriddenStyles[id];
  							if (styleOverride) {
  								if (styleOverride[layerName]) {
  									styleOptions = styleOverride[layerName];
  								} else {
  									styleOptions = styleOverride;
  								}
  							}
  						}
  	
  						if (styleOptions instanceof Function) {
  							styleOptions = styleOptions(feat.properties, coords.z);
  						}
  	
  						if (!(styleOptions instanceof Array)) {
  							styleOptions = [styleOptions];
  						}
  	
  						if (!styleOptions.length) {
  							continue;
  						}
  	
  						var featureLayer = this._createLayer(feat, pxPerExtent);
  	
  						for (var j = 0; j < styleOptions.length; j++) {
  							var style = L.extend({}, L.Path.prototype.options, styleOptions[j]);
  							featureLayer.render(renderer, style);
  							renderer._addPath(featureLayer);
  						}
  	
  						if (this.options.interactive) {
  							featureLayer.makeInteractive();
  						}
  	
  						if (storeFeatures) {
  							renderer._features[id] = {
  								layerName: layerName,
  								feature: featureLayer
  							};
  						}
  					}
  	
  				}
  	
  			}
  		
  			if (this._map != null) {
  				renderer.addTo(this._map);
  			}
  	
  			L.Util.requestAnimFrame(done.bind(coords, null, null));
  
  		}.bind(this));
  
  		return renderer.getContainer();
  	},
  
  	// 🍂method setFeatureStyle(id: Number, layerStyle: L.Path Options): this
  	// Given the unique ID for a vector features (as per the `getFeatureId` option),
  	// re-symbolizes that feature across all tiles it appears in.
  	setFeatureStyle: function(id, layerStyle) {
  		this._overriddenStyles[id] = layerStyle;
  
  		for (var tileKey in this._vectorTiles) {
  			var tile = this._vectorTiles[tileKey];
  			var features = tile._features;
  			var data = features[id];
  			if (data) {
  				var feat = data.feature;
  
  				var styleOptions = layerStyle;
  				if (layerStyle[data.layerName]) {
  					styleOptions = layerStyle[data.layerName];
  				}
  
  				this._updateStyles(feat, tile, styleOptions);
  			}
  		}
  		return this;
  	},
  
  	// 🍂method setFeatureStyle(id: Number): this
  	// Reverts the effects of a previous `setFeatureStyle` call.
  	resetFeatureStyle: function(id) {
  		delete this._overriddenStyles[id];
  
  		for (var tileKey in this._vectorTiles) {
  			var tile = this._vectorTiles[tileKey];
  			var features = tile._features;
  			var data = features[id];
  			if (data) {
  				var feat = data.feature;
  				var styleOptions = this.options.vectorTileLayerStyles[ data.layerName ] ||
  				L.Path.prototype.options;
  				this._updateStyles(feat, tile, styleOptions);
  			}
  		}
  		return this;
  	},
  
  	// 🍂method getDataLayerNames(): Array
  	// Returns an array of strings, with all the known names of data layers in
  	// the vector tiles displayed. Useful for introspection.
  	getDataLayerNames: function() {
  		return Object.keys(this._dataLayerNames);
  	},
  
  	_updateStyles: function(feat, renderer, styleOptions) {
  		styleOptions = (styleOptions instanceof Function) ?
  			styleOptions(feat.properties, renderer.getCoord().z) :
  			styleOptions;
  
  		if (!(styleOptions instanceof Array)) {
  			styleOptions = [styleOptions];
  		}
  
  		for (var j = 0; j < styleOptions.length; j++) {
  			var style = L.extend({}, L.Path.prototype.options, styleOptions[j]);
  			feat.updateStyle(renderer, style);
  		}
  	},
  
  	_createLayer: function(feat, pxPerExtent, layerStyle) {
  		var layer;
  		switch (feat.type) {
  		case 1:
  			layer = new PointSymbolizer(feat, pxPerExtent);
  			break;
  		case 2:
  			layer = new LineSymbolizer(feat, pxPerExtent);
  			break;
  		case 3:
  			layer = new FillSymbolizer(feat, pxPerExtent);
  			break;
  		}
  
  		if (this.options.interactive) {
  			layer.addEventParent(this);
  		}
  
  		return layer;
  	},
  });
  
  /*
   * 🍂section Extension methods
   *
   * Classes inheriting from `VectorGrid` **must** define the `_getVectorTilePromise` private method.
   *
   * 🍂method getVectorTilePromise(coords: Object): Promise
   * Given a `coords` object in the form of `{x: Number, y: Number, z: Number}`,
   * this function must return a `Promise` for a vector tile.
   *
   */
  L.vectorGrid = function (options) {
  	return new L.VectorGrid(options);
  };
  