# component/label.js

    import * as d3 from "d3";
    import { colorParse } from "../colorHelper.js";

    /**
     * Reusable 3D Label Component
     *
     * @module
     */
    export default function() {

    	/* Default Properties */
    	let dimensions = { x: 40, y: 40, z: 40 };
    	let color = "black";
    	let classed = "d3X3dLabel";
    	let offset = 0;

    	/* Scales */
    	let xScale;
    	let yScale;
    	let zScale;

    	/**
    	 * Constructor
    	 *
    	 * @constructor
    	 * @alias label
    	 * @param {d3.selection} selection - The chart holder D3 selection.
    	 */
    	const my = function(selection) {
    		selection.each(function(data) {

    			const element = d3.select(this)
    				.classed(classed, true)
    				.attr("id", (d) => d.key);

    			const makeSolid = (el, color) => {
    				el.append("Appearance")
    					.append("Material")
    					.attr("diffuseColor", colorParse(color) || "0 0 0");
    			};

    			const labelSelect = element.selectAll(".label")
    				.data([data]);

    			let label = labelSelect.enter()
    				.append("Transform")
    				.attr("translation", (d) => (xScale(d.x) + " " + yScale(d.y) + " " + zScale(d.z)))
    				.classed("label", true)
    				.append("Billboard")
    				.attr("axisOfRotation", "0 0 0")
    				.append("Transform")
    				.attr("translation", (d) => (offset + " " + offset + " " + offset))
    				.append("Shape")
    				.call(makeSolid, color)
    				.append("Text")
    				.attr("string", (d) => d.key)
    				.append("FontStyle")
    				.attr("size", 1)
    				.attr("family", "SANS")
    				.attr("style", "BOLD")
    				.attr("justify", "START");

    			label.merge(labelSelect);

    			labelSelect.transition()
    				.ease(d3.easeQuadOut)
    				.attr("translation", (d) => (xScale(d.x) + " " + yScale(d.y) + " " + zScale(d.z)));
    		});
    	};

    	/**
    	 * Dimensions Getter / Setter
    	 *
    	 * @param {{x: number, y: number, z: number}} _v - 3D object dimensions.
    	 * @returns {*}
    	 */
    	my.dimensions = function(_v) {
    		if (!arguments.length) return dimensions;
    		dimensions = _v;
    		return this;
    	};

    	/**
    	 * X Scale Getter / Setter
    	 *
    	 * @param {d3.scale} _v - D3 scale.
    	 * @returns {*}
    	 */
    	my.xScale = function(_v) {
    		if (!arguments.length) return xScale;
    		xScale = _v;
    		return my;
    	};

    	/**
    	 * Y Scale Getter / Setter
    	 *
    	 * @param {d3.scale} _v - D3 scale.
    	 * @returns {*}
    	 */
    	my.yScale = function(_v) {
    		if (!arguments.length) return yScale;
    		yScale = _v;
    		return my;
    	};

    	/**
    	 * Z Scale Getter / Setter
    	 *
    	 * @param {d3.scale} _v - D3 scale.
    	 * @returns {*}
    	 */
    	my.zScale = function(_v) {
    		if (!arguments.length) return zScale;
    		zScale = _v;
    		return my;
    	};

    	/**
    	 * Color Getter / Setter
    	 *
    	 * @param {string} _v - Color (e.g. "red" or "#ff0000").
    	 * @returns {*}
    	 */
    	my.color = function(_v) {
    		if (!arguments.length) return color;
    		color = _v;
    		return my;
    	};

    	/**
    	 * Offset Getter / Setter
    	 *
    	 * @param {number} _v - Label offset number.
    	 * @returns {*}
    	 */
    	my.offset = function(_v) {
    		if (!arguments.length) return offset;
    		offset = _v;
    		return my;
    	};

    	return my;
    }