# component/axisThreePlane.js

    import * as d3 from "d3";
    import componentAxis from "./axis";

    /**
     * Reusable 3D Multi Plane Axis Component
     *
     * @module
     */
    export default function() {

    	/* Default Properties */
    	let dimensions = { x: 40, y: 40, z: 40 };
    	let colors = ["blue", "red", "green"];
    	let classed = "d3X3dAxisThreePlane";
    	let labelPosition = "proximal";

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

    	/* Components */
    	const xzAxis = componentAxis();
    	const yzAxis = componentAxis();
    	const yxAxis = componentAxis();
    	const zxAxis = componentAxis();

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

    			const element = d3.select(this)
    				.classed(classed, true);

    			const layers = ["xzAxis", "yzAxis", "yxAxis", "zxAxis"];
    			element.selectAll("group")
    				.data(layers)
    				.enter()
    				.append("Group")
    				.attr("class", (d) => d);

    			xzAxis.scale(xScale)
    				.direction("x")
    				.tickDirection("z")
    				.tickSize(zScale.range()[1] - zScale.range()[0])
    				.color("blue")
    				.labelPosition(labelPosition);

    			yzAxis.scale(yScale)
    				.direction("y")
    				.tickDirection("z")
    				.tickSize(zScale.range()[1] - zScale.range()[0])
    				.color("red")
    				.labelPosition(labelPosition);

    			yxAxis.scale(yScale)
    				.direction("y")
    				.tickDirection("x")
    				.tickSize(xScale.range()[1] - xScale.range()[0])
    				.color("red")
    				.labelPosition(labelPosition);

    			zxAxis.scale(zScale)
    				.direction("z")
    				.tickDirection("x")
    				.tickSize(xScale.range()[1] - xScale.range()[0])
    				.color("black")
    				.labelPosition(labelPosition);

    			// We only want 2 sets of labels on the y axis if they are in distal position.
    			if (labelPosition === "proximal") {
    				yxAxis.tickFormat("");
    			} else {
    				yxAxis.tickFormat((d) => d);
    			}

    			element.select(".xzAxis")
    				.call(xzAxis);

    			element.select(".yzAxis")
    				.call(yzAxis);

    			element.select(".yxAxis")
    				.call(yxAxis);

    			element.select(".zxAxis")
    				.call(zxAxis);
    		});
    	};

    	/**
    	 * 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;
    	};

    	/**
    	 * Colors Getter / Setter
    	 *
    	 * @param {Array} _v - Array of colours used by color scale.
    	 * @returns {*}
    	 */
    	my.colors = function(_v) {
    		if (!arguments.length) return colors;
    		colors = _v;
    		return my;
    	};

    	/**
    	 * Label Position Getter / Setter
    	 *
    	 * @param {string} _v - Position ("proximal" or "distal")
    	 * @returns {*}
    	 */
    	my.labelPosition = function(_v) {
    		if (!arguments.length) return labelPosition;
    		labelPosition = _v;
    		return my;
    	};

    	return my;
    }