(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
	typeof define === 'function' && define.amd ? define(['exports'], factory) :
	(factory((global.patternGrid = global.patternGrid || {}), global.d3));
}(this, function (exports,d3) { 'use strict';

	function circlePatternGridLayout() {

    var circleRadius = undefined;
    var spacing = { horizontal: 0, vertical: 0 };
    var margin = { top: 0, left: 0 };
    var imageUrl = undefined;
    var id = "patternGrid";

    var pattern = d3.select("defs").append("pattern")
			.attr('patternUnits', 'userSpaceOnUse');

		function circleLayout() {
			setAttributes();
      return circleLayout;
		}

    function setAttributes() {
			pattern.select("image").remove();

      pattern
      	.attr("id", id)
        .attr("width", circleRadius + spacing.horizontal)
        .attr("height", circleRadius + spacing.vertical)
        .attr("x", margin.left + (circleRadius / 2) + spacing.horizontal)
        .attr("y", margin.top + (circleRadius / 2) + spacing.vertical)
        .append("image")
        .attr("xlink:href", imageUrl)
        .attr("width", circleRadius)
        .attr("height", circleRadius);
		}

		circleLayout.config = function(cfg) {
			if (cfg.image) {
				imageUrl = cfg.image;
			}
			if (cfg.radius) {
				circleRadius = cfg.radius;
			}
			if (cfg.padding) {
				spacing.horizontal = cfg.padding[0];
     		spacing.vertical = cfg.padding[1];
			}
			if (cfg.margin) {
				margin.top = cfg.margin[0];
				margin.left = cfg.margin[1];
			}
			if (cfg.id) {
				id = cfg.id;
			}
			return circleLayout();
		};

		return circleLayout;
	}

	var version = "0.0.1";

	exports.version = version;
  exports.circleLayout = circlePatternGridLayout;
}));