finlabsindia/wp-content/themes/vamtam-consulting/vamtam/assets/js/plugins/thirdparty/css-variables-polyfill.js

let cssVarPoly = {
	init: function() {
		// first lets see if the browser supports CSS variables
		// No version of IE supports window.CSS.supports, so if that isn't supported in the first place we know CSS variables is not supported
		// Edge supports supports, so check for actual variable support
		if (window.CSS && window.CSS.supports && window.CSS.supports('(--foo: red)')) {
			// this browser does support variables, abort
			console.log('your browser supports CSS variables, aborting and letting the native support handle things.');
			return;
		} else {
			// edge barfs on console statements if the console is not open... lame!
			console.log('no support for you! polyfill all (some of) the things!!');
			document.querySelector('body').classList.add('cssvars-polyfilled');
		}

		cssVarPoly.ratifiedVars = {};
		cssVarPoly.varsByBlock = {};
		cssVarPoly.oldCSS = {};
		cssVarPoly.media = {};
		cssVarPoly.hrefs = {};

		// start things off
		cssVarPoly.findCSS();
		cssVarPoly.updateCSS();
	},

	// see https://stackoverflow.com/a/6969486
	escapeRegExp: function(str) {
	  return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
	},

	// find all the css blocks, save off the content, and look for variables
	findCSS: function() {
		let styleBlocks = document.querySelectorAll('style:not(.inserted),link[type="text/css"]');

		// we need to track the order of the style/link elements when we save off the CSS, set a counter
		let counter = 1;

		// loop through all CSS blocks looking for CSS variables being set
		[].forEach.call(styleBlocks, function(block) {
			// console.log(block.nodeName);
			let theCSS = '';
			if (block.nodeName === 'STYLE') {
				// console.log("style");
				theCSS = block.innerHTML;
				cssVarPoly.findSetters(theCSS, counter);
			} else if (block.nodeName === 'LINK' && block.getAttribute('href').match( /bb-plugin|wp-content\/themes/ ) ) {
				cssVarPoly.media[counter] = block.getAttribute( 'media' );
				cssVarPoly.hrefs[counter] = block.getAttribute( 'href' );

				cssVarPoly.getLink(block.getAttribute( 'href' ), counter, function(counter, request) {
					// no setters in links for us
					// cssVarPoly.findSetters(request.responseText, counter);
					cssVarPoly.oldCSS[counter] = request.responseText;
					cssVarPoly.updateCSS();
				});
				theCSS = '';
			}
			// save off the CSS to parse through again later. the value may be empty for links that are waiting for their ajax return, but this will maintain the order
			// console.log( counter, block );
			cssVarPoly.oldCSS[counter] = theCSS;
			counter++;
		});
	},

	// find all the "--variable: value" matches in a provided block of CSS and add them to the master list
	findSetters: function(theCSS, counter) {
		// console.log(theCSS);
		cssVarPoly.varsByBlock[counter] = theCSS.match(/(--[-\w]+:.*;)/g) || [];
	},

	// run through all the CSS blocks to update the variables and then inject on the page
	updateCSS: function() {
		// first lets loop through all the variables to make sure later vars trump earlier vars
		cssVarPoly.ratifySetters(cssVarPoly.varsByBlock);

		// loop through the css blocks (styles and links)
		for (let curCSSID in cssVarPoly.oldCSS) {
			// console.log("curCSS:",cssVarPoly.oldCSS[curCSSID]);

			let cachedCSS = cssVarPoly.hrefs[ curCSSID ] ? localStorage.getItem( 'vamtam-theme-css-' + cssVarPoly.hrefs[ curCSSID ] ) : null;
			let newCSS;

			if ( ! cachedCSS ) {
				newCSS = cssVarPoly.replaceGetters(cssVarPoly.oldCSS[curCSSID], cssVarPoly.ratifiedVars);

				if ( cssVarPoly.hrefs[ curCSSID ] ) {
					localStorage.setItem( 'vamtam-theme-css-' + cssVarPoly.hrefs[ curCSSID ], newCSS );
				}
			} else {
				newCSS = cachedCSS;
			}

			// put it back into the page
			// first check to see if this block exists already
			if (document.querySelector('#inserted' + curCSSID)) {
				// console.log("updating")
				document.querySelector('#inserted' + curCSSID).innerHTML = newCSS;
			} else {
				var style = document.createElement('style');
				style.type = 'text/css';
				style.innerHTML = newCSS;
				style.classList.add('inserted');
				style.id = 'inserted' + curCSSID;

				if ( cssVarPoly.media[ curCSSID ] ) {
					style.media = cssVarPoly.media[ curCSSID ];
				}

				document.getElementsByTagName('head')[0].appendChild(style);
				// console.log("adding", curCSSID, style);
			}
		};
	},

	// parse a provided block of CSS looking for a provided list of variables and replace the --var-name with the correct value
	replaceGetters: function(curCSS, varList) {
		if ( curCSS ) {
			// console.log(varList);
			for (let theVar in varList) {
				// console.log(theVar);
				// match the variable with the actual variable name
				let getterRegex = new RegExp('var\\(\\s*' + cssVarPoly.escapeRegExp( theVar ) + '\\s*\\)', 'g');

				curCSS = curCSS.replace(getterRegex, varList[theVar]);
			}

			/*
			// now check for any getters that are left that have fallbacks
			let getterRegex2 = new RegExp('var\\(\\s*.+\\s*,\\s*(.+)\\)', 'g');
			// console.log(curCSS);
			let matches = curCSS.match(getterRegex2);
			if (matches) {
				// console.log("matches",matches);
				matches.forEach(function(match) {
					// console.log(match.match(/var\(.+,\s*(.+)\)/))
					// find the fallback within the getter
					curCSS = curCSS.replace(match, match.match(/var\(.+,\s*(.+)\)/)[1]);
				});
			}
			*/
		}


		// console.log(curCSS);
		return curCSS;
	},

	// determine the css variable name value pair and track the latest
	ratifySetters: function(varList) {
		// console.log("varList:",varList);
		// loop through each block in order, to maintain order specificity
		for (let curBlock in varList) {
			let curVars = varList[curBlock];
			// console.log("curVars:",curVars);
			// loop through each var in the block
			curVars.forEach(function(theVar) {
				// console.log(theVar);
				// split on the name value pair separator
				let matches = theVar.split(':');

				// console.log(matches);
				// put it in an object based on the varName. Each time we do this it will override a previous use and so will always have the last set be the winner
				// 0 = the name, 1 = the value, strip off the ; if it is there
				let name = matches[0].trim();
				let value = matches.slice(1).join( ':' ).trim();

				cssVarPoly.ratifiedVars[ name ] = value.replace(/;/, '');
			});
		};
		// console.log(ratifiedVars);
	},

	// get the CSS file (same domain for now)
	getLink: function(url, counter, success) {
		// console.log( 'will get: ', url );
		var request = new XMLHttpRequest();
		request.open('GET', url, true);
		request.overrideMimeType('text/css;');
		request.onload = function() {
			if (request.status >= 200 && request.status < 400) {
				// Success!
				// console.log(request.responseText);
				if (typeof success === 'function') {
					success(counter, request);
				}
			} else {
				// We reached our target server, but it returned an error
				console.warn('an error was returned from:', url);
			}
		};

		request.onerror = function() {
			// There was a connection error of some sort
			console.warn('we could not get anything from:', url);
		};

		request.send();
	}

};

// hash = function(s){
//   return s.split("").reduce(function(a,b){a=((a<<5)-a)+b.charCodeAt(0);return a&a},0);
// }
cssVarPoly.init();