// ==UserScript==
// @name        Block stupid fonts
// @namespace   -
// @description Block stupid fonts
// @version     1
// ==/UserScript==
//
//
/**
 * Userscript to whitelist certain fonts and block the rest.
 * Author: Hiltjo Posthuma <hiltjo AT codemadness DOT org>
 * License: WTFPL.
 */
(function() {
	/* These fonts are kindof OK (imho)... */
	var whitelist = [
		/arial/i,
		/helvetica/i,
		/liberation sans/i,
		/verdana/i,
		/tahoma/i,
		/serif/i,
		/sans-serif/i,
		/monospace/i
	];
	var els = document.getElementsByTagName('*');
	var blocked = {}; /* blocked cache */
	var whitelisted = {};
	for(var i = 0; i < els.length; i++) {
		var fontfamily = window.getComputedStyle(els[i], null).getPropertyValue('font-family') || '';
		if(fontfamily == '')
			continue;
		var fonts = fontfamily.split(',');
		var newfonts = [];
		var replaced = 0; /* amount of fonts replaced for this property */
		for(var j = 0; j < fonts.length; j++) {
			var iswhitelisted = whitelisted[fonts[j]] || 0;
			blocked[fonts[j]] = blocked[fonts[j]] || 0; /* make sure blocked[font] is set */
			if(!iswhitelisted && !blocked[fonts[j]]) { /* lookup (not blocked or whitelisted already). */
				for(var k = 0; k < whitelist.length; k++) { /* check against whitelist */
					if(fonts[j].match(whitelist[k])) {
						whitelisted[fonts[j]] = (whitelisted[fonts[j]] || 0) + 1; /* save for whitelisted faster lookup */
						iswhitelisted = true;
						break;
					}
				}
			}
			if(iswhitelisted) {
				newfonts.push(fonts[j]);
				replaced++;
			} else
				blocked[fonts[j]]++; /* save for blocked faster lookup and stats */
		}
		if(replaced != fonts.length) { /* Only set style if some fonts were replaced. */
			var fns = newfonts.join(',');
			if(fns.length)
				els[i].style.fontFamily = fns;
			else
				els[i].style.fontFamily = null; 
		}
	}
	for(key in blocked) /* stats */
		if(blocked[key] > 0)
			console.log('FontBlock: blocked ' + key + ' ' + blocked[key] + ' times');
})();