(function($){
	var persistFont = function (font) {
		// one week
		var duration = 7 * 24 * 3600 * 1000;
		var expires = (new Date((new Date()).getTime() + duration)).toGMTString();
		document.cookie = 'rb_dd_fontsize=' + escape(font) + ';expires=' + expires + ';path=/';
	};
	
	$(document).ready(function() {
		// read font size from cookie
		var cookie = document.cookie;
		var result = cookie.match(/rb_dd_fontsize=([a-z]+)/);
		if (result) {
			$('body').addClass('font-' + result[1]);
		}
		
		$('a.btn-change-font-size').click(function() {
			// font size classes to loop through
			var fonts = ['normal', 'l', 'xl'];
			
			// set the default font
			var body = $('body');
			
			var newFont;
			for (var i = 0; i < fonts.length; i++) {
				var font = fonts[i];
				if (body.is('.font-' + font)) {
					body.removeClass('font-' + font);
					newFont = fonts[(i + 1) % fonts.length];
					break;
				}
			}
			if (!newFont) {
				newFont = fonts[1];
			}
			body.addClass('font-' + newFont);
			persistFont(newFont);
		});
	});
})(jQuery);