FuseBox.global("__fsbx_css", function (__filename: string, contents?: string): void {
    if (FuseBox.isServer) {
        return;
    }
    var styleId = __filename.replace(/[\.\/]+/g, '-');
    if (styleId.charAt(0) === '-') styleId = styleId.substring(1);
    var exists = document.getElementById(styleId);
    if (!exists) {
        //<link href="//fonts.googleapis.com/css?family=Covered+By+Your+Grace" rel="stylesheet" type="text/css">
        var s = document.createElement(contents ? 'style' : 'link');
        s.id = styleId;
        s.type = 'text/css';
        if (contents) {
            s.innerHTML = contents;
        } else {
            (s as HTMLLinkElement).rel = 'stylesheet';
            (s as HTMLLinkElement).href = __filename;
        }
        document.getElementsByTagName('head')[0].appendChild(s);
    } else {
        if (contents) {
            exists.innerHTML = contents;
        }
    }
});

/**
 * Listens to 'async' requets and if the name is a css file
 * wires it to `__fsbx_css`
 */
FuseBox.on('async', function (name) {
    if (FuseBox.isServer) {
        return;
    }
    if (/\.css$/.test(name)) {
        __fsbx_css(name);
        return false;
    }
});