(_ => {
    const cname = (process.env.DOMAIN_CNAME || "").trim().split(/[\,\/\|\ ]/).filter((e: string) => e.length > 0);
    const domain = (process.env.DOMAIN || "127.0.0.1").trim();
    const is_ip = /\d+\.\d+\.\d+\.\d+/.test(domain);

    module.exports = (req: any, res: any, cb: () => void) => {
        const origin = req.headers.origin;
        const urls = new Set([
            `http://${domain}`,
            `https://${domain}`
        ]);

        if (!is_ip) {
            cname.forEach((e: string) => {
                urls.add("http://" + e + "." + domain);
                urls.add("https://" + e + "." + domain);
            });
        };

        if (urls.has(origin)) {
            res.setHeader("Access-Control-Allow-Origin", origin);
        };

        res.setHeader("Access-Control-Allow-Credentials", true);
        res.setHeader("Access-Control-Allow-Methods", "GET,PUT,PATCH,POST,DELETE");
        res.setHeader("Access-Control-Allow-Headers", "X-Requested-With, X-HTTP-Method-Override, Content-Type, Accept");

        cb();
    };
})();