watchparty/functions/modules/authenticator.js

const admin = require("firebase-admin");
const Logger = require("../Logger");
const mLogger = new Logger("modules", "authenticator");

module.exports = (req, res, next) => {
  mLogger.start();
  res.set("Access-Control-Allow-Origin", ["*"]);
  if (req.url === "/") {
    mLogger.success("HEARTBEAT", { URL: req.url });
    res.status(200).send({ message: "ALIVE" });
    return next();
  }
  if (req.method === "OPTIONS") {
    mLogger.success("OPTIONS CALL", { URL: req.url });
    res.status(200).send();
    return next();
  }
  if (req.headers.authorization) {
    try {
      const token = req.headers.authorization.split(" ")[1];
      const reqToken = token.split(":")[0];
      const reqUid = token.split(":")[1];
      admin
        .auth()
        .verifyIdToken(reqToken)
        .then((user) => {
          if (user.uid === reqUid) {
            if (req.method === "POST") {
              const bodydata = JSON.parse(req.body);
              bodydata.uid = user.uid;
              req.body = JSON.stringify(bodydata);
            }
            if (
              req.method === "GET" ||
              req.method === "DELETE" ||
              req.method === "PUT"
            ) {
              req.body = JSON.stringify({ uid: user.uid });
            }
            mLogger.success("AUTHORIZED", { URL: req.url, UID: reqUid });
            return next();
          } else {
            mLogger.success("NOT AUTHORIZED", { URL: req.url });
            return res.status(401).send({ message: "Unauthorized" });
          }
        })
        .catch((err) => {
          mLogger.error("AUTH VALIDATE FIREBASE ERROR", {
            URL: req.url,
            Error: err,
          });
          return res
            .status(500)
            .send({ message: "Unable to verify user token" });
        });
    } catch (err) {
      mLogger.error("AUTH VALIDATE ERROR", { URL: req.url, Error: err });
      return res
        .status(401)
        .send({ message: "Something went wrong when authorizing" });
    }
  } else {
    mLogger.error("NO AUTH TOKEN", { URL: req.url });
    res.status(401).send({ message: "Got no user token" });
  }
  return 0;
};