Callback for Square OAuth

square_callback.js

router.get("/callback", (req, res) => {
  const tokenURL = "https://connect.squareup.com/oauth2/token";
  const redirectURI = "https://square-oauth-example.glitch.me/auth/callback";

  if (req.query.state === req.auth.state) {
    axios
      .post(tokenURL, {
        client_id: CLIENT_ID,
        client_secret: SECRET,
        code: req.query.code,
        redirect_uri: redirectURI
      })
      .then((token) => {
        axios
          .get("https://connect.squareup.com/v1/me", {
            "headers": {
              "Authorization": `Bearer ${token.data.access_token}`
            }
          })
          .then((user) => {
            User.create({
              name: user.data.name,
              email: user.data.email,
              squareId: user.data.id,
              accessToken: User.encryptToken(token.data.access_token),
              tokenExp: token.data.expires_at
            }).then((user) => {
              req.auth.isLoggedIn = true;
              req.auth.userId = user.id;
              res.location(`/authorized`);
              res.redirect(301, `/authorized`);
            });
          })
          .catch(error => {
            console.log(error)
            res.status(500).send(error.data);
          });
      })
      .catch(error => {
        console.log(error)
        res.status(500).send(error.data);
      });
  } else {
    res.redirect("/");
  }
});