//simulate BMA SSO behavior Authenticator and reverse proxy
//cookie with token is the final product of SSO

require("dotenv").config();
const cookieParser = require('cookie-parser');
const querystring = require("querystring");

const port = Number(process.env.SSO_PORT) || 80;
const express = require("express");
const cors = require('cors');
const jwt = require("jsonwebtoken");
const fs = require("fs");
const axios = require("axios");

const cookieName = process.env.SSO_COOKIE_NAME || "ssotoken";
const privateKey = fs.readFileSync(`${process.cwd()}/BMA`, "utf8");
const signOptions = {
  issuer: "BMA corp",
  subject: "sso@bangkok.go.th",
  audience: "http://sso.bangkok.go.th",
  expiresIn: "12h",
  algorithm: "RS256",
};

const urlKeycloakToken = `${process.env.KC_URL}/realms/${process.env.KC_REALMS}/protocol/openid-connect/token`;

const app = express();
app.use(cors({
  origin: "*",
  credentials: true,
}));
app.use(express.urlencoded({ extended: true }));
app.use(express.json());
app.use(cookieParser());
app.post("/signin", async (req, res) => {

  try {
    const login_user = req.body;

    const formdata = new URLSearchParams();
    formdata.append("grant_type", "password");
    formdata.append("client_id", process.env.VITE_CLIENTID_KEYCLOAK);
    formdata.append("username", login_user.username);
    formdata.append("password", login_user.password);

    // console.log("formdata===>", formdata);

    const response = await axios.post(urlKeycloakToken, formdata, {
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
      },
    });

    if (response.data) {
      const payload = { username: login_user.username };
      let token = jwt.sign(payload, privateKey, signOptions);

      res.cookie(cookieName, token, {
        maxAge: 1000 * 60 * 60 * 24, // กำหนด timeout หน่วยเป็น millisecond
        path: "/",
        httpOnly: true,
      });

      res.sendStatus(200);
    } else {
      res.status(401).send("Incorrect user or password");
    }
  } catch (error) {
    res.status(500).send("Incorrect user or password!");
  }
});

// kcauth
const useBMA = Boolean(process.env.USE_BMA) || false;
const publicKeyLanding = fs.readFileSync(`${process.cwd()}/BMA.pub.pem`, "utf8");
const clientSecret = process.env.KC_CLIENT_SECRET;
const clientId = process.env.KC_CLIENT_ID;

app.post("/kcauth", async (req, res) => {
  try {
    const cookies = req.cookies;
    const tokenSSO = cookies[cookieName];

    let decodedToken = "";
    if (useBMA) {
      decodedToken = jwt.decode(tokenSSO);
    } else {
      decodedToken = jwt.verify(tokenSSO, publicKeyLanding);
    }

    let d = JSON.parse(JSON.stringify(decodedToken));
    // console.log("==== username from cookies ====", d);
    const username = d.username;

    // create body for admin token
    let body = {
      client_id: clientId,
      client_secret: clientSecret,
      grant_type: "client_credentials",
    };

    const postData = querystring.stringify(body);

    // get admin token
    const response = await axios.post(urlKeycloakToken, postData, {
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
      },
    });
    // console.log("==== admin token ====");
    const adminToken = response.data.access_token;
    // console.log(adminToken);

    // create body for user token
    let body2 = {
      client_id: clientId,
      client_secret: clientSecret,
      grant_type: "urn:ietf:params:oauth:grant-type:token-exchange",
      subject_token: adminToken,
      requested_token_type: "urn:ietf:params:oauth:token-type:refresh_token",
      audience: clientId,
      requested_subject: username,
    };

    const postData2 = querystring.stringify(body2);
    // console.log("==== postData2 ====");
    // console.log(body2);

    // get admin token
    const tokenResponse = await axios.post(urlKeycloakToken, postData2, {
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
      },
    });

    // console.log("==== user token ====");
    // console.log(tokenResponse.data);
    // await postLog('เข้าสู่ระบบ', tokenResponse.data.access_token);

    res.status(200).send(tokenResponse.data);

  } catch (error) {
    // console.log("error===>", error);

    res.status(401).send(error);
  }
})

// app.use(express.static(path.join(__dirname, "public-sso")));

// app.get("/", (_req, res) => {
//   res.sendFile(`${process.cwd()}/sso.js`);
// });

console.log("Start BMA SSO Simulator at port " + port);
app.listen(port);