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 CryptoJS = require("crypto-js");
const secretKey = "uuidSecretKey2025"; // ใช้เป็นคีย์สำหรับเข้ารหัส

const cookieName = process.env.SSO_COOKIE_NAME || "ssotoken";
const privateKey = fs.readFileSync(`./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();

// ตั้งค่าการป้องกัน Origin
const allowedOrigins = ['https://hrms.bangkok.go.th', 'https://hrms.chin.in.th', 'https://hrmsbkk.case-collection.com', 'http://localhost:3002']; // อนุญาตเฉพาะ domain ที่กำหนด  //http://localhost:3002

app.use(cors({
  // origin: function (origin, callback) {
  //   if (allowedOrigins.includes(origin)) {
  //     callback(null, true);  // อนุญาต
  //   } else {
  //     callback(new Error('Origin not allowed by CORS'));  // ปฏิเสธ
  //   }
  // },
  methods: ['GET', 'POST'], // จำกัดเฉพาะ method ที่อนุญาต
  credentials: true,
}));

app.use(express.urlencoded({ extended: true }));
app.use(express.json());
app.use(cookieParser());

app.get("/api/v1/sso", async (req, res) => {
  res.status(200).send("HRMS API SSO");
});

app.post("/api/v1/sso/signin", async (req, res) => {
  const origin = req.headers.origin;
  if (allowedOrigins.includes(origin)) {
    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);

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

        const uid = await CryptoJS.AES.encrypt(login_user.username, secretKey).toString();
        res.status(200).send({ uid });

      }).catch((err) => {
        if (err.status) {
          res.status(401).send("Incorrect user or password");
        } else
          res.status(err.status).send(error);
      });
    } catch (error) {
      res.status(500).send(error);
    }
  } else {
    res.status(403).json({ error: 'Forbidden: Origin not allowed' });
  }
});

app.post("/api/v1/sso/kcauth", async (req, res) => {
  const origin = req.headers.origin;
  if (allowedOrigins.includes(origin)) {
    try {
      // kcauth
      // const useBMA = Boolean(process.env.USE_BMA) || false;
      // const publicKeyLanding = fs.readFileSync(`./BMA.pub.pem`, "utf8");
      const clientSecret = process.env.KC_CLIENT_SECRET;
      const clientId = process.env.KC_CLIENT_ID;

      // const cookies = req.cookies;
      // const tokenSSO = cookies[cookieName];
      //if (tokenSSO) {
      //   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);
      //   username = d.username;
      // }

      // send uid from client
      const uid = req.body.uid;
      if (!uid) {
        res.status(401).send("Unauthorized");
        return;
      }

      let username = "";
      const bytes = CryptoJS.AES.decrypt(uid, secretKey);
      const decrypted = bytes.toString(CryptoJS.enc.Utf8);
      username = decrypted;

      // 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);

      // get token for user
      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.cookie('oldssotoken', tokenSSO, {
      //   maxAge: 1000 * 60 * 60 * 24, // กำหนด timeout หน่วยเป็น millisecond
      //   path: "/",
      //   httpOnly: true,
      // });

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

    } catch (error) {
      res.status(500).send(error);
    }
  } else {
    res.status(403).json({ error: 'Forbidden: Origin not allowed' });
  }
})

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