import express from 'express';
import {
  generateRegistrationOptions,
  verifyRegistrationResponse,
  generateAuthenticationOptions,
  verifyAuthenticationResponse,
} from '@simplewebauthn/server';
import dbClient from './../db/index.js';
import crypto from 'node:crypto';
import limitedUsers from '../middlewares/limitedUsers.js';

var router = express.Router();

const userPasskeys = [];
const origin = `https://${process.env.RP_ID}`;

const challenges = {};
const users = {};
const currentLogin = {};

router.get("/register", limitedUsers, function(_, res) {
  res.render("users/register");
});

router.get("/login", function(_, res) {
  res.render("users/login");
});

router.get("/generate-auth-options/:username", async function(req, res, next) {
  dbClient.query({
    text: 'SELECT * FROM users WHERE username=$1',
    values: [req.params.username]
  })
    .then((result) => {
      const user = result.rows[0];
      if (!user) {
        throw new Error("ya pas de user wesh");
      }
      return dbClient.query({
        text: `
          SELECT *
          FROM user_passkeys up
          JOIN passkeys ON up.passkey_id = passkeys.id
          WHERE up.user_id = $1
        `,
        values: [user.id]
      });
    })
    .then(async (passkeyData) => {
      const options = await generateAuthenticationOptions({
        rpID: process.env.RP_ID,
        allowCredentials: passkeyData.rows.map(passkey => ({
          id: passkey.id,
          transports: passkey.transports,
        })),
      });

      currentLogin[req.params.username] = options;
      return options;
    })
    .then((options) => {
      res.json(options);
    })
    .catch((err) => {
      console.error("Error in login");
      console.error(err);
      next(err);
    });
});

router.post("/verify-auth/", function(req, res) {
  console.log("Verify auth");
  const { authResp, username } = req.body;

  dbClient.query({
    text: 'SELECT * FROM users WHERE username=$1',
    values: [username]
  })
    .then((result) => {
      const user = result.rows[0];
      if (!user) {
        throw new Error("ya pas de user wesh");
      }
      return dbClient.query({
        text: `
          SELECT *
          FROM passkeys
          WHERE id = $1
        `,
        values: [authResp.id]
      });
    })
    .then(async (passkeyData) => {
      const passkey = passkeyData.rows[0];

      return verifyAuthenticationResponse({
        response: authResp,
        expectedChallenge: currentLogin[username].challenge,
        expectedOrigin: origin,
        expectedRPID: process.env.RP_ID,
        credential: {
          id: passkey.id,
          publicKey: new Uint8Array(passkey['public_key']),
          counter: passkey.counter,
          transports: passkey.transports,
        },
        equireUserVerification: false,
      });
    })
    .then(verification => {
      const header = Buffer.from(JSON.stringify({
        'alg': 'HS256',
        'type': "JWT"
      })).toString('base64url');
      const payload = Buffer.from(JSON.stringify({
        verified: true,
        username: username
      })).toString('base64url');

      const hash = crypto.createHmac('sha256', process.env.AUTH_JWT_SECRET);
      hash.update(header + "." + payload);
      const token = header + "." + payload + "." + hash.digest('base64url');

      res.cookie('auth_token', token, {
        httpOnly: true,
        secure: true,
        sameSite: 'Strict'
      });

      res.send(verification);
    })
    .catch(err => {
      console.log("ya erreur")
      console.error(err);
      res.status(400).send({ error: err.message });
    });
});

router.post("/register/setup", limitedUsers, async function(req, res, next) {
  const { username } = req.body;

  generateRegistrationOptions({
    rpName: process.env.RP_NAME,
    rpID: process.env.RP_ID,
    userName: username,
    attestationType: 'none',
    excludeCredentials: userPasskeys.map(passkey => ({
      id: passkey.id,
      transports: passkey.transports,
    })),
    authenticatorSelection: {
      residentKey: 'preferred',
      userVerification: 'preferred',
      authenticatorAttachment: 'platform',
    },
  })
    .then((options) => {
      challenges[username] = options.challenge;
      users[username] = options.user;
      res.send(options);
    })
    .catch((err) => {
      console.error("Something went wrong");
      console.error(err);
      next(err);
    });

});

router.post("/register/verify", limitedUsers, function(req, res, next) {
  const { registration, username } = req.body;
  verifyRegistrationResponse({
    response: registration,
    expectedChallenge: challenges[username],
    expectedOrigin: origin,
    expectedRPID: process.env.RP_ID,
  })
    .then(async (verification) => {
      const user = users[username];

      await dbClient.query("BEGIN");
      
      await dbClient.query({
        text: 'INSERT INTO users(id, username) VALUES($1, $2)',
        values: [user.id, user.name],
      });

      await dbClient.query({
        text: 'INSERT INTO passkeys(id, public_key, counter, transports) VALUES($1, $2, $3, $4)',
        values: [
          verification.registrationInfo.credential.id,
          Buffer.from(verification.registrationInfo.credential.publicKey),
          verification.registrationInfo.credential.counter,
          verification.registrationInfo.credential.transports.join(',')
        ]
      });
      
      await dbClient.query({
        text: 'INSERT INTO user_passkeys(user_id, passkey_id) VALUES($1, $2)',
        values: [user.id, verification.registrationInfo.credential.id]
      });

      dbClient.query("COMMIT");
      res.send(verification);
    })
    .catch((err) => {
      dbClient.query("ROLLBACK");
      console.error("Something went wrong")
      console.error(err);
      next(err);
    })
    .finally(() => {
      delete challenges[username];
      delete users[username];
    });
});


export default router;