import bcrypt from 'bcrypt'
import crypto from 'crypto'
import jwt from 'jsonwebtoken'
import { Router } from 'express'
import { glauth } from '../libs/database.js'
import execawait from '../libs/execawait.js'

export const SECRET = process.env.TK_SECRET ?? crypto.generateKeySync("aes", { length: 128 }).export().toString()
const AUTH = Router()
let valid = {}

/**
 * This is needed because GLAuth (GLAuth's bcrypt) and Node (Node's bcrypt) read hashes differently.
 * @param {string} hash The hash to be converted to hex.
 * @returns {string} hex of hash
 */
function hash2hex(hash) {
    return hash
        .split('')
        .map(e => e
            .charCodeAt(0)
            .toString(16)
        )
        .join('')
}

AUTH.post('/register', async (req, res) => {
    const { captcha, password, username } = req.body

    if (!username || !password || !captcha)
        return(res.send(`Not entered:${username ? '' : ' username,'}${password ? '' : ' password,'}${captcha ? '' : ' captcha'}`))

    if (!valid[captcha])
        return(res.send("Invalid captcha!"))

    const captchaAge = Math.abs((valid[captcha].getTime() - new Date().getTime())/1000)

    if (captchaAge > 600)
        return(res.send("Invalid captcha!"))

    // Does the username match the requirements?
    if (!(/^\w{2,20}$/.test(username)))
        return(res.send("Username does not match the requirements"))

    if ((await glauth.query("SELECT * FROM users WHERE lower(name) = lower($1::text)", [ username ])).rowCount)
        return(res.send("User already exists"))

    // Expire the captcha.
    delete valid[captcha]

    bcrypt.hash(password, 12).then(
        hash => {
            const hexHash = hash2hex(hash)
            glauth.query(
                "INSERT INTO users(name, mail, primarygroup, passbcrypt, qam_pass) VALUES($1::text, $2::text, 0, $3::text, $4::text)",
                [ username, `${username}@qwik.space`, hexHash, hash ]
            ).then(
                () => res.send("Account registered!")
            ).catch(
                err => res.json({ _: "Sorry an error occured!", err })
            )
        }
    )
})

AUTH.post('/login', async (req, res) => {
    const { password, username } = req.body

    // Was input sent?
    if (!username || !password )
        return(res.send(`Not entered:${username ? '' : ' username,'}${password ? '' : ' password'}`))

    const user = (await glauth.query("SELECT * FROM users WHERE lower(name) = lower($1::text)", [ username ])).rows[0]

    if (!user)
        return(res.send("User doesn't exist!"))

    bcrypt.compare(password, user.qam_pass).then(
        async match => {
            if (!match)
                return res.send("Password is incorrect!")

            const bearer = {
                name: user.name,
                id: user.uidnumber,
                group: (await glauth.query("SELECT name FROM ldapgroups WHERE gidnumber = $1::int", [ user.primarygroup ])).rows[0].name
            }
            
            const token = jwt.sign(
                bearer,
                SECRET,
                { expiresIn: '1h' }
            )

            const fourHoursInMillis = 60 * 60 * 1000
            res.cookie(
                'api-token',
                token,
                {
                    expires: new Date(Date.now() + fourHoursInMillis),
                    httpOnly: true,
                    signed: true
                }
            ).redirect('/manager')
        }
    )
})

AUTH.post('/changePass', async (req, res) => {
    const { newPass, oldPass } = req.body

    // Was input sent?
    if (!newPass|| !oldPass )
        return(res.send(`Not entered:${newPass ? '' : ' new password,'}${oldPass ? '' : ' old password'}`))

    const token = jwt.verify(req.signedCookies["api-token"], SECRET)

    if (!token)
        return res.send("Token error! Please sign in ag    ain anusername = token.named retry...")

    const username = token.name

    const user = (await glauth.query("SELECT * FROM users WHERE lower(name) = lower($1::text)", [ username ])).rows[0]

    if (!user)
        return(res.send("User doesn't exist!"))

    bcrypt.compare(oldPass, user.qam_pass).then(
        async match => {
            if (!match)
                return res.send("Password's is incorrect!")
            
            const newPassHash = await bcrypt.hash(newPass, 12)
            const newPassHexHash = hash2hex(newPassHash)

            glauth.query("UPDATE users SET qam_pass = $1::text, passbcrypt = $2::text WHERE name = $3::text", [ newPassHash, newPassHexHash, username ])
                .then(
                    () => res.send("Successfully changed password!")
                ).catch(
                    () => res.send("Database error while changing password!")
                )
        }
    )
})

AUTH.get('/captcha', async (req, res) => {
    const captcha = crypto.randomBytes(3).toString('hex')
    await execawait(`./captcha.sh ${captcha} > captcha.png`)

    // Make it valid for 10 minutes
    valid[captcha] = new Date(Date.now() + 10 * 60 * 1000)

    // Send the captcha image
    res.contentType('image/png')
        .sendFile('captcha.png', { root: './' })
})


export default AUTH