const crypto = require('crypto')

const db = require('../db')

function generateOTP (name) {
  const otp = crypto.randomBytes(32).toString('hex')

  const sql = 'insert into one_time_passes (token, name) values ($1, $2)'

  return db.none(sql, [otp, name])
    .then(() => otp)
}

function validateOTP (otp) {
  const sql = `delete from one_time_passes
    where token=$1
    returning name, created < now() - interval '1 hour' as expired`

  return db.one(sql, [otp])
    .then(r => ({success: !r.expired, expired: r.expired, name: r.name}))
    .catch(() => ({success: false, expired: false}))
}

function register (otp) {
  return validateOTP(otp)
    .then(r => {
      if (!r.success) return r

      const token = crypto.randomBytes(32).toString('hex')
      const sql = 'insert into user_tokens (token, name) values ($1, $2)'

      return db.none(sql, [token, r.name])
        .then(() => ({success: true, token: token}))
    })
    .catch(() => ({success: false, expired: false}))
}

function authenticate (token) {
  const sql = 'select token from user_tokens where token=$1'

  return db.one(sql, [token]).then(() => true).catch(() => false)
}

module.exports = {
  generateOTP,
  register,
  authenticate
}