const fs = require('fs')
const pify = require('pify')
const readFile = pify(fs.readFile)
const crypto = require('crypto')
const baseX = require('base-x')

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

const ALPHA_BASE = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:'
const bsAlpha = baseX(ALPHA_BASE)

const CA_PATH = process.env.CA_PATH
const HOSTNAME = process.env.HOSTNAME

const unpair = pairing.unpair

function totem(name) {
  return readFile(CA_PATH).then(data => {
    const caHash = crypto.createHash('sha256').update(data).digest()
    const token = crypto.randomBytes(32)
    const hexToken = token.toString('hex')
    const caHexToken = crypto
      .createHash('sha256')
      .update(hexToken)
      .digest('hex')
    const buf = Buffer.concat([caHash, token, Buffer.from(HOSTNAME)])
    const sql =
      'insert into pairing_tokens (token, name) values ($1, $3), ($2, $3)'

    return db
      .none(sql, [hexToken, caHexToken, name])
      .then(() => bsAlpha.encode(buf))
  })
}

module.exports = { totem, unpair }