'use strict'

const express = require('express')
const net = require('net')
const bodyParser = require('body-parser')
const fs = require('fs')
const torm = require('./tor.js')
const logm = require('./log.js')

const timeout_sock = 120 * 60 * 1000 // 120 minute * 60 second/minute * 1000 ms/second

const counter = function*(count) {
  while (true) {
    yield count
    count++
  }
}
const idgen = counter(0)

const socks = {}

const clean_sock = (tor, sock_id) => () => {
  if (!socks[sock_id]) {
    console.error(`Server ${sock_id} does not exist`)
    return "Unable to find the desired server"
  }

  if (socks[sock_id].timer)
    clearTimeout(socks[sock_id].timer)
  if (socks[sock_id].hs)
    tor.destroyHiddenService(socks[sock_id].hs, err => err ? console.error(err) : null)

  delete socks[sock_id]
  console.info(`Server ${sock_id} has been cleaned`)
  return null
}

const register_routes = (app, echo_server, tor) => {
  app.post('/hidden_service', (req, res) => {
    const id = idgen.next().value
    const port = echo_server.address().port
    const to = setTimeout(clean_sock(tor, id), timeout_sock)
    tor.createHiddenService(
      [{virtualPort: port, target: `127.0.0.1:${port}`}],
      (err, data) => {
        if (err) {
          console.error("Unable to create Tor Hidden Service", err)
          res.send({err: err})
          return
        }
        socks[id] = {timer: to, hs: data.serviceId}
        console.info(`Service online at ${data.serviceId}.onion:${port} for ${timeout_sock}ms`)
        res.send({err: null, id: id, hs: data.serviceId, port: port})
      })
  })

  app.delete('/hidden_service', (req, res) => {
    const sock_id = req.body.id
    const err = clean_sock(tor, sock_id)()
    res.send({err: err})
    console.info(`Server ${sock_id} has been deleted with error "${err}"`)
  })
}

const init_http = (echo_server, tor) => new Promise((resolve, reject) => {
  const app = express()
  app.use(bodyParser.json())
  register_routes(app, echo_server, tor)
  app.listen(3000, () => {
    console.info("HTTP module has been inited")
    resolve(app)
  })
})

const init_echo = new Promise((resolve, reject) => {
  const echo_server = net.createServer()
  echo_server
    .on('error', err => {
      console.error("Unable to create socket", err)
      reject(err)
    })
    .on('connection', socket => socket.on('data', socket.write)) // echo socket
    .on('listening', () => {
      console.info("Echo module has been inited")
      resolve(echo_server)
    })
    .listen()
})

const init = () => {
  Promise.all([init_echo, logm.init.then(res => torm.init(res[0], res[1]))])
    .then(values => init_http(values[0], values[1]))
    .catch(console.error)
}

init()