'use strict'

const request = require('request')
const socks_client = require('socks').SocksClient
const fs = require('fs')
const torm = require('./tor.js')
const logm = require('./log.js')
const worker = require('./worker.js')

const measure_interval = 1000
const measure_count = 600
const parralelism = 100
const base_url = process.env.SERVER_URL || "http://127.0.0.1:3000"

const repeat_for = (times, delay, fn) => new Promise((resolve, reject) => {
  const timer = setInterval(() => {
    if (times-- <= 0) {
      clearInterval(timer)
      resolve()
      return
    }
    try {
      fn()
    } catch(err) {
      clearInterval(timer)
      reject(err)
      return
    }
  }, delay)
})

const doMeasure = socket => () => {
  socket.write(`${Date.now().toString()}\n`)
}

const clean = (id) => new Promise((resolve, reject) => {
  request({uri: `${base_url}/hidden_service`, method: "DELETE", json: {id: id}}, (err,res,body) => {
    if (err) reject(err)
    if (body.err) reject(body.err)
    resolve(body)
  })
})

const wait_for_proxy = (socks_opt, max) => new Promise((resolve, reject) => {
  const loop = cur => {
    socks_client.createConnection(socks_opt, (err, info) => {
      if (err && max <= 0) {
        console.error("No more retry")
        reject("No more retry")
        return
      }

      if (err) {
        console.error(`Proxy failed to build with error "${err.message}", ${cur} retries left...`)
        setTimeout(loop, 5000, cur - 1)
        return
      }

      resolve(info)
    })
  }
  loop(max)
})

const create_hidden_service = base_url => new Promise((resolve, reject) => {
  request.post(`${base_url}/hidden_service`, {json: {}}, (err,res,body) => {
    if (err) {
      reject(err)
      return
    }
    if (!body.hs || !body.port) reject("Missing value from API endpoint")
    else resolve(body)
  })
})

const wait_for_hs = socks_port =>
  create_hidden_service(base_url)
    .then(body => Promise.all([
      body,
      logm.get_write_fd(`logs/${Date.now()}-${body.hs}.onion-client.log`)
    ]))
    .then(([body, log]) => {
      fs.write(log, `#info ${Date.now().toString()} Got ${body.hs}:${body.port}\n`,() => {})
      console.info(`We got this hidden service: ${body.hs} on port ${body.port}`)
      const socks_opt = {
        proxy: {ipaddress: '127.0.0.1', port: socks_port, type: 5},
        command: 'connect',
        destination: { host: `${body.hs}.onion`, port: body.port }
      }

      /*
      // used to speedup tests
      socks_opt.destination.host = "ysw5uau3pbjaviha.onion"
      socks_opt.destination.port = 43035
      */
      return Promise.all([
        wait_for_proxy(socks_opt, 120),
        {body: body, socks_opt: socks_opt, log: log}
      ])
    })
    .then(([info, data]) => new Promise((resolve, reject) => {
      info.socket.on('close', () => resolve(data))
      info.socket.destroy()
    }))

const do_measurement = data =>
  Promise.all([wait_for_proxy(data.socks_opt), data])
    .then(([info, data]) => {
      const socks_opt = data.socks_opt
      fs.write(data.log, `#info ${Date.now().toString()} Socks has been created, HS is up\n`, () => {})
      console.info(`SOCKS proxy to ${socks_opt.destination.host}:${socks_opt.destination.port} has been created`)

      const recv_back = new Promise((resolve, reject) => {
        setTimeout(reject, measure_count * measure_interval + 2 * 60 * 1000, "Receive answer timed out")
        let missing = measure_count
        info.socket.on('data', recv_data => {
          const tss = recv_data.split('\n')
          tss.pop() // Remove last empty line
          tss.forEach((ts, idx) => {
            fs.write(data.log, `delta_timestamp, ${missing}, ${socks_opt.destination.host}, ${socks_opt.destination.port}, ${Date.now()}, ${ts}\n`, () => {})
            if (idx > 0) fs.write(data.log, `#info aggregation: ${missing} was aggregated with ${missing + idx} for ${socks_opt.destination.host}\n`, () => {})
            if (--missing == 0) resolve()
          })
        })
      })

      info.socket.setNoDelay(true)
      info.socket.setEncoding("utf-8")
      data.info = info

      return Promise.all([
        recv_back,
        repeat_for(measure_count, measure_interval, doMeasure(info.socket)),
        data
      ])
    })
    .then(([recv_back, repeat, data]) => {
      data.info.socket.destroy()
      fs.write(data.log, `#info ${Date.now().toString()} Done\n`, () => fs.close(data.log, () => {}))
      console.info(`Measurement terminated for ${data.socks_opt.destination.host}\n`)
      return Promise.all([clean(data.body.id), data])
    })
    .then(([cl, data]) => {
      console.info(`Done for ${data.socks_opt.destination.host}`)
    })
    .catch(err => {
      data.info.socket.destroy()
      fs.write(data.log, `#info ${Date.now().toString()} ERROR occured\n`, () => fs.close(data.log, () => {}))
      console.error(err)
    })

const wait_bootstrap = tor => new Promise((resolve, reject) => {
  const loop = () => {
    console.info("Waiting for bootstrap, next check in 5s...")
    setTimeout(() => {
      tor.getInfo("status/circuit-established", (err, res) => {
        if (err) reject(err)
        else if (res == '0\n') loop()
        else resolve()
      })
    }, 5000)
  }
  loop()
})

const get_socks_port = tor => new Promise((resolve, reject) => {
  tor.getInfo('net/listeners/socks', (err, result) => {
    if (err) {
      reject(err)
      return
    }

    const port = parseInt(result.match(/:(\d+)/)[1])
    console.info(`Tor daemon accepts SOCKS connections on port ${port}`)
    resolve(port)
  })
})

logm
  .init
  .then(([stream_fd, circ_fd]) => torm.init(stream_fd, circ_fd))
  .then(tor => Promise.all([
    get_socks_port(tor),
    wait_bootstrap(tor),
    tor
  ]))
  //.then(([socks_port, boot, tor]) => one_req(socks_port))
  .then(([socks_port, boot, tor]) => {
    const hs_spawn_worker = new worker(200, 5000)
    const measurement_worker = new worker(100, 1000)

    for (let i = 0; i < 200; i++) {
      hs_spawn_worker.add(() => wait_for_hs(socks_port))
    }

    hs_spawn_worker.on('success', v => {
      console.debug("HS ready, forwarding it to measurement")
      measurement_worker.add(() => do_measurement(v))
    })

    hs_spawn_worker.on('error', e => {
      console.error("Failed to create HS", e)
      hs_spawn_worker.add(() => wait_for_hs(socks_port))
    })

    measurement_worker.on('success', v => {
      console.debug("Measurement done, readding token to HS")
      hs_spawn_worker.add(() => wait_for_hs(socks_port))
    })

    measurement_worker.on('error', e => {
      console.error("Failed to do a measurement, readding token to HS")
      hs_spawn_worker.add(() => wait_for_hs(socks_port))
    })

    //let loop = () => one_req(socks_port).then(loop).catch(console.error)
    //for (let i = 0; i < 100; i++) setTimeout(loop, i * 10 * 1000)
  })
  .catch(console.error)

  
// status/bootstrap-phase
// status/circuit-established
// status/enough-dir-info
// status/good-server-descriptor
// status/accepted-server-descriptor