const fs = require('fs')
const os = require('os')
const path = require('path')
const hyperdrive = require('../../extra/dillo-dat/node_modules/hyperdrive')
const hyperdiscovery = require('../../extra/dillo-dat/node_modules/hyperdiscovery')

function ready (archive) {
  return new Promise((resolve, reject) => archive.ready(err => err ? reject(err) : resolve()))
}

function writeFile (archive, name, data) {
  return new Promise((resolve, reject) => archive.writeFile(name, data, err => err ? reject(err) : resolve()))
}

function readFile (archive, name) {
  return new Promise((resolve, reject) => archive.readFile(name, (err, data) => err ? reject(err) : resolve(data)))
}

function listening (swarm) {
  if (swarm.address()) return Promise.resolve(swarm.address())
  return new Promise(resolve => swarm.once('listening', () => resolve(swarm.address())))
}

function sleep (ms) { return new Promise(resolve => setTimeout(resolve, ms)) }

async function main () {
  const root = fs.mkdtempSync(path.join(process.env.DDAT_TEST_DIR || os.tmpdir(), 'ddat-js-p2p-'))
  let source, replica, sourceSwarm, replicaSwarm
  try {
    source = hyperdrive(path.join(root, 'source'))
    await ready(source)
    const key = source.key.toString('hex')
    const address = 'dat://' + key
    await writeFile(source, 'hello.txt', 'hello from old dillo-dat v1')
    await writeFile(source, 'hello.txt', 'hello from old dillo-dat v2')
    if (source.key.toString('hex') !== key) throw new Error('JS archive address changed after update')
    replica = hyperdrive(path.join(root, 'replica'), source.key, {sparse: true})
    await ready(replica)

    sourceSwarm = hyperdiscovery(source, {port: 0, discovery: false, dht: false, dns: false, utp: false})
    replicaSwarm = hyperdiscovery(replica, {port: 0, discovery: false, dht: false, dns: false, utp: false})
    const sourceAddress = await listening(sourceSwarm)
    const replicaAddress = await listening(replicaSwarm)
    const topic = source.discoveryKey
    sourceSwarm.addPeer(topic, {host: '127.0.0.1', port: replicaAddress.port})
    replicaSwarm.addPeer(topic, {host: '127.0.0.1', port: sourceAddress.port})

    const deadline = Date.now() + 15000
    let result
    while (Date.now() < deadline) {
      try { result = await readFile(replica, 'hello.txt'); break } catch (_) { await sleep(100) }
    }
    if (!result || result.toString() !== 'hello from old dillo-dat v2') throw new Error('old JS replication did not deliver the latest file')
    process.stdout.write('old Dillo Dat JS create/update/address/xfer: PASS ' + address +
      ' metadata=' + source.metadata.length + ' content=' + source.content.length + '\n')
  } finally {
    if (sourceSwarm) sourceSwarm.destroy()
    if (replicaSwarm) replicaSwarm.destroy()
    if (source) source.close()
    if (replica) replica.close()
    if (process.env.DDAT_TEST_KEEP === '1') {
      process.stdout.write('kept old JS source and replica at ' + root + '\n')
    } else {
      fs.rmSync(root, {recursive: true, force: true})
    }
  }
}

main().catch(err => { console.error(err); process.exitCode = 1 })