'use strict'

// Narrow diagnostic: validates the installed Hyperswarm/HyperDHT package and
// the local bootstrap node independently of Cabal's Hypercore replication.
const assert = require('assert')
const crypto = require('crypto')
const dgram = require('dgram')
const { loadCabalCore } = require('./cable_hyperswarm')

const { requireCabal } = loadCabalCore()
const DHT = requireCabal('hyperdht')
const Swarm = requireCabal('hyperswarm')

function freePort () {
  return new Promise((resolve, reject) => {
    const socket = dgram.createSocket('udp4')
    socket.once('error', reject)
    socket.bind(0, '127.0.0.1', () => {
      const port = socket.address().port
      socket.close(err => err ? reject(err) : resolve(port))
    })
  })
}

async function main () {
  const portA = await freePort()
  const portB = await freePort()
  const relayPort = await freePort()
  const useBuiltin = process.env.HYPERSWARM_TEST_BUILTIN === '1'
  const bootstrapPort = useBuiltin ? 0 : await freePort()
  const bootstrap = useBuiltin ? null : DHT.bootstrapper(bootstrapPort, '127.0.0.1', { host: '127.0.0.1' })
  const relay = useBuiltin ? null : new DHT({
    bootstrap: ['127.0.0.1:' + bootstrapPort], host: '127.0.0.1', port: relayPort,
    ephemeral: false, firewalled: false
  })
  const swarms = []
  try {
    if (bootstrap) await bootstrap.ready()
    if (relay) await relay.ready()
    if (bootstrap) console.log('bootstrap state', { id: Boolean(bootstrap.id), ephemeral: bootstrap.ephemeral, storage: Boolean(bootstrap._persistent) })
    if (relay) console.log('relay state', { id: Boolean(relay.id), ephemeral: relay.ephemeral, storage: Boolean(relay._persistent) })
    const endpoint = useBuiltin ? undefined : '127.0.0.1:' + relayPort
    for (const port of [portA, portB]) {
      const dht = new DHT({ ...(useBuiltin ? {} : { bootstrap: [endpoint] }), host: '127.0.0.1', port,
        ephemeral: false, firewalled: false })
      dht._nat.add('127.0.0.1', port)
      const swarm = new Swarm({ dht })
      dht.on('error', err => console.error('DHT error:', err.message))
      swarm.on('error', err => console.error('swarm error:', err.message))
      swarms.push(swarm)
    }
    const [a, b] = swarms
    const topic = crypto.randomBytes(32)
    let connected = 0
    const onConnection = socket => { connected++; socket.on('error', () => {}) }
    a.on('connection', onConnection)
    b.on('connection', onConnection)
    const onDiscoveryError = (label) => err => console.error(label + ' discovery error:', err && (err.stack || err))
    const discoveryA = a.join(topic, { server: true, client: false, onerror: onDiscoveryError('A') })
    const aFlushed = await discoveryA.flushed()
    const discoveryB = b.join(topic, { server: false, client: true, onerror: onDiscoveryError('B') })
    const bFlushed = await discoveryB.flushed()
    console.log('Hyperswarm discovery flush:', aFlushed + '/' + bFlushed)
    console.log('DHT node tables:', {
      a: a.dht.toArray(), b: b.dht.toArray(),
      relay: relay && relay.table.toArray().map(node => ({ host: node.host, port: node.port }))
    })
    if (relay) console.log('relay stored topic peers:', relay._persistent.records.get(topic.toString('hex'), 20).length)
    const lookup = b.dht.lookup(topic)
    const lookupResults = []
    lookup.on('data', result => lookupResults.push(result.peers.length))
    await lookup.finished()
    console.log('explicit topic lookup peer counts:', lookupResults)
    const deadline = Date.now() + 20000
    while (connected < 2 && Date.now() < deadline) await new Promise(resolve => setTimeout(resolve, 100))
    const discovered = connected >= 2
    console.log('Hyperswarm state:', { connections: [a.connections.size, b.connections.size],
      queued: [a.connecting, b.connecting], peerEntries: [a.peers.size, b.peers.size] })
    if (!discovered) {
      console.log('DHT discovery did not connect both local nodes; trying direct Hyperswarm peers to isolate transport')
      a.joinPeer(b.keyPair.publicKey)
      b.joinPeer(a.keyPair.publicKey)
      const directDeadline = Date.now() + 10000
      while (connected < 2 && Date.now() < directDeadline) await new Promise(resolve => setTimeout(resolve, 100))
    }
    assert(connected >= 2, 'local Hyperswarm peers failed direct transport too')
    console.log('local Hyperswarm transport: PASS')
    if (!discovered) {
      console.error('local DHT discovery: FAIL (the bootstrap node did not yield peer addresses)')
      process.exitCode = 1
    } else console.log('local Hyperswarm DHT discovery: PASS')
  } finally {
    for (const swarm of swarms) { try { await swarm.destroy() } catch (_) {} }
    if (relay) { try { await relay.destroy() } catch (_) {} }
    if (bootstrap) { try { await bootstrap.destroy() } catch (_) {} }
  }
}

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