import test from 'brittle'
import { readFile } from 'node:fs/promises'
import { EventEmitter } from 'node:events'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

const __dirname = dirname(fileURLToPath(import.meta.url))

async function load() {
  const parts = await Promise.all([
    readFile(join(__dirname, '../lib/irc/irc-parse.js'), 'utf8'),
    readFile(join(__dirname, '../lib/irc/irc-isupport.js'), 'utf8'),
    readFile(join(__dirname, '../lib/irc/irc-sasl.js'), 'utf8'),
    readFile(join(__dirname, '../lib/irc/irc-state.js'), 'utf8'),
    readFile(join(__dirname, '../lib/irc/irc-config.js'), 'utf8'),
    readFile(join(__dirname, '../lib/irc/irc-client.js'), 'utf8')
  ])
  const hook = {}
  new Function(
    'exports',
    parts.join('\n') +
      '\nexports.bareIrcCreateClient = bareIrcCreateClient;\nexports.bareIrcSaslPlainChunks = bareIrcSaslPlainChunks;\nexports.bareIrcParseIsupport = bareIrcParseIsupport;\n'
  )(hook)
  return hook
}

function fakeSocket() {
  const s = new EventEmitter()
  s.writes = []
  s.write = function (x) {
    s.writes.push(String(x))
    return true
  }
  s.end = function () {
    s.emit('close')
  }
  return s
}

test('CAP LS 302 then NICK USER on attach', async (t) => {
  const h = await load()
  const sock = fakeSocket()
  const c = h.bareIrcCreateClient({ nick: 'tester' })
  c.attach(sock)
  const blob = sock.writes.join('')
  t.ok(/CAP LS :?302/.test(blob))
  t.ok(/NICK :?tester/.test(blob))
  t.ok(blob.includes('USER '))
})

test('PING answers PONG; 001 assigns nick and CAP REQ', async (t) => {
  const h = await load()
  const sock = fakeSocket()
  const c = h.bareIrcCreateClient({ nick: 'alice' })
  let registered = ''
  c.on('registered', (p) => {
    registered = p.nick
  })
  c.attach(sock)
  sock.emit('data', 'PING :irc.example.com\r\n')
  t.ok(/PONG\s+:?irc\.example\.com/.test(sock.writes.join('')))
  sock.emit(
    'data',
    ':irc.example.com CAP * LS :sasl multi-prefix echo-message\r\n'
  )
  t.ok(sock.writes.join('').includes('CAP REQ'))
  sock.emit(
    'data',
    ':irc.example.com CAP * ACK :sasl multi-prefix echo-message\r\n'
  )
  sock.emit('data', ':irc.example.com CAP * ACK :sasl\r\n')
  sock.emit('data', ':irc.example.com 001 alice :Welcome to the network\r\n')
  t.is(registered, 'alice')
  t.is(c.state.nick, 'alice')
})

test('PRIVMSG lands in channel buffer', async (t) => {
  const h = await load()
  const sock = fakeSocket()
  const c = h.bareIrcCreateClient({ nick: 'alice' })
  c.attach(sock)
  sock.emit('data', ':bob!b@h PRIVMSG #chan :hello there\r\n')
  const buf = Object.values(c.state.buffers).find((b) => b.kind === 'channel')
  t.ok(buf)
  t.is(buf.name, '#chan')
  t.ok(buf.lines.some((l) => l.text === 'hello there' && l.from === 'bob'))
})

test('SASL PLAIN payload is null-separated base64', async (t) => {
  const h = await load()
  const chunks = h.bareIrcSaslPlainChunks('user', 'pass')
  t.ok(chunks.length >= 1)
  const raw = Buffer.from(chunks.join(''), 'base64').toString('utf8')
  t.is(raw, '\0user\0pass')
})

test('ISUPPORT tokens parse', async (t) => {
  const h = await load()
  const tok = h.bareIrcParseIsupport([
    'alice',
    'CHANTYPES=#&',
    'NICKLEN=16',
    'are supported by this server'
  ])
  t.is(tok.CHANTYPES, '#&')
  t.is(tok.NICKLEN, '16')
})