'use strict'

// Exercise the APIs that cabal-cli 15.x uses, with two independent local
// Cabal clients connected by the same live Hypercore replication streams.
const assert = require('assert')
const fs = require('fs')
const os = require('os')
const path = require('path')
const EventEmitter = require('events')
const Module = require('module')
const Client = require(process.env.CABAL_CLIENT_MODULE || 'cabal-client')

function once (emitter, event, predicate = () => true, timeoutMs = 12000) {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => {
      emitter.removeListener(event, listener)
      reject(new Error(`timed out waiting for Cabal ${event}`))
    }, timeoutMs)
    function listener (value) {
      if (!predicate(value)) return
      clearTimeout(timer)
      emitter.removeListener(event, listener)
      resolve(value)
    }
    emitter.on(event, listener)
  })
}

function close (client, details) {
  return new Promise((resolve, reject) => client.removeCabal(details.key, err => err ? reject(err) : resolve()))
}

function waitForUserName (details, name, timeoutMs = 12000) {
  return new Promise((resolve, reject) => {
    const deadline = Date.now() + timeoutMs
    const poll = () => {
      const user = Object.values(details.getUsers()).find(candidate => candidate.name === name)
      if (user) return resolve(user)
      if (Date.now() >= deadline) return reject(new Error(`${name} nickname did not replicate`))
      setTimeout(poll, 25)
    }
    poll()
  })
}

function createCliScreen (client) {
  const clientPath = require.resolve(process.env.CABAL_CLIENT_MODULE || 'cabal-client')
  const cliDirectory = path.resolve(path.dirname(clientPath), '..', '..')
  const screenPath = path.join(cliDirectory, 'neat-screen.js')
  const originalLoad = Module._load
  function fakeNeatLog () {
    const input = new EventEmitter()
    input.cursor = 0
    input.rawLine = () => ''
    input.set = () => {}
    return {
      input,
      render: () => {},
      clear: () => {},
      use: plugin => {
        const state = {}
        plugin(state, new EventEmitter())
      }
    }
  }
  Module._load = function (request, parent, isMain) {
    if (request === 'neat-log') return fakeNeatLog
    return originalLoad.call(this, request, parent, isMain)
  }
  try {
    const NeatScreen = require(screenPath)
    return new NeatScreen({
      client,
      frontendConfig: { messageTimeformat: '%H:%M:%S', messageIndent: 'nick' }
    })
  } finally {
    Module._load = originalLoad
  }
}

async function main () {
  const root = fs.mkdtempSync(path.join(process.env.CABAL_TEST_DIR || os.tmpdir(), 'cabal-cli-features-'))
  const sourceClient = new Client({ config: { dbdir: path.join(root, 'alice'), preferredPort: 0 } })
  const peerClient = new Client({ config: { dbdir: path.join(root, 'bob'), preferredPort: 0 } })
  let alice, bob, aliceStream, bobStream, screen
  try {
    alice = await sourceClient.createCabal()
    const roomKey = alice.key
    assert.match(roomKey, /^[0-9a-f]{64}$/i, 'create room returns a Cabal room key')

    bob = await peerClient.addCabal(`cabal://${roomKey}`)
    aliceStream = alice.core.replicate(true)
    bobStream = bob.core.replicate(false)
    aliceStream.on('error', () => {})
    bobStream.on('error', () => {})
    aliceStream.pipe(bobStream).pipe(aliceStream)

    const aliceNick = once(alice, 'publish-nick', update => update.name === 'alice')
    alice.processLine('/nick alice')
    await aliceNick
    const aliceChannel = once(alice, 'channel-join', update => update.channel === 'lobby')
    alice.processLine('/join lobby')
    await aliceChannel
    const secondChannel = once(alice, 'channel-join', update => update.channel === 'garden')
    alice.processLine('/join garden')
    await secondChannel
    assert(alice.getJoinedChannels().includes('lobby'))
    assert(alice.getJoinedChannels().includes('garden'))

    screen = createCliScreen(sourceClient)
    const cliChannels = alice.getChannels({ includePM: true, onlyJoined: true })
    alice.focusChannel(cliChannels[0])
    screen.neat.input.emit('ctrl-n')
    assert.strictEqual(alice.getCurrentChannel(), cliChannels[1], 'the cabal-cli Ctrl+N handler advances channels')
    screen.neat.input.emit('ctrl-n')
    assert.strictEqual(alice.getCurrentChannel(), cliChannels[2], 'the cabal-cli Ctrl+N handler continues the cycle')
    alice.focusChannel('lobby')

    const bobJoined = once(alice, 'channel-join', update => update.channel === 'lobby' && !update.isLocal)
    const bobChannel = once(bob, 'channel-join', update => update.channel === 'lobby')
    bob.processLine('/join lobby')
    await bobChannel
    await bobJoined
    const bobNick = once(bob, 'publish-nick', update => update.name === 'bob')
    bob.processLine('/nick bob')
    await bobNick
    await waitForUserName(alice, 'bob')

    const fromAlice = 'hello from Alice in the lobby'
    const gotAlice = once(bob, 'new-message', update =>
      update.channel === 'lobby' && update.message.value.content.text === fromAlice)
    alice.processLine(fromAlice)
    await gotAlice

    // Verify the actual room stream carries the published nickname record to Bob.
    await waitForUserName(bob, 'alice')

    const fromBob = 'hello back from Bob'
    const gotBob = once(alice, 'new-message', update =>
      update.channel === 'lobby' && update.message.value.content.text === fromBob)
    bob.processLine(fromBob)
    await gotBob

    aliceStream.destroy()
    bobStream.destroy()
    aliceStream = bobStream = null
    process.stdout.write(`cabal-cli 15.x room, /join, /nick, Ctrl+N channel cycle, and two-peer chat: PASS room=cabal://${roomKey}\n`)
  } finally {
    if (aliceStream) aliceStream.destroy()
    if (bobStream) bobStream.destroy()
    if (screen) {
      if (screen.updateTimer) clearTimeout(screen.updateTimer)
      if (alice && screen._updateHandler && screen._updateHandler[alice.key])
        alice.removeListener('update', screen._updateHandler[alice.key])
    }
    if (alice) await close(sourceClient, alice)
    if (bob) await close(peerClient, bob)
    fs.rmSync(root, { recursive: true, force: true })
  }
}

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