const WebSocket = require('ws')
const config = require('../config')
const dbPool = require('./database')
const request = require('request')
const log = require('debug')('BOT:IRC')
const {
  msgSplit
} = require('./twitchParser')

/** @type {WebSocket} */
var ws = null

if (config.twitch.refresh_token && typeof config.twitch.refresh_token === 'string' && config.twitch.refresh_token.length > 0) {
  runBot()
}

function runBot() {
  ws = new WebSocket(`wss://${config.twitch.chat_host}:443`, 'irc')

  ws.on('open', handleOpen)

  ws.on('message', handleMessage)

  ws.on('error', handleError)

  ws.on('close', handleExit)
}

function handleError(err) {
  console.error(err)
  ws = null
  runBot()
  // do reconnect
}

function handleExit(code) {
  // do reconnect
  ws = null
  runBot()
}

function handleMessage(data) {
  // socket message convert to string
  let d = data.toString()
  // split message with \n
  // filter array remove empty element
  // replace \r to empty
  let darr = d.split(/\n/).filter(t => t).map(t => t.replace(/\r$/, ''))

  for (let i in darr) {
    log(darr[i])
    // parse message
    msgSplit(ws, darr[i]).then(() => { /* pass */ })
  }
}

/**
 * WebSocket Open Action
 */
async function handleOpen() {
  // from pool get db connection
  let db = await dbPool.connect()

  let body = null
  try {
    let options = {
      method: 'POST',
      url: config.twitch.token_url,
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Accept': 'application/json'
      },
      form: {
        grant_type: 'refresh_token',
        refresh_token: config.twitch.refresh_token,
        client_id: config.twitch.client_id,
        client_secret: config.twitch.secret
      }
    }
    body = await new Promise((resolve, reject) => {
      // get new token with refresh_token
      request(options, function (error, response, body) {
        if (error) {
          reject(error)
          return
        }
        if (typeof body === 'string') body = JSON.parse(body)
        resolve(body)
      })
    })
  } catch (err) {
    console.log(err)
  }

  if (body === null || !('access_token' in body)) throw new Error('access token not found')

  // login to twitch irc
  ws.send('PASS oauth:' + body.access_token)
  ws.send('NICK mtfosbot')
  ws.send('CAP REQ :twitch.tv/membership :twitch.tv/commands')

  // 取得要加入的頻道列表
  let query = `select "name", "join" from "public"."channels" where "join" = $1`
  let param = [true]
  let result = await db.query(query, param)

  // release pool connection
  await db.end()

  if (result !== null && result.rows.length > 0) {
    for (let row of result.rows) {
      if ('name' in row) {
        ws.send('JOIN #' + row.name)
      }
    }
  }
}

module.exports = ws