import myError from '../api/myError'
import * as rateLimiteFlexible from 'rate-limiter-flexible'
import * as redis from 'redis'

export const globalRedisClient = redis.createClient({ 
  port: process.env.REDIS_PORT, 
  host: process.env.REDIS_HOST,
  enable_offline_queue: false 
})
globalRedisClient.on('connect', function (err) {
  console.log('Redis-server is connected')
})
globalRedisClient.on('error', function (err) {
  console.log('Error ' + err)
})

const RateLimiterRedis = rateLimiteFlexible.RateLimiterRedis





const maxWrongAttemptsByIPperDay = 100
const maxConsecutiveFailsByUsernameAndIP = 5

const rateLimiterRedis = new RateLimiterRedis({
  storeClient: globalRedisClient,
  points: maxWrongAttemptsByIPperDay, // Number of points
  duration: 1000, // Per second,
  blockDuration: 60 * 60 // Per second
})

export const rateLimiterMiddleware = (req, res, next) => {
  rateLimiterRedis.consume(req.ip)
    .then(() => {
      next()
    })
    .catch(err => {
      err.statusCode = 429
      err.clientCode = 11
      err.clientMessage = 'درخواست بیش از حد انجام داده اید! بعد از یک ساعت دیگر دوباره اقدام بفرمایید!'
      err.messageEnglish = 'Too Many Requests'
      next(err)
    })
}

const limiterSlowBruteByIP = new RateLimiterRedis({
  storeClient: globalRedisClient,
  keyPrefix: 'login_fail_ip_per_day',
  points: maxWrongAttemptsByIPperDay,
  duration: 60 * 60 * 24,
  blockDuration: 60 * 60 * 24 // Block for 1 day, if 100 wrong attempts per day
})

const limiterConsecutiveFailsByUsernameAndIP = new RateLimiterRedis({
  storeClient: globalRedisClient,
  keyPrefix: 'login_fail_consecutive_username_and_ip',
  points: maxConsecutiveFailsByUsernameAndIP,
  duration: 60 * 60, // Store number for 90 days since first fail
  blockDuration: 60 * 60 // Block for 1 hour
})

const getUsernameIPkey = (username, ip) => `${username}_${ip}`

export async function preventBruteForce (req, res, next) {
  const ipAddr = req.ip
  const usernameIPkey = getUsernameIPkey(req.body.email, ipAddr)

  const [resUsernameAndIP, resSlowByIP] = await Promise.all([
    limiterConsecutiveFailsByUsernameAndIP.get(usernameIPkey),
    limiterSlowBruteByIP.get(ipAddr)
  ])
  let retrySecs = 0

  // Check if IP or Username + IP is already blocked
  if (resSlowByIP !== null && resSlowByIP.consumedPoints > maxWrongAttemptsByIPperDay) {
    retrySecs = Math.round(resSlowByIP.msBeforeNext / 1000) || 1
  } else if (resUsernameAndIP !== null && resUsernameAndIP.consumedPoints > maxConsecutiveFailsByUsernameAndIP) {
    retrySecs = Math.round(resUsernameAndIP.msBeforeNext / 1000) || 1
  }

  if (retrySecs > 0) {
    const error = new myError(`Too many requests for user ${req.body.email} with ip ${ipAddr}`, 1, 429, 'درخواست بیش از حد انجام داده اید! بعد از یک ساعت دیگر دوباره اقدام بفرمایید!', 'خطا رخ داد')
    next(error)
  } else {
    limiterConsecutiveFailsByUsernameAndIP.consume(usernameIPkey)
    limiterSlowBruteByIP.consume(ipAddr)
    next()
  }
}