const {RateLimiterPostgres, RateLimiterUnion} = require('rate-limiter-flexible');
const pg = require('../../db/pg')

const globalOptions = {
  storeClient: pg,
  tableName: 'sos.rate_limits',
  tableCreated: true
}

function createRateLimit(maxTimes, duration, prefix) {
  return new RateLimiterPostgres({
    ...globalOptions,
    points: maxTimes,
    inmemoryBlockOnConsumed: maxTimes,
    keyPrefix: prefix,
    duration
  })
}

module.exports = {};

const loginRateLimits = [
  // Once per ten seconds
  createRateLimit(1, 10, 'logon1'),
  // Ten tries in five minutes
  createRateLimit(10, 5 * 60, 'logon2'),
  // One hundred in a day
  createRateLimit(100, 24 * 60 * 60, 'logon3')
]

const loginRateLimitPool = new RateLimiterUnion(...loginRateLimits)

module.exports.loginRateLimit = async (req, res) => {
  try {
    await loginRateLimitPool.consume(req.body.email)
    return 'next';
  } catch (limits) {
    const wait = Math.max(...Object.values(limits).map(limit => limit?.msBeforeNext || 1));

    res.status(429)
    res.set({
      'Retry-After': Math.ceil(wait / 1000)
    })

    res.json({errors: [{
      param: 'email',
      msg: `Too many password attempts, please wait ${Math.ceil(wait / 1000)} seconds`
    },{
      param: 'password',
      msg: ' '
    }]})
  }
}

module.exports.loginRateLimit.reset = email => Promise.all(
  loginRateLimits.map(rateLimit => 
    rateLimit.delete(email)  
  )
)