node-fftcg/backend/session.coffee

# node libraries
redis = (require 'redis')
crypto = (require 'crypto')
logger = (require 'logging').default 'session'

# expiry times in seconds
TIMES =
  minute: 60
  hour:   60 * 60
  day:    60 * 60 * 24
  week:   60 * 60 * 24 * 7
  month:  60 * 60 * 24 * 7 * 4

EXPIRY =
  # games expire 1 week after last action
  game:    1 * TIMES.week
  # logins expire 1 month after last action
  login:   1 * TIMES.month


FFTCGSESSION = () ->
  @db = redis.createClient 6379, 'redis'

  @db.on 'error', (err) ->
    logger.error err.message

  return

FFTCGSESSION::login = (login) ->
  that = @

  new Promise (resolve, reject) ->
    hmac = crypto.createHmac 'sha256', Math.random().toString()
    hmac.update login
    digest = hmac.digest 'hex'

    that.db.setex digest, EXPIRY.login, login, (err) ->
      if err
        reject err

      else
        resolve digest


FFTCGSESSION::action = (digest) ->
  that = @

  new Promise (resolve, reject) ->
    that.db.get digest (err, res) ->
      logger.info 'err', err, 'res', res

      if err
        reject err

      else if res == 0
        resolve null

      else
        that.db.expire digest, EXPIRY.login, (err, res) ->
          if err
            reject err

          else
            resolve res

module.exports = FFTCGSESSION