cluster = require "cluster"
dns = require "dns"

exports.toNumber = (x) ->
    x = Number(x)
    if x >= 0
      return x
    return false

exports.isPipeName = (s) ->
    typeof s is 'string' and exports.toNumber(s) is false

exports.errnoException = (errorno, syscall) ->
  e = new Error(syscall + ' ' + errorno)
  e.errno = e.code = errorno
  e.syscall = syscall
  return e

# helper function to parse from an arguments array the parameters to pass to _netClusterListen
exports.getPortArguments = (args, cb) ->
    port = exports.toNumber args[0]
    backlog = exports.toNumber(args[1] || exports.toNumber(args[2]))

    if args.length is 0 or typeof args[0] is "function"
      return cb null, ["0.0.0.0", 0, null, backlog]
    else if typeof args[1] is "undefined" or typeof args[1] is "function" || typeof args[1] is "number"
      return cb null, ["0.0.0.0", port, 4, backlog]
    else
      dns.lookup args[1], (err, ip, addressType) ->
        return cb err if err
        unless ip
          ip = "0.0.0.0"
          addressType = 4
        return cb null, [ip, port, addressType, backlog]

##
# whether or not we should intercept the call to listen
#
# requirements:
# * must be a worker in a cluster environment
# * must be attempting to listen on port 0
exports.shouldDoIntercept = (args)->
  # only intercept if we're a worker
  return false unless cluster.isWorker

  port = exports.toNumber args[0]

  # copying if else if statement from node's net module
  # only intercept if we're attaching to the net and the port is 0
  if args.length is 0 or typeof args[0] is "function"
    return true
  else if args[0] and typeof args[0] is "object"
    return false
  else if exports.isPipeName args[0]
    return false
  else if typeof args[1] is "undefined" or typeof args[1] is "function" or typeof args[1] is "number"
    return port == 0
  else
    return port == 0