import
  net,
  asyncnet,
  asyncdispatch,
  asyncutils,
  punch

from strutils import format, join
from nativesockets import setSockOptInt
from os import paramCount, paramStr

var IPPROTO_IP {.importc: "IPPROTO_IP", header: "<netinet/in.h>".}: cint
var IP_TTL {.importc: "IP_TTL", header: "<netinet/in.h>".}: cint

proc usage() =
  echo("Usage: $# client|server".format(paramStr(0)))

proc processInput(client: AsyncSocket) {.async.} =
  while true:
    let input = await asyncReadline()
    await client.send(input & "\c\L")

proc connectAsClient(clientAddress: string,
                     clientPort: Port,
                     serverAddress: string,
                     serverPort: Port) {.async.} =
  var client = newAsyncSocket()
  client.setSockOpt(OptReuseAddr, true)
  client.getFd().setSockOptInt(IPPROTO_IP, IP_TTL, 2)
  client.bindAddr(clientPort, clientAddress)
  try:
    echo "trying to connect"
    await client.connect(serverAddress, serverPort)
    let (address, port) = client.getPeerAddr()
    echo("connected to $#:$#!".format(address, port.uint16))
    asyncCheck processInput(client)
    while true:
      let line = await client.recvLine()
      if line.len == 0: break
      echo("server responded: $#".format(line))
  except OSError as e:
    echo("Error: $#".format(e.msg))

proc processClient(client: AsyncSocket) {.async.} =
  while true:
    let line = await client.recvLine()
    if line.len == 0: break
    echo("client sent message: $#".format(line))
    await client.send(line & "\c\L")

proc runServer(serverAddress: string,
               serverPort: Port,
               clientAddress: string,
               clientPort: Port) {.async.} =
  var server = newAsyncSocket()
  server.setSockOpt(OptReuseAddr, true)
  server.bindAddr(serverPort)
  server.listen()
  echo("listening on port $#".format(serverPort.uint16))
  while true:
    let client = await server.accept()
    let (address, port) = client.getPeerAddr()
    echo("client $#:$# connected!".format(address, port.uint16()))
    asyncCheck processClient(client)

proc main() =
  if paramCount() != 1:
    usage()
    return
  let serverAddress = "176.95.209.87"
  let serverPort = Port(80)
  let clientAddress = $getPrimaryIPAddr(parseIpAddress(serverAddress))
  let clientPort = Port(1234)
  case paramStr(1)
  of "client":
    asyncCheck punchHoleAsClient(clientAddress, clientPort, serverAddress, serverPort)
    asyncCheck connectAsClient(clientAddress, clientPort, serverAddress, serverPort)
    try:
      runForever()
    except NetworkInterfaceError as e:
      echo(e.msg)
    except PunchHoleError as e:
      echo(e.msg)
  of "server":
    asyncCheck runServer(serverAddress, serverPort, clientAddress, clientPort)
    try:
      runForever()
    except ValueError:
      echo "server got ValueError!"
      discard
  else:
    usage()

when isMainModule:
  main()