#
# Copyright(C) 2008 Gareth Nelson
#
# This code is made available under the GNU General Public License
# version 2 or any other licensing terms which the author grants
# in writing.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#

# A gloriously simple Erlang port in python

import sys
import struct
import thread

def default_handler(msg):
    sys.stderr.write('Got a message from erlang! w00t! ' + str(msg) + '\n')

class ErlangPort:
   def __init__(self):
       self.handler = default_handler
       self.running = True
   def read_msg(self):
       size_buf = sys.stdin.read(2)
       if len(size_buf)==2:
          (pack_len,) = struct.unpack('!h',size_buf)
          return sys.stdin.read(pack_len)
       else:
          return None
   def send_msg(self,msg_data):
       size_buf = struct.pack('!h',len(msg_data))
       sys.stdout.write(size_buf)
       sys.stdout.write(msg_data)
   def start(self):
       self.recv_thread = thread.start_new_thread(self.recv_loop,())
   def recv_loop(self):
       while self.running:
          msg = None
          try:
            msg = self.read_msg()
          except Exception,e:
            print str(e)
          if not (msg==None):
             self.default_handler(msg)