import asyncore
import socket
import sys

everyone = {}

class ConnectionHandler(asyncore.dispatcher):
  def __init__(self, sock):
    asyncore.dispatcher.__init__(self, sock)
    self.name = ""  
    self.state = 0 # 0: waiting for name; 1: connected; 2: closed
    self.readBuffer = ""
    self.writeBuffer = ""
  
  def handle_read(self):
    self.readBuffer = self.readBuffer + self.recv(4196)
    while True:
      i = self.readBuffer.find("\r\n")
      if i >= 0:
        [line, self.readBuffer] = self.readBuffer.split("\r\n", 1)
        self.doCommand(line)
      else:
        break
      
  def handle_write(self):
    n = self.send(self.writeBuffer)
    self.writeBuffer = self.writeBuffer[n:]
    
  def writable(self):
    return len(self.writeBuffer) > 0
    
  def readable(self):
    return self.state < 2
  
  def handle_close(self):
    if self.name in everyone:
      del everyone[self.name]
      for who in everyone:
        everyone[who].respond("disconnect "+self.name)
    self.state = 2
    self.close()
    
  def respond(self, msg):
    self.writeBuffer = self.writeBuffer + msg + "\r\n"
    
  def invalid(self, msg):
    self.respond("Invalid command: '"+msg+"'")

  def sendMessage(self, who, msg):
    if self.state == 1:
      self.respond("FROM "+who+" "+msg)
    
  def doCommand(self, line):
    if self.state == 0: # not yet connected?
      if line.count(" ") < 1:
        self.invalid(line)
        return
      [cmd, arg] = line.split(" ", 1)
      if cmd == "login" and arg.count(" ") == 0:
        self.name = arg
        for who in everyone:
          everyone[who].respond("connect "+arg)
        everyone[arg] = self
        self.state = 1
        self.respond("login ok")
      else:
        self.invalid("You must log in with a name without spaces")
    elif self.state == 1: # already connected
      parts = line.split(" ", 1)
      cmd = parts[0]
      if len(parts) > 1:
        rest = parts[1]
      if cmd == "message":
        [who, message] = rest.split(" ", 1)
        if who in everyone:
          everyone[who].sendMessage(self.name, message)
        self.respond("message ok")
      elif cmd == "broadcast":
        for who in everyone:
          everyone[who].sendMessage(self.name, rest)
        self.respond("broadcast ok")
      elif cmd == "who":
        arr = []
        for who in everyone:
          arr.append(who)
        self.respond("who "+",".join(arr))
      else:
        self.invalid(line)
    else:
      self.invalid("bad state? "+str(self.state))

class Listener(asyncore.dispatcher):
  def __init__(self, port):
    asyncore.dispatcher.__init__(self)
    self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
    self.bind(("0.0.0.0", port))
    self.listen(1)
    
  def handle_accept(self):
    c = self.accept()
    ConnectionHandler(c[0])
    
def main():
  port = int(sys.argv[1])
  server = Listener(port)
  print "listening on", port
  try:
    asyncore.loop()
  except KeyboardInterrupt:
    print "finishing"
    server.close()
  
if __name__ == "__main__":
  main()